6:27 oh fucking hell this line... my heart can only take so much
@kiancharlescostuya32682 ай бұрын
Here are 3 reasons why a centrifugal purifier might not reach its intended bowl speed: Mechanical Issues: Bowl Imbalance: A worn bearing, loose internal components, or foreign object contamination within the bowl can cause it to become imbalanced. This imbalance creates vibrations and resistance that the motor needs to overcome, hindering it from reaching the desired speed. Drive System Problems: Faulty belts, couplings, or gears in the power transmission system between the motor and the bowl can slip or wear, reducing the rotational force transferred to the bowl. Process Issues: Excessive Feed Rate: If the purifier is overloaded with influent exceeding its processing capacity, the motor might struggle to maintain speed due to the increased load on the bowl. Control System Malfunction: Faulty Speed Sensor: A malfunctioning sensor might provide inaccurate speed readings to the control system, causing it to misinterpret the actual speed and not provide enough power to the motor to reach the target speed. Control System Failure: In some cases, the control system itself might malfunction, preventing it from sending the correct signals to the motor to achieve the desired speed.
@crudaarielf.11132 ай бұрын
Nav Arch 1. Explain the following • Bow - The bow is the forward part of the hull, serving as the leading edge that cuts through the water as the vessel moves. Its design is critical for the ship's hydrodynamics, affecting factors such as resistance, stability, and seaworthiness. Different bow designs, like the traditional clipper bow or the modern bulbous bow, are used to optimize the vessel's performance for specific operating conditions and requirements. The bow also houses important features like the anchor and anchor windlass. • Hull - The hull is the main body of the ship, providing the structural integrity and buoyancy. It is the watertight shell that supports the weight of the vessel, its cargo, and equipment. The hull design, including its length, width, depth, and shape, influences the ship's stability, speed, and maneuverability. Different hull types, such as displacement hulls, planing hulls, or catamaran hulls, are used for various applications and operating environments. The hull also includes features like the keel, bilge, and stern, which all contribute to the overall performance and handling of the vessel. • Keel - The keel is a central structural component that runs along the bottom of the hull, from the bow to the stern. It acts as the backbone of the ship, providing longitudinal strength and stability. The keel helps to prevent the ship from drifting sideways and aids in keeping the vessel on course. It also helps to resist the lateral forces generated by the wind and waves, contributing to the vessel's stability and seaworthiness. The keel design can vary, with some vessels having a flat keel, a V-shaped keel, or a bulbous keel, depending on the specific requirements and intended use of the ship. 2. Explain the following types of ships according to its design • General Cargo -or dry cargo ships are designed to carry different types of dry cargoes. Thanks to their built-in cargo loading equipment, their flexibility in loading and unloading is increased. • Oil Tanker - Liquids are transported by means of tanker vessels. These liquids include crude oil, gases, and chemicals. • Bulk Carrier - This type of merchant vessel is designed to carry large amounts of cargoes that do not need packaging or are carried in bulk such as coal, grains, ore, cement and etc. 3. What is Intact and Damage Stability • Intact Stability: Passenger cruise ships must maintain intact stability to ensure passenger comfort and safety. Stability criteria such as GM and range of stability are rigorously evaluated during design and must comply with regulatory standards. (Additional you may or may not add) • Intact stability ensures the ship can withstand external forces like wind, waves, or shifting cargo without tipping over excessively. Imagine a seesaw - intact stability makes sure the ship recovers quickly from a tilt, just like a well-balanced seesaw bouncing back after a dip. This is achieved through careful design considerations like the center of gravity (weight distribution) and the center of buoyancy (upward water pressure acting against the hull). • Damage Stability: In addition to intact stability, cruise ships are required to demonstrate adequate damage stability. This involves assessing the vessel's ability to remain afloat and upright in the event of damage to the hull, such as from a collision or grounding. (Additional you may or may not add) • Damage stability considers what happens if the hull is breached, perhaps due to a collision or grounding. Here, the focus is on how well the ship can stay afloat even with flooding in certain compartments. Imagine multiple watertight compartments within the hull, like separate rooms in a house. Damage stability analyzes how flooding in one compartment might affect the ship's overall balance (trim) and how deep it sits in the water (draft). Ships are designed with these watertight compartments to minimize flooding and improve survivability in case of damage. 4. Construction of watertight doors according SOLAS. 5. What is Archimedes principle? • The Archimedes principle states that the buoyant force exerted on an object that is submerged partially or completely in a fluid is equal to the weight of the fluid that is displaced by the object. Buoyant Force - refers to the upward-directed force that a fluid (either a liquid or a gas) exerts on an object that is partially or completely immersed in the fluid. Displacement of Fluid - Displacement is the general term used to indicate the mass of the vessel. A ship's displacement is the volume of water it displaces when it is floating, and measured in cubic meters. 6. Forces that leads to stress and strains on ships • Waves - As a ship moves through the water, the wave-induced motion can cause bending and torsional stresses, leading to hogging (the middle of the ship bending upwards) and sagging (the middle of the ship bending downwards) of the hull. • Tensile Force - which acts to pull the ship's structure apart, causing it to stretch or elongate. These tensile forces can be experienced in the ship's hull, superstructure, and other structural elements. • Compression - act to push the ship's structure together, causing it to shorten or buckle. Compression can be experienced in the ship's hull, especially in the bottom and sides, as well as in the superstructure. • Shear Force - These forces act to slide one part of the ship's structure relative to another, causing the material to experience distortion. Shear stresses can be particularly problematic in areas where the ship's structure changes, such as at the transitions between the hull and the superstructure • Torsional Force - can twist the ship's structure, causing it to experience rotational stresses. These forces can be experienced in the ship's hull, especially in the midship section, as well as in the superstructure and other structural elements.
@crudaarielf.11132 ай бұрын
AUX MACH 1. What is interface and how does it affect the separation efficiency? • On board ships, the term "interface" refers to the boundary between the two immiscible liquid phases, such as oil and water, within a separator. This interface plays a critical role in determining the separation efficiency of the system. Firstly, the position of the interface, or phase boundary, needs to be properly maintained at the correct level within the separator. If the interface is too high, it can lead to carry-over of water into the oil stream, while a too low interface can result in oil being carried over into the water stream. Maintaining the optimal interface level is crucial for achieving the desired separation outcomes. 2. Explain Follow up and Non-Follow up controls on steering gear. 2. Explain how operating water in purifiers work • Purifiers, especially those used for oil treatment on ships, rely on a clever system of pressurized water called operating water to open and close the centrifuge bowl. Imagine this water acting like a powerful hydraulic fluid. To seal the bowl for purification, high-pressure water fills the "closing water" chamber. This pressure pushes a piston or cylinder upwards, creating a tight seal with a ring on the bowl. This pressurized state might be constant or pulsed depending on the system. When it's time to expel waste, the water flow is diverted to the "opening water" chamber. This opposing pressure pushes another piston or cylinder down, overcoming the closing force. This slight downward movement opens ports in the bowl, allowing accumulated waste like sludge to be discharged. Some purifiers might even have a dedicated "conditioning water" line for flushing or cleaning tasks within the bowl or pipes. In essence, operating water is the hidden powerhouse that precisely controls the opening and closing of the centrifuge bowl throughout the purification and waste removal cycles. 3. working principle of rotary steering gear - A rotary vane steering gear is a mechanism on ships specifically designed to control the rudder's direction, influencing the vessel's course. It uses a rotating cylindrical housing with fixed and movable vanes to achieve this. In a rotary vane steering system, the helmsman's turn of the steering wheel translates into an electrical signal via the telemotor. This signal is amplified and sent to the power unit, which uses electric motors and pumps to generate high-pressure hydraulic fluid. The transmission system, comprised of valves and pipes, channels this fluid to the rotary vane. Here, specific chambers are pressurized based on the signal, causing the vanes within the housing to rotate. This rotational force is transferred to the rudder stock, ultimately turning the rudder blade and steering the ship. Additional components like the rudder angle indicator provide feedback on the rudder's position, while the hydraulic reservoir stores fluid, filters keep it clean, and safety relief valves protect the system from pressure overload. 4. common faults found in steering gear • Oil Leaks: Leaks in the hydraulic system can reduce pressure and hinder the steering's effectiveness. It's crucial to address leaks promptly to avoid complete system failure. • Discrepancy Between Rudder and Helm: Sometimes, the actual turn of the rudder doesn't match the angle indicated on the ship's wheel (helm). This can be due to issues with linkages, adjustments, or faulty sensors. • Steering Difficulty: Difficulty turning the wheel or sluggish response can indicate problems like friction in the system, pump issues, or low hydraulic pressure. • Excessive Noise: Unusual noises coming from the steering gear can signify internal wear, malfunctioning pumps, or air trapped in the hydraulic system. • High Oil Temperatures: Overheating oil can damage components and reduce lubrication. This might be caused by excessive use, blocked filters, or malfunctioning coolers. • Rudder Movement Beyond Limits: The rudder should only turn within a specific range. Uncontrolled or excessive movement can occur due to mechanical failures or faulty limit switches. • No Remote Control Steering: Modern ships often have remote steering options from the bridge. Failure of these systems could be due to problems with pumps, valves, or the control system itself. • Rudder Angle Transmitter or Tiller Link Issues: These components are crucial for translating helm input into rudder movement. Faulty sensors or damaged linkages can disrupt this communication 5. Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situations. Procedures for emergency steering includes; • Establish communication with the bridge • Switch over to local control on all starter cabinets • Control the rudder on command from the bridge by operating the pilot valves on the main valve block • Activate the pilot for main spool, and the pilot for idling valve • When the rudder is given order, release the pilot for idling valve and then the pilot for main valve 6. Operating Principles of Refrigeration System The operating principles of a refrigeration system, which is composed of the main components of a compressor, condenser, expansion valve, and evaporator, are as follows: The refrigeration cycle begins with the compressor, which is the heart of the system. The compressor takes in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it, increasing its pressure and temperature. This high-pressure, high-temperature refrigerant vapor is then sent to the condenser. In the condenser, the hot refrigerant vapor transfers its heat to the surrounding air or water, causing the refrigerant to condense into a high-pressure, high-temperature liquid. As the refrigerant condenses, it releases the latent heat of vaporization, which is carried away by the air or water flowing through the condenser. The high-pressure, high-temperature liquid refrigerant then flows through the expansion valve, which is a metering device. As the refrigerant passes through the expansion valve, its pressure and temperature drop dramatically due to the Joule-Thomson effect. This low-pressure, low-temperature liquid refrigerant is then fed into the evaporator. In the evaporator, the low-pressure, low-temperature refrigerant absorbs heat from the surrounding environment, such as the air or water being cooled. As the refrigerant absorbs heat, it undergoes a phase change from a liquid to a vapor, becoming a low-pressure, low-temperature refrigerant vapor. This vapor is then drawn back into the compressor, completing the refrigeration cycle. The continuous cycling of the refrigerant through these four main components (compressor, condenser, expansion valve, and evaporator) is what allows the refrigeration system to remove heat from the desired space and transfer it to the surrounding environment, effectively cooling the target area.
@crudaarielf.11132 ай бұрын
AUX MACH 1. What is interface and how does it affect the separation efficiency? • On board ships, the term "interface" refers to the boundary between the two immiscible liquid phases, such as oil and water, within a separator. This interface plays a critical role in determining the separation efficiency of the system. Firstly, the position of the interface, or phase boundary, needs to be properly maintained at the correct level within the separator. If the interface is too high, it can lead to carry-over of water into the oil stream, while a too low interface can result in oil being carried over into the water stream. Maintaining the optimal interface level is crucial for achieving the desired separation outcomes. 2. Explain Follow up and Non-Follow up controls on steering gear. 2. Explain how operating water in purifiers work • Purifiers, especially those used for oil treatment on ships, rely on a clever system of pressurized water called operating water to open and close the centrifuge bowl. Imagine this water acting like a powerful hydraulic fluid. To seal the bowl for purification, high-pressure water fills the "closing water" chamber. This pressure pushes a piston or cylinder upwards, creating a tight seal with a ring on the bowl. This pressurized state might be constant or pulsed depending on the system. When it's time to expel waste, the water flow is diverted to the "opening water" chamber. This opposing pressure pushes another piston or cylinder down, overcoming the closing force. This slight downward movement opens ports in the bowl, allowing accumulated waste like sludge to be discharged. Some purifiers might even have a dedicated "conditioning water" line for flushing or cleaning tasks within the bowl or pipes. In essence, operating water is the hidden powerhouse that precisely controls the opening and closing of the centrifuge bowl throughout the purification and waste removal cycles. 3. working principle of rotary steering gear - A rotary vane steering gear is a mechanism on ships specifically designed to control the rudder's direction, influencing the vessel's course. It uses a rotating cylindrical housing with fixed and movable vanes to achieve this. In a rotary vane steering system, the helmsman's turn of the steering wheel translates into an electrical signal via the telemotor. This signal is amplified and sent to the power unit, which uses electric motors and pumps to generate high-pressure hydraulic fluid. The transmission system, comprised of valves and pipes, channels this fluid to the rotary vane. Here, specific chambers are pressurized based on the signal, causing the vanes within the housing to rotate. This rotational force is transferred to the rudder stock, ultimately turning the rudder blade and steering the ship. Additional components like the rudder angle indicator provide feedback on the rudder's position, while the hydraulic reservoir stores fluid, filters keep it clean, and safety relief valves protect the system from pressure overload. 4. common faults found in steering gear • Oil Leaks: Leaks in the hydraulic system can reduce pressure and hinder the steering's effectiveness. It's crucial to address leaks promptly to avoid complete system failure. • Discrepancy Between Rudder and Helm: Sometimes, the actual turn of the rudder doesn't match the angle indicated on the ship's wheel (helm). This can be due to issues with linkages, adjustments, or faulty sensors. • Steering Difficulty: Difficulty turning the wheel or sluggish response can indicate problems like friction in the system, pump issues, or low hydraulic pressure. • Excessive Noise: Unusual noises coming from the steering gear can signify internal wear, malfunctioning pumps, or air trapped in the hydraulic system. • High Oil Temperatures: Overheating oil can damage components and reduce lubrication. This might be caused by excessive use, blocked filters, or malfunctioning coolers. • Rudder Movement Beyond Limits: The rudder should only turn within a specific range. Uncontrolled or excessive movement can occur due to mechanical failures or faulty limit switches. • No Remote Control Steering: Modern ships often have remote steering options from the bridge. Failure of these systems could be due to problems with pumps, valves, or the control system itself. • Rudder Angle Transmitter or Tiller Link Issues: These components are crucial for translating helm input into rudder movement. Faulty sensors or damaged linkages can disrupt this communication 5. Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situations. Procedures for emergency steering includes; • Establish communication with the bridge • Switch over to local control on all starter cabinets • Control the rudder on command from the bridge by operating the pilot valves on the main valve block • Activate the pilot for main spool, and the pilot for idling valve • When the rudder is given order, release the pilot for idling valve and then the pilot for main valve 6. Operating Principles of Refrigeration System The operating principles of a refrigeration system, which is composed of the main components of a compressor, condenser, expansion valve, and evaporator, are as follows: The refrigeration cycle begins with the compressor, which is the heart of the system. The compressor takes in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it, increasing its pressure and temperature. This high-pressure, high-temperature refrigerant vapor is then sent to the condenser. In the condenser, the hot refrigerant vapor transfers its heat to the surrounding air or water, causing the refrigerant to condense into a high-pressure, high-temperature liquid. As the refrigerant condenses, it releases the latent heat of vaporization, which is carried away by the air or water flowing through the condenser. The high-pressure, high-temperature liquid refrigerant then flows through the expansion valve, which is a metering device. As the refrigerant passes through the expansion valve, its pressure and temperature drop dramatically due to the Joule-Thomson effect. This low-pressure, low-temperature liquid refrigerant is then fed into the evaporator. In the evaporator, the low-pressure, low-temperature refrigerant absorbs heat from the surrounding environment, such as the air or water being cooled. As the refrigerant absorbs heat, it undergoes a phase change from a liquid to a vapor, becoming a low-pressure, low-temperature refrigerant vapor. This vapor is then drawn back into the compressor, completing the refrigeration cycle. The continuous cycling of the refrigerant through these four main components (compressor, condenser, expansion valve, and evaporator) is what allows the refrigeration system to remove heat from the desired space and transfer it to the surrounding environment, effectively cooling the target area.
@user-lq9vc5zf2u2 ай бұрын
Nav Arch 1. Explain the following • Bow - The bow is the forward part of the hull, serving as the leading edge that cuts through the water as the vessel moves. Its design is critical for the ship's hydrodynamics, affecting factors such as resistance, stability, and seaworthiness. Different bow designs, like the traditional clipper bow or the modern bulbous bow, are used to optimize the vessel's performance for specific operating conditions and requirements. The bow also houses important features like the anchor and anchor windlass. • Hull - The hull is the main body of the ship, providing the structural integrity and buoyancy. It is the watertight shell that supports the weight of the vessel, its cargo, and equipment. The hull design, including its length, width, depth, and shape, influences the ship's stability, speed, and maneuverability. Different hull types, such as displacement hulls, planing hulls, or catamaran hulls, are used for various applications and operating environments. The hull also includes features like the keel, bilge, and stern, which all contribute to the overall performance and handling of the vessel. • Keel - The keel is a central structural component that runs along the bottom of the hull, from the bow to the stern. It acts as the backbone of the ship, providing longitudinal strength and stability. The keel helps to prevent the ship from drifting sideways and aids in keeping the vessel on course. It also helps to resist the lateral forces generated by the wind and waves, contributing to the vessel's stability and seaworthiness. The keel design can vary, with some vessels having a flat keel, a V-shaped keel, or a bulbous keel, depending on the specific requirements and intended use of the ship. 2. Explain the following types of ships according to its design • General Cargo -or dry cargo ships are designed to carry different types of dry cargoes. Thanks to their built-in cargo loading equipment, their flexibility in loading and unloading is increased. • Oil Tanker - Liquids are transported by means of tanker vessels. These liquids include crude oil, gases, and chemicals. • Bulk Carrier - This type of merchant vessel is designed to carry large amounts of cargoes that do not need packaging or are carried in bulk such as coal, grains, ore, cement and etc. 3. What is Intact and Damage Stability • Intact Stability: Passenger cruise ships must maintain intact stability to ensure passenger comfort and safety. Stability criteria such as GM and range of stability are rigorously evaluated during design and must comply with regulatory standards. (Additional you may or may not add) • Intact stability ensures the ship can withstand external forces like wind, waves, or shifting cargo without tipping over excessively. Imagine a seesaw - intact stability makes sure the ship recovers quickly from a tilt, just like a well-balanced seesaw bouncing back after a dip. This is achieved through careful design considerations like the center of gravity (weight distribution) and the center of buoyancy (upward water pressure acting against the hull). • Damage Stability: In addition to intact stability, cruise ships are required to demonstrate adequate damage stability. This involves assessing the vessel's ability to remain afloat and upright in the event of damage to the hull, such as from a collision or grounding. (Additional you may or may not add) • Damage stability onsiders what happens if the hull is breached, perhaps due to a collision or grounding. Here, the focus is on how well the ship can stay afloat even with flooding in certain compartments. Imagine multiple watertight compartments within the hull, like separate rooms in a house. Damage stability analyzes how flooding in one compartment might affect the ship's overall balance (trim) and how deep it sits in the water (draft). Ships are designed with these watertight compartments to minimize flooding and improve survivability in case of damage. 4. Construction of watertight doors according SOLAS. 5. What is Archimedes principle? • The Archimedes principle states that the buoyant force exerted on an object that is submerged partially or completely in a fluid is equal to the weight of the fluid that is displaced by the object. Buoyant Force - refers to the upward-directed force that a fluid (either a liquid or a gas) exerts on an object that is partially or completely immersed in the fluid. Displacement of Fluid - Displacement is the general term used to indicate the mass of the vessel. A ship's displacement is the volume of water it displaces when it is floating, and measured in cubic meters. 6. Forces that leads to stress and strains on ships • Waves - As a ship moves through the water, the wave-induced motion can cause bending and torsional stresses, leading to hogging (the middle of the ship bending upwards) and sagging (the middle of the ship bending downwards) of the hull. • Tensile Force - which acts to pull the ship's structure apart, causing it to stretch or elongate. These tensile forces can be experienced in the ship's hull, superstructure, and other structural elements. • Compression - act to push the ship's structure together, causing it to shorten or buckle. Compression can be experienced in the ship's hull, especially in the bottom and sides, as well as in the superstructure. • Shear Force - These forces act to slide one part of the ship's structure relative to another, causing the material to experience distortion. Shear stresses can be particularly problematic in areas where the ship's structure changes, such as at the transitions between the hull and the superstructure • Torsional Force - can twist the ship's structure, causing it to experience rotational stresses. These forces can be experienced in the ship's hull, especially in the midship section, as well as in the superstructure and other structural elements.
@user-lq9vc5zf2u2 ай бұрын
AUTO 1. What is Reverse Power Relay and how it works The reverse power relay is a vital protective device used in electrical power generation systems, particularly in generators, to prevent reverse power flow. Its primary function is to detect when the generator is operating in a reverse power condition and take appropriate action to safeguard the generator and the electrical system. During normal generator operation, the power flows from the generator towards the grid or load, which is the intended direction. However, a reverse power condition can occur when the power flow reverses, and the generator starts to consume power instead of generating it. This can happen due to various reasons, such as a failure in the prime mover (e.g., turbine, engine), a loss of load, or a fault in the electrical system. The reverse power relay monitors the direction of the active power flow (real power) in the generator circuit. When the relay detects a reverse power flow, it senses that the generator is operating in a reverse power condition. In response, the relay will initiate a trip signal to the generator's circuit breaker, causing the generator to be quickly disconnected from the electrical system. This rapid disconnection helps prevent damage to the generator, such as mechanical stress, overheating, or potential backfeeding into the prime mover. 2. What is preferential trip and how does it work in generator system The preferential trip is a crucial protective feature in generator systems that prioritizes the tripping or disconnection of specific equipment or components in the event of a fault or abnormal condition. The primary purpose of this mechanism is to ensure that the most critical or sensitive elements within the generator system are isolated and protected first, minimizing the overall impact and potential damage to the entire system. When a fault or an abnormal condition occurs in the generator system, such as an overload, short circuit, or any other type of disturbance, the protective relays and devices within the system detect the issue. The preferential trip mechanism is then activated, and it prioritizes the tripping or disconnection of the most critical components based on their importance and the potential consequences of their failure. For example, in a generator system, the preferential trip might prioritize the disconnection of the generator itself, followed by the disconnection of other auxiliary equipment, such as transformers, switchgear, or feeders. This selective tripping helps to contain the impact of the fault or abnormal condition and prevent it from spreading to the entire generator system. 3. What are the advantages and disadvantages of electrical and pneumatic control Electrical Control Advantages: • Faster response times compared to pneumatic systems • More precise and accurate control • Easier to integrate with other electronic systems on the ship • Require less maintenance and fewer moving parts • Allow for remote monitoring and control of systems Electrical Control Disadvantages: • Susceptibility to electrical failures and power outages • Potential safety concerns with high voltage/current • Require specialized maintenance and repair expertise • Can be more complex and costly to install initially Pneumatic Control Advantages: • Intrinsically safe operation, no risk of electrical sparks • Can operate reliably even with power failures • Simple and robust design with fewer moving parts • Can provide good force and torque for actuating valves/dampers • Lower installation and maintenance costs Pneumatic Control Disadvantages: • Slower response times compared to electrical controls • Less precise and accurate control • Require compressed air supply system to be maintained • Potential for air leaks in the piping network • Limited ability to integrate with digital control systems 4. PLC programming languages • Ladder Logic (LAD) - is a graphical programming language that mimics the appearance of electrical relay circuits. It uses ladder-like rungs to represent logical control circuits. Ladder Logic is particularly suited for representing discrete logic operations and is widely used in industries where relay-based control systems are prevalent. It is easy to understand for those with a background in electrical wiring and control circuits. • Structured Text (ST) - is a high-level programming language that follows a structured programming approach and uses statements and expressions to define control logic. It allows for complex calculations, mathematical operations, and conditional branching. ST is particularly suited for mathematical computations, data manipulation, and complex control algorithms. • Function Block Diagram (FBD) - is a graphical programming language that represents control logic as a network of interconnected function blocks. These function blocks encapsulate specific control functions and can be interconnected to create complex control algorithms. FBD is visually similar to electronic circuit diagrams and is useful for designing and representing control systems in a modular and structured manner. It is commonly used for systems with complex interconnections and for implementing reusable control modules. 5. three application of PLC onboard • PLC Alarm Annunciator System - An alarm annunciator system is used to monitor and display alarms from various ship systems and equipment. A PLC can be employed to collect alarm signals from different sensors and control devices, process the signals, and activate visual and audible alarms on the annunciator panel. The PLC can also log alarm events, provide alarm prioritization, and facilitate remote monitoring and control. • PLC Boiler Startup System - A PLC-based boiler startup system can automate and sequence the startup process, ensuring proper procedures are followed. The PLC can control boiler parameters such as fuel supply, air flow, water level, and safety interlocks. It can monitor and regulate the boiler operation, including ignition, fuel firing rate, and water level control. • PLC Separator Control System - Separators are used on ships to remove impurities and separate different components from fluids, such as fuel oils and lubricating oils. A PLC-based separator control system can monitor and control the operation of the separator, including flow rates, temperatures, pressures, and discharge conditions. The PLC can adjust valve positions, monitor levels, and provide alarms or shut down the system in case of abnormal conditions. • PLC Main Engine Remote Control System - . A PLC-based remote control system for the main engine allows for centralized control and monitoring from a control room or bridge. The PLC can receive commands from the control station and control the engine's speed, direction, fuel supply, cooling water flow, and other parameters. It can also monitor engine performance, collect data, and provide alarms and safety interlocks. 6. Basic Components of PLC 1. Input: The input section of a PLC is responsible for receiving signals from various input devices such as sensors, switches, and other field devices. It converts these signals into digital data that the PLC's processor can interpret. The input section ensures that the PLC can monitor and react to changes in the external environment. 2. Processor: The processor, also known as the central processing unit (CPU), is the core component of the PLC. It executes the control program stored in the memory and performs various operations, including arithmetic calculations, logical decisions, and data manipulation. The processor continuously scans the input signals, processes them based on the programmed instructions, and generates appropriate output signals. 3. Memory: The memory in a PLC stores the control program, data, and variables required for operation. It is typically divided into two main types: o Program Memory: This non-volatile memory holds the user-defined control program. It contains the ladder logic, function block diagrams, or other programming languages used to implement the control logic. The program memory is retained even when the PLC loses power. o Data Memory: This volatile memory stores data and variables used during program execution. It includes input and output values, internal registers, timers, counters, and other temporary data. Data memory is cleared when the PLC loses power. 4. Output: The output section of a PLC is responsible for sending control signals to external devices such as motors, actuators, solenoid valves, and other output devices. It converts the digital data generated by the processor into appropriate electrical or pneumatic signals that actuate the output devices. The output section allows the PLC to control and manipulate the physical processes in the external world.
@user-lq9vc5zf2u2 ай бұрын
AUX MACH 1. What is interface and how does it affect the separation efficiency? • On board ships, the term "interface" refers to the boundary between the two immiscible liquid phases, such as oil and water, within a separator. This interface plays a critical role in determining the separation efficiency of the system. Firstly, the position of the interface, or phase boundary, needs to be properly maintained at the correct level within the separator. If the interface is too high, it can lead to carry-over of water into the oil stream, while a too low interface can result in oil being carried over into the water stream. Maintaining the optimal interface level is crucial for achieving the desired separation outcomes. 2. Explain Follow up and Non-Follow up controls on steering gear. 2. Explain how operating water in purifiers work • Purifiers, especially those used for oil treatment on ships, rely on a clever system of pressurized water called operating water to open and close the centrifuge bowl. Imagine this water acting like a powerful hydraulic fluid. To seal the bowl for purification, high-pressure water fills the "closing water" chamber. This pressure pushes a piston or cylinder upwards, creating a tight seal with a ring on the bowl. This pressurized state might be constant or pulsed depending on the system. When it's time to expel waste, the water flow is diverted to the "opening water" chamber. This opposing pressure pushes another piston or cylinder down, overcoming the closing force. This slight downward movement opens ports in the bowl, allowing accumulated waste like sludge to be discharged. Some purifiers might even have a dedicated "conditioning water" line for flushing or cleaning tasks within the bowl or pipes. In essence, operating water is the hidden powerhouse that precisely controls the opening and closing of the centrifuge bowl throughout the purification and waste removal cycles. 3. working principle of rotary steering gear - A rotary vane steering gear is a mechanism on ships specifically designed to control the rudder's direction, influencing the vessel's course. It uses a rotating cylindrical housing with fixed and movable vanes to achieve this. In a rotary vane steering system, the helmsman's turn of the steering wheel translates into an electrical signal via the telemotor. This signal is amplified and sent to the power unit, which uses electric motors and pumps to generate high-pressure hydraulic fluid. The transmission system, comprised of valves and pipes, channels this fluid to the rotary vane. Here, specific chambers are pressurized based on the signal, causing the vanes within the housing to rotate. This rotational force is transferred to the rudder stock, ultimately turning the rudder blade and steering the ship. Additional components like the rudder angle indicator provide feedback on the rudder's position, while the hydraulic reservoir stores fluid, filters keep it clean, and safety relief valves protect the system from pressure overload. 4. common faults found in steering gear • Oil Leaks: Leaks in the hydraulic system can reduce pressure and hinder the steering's effectiveness. It's crucial to address leaks promptly to avoid complete system failure. • Discrepancy Between Rudder and Helm: Sometimes, the actual turn of the rudder doesn't match the angle indicated on the ship's wheel (helm). This can be due to issues with linkages, adjustments, or faulty sensors. • Steering Difficulty: Difficulty turning the wheel or sluggish response can indicate problems like friction in the system, pump issues, or low hydraulic pressure. • Excessive Noise: Unusual noises coming from the steering gear can signify internal wear, malfunctioning pumps, or air trapped in the hydraulic system. • High Oil Temperatures: Overheating oil can damage components and reduce lubrication. This might be caused by excessive use, blocked filters, or malfunctioning coolers. • Rudder Movement Beyond Limits: The rudder should only turn within a specific range. Uncontrolled or excessive movement can occur due to mechanical failures or faulty limit switches. • No Remote Control Steering: Modern ships often have remote steering options from the bridge. Failure of these systems could be due to problems with pumps, valves, or the control system itself. • Rudder Angle Transmitter or Tiller Link Issues: These components are crucial for translating helm input into rudder movement. Faulty sensors or damaged linkages can disrupt this communication 5. Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situations. Procedures for emergency steering includes; • Establish communication with the bridge • Switch over to local control on all starter cabinets • Control the rudder on command from the bridge by operating the pilot valves on the main valve block • Activate the pilot for main spool, and the pilot for idling valve • When the rudder is given order, release the pilot for idling valve and then the pilot for main valve 6. Operating Principles of Refrigeration System The operating principles of a refrigeration system, which is composed of the main components of a compressor, condenser, expansion valve, and evaporator, are as follows: The refrigeration cycle begins with the compressor, which is the heart of the system. The compressor takes in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it, increasing its pressure and temperature. This high-pressure, high-temperature refrigerant vapor is then sent to the condenser. In the condenser, the hot refrigerant vapor transfers its heat to the surrounding air or water, causing the refrigerant to condense into a high-pressure, high-temperature liquid. As the refrigerant condenses, it releases the latent heat of vaporization, which is carried away by the air or water flowing through the condenser. The high-pressure, high-temperature liquid refrigerant then flows through the expansion valve, which is a metering device. As the refrigerant passes through the expansion valve, its pressure and temperature drop dramatically due to the Joule-Thomson effect. This low-pressure, low-temperature liquid refrigerant is then fed into the evaporator. In the evaporator, the low-pressure, low-temperature refrigerant absorbs heat from the surrounding environment, such as the air or water being cooled. As the refrigerant absorbs heat, it undergoes a phase change from a liquid to a vapor, becoming a low-pressure, low-temperature refrigerant vapor. This vapor is then drawn back into the compressor, completing the refrigeration cycle. The continuous cycling of the refrigerant through these four main components (compressor, condenser, expansion valve, and evaporator) is what allows the refrigeration system to remove heat from the desired space and transfer it to the surrounding environment, effectively cooling the target area.
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Good, I couldn't be bothered to do one more hell bullet with the credits, when the game is full of that mess😑. So I figured I'd come see this cutscene, since I got ending a-b-c-d only. Needless to say, it's good to be done with it🤷🏿♂️
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15. Power Management Systems (PMS) ● Automatic Synchronizing - PMS enables automatic synchronization of multiple generators or power sources to ensure a smooth and stable transition during power transfer or parallel operation. It synchronizes the frequency, phase, and voltage of the sources before connecting them to the grid or load. ● Automatic Load Sharing - PMS facilitates the automatic sharing of electrical loads among multiple generators in a synchronized system. It distributes the load based on the capacity and availability of each generator, ensuring efficient utilization and preventing overloading. ● Automatic Start/Stop/Stby Generators according to Load Demand - PMS monitors the load demand and automatically starts, stops, or puts standby generators into operation as required. It ensures that the available generators match the load demand, optimizing fuel consumption and minimizing downtime. ● Large Motors Automatic - PMS includes features to automatically block or unblock the starting of large motors based on system conditions. This prevents excessive starting currents, voltage drops, or other undesirable effects that may occur during motor startup. ● Blocking Load Analysis and Monitoring - PMS continuously monitors and analyzes the load profile, voltage, current, and other parameters to identify abnormalities or deviations from the desired operating conditions. It provides real-time information and alerts to operators for effective load management. ● Three (3) Phase Management and Voltage Matching - PMS manages the three-phase power distribution, ensuring balanced loads across all phases. It also maintains voltage matching between generators and loads to prevent voltage imbalances and equipment damage. ● Redundant Power Distribution - PMS incorporates redundancy in power distribution to ensure uninterrupted power supply. It monitors the status of multiple power sources and automatically switches to an alternative source in case of a failure or outage. ● Frequency Control - PMS regulates and stabilizes the frequency of the power system within acceptable limits. It adjusts the engine speed or the load sharing among generators to maintain the desired frequency and prevent frequency deviations that can affect sensitive equipment. ● Blackout Start - PMS enables automatic starting of standby generators in the event of a blackout or loss of main power supply. It ensures a seamless transition to backup power and minimizes disruption to critical operations. ● Selection of Generators Pioit(fist - PMS provides intelligent algorithms for selecting the most appropriate generators based on factors like load demand, generator capacity, fuel efficiency, and maintenance requirements. It optimizes generator selection to achieve the best performance and cost-effectiveness. 16. M.E. Fresh Water Cooling System ● Introduction to Fresh Water Cooling System - The Fresh Water Cooling System is an essential component of marine engines (M.E.) that helps maintain the temperature of the engine within optimal operating limits. It utilizes fresh water as a cooling medium to remove excess heat generated during engine operation. ● Component of Fresh Water Cooling System ● Fresh Water circulating pump - The circulating pump is responsible for circulating the fresh water through the cooling system. It ensures a continuous flow of water to carry away heat from the engine components. ● Heat exchanger - The heat exchanger transfers the heat from the engine coolant to a separate cooling medium, such as seawater or air. It consists of tubes or plates that facilitate the exchange of heat between the coolant and the cooling medium. ● Expansion Tank - The expansion tank, also known as the header tank or surge tank, provides a reservoir for the coolant. It accommodates the expansion and contraction of the coolant due to temperature variations and helps maintain the proper coolant level in the system. ● Thermostat -The thermostat regulates the flow of coolant within the cooling system. It opens or closes based on the engine temperature, allowing the coolant to flow through the system when the engine reaches the desired operating temperature. ● Piping and fittings -The piping and fittings connect various components of the cooling system, allowing the flow of coolant. They are designed to withstand the temperature and pressure requirements of the system. ● Cooling Medium - The cooling medium in a fresh water cooling system is typically fresh water, which is circulated through the engine to remove heat. The fresh water absorbs the thermal energy generated by the engine and carries it to the heat exchanger for dissipation. ● Circulation System - The circulation system comprises the pump, piping, and fittings that facilitate the movement of the coolant through the cooling system. It ensures a continuous flow of fresh water to regulate the engine temperature effectively. ● What is OFFSET and what does it signify? - "offset" refers to the difference between the desired setpoint and the actual process variable value when the control loop is in a steady state. It signifies the deviation that remains even when the control loop is supposed to be maintaining the process variable at the setpoint. For example, if our control system held the temperature at 100.5°C consistently (even though the set point was 100.0°C), then an offset of 0.5°C exists. ● What is "proportional band" and what happens if the proportional band is too wide and too narrow - The proportional band determines the range of error values over which the control output will change in proportion to the error. If the proportional band is too wide, it means that the control output will change gradually even for small errors. This can result in slow response and sluggish control. It may take longer for the control system to bring the process variable back to the setpoint, leading to larger deviations and potentially prolonged instability. - On the other hand, if the proportional band is too narrow, the control output will change rapidly for even small errors. This can result in overshoot and oscillations around the setpoint. The control system may become overly sensitive to small disturbances, leading to instability and erratic behavior. Finding the right proportional band is crucial for achieving a well-tuned control system. It depends on the dynamics of the process being controlled and the desired response characteristics. A properly tuned proportional band allows the control system to respond quickly to errors while avoiding excessive oscillations or overshoot, leading to stable and accurate control of the process variable. ● What is a reverse power relay and how does it work onboard a ship? - Is a protective device used to detect and respond to reverse power flow. Reverse power flow occurs when power flows from a generator to its prime mover (usually an engine) instead of from the prime mover to the generator, which is the normal operating condition. Onboard ships, the reverse power relay is typically installed in the generator circuit to protect the prime mover (such as a diesel engine) from damage caused by reverse power flow. The relay monitors the power flow direction and activates when it detects reverse power flow beyond a preset threshold. When reverse power flow is detected, the reverse power relay operates to disconnect the generator from the electrical system. This action prevents further power flow in the reverse direction, protecting the prime mover from potential damage. The relay may also activate an alarm or provide a signal to indicate the reverse power condition. - ● What is a preferential trip and how do they apply onboard? - Preferential trip, also known as selective tripping or selective shutdown, is a technique used in electrical systems to prioritize the disconnection of specific loads or equipment during fault conditions. It is implemented to ensure that critical or essential equipment remains operational while non-critical loads are selectively disconnected. - Onboard ships, preferential trip schemes are used to protect essential systems and equipment. For example, in the event of a fault or overload, the preferential trip system will first disconnect non-essential loads or equipment, such as lighting circuits or non-essential machinery. This allows the electrical system to prioritize the supply of power to critical systems, such as navigation equipment, communication systems, propulsion machinery, and safety systems. - The implementation of preferential trip systems involves setting up a hierarchical arrangement of protective devices, such as circuit breakers or relays, with different time-delay settings and coordination characteristics. These devices are coordinated to selectively trip or isolate specific circuits or equipment based on their priority level during fault conditions. By doing so, the preferential trip system helps maintain the availability of critical systems while minimizing the impact of faults on non-essential loads.
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AUTO 12. Boiler Drum Level Control System ● Introduction to Boiler Drum Level Control - Boiler drum level control is crucial for several reasons, including safety and efficiency. Maintaining the correct water level in the drum ensures an adequate supply of water for steam generation, preventing overheating or flooding. It also promotes optimal steam quality and thermal efficiency, avoiding energy losses and reducing overall boiler efficiency. ● Boiler Drum Level Measurement - Accurate measurement of the drum level is essential for effective control. Common methods of drum level measurement include float-operated devices, differential pressure transmitters, and guided wave radar. These instruments provide real-time feedback on the water level in the drum, which is used by the control system to make adjustments. ● Single-Element Control System - A single-element control system utilizes only the drum level measurement to control the boiler feedwater flow. It is a basic control strategy that adjusts the feedwater flow based on the drum level deviation from the desired setpoint. However, this approach may not account for variations in steam demand and can lead to instability or improper control. ● Two-Element Control System - A two-element control system incorporates an additional measurement, typically steam flow or feedwater flow, along with the drum level. This additional input helps account for variations in steam demand and provides better control. The control system adjusts the feedwater flow based on both the drum level and the secondary measurement. ● Three-Element Control System - A three-element control system further enhances control accuracy by adding a measurement of the steam flow rate. It considers the rate of change of the drum level, along with the drum level and steam flow, to make more precise adjustments to the feedwater flow. This system provides faster response and improved stability. ● Control Algorithms (PID Control) - Proportional-Integral-Derivative (PID) control algorithms are commonly used in boiler drum level control systems. PID controllers calculate the control output based on the error (difference between the desired setpoint and the measured value), the integral of the error over time, and the rate of change of the error. These algorithms help fine-tune the control response and maintain stability. ● Control Valve Operation - Control valves are used to regulate the flow of feedwater into the boiler drum. The control system sends signals to the control valve to open or close based on the desired drum level. The valve position determines the flowrate of feedwater, which affects the water level in the drum. ● Alarm and Trip Systems -Boiler drum level control systems incorporate alarm and trip systems to ensure safety. Alarms are activated when the drum level deviates from the desired range, indicating potential issues. Trip systems initiate automatic shutdown or protective actions if the drum level reaches critical levels, preventing damage to the boiler and associated equipment. ● Control System Integration - Boiler drum level control systems are typically integrated into a larger control system that oversees the overall operation of the boiler. Integration includes communication with other control loops, monitoring of critical parameters, and coordination with safety systems. 13. Basic Boiler drum level and combustion control system ● Importance of Drum Level Control - Drum level control in boilers is essential for safe and efficient operation. Maintaining the correct water level ensures an adequate supply of water for steam generation, preventing overheating or flooding. It enhances safety and optimizes steam quality and thermal efficiency, avoiding energy losses and reducing overall boiler efficiency. ● Components of Drum Level Control System ● Level Measuring Device: It is used to measure the water level in the steam drum. Commonly used devices include float-operated devices, capacitance probes, and differential pressure transmitters. ● Level Controller: The level controller compares the measured drum level with the desired setpoint and calculates the error. It generates an output signal to adjust the water flow into the drum based on the error. ● Control Valve: The control valve regulates the flow of feedwater into the boiler drum. It is modulated by the level controller to maintain the desired drum level. ● Feedwater Pump: The feedwater pump supplies water to the boiler drum based on the control signal from the level controller. ● Combustion Control - Combustion control in a boiler system involves maintaining the proper ratio of fuel and air for efficient and safe combustion. It aims to achieve complete combustion while minimizing the emission of pollutants. ● Components of Combustion Control System ● Fuel Flow Control: This component regulates the flow rate of fuel into the combustion chamber. It can be achieved using control valves or variable speed drives for pumps or fans, depending on the type of fuel. ● Air Flow Control: The air flow control system adjusts the supply of combustion air to the burner. It ensures that the correct amount of air is available for efficient combustion. Control dampers or variable speed drives for fans are commonly employed for air flow control. ● Oxygen Trim System: An oxygen trim system measures the oxygen content in the flue gas and adjusts the air-fuel ratio accordingly. This helps to optimize combustion efficiency and reduce emissions. ● Burner Management System (BMS): The BMS ensures the safe and reliable operation of the burner. It includes safety interlocks, flame detection systems, and fuel trip systems to prevent hazards such as flame failure, high or low gas pressure, or ignition failures. ● Air-Fuel Ratio Control - Maintaining the proper air-fuel ratio is crucial for efficient combustion. The air-fuel ratio control system adjusts the flow rates of fuel and combustion air to achieve the desired ratio. It typically utilizes feedback control loops to monitor and regulate the air and fuel flows based on measurements such as oxygen content in the flue gas or analysis of combustion products. ● Flame Monitoring and Safety Systems - Flame monitoring and safety systems are essential to ensure safe and reliable boiler operation. These systems include flame detectors that continuously monitor the presence and stability of the flame. If the flame is lost or unstable, the safety system initiates appropriate actions, such as shutting off the fuel supply and activating alarms or safety interlocks to prevent hazardous conditions. 14. Basic Main Engine Remote Control Starting System ● Introduction to Main Engine Starting - The Main Engine Remote Control Starting System is responsible for initiating the starting sequence of the main engine in a marine vessel. It allows for the remote control and monitoring of the starting process, ensuring safe and efficient engine operation. ● Components of Remote Control Starting System ● Starting air distributor - the starting air distributor is a device that distributes compressed air to the engine cylinders during the starting process. It ensures that the correct amount of air is supplied to each cylinder for combustion. ● Air compressors - Air compressors supply the compressed air required for starting the engine. They compress atmospheric air and store it in starting air receivers. ● Starting air receivers - Starting air receivers are vessels that store the compressed air from the air compressors. They provide a reservoir of air for the starting process and ensure a continuous supply of air during engine starting. ● Control valves - Control valves regulate the flow of starting air from the starting air receivers to the engine cylinders. They open and close according to the commands from the control system, allowing the precise timing and distribution of air to the cylinders. ● Safety interlocks - Safety interlocks are mechanisms that ensure the starting process can only be initiated under safe conditions. They may include prerequisites such as proper fuel supply, sufficient lubrication, and correct engine parameters before allowing the starting sequence to begin. ● Starting Air Distribution System - The starting air distribution system consists of the starting air receivers, control valves, and piping network. Compressed air from the receivers is directed to the engine cylinders through the control valves. The distribution system ensures that the starting air reaches each cylinder at the right time and in the correct quantity for reliable combustion. ● Control Valves and Timing Devices - Control valves in the starting system are responsible for regulating the flow of starting air to the engine cylinders. They open and close based on signals from the control system to ensure precise timing and synchronization of the starting process. Timing devices may also be incorporated to control the duration of air supply to each cylinder. ● Safety Interlocks and Protections - Safety interlocks play a crucial role in the remote control starting system. They prevent the starting process from being initiated if certain safety conditions are not met. For example, the interlocks may check for proper fuel supply, lubrication, or engine parameters to ensure safe starting operations. Protections are in place to safeguard against abnormal conditions, such as high cylinder temperatures or abnormal engine speed. ● Control Panel Operation - The control panel is the interface for operating the remote control starting system. It allows the operator to start, stop, and monitor the main engine starting process. The control panel provides indicators, alarms, and controls for the various components, facilitating safe and efficient engine starting.
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What is the difference between plan view and elevation view? - A plan view in navigational architecture is a top-down representation of a ship or vessel, providing a bird's-eye view of the layout and arrangement of decks, compartments, and structures. It offers a two-dimensional perspective and is commonly used to illustrate the horizontal distribution of spaces, such as navigation equipment, cargo holds, accommodation areas, and deck layouts. On the other hand, an elevation view shows the ship's profile from a side view, offering a two-dimensional representation of the ship's height and structure. It focuses on the vertical arrangement of decks, superstructures, masts, funnels, and other features, providing insights into the ship's external appearance and proportions. Both plan view and elevation view are essential in understanding the spatial organization and design of a ship. - Give at least two examples of longitudinal force acting on ships - Longitudinal forces refer to forces that act along the length or longitudinal axis of a ship. These forces can affect the ship's motion, stability, and performance during navigation. Some common longitudinal forces includes: 1. Propulsive Force: The propulsive force is generated by the ship's propulsion system and acts in the direction of the ship's motion. It propels the ship forward or astern, driving it through the water. The magnitude of the propulsive force depends on factors such as the power of the propulsion system, the efficiency of the propellers or thrusters, and the ship's speed. 2. Resistance Force: Resistance force is the opposing force experienced by a ship as it moves through the water. It acts in the opposite direction to the ship's motion and is caused by various factors, including water friction, wave resistance, and form drag. The resistance force depends on the ship's hull shape, speed, displacement, and environmental conditions. Minimizing resistance is crucial for optimizing fuel efficiency and improving the ship's performance. 3. Wind Force: Wind force can exert a longitudinal force on a ship when the wind blows parallel or nearly parallel to the ship's longitudinal axis. Depending on the wind direction, it can act as a driving force, pushing the ship forward, or as a retarding force, opposing the ship's motion. The magnitude of the wind force depends on factors such as wind speed, ship's profile area exposed to the wind, and wind angle relative to the ship's heading. 4. Current Force: Current force refers to the force exerted by water currents on a ship. If the current flows in the same direction as the ship's intended course, it can act as a driving force, aiding the ship's propulsion. Conversely, if the current flows in the opposite direction, it can act as a retarding force, opposing the ship's progress. The magnitude of the current force depends on the speed and direction of the water current. Two types of stresses experienced onboard 1. Tensile Stress: Tensile stress is a type of stress that occurs when a force is applied to stretch or elongate a material. Onboard a ship, tensile stress can arise in components such as cables, ropes, and chains that are subjected to pulling or tension forces. For example, mooring lines or towing cables experience tensile stress when supporting the weight and forces exerted on the ship during docking, anchoring, or towing operations. 2. Compressive Stress: Compressive stress is the opposite of tensile stress and occurs when a material is subjected to forces that tend to compress or shorten it. In a ship's structure, compressive stress can occur in columns, pillars, or support structures that bear the weight and loads of the ship's decks, superstructures, or cargo. It is important to ensure that these structural elements can withstand the compressive forces and maintain their stability. 3. Shear Stress: Shear stress refers to the stress that occurs when parallel forces act in opposite directions, causing one layer of a material to slide or deform relative to another layer. Onboard a ship, shear stress can be experienced in components such as hull plating, beams, or connections subjected to lateral or transverse forces, such as those caused by waves or ship motions. Shear stress analysis is crucial to ensure the structural integrity and resistance to deformation of these components. 4. Bending Stress: Bending stress occurs when a material is subjected to a combination of tension and compression forces, resulting in bending or flexure. In a ship's structure, bending stress can be present in components such as beams, girders, or keels, which are subjected to loads that cause them to bend or deflect. Proper design and analysis are essential to ensure that these components can withstand the bending stress without experiencing excessive deformation or failure. 5. Fatigue Stress: Fatigue stress is a type of stress that occurs over time due to repeated or cyclic loading. Ships often experience cyclic loads from wave impacts, vibration, or machinery operations, leading to fatigue stresses. Fatigue stress can gradually weaken the ship's structure or components, potentially leading to cracks, fractures, or failures. Proper inspection, maintenance, and fatigue analysis techniques are employed to manage and mitigate fatigue stress onboard ships. What are the differences between Flare and Tumblehome? ● Flare: Flare refers to the outward curvature or widening of the ship's hull as it moves from the waterline towards the upper portions of the ship's sides. In other words, the hull gradually angles outward or expands in width. Flare is often seen in vessels that operate in rough sea conditions, such as offshore supply vessels, fishing boats, or ships designed for icebreaking. The flare helps to deflect waves and spray away from the ship, improving stability and reducing the likelihood of water coming over the sides. ● Tumblehome: Tumblehome, on the other hand, refers to the inward curvature or narrowing of the ship's hull as it moves from the waterline towards the upper portions of the ship's sides. In contrast to flare, the hull gradually angles inward or tapers in width. Tumblehome was a common design feature in older ship designs and is occasionally seen in yachts and sailboats. Tumblehome can help reduce a ship's beam (the width of the ship) and potentially improve maneuverability. However, it may also lead to a reduction in stability and interior space.
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Watertight Doors and Openings: Install watertight doors and openings in bulkheads to allow access between compartments while maintaining watertight integrity. Ensure that watertight doors are properly designed, constructed, and maintained to withstand water pressure. Implement appropriate sealing mechanisms, such as rubber gaskets or hydraulic systems, to achieve water tightness. Week 12 The free surface effect is a crucial consideration in the stability of vessels, particularly those containing liquid cargo or with partially filled tanks. When a vessel experiences motion, the liquid within its tanks tends to slosh around, creating what is known as a free surface effect. This effect can have significant implications for the vessel's stability and overall safety. Here's how: Shift in Center of Gravity (CG): The movement of liquid within the tanks alters the vessel's center of gravity. As the liquid sloshes from one side to another, the center of gravity of the vessel shifts accordingly. If the liquid moves to one side, it effectively raises the center of gravity on that side, potentially leading to instability. This shift in the center of gravity can make the vessel more prone to listing or capsizing. Reduction in Metacentric Height (GM): The metacentric height (GM) is a measure of a vessel's stability. It represents the distance between the center of gravity (CG) and the metacenter (M), which is a point of intersection of the centerline of the vessel with the centerline of the buoyancy force. When liquid sloshes around in partially filled tanks, it can reduce the metacentric height. A lower GM makes the vessel less stable and more susceptible to rolling motions, especially in rough seas. Increased Rolling Motion: The presence of a free surface amplifies the rolling motion of the vessel. As the liquid sloshes from side to side, it generates momentum that can cause the vessel to roll more violently. This increased rolling motion not only affects the comfort of those on board but also poses a safety risk, particularly if the rolling becomes severe enough to lead to a capsize. Dynamic Stability: The free surface effect also affects the dynamic stability of the vessel. Dynamic stability refers to the vessel's ability to return to an upright position after being inclined by external forces, such as waves or wind. The presence of a free surface can dampen the vessel's dynamic stability, making it more difficult for the vessel to recover from heeling moments. The effects of a liquid's free surface inside a tank are complex and encompass various principles in fluid dynamics, hydrostatics, and tank design. Here's a breakdown of how each of these factors influences the behavior of the liquid and consequently impacts vessel stability: Fluid Dynamics: Free Surface Flows: Fluid dynamics govern the movement of liquids within a tank, especially when the liquid surface is free. The sloshing and wave-like motion of the liquid can occur due to the vessel's movement or external forces. Understanding these flows is essential for predicting the behavior of the liquid cargo and its impact on the vessel's stability. Wave Propagation: The free surface of the liquid can propagate waves within the tank, which can interact with the vessel's structure and contribute to dynamic loads. These waves can amplify if resonance conditions are met, leading to potentially hazardous situations. Hydrostatics: Hydrostatic principles determine the pressure distribution within the liquid and its equilibrium state. The weight of the liquid exerts hydrostatic pressure on the tank walls and bottom. Changes in liquid level or distribution affect this pressure distribution, which in turn influences the vessel's stability characteristics. Buoyancy: Buoyancy forces act on the immersed portion of the tank, exerting an upward force counteracting the weight of the liquid. Changes in the liquid's distribution alter the buoyant force distribution, affecting the vessel's overall buoyancy and stability. Tank Design and Stability: Tank design plays a crucial role in mitigating the effects of the liquid's free surface. Baffles, anti-sloshing devices, and other structural features are incorporated to minimize sloshing and dampen the impact of wave propagation. Proper tank design is essential to maintain the vessel's stability under various operating conditions. Stability calculations take into account the dynamic effects of the liquid cargo within the tanks. Stability criteria, such as the metacentric height and the range of stability, are evaluated considering the free surface effect to ensure the vessel remains safe and stable during its operations. Capillary and Surface Tension: Capillary action and surface tension phenomena can influence the behavior of the liquid at the free surface. These effects may be minor compared to other factors but can contribute to the overall dynamics of the liquid and its interaction with the tank walls. Stability requirements for different types of ships vary depending on their intended purpose, design, and operational characteristics. Here's an overview of stability considerations for various types of ships: General Stability Concepts: Metacentric Height (GM): GM is a fundamental concept in ship stability. It represents the distance between the center of gravity (G) and the metacenter (M), which is a point of intersection of the centerline of the vessel with the centerline of the buoyancy force. A larger GM typically indicates greater stability, as the vessel will have a stronger tendency to return to its upright position after being heeled by external forces. Cargo and Container Ships: Stowage and Loading: Cargo and container ships must adhere to strict stowage and loading procedures to maintain stability. Proper distribution of cargo weight and securing of containers are critical to prevent excessive list or trim. Freeboard Requirement: Freeboard is the distance between the waterline and the main deck of the ship. Cargo and container ships are subject to international regulations governing minimum freeboard requirements, which ensure adequate reserve buoyancy and stability, especially in rough seas. Tankers: Liquid Dynamics: Tankers transport liquid cargo, which introduces unique stability challenges due to the dynamic behavior of the liquid within the tanks. Sloshing and free surface effects can significantly impact stability, requiring careful consideration during design and operation. Ballast Systems: Tankers often utilize ballast systems to control stability by adjusting the distribution of weight within the vessel. Ballasting and deballasting operations help optimize stability depending on cargo load and environmental conditions. Passenger Cruise Ships: Intact Stability: Passenger cruise ships must maintain intact stability to ensure passenger comfort and safety. Stability criteria such as GM and range of stability are rigorously evaluated during design and must comply with regulatory standards. Damage Stability: In addition to intact stability, cruise ships are required to demonstrate adequate damage stability. This involves assessing the vessel's ability to remain afloat and upright in the event of damage to the hull, such as from a collision or grounding.
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NAV ARCH Week 9 Propulsion System: This includes the main engines, propellers, shafting, and any thrusters. Typically, the main engines are located in the engine room, with propellers at the stern. The shafting connects the engine to the propeller, usually passing through the ship's hull. Thrusters, if present, are often positioned at the bow and/or stern for improved maneuverability. Fuel Systems: Fuel tanks are strategically placed to ensure stability and weight distribution. They are commonly located in the lower part of the ship's hull to maintain stability, with piping systems running to the engine room. Fuel filters, pumps, and other equipment are usually installed nearby for efficient fuel delivery. Cooling Systems: Heat exchangers, pumps, and piping are arranged to cool the engines and other machinery. Heat exchangers are often placed near the engines to transfer heat to the ship's cooling water system or to separate cooling systems for various machinery. Exhaust Systems: Exhaust pipes from the engines lead to funnels or stacks above the ship's deck to release exhaust gases safely. These are often located aft to minimize interference with crew areas and to prevent exhaust from affecting navigation. Air Systems: Air intakes for engine combustion and ventilation are positioned to ensure a steady flow of fresh air. Ventilation systems throughout the ship maintain a comfortable environment for crew and prevent the buildup of hazardous gases. Electrical Systems: Generators, switchboards, and distribution panels are placed in the engine room or a dedicated electrical room. Wiring runs throughout the ship to provide power to various systems and equipment. Emergency backup systems are also incorporated for critical functions. Automation and Control Systems: Control panels and instrumentation are located in the engine control room for monitoring and controlling the propulsion and auxiliary systems. These systems often include advanced automation for optimal performance and fuel efficiency. In terms of stability, the arrangement of these systems must be carefully considered to maintain the ship's center of gravity and stability characteristics. The weight distribution of equipment and machinery, along with fuel and cargo, must be balanced to ensure the ship remains stable in various sea conditions. Additionally, modern ships often employ stability management systems that monitor and adjust ballast and trim to optimize stability throughout the voyage. Week 10 "Compartmentation" refers to the division of a ship's interior into separate compartments or sections. This is a fundamental principle in ship design aimed at enhancing safety, particularly in the event of flooding or damage. Each compartment is typically bounded by watertight bulkheads, floors, and ceilings, creating a barrier that prevents water from freely flowing throughout the vessel. Watertight integrity, therefore, relies heavily on the effectiveness of compartmentation. Here's how it affects the ship's safety: Damage Containment: If a ship suffers damage, whether from a collision, grounding, or other mishap, compartmentation limits the spread of water to the affected area. By confining flooding to a single or a few compartments, the ship can maintain stability and buoyancy, reducing the risk of sinking. Stability: Compartmentation helps maintain the ship's stability by preventing water from accumulating unevenly. Even if one compartment floods, the rest of the vessel remains relatively unaffected, allowing the ship to maintain its proper trim and stability. Safety: Compartmentation enhances the safety of passengers and crew by providing time for evacuation or for addressing the source of flooding. It slows down the rate of flooding, giving responders more time to mitigate the situation. Redundancy: Large ships often feature redundant compartments, meaning that even if one compartment is compromised, there are multiple backup compartments to maintain buoyancy and stability. This redundancy adds an extra layer of safety. Regulatory Compliance: Compartmentation is typically subject to international maritime regulations, such as those outlined by the International Maritime Organization (IMO). These regulations specify standards for the construction, placement, and maintenance of watertight bulkheads and doors to ensure adequate compartmentation and watertight integrity. However, while compartmentation is a crucial aspect of ship safety, it's not foolproof. Compromises in compartmentation due to factors like structural weaknesses, inadequate maintenance, or improper sealing of doors and hatches can undermine watertight integrity. Additionally, modern ships often have complex systems running through bulkheads, such as piping and cabling, which may introduce vulnerabilities if not properly managed. Overall, compartmentation remains a cornerstone of ship design and safety, providing a critical defense against the hazards of flooding and damage at sea. Week 11 Watertight bulkheads are structural divisions within a ship's hull designed to prevent the ingress of water in case of damage to the vessel's hull. These bulkheads play a crucial role in maintaining the ship's stability and integrity, particularly in the event of a flooding incident. According to SOLAS Regulation, the construction of watertight bulkheads in ships must adhere to several key requirements: Integrity: Watertight bulkheads should be constructed with materials and design that ensure their structural integrity and prevent water penetration. They must be capable of withstanding the pressure exerted by water and should not deform or collapse under such pressure. Watertightness: Bulkheads should be constructed to be watertight, meaning they should prevent the passage of water under normal operating conditions as well as during flooding situations. Proper sealing mechanisms, such as gaskets, welds, or other approved methods, must be employed to maintain the watertight integrity of the bulkheads. Extent and Location: SOLAS specifies the minimum number and location of watertight bulkheads based on the ship's length, type, and purpose. The objective is to divide the ship into compartments to minimize the risk of progressive flooding and maintain the ship's stability even in the event of damage to one or more compartments. Penetrations and Openings: Watertight bulkheads should have limited or no openings, and any penetrations through the bulkheads, such as pipes, cables, or ventilation ducts, must be properly sealed to maintain their watertightness. Penetrations should be minimized, and if necessary, they should have appropriate watertight closures or fittings. Doors and Hatches: Bulkhead doors and hatches must also meet specific watertightness criteria. They should be designed and constructed to resist water pressure and remain watertight under various conditions. Additionally, these doors and hatches should have a means of securing them in the closed position to prevent unintentional opening during flooding situations. Inspection and Maintenance: Regular inspection and maintenance of watertight bulkheads are crucial to ensure their ongoing effectiveness. Ship operators and owners are responsible for maintaining the structural integrity and watertightness of the bulkheads, including conducting inspections, testing seals, and promptly addressing any identified issues or deficiencies. It's important to note that while SOLAS provides guidelines and regulations for watertight bulkheads, the specific requirements may vary depending on the ship's size, type, and intended operations. Ship designers, builders, and operators should consult the relevant SOLAS regulations, classification societies, and other applicable standards to ensure compliance with the specific requirements for their vessels. To ensure the construction of watertight bulkheads, here are some recommended guidelines and considerations: Bulkhead Construction Standards: Follow industry standards and regulations for shipbuilding and maritime engineering, such as those set by classification societies like the International Association of Classification Societies (IACS) or national regulatory bodies. Refer to specific guidelines and requirements for bulkhead construction provided by the regulatory authorities. Placement and Arrangement: Determine the locations of bulkheads based on the ship's design, purpose, and intended use. Consider factors such as the ship's stability, structural integrity, and the potential impact of water ingress on different compartments. Place bulkheads at appropriate intervals to create separate watertight compartments throughout the ship. Watertight Integrity Criteria: Ensure that bulkheads meet specific watertight integrity criteria, which may include pressure and leakage tests. Use suitable materials for construction that are resistant to corrosion, fatigue, and deformation. Implement proper welding or joining techniques to maintain watertightness. Strength and Stability Requirements: Design bulkheads to withstand hydrostatic and hydrodynamic pressures, as well as potential impacts from cargo, environmental forces, or accidents. Consider the strength and stability requirements outlined by the classification societies or regulatory bodies. Use appropriate structural reinforcements, such as stiffeners or girders, to enhance the strength of bulkheads. Double Bottom and Double Hull Design: Consider incorporating a double bottom or double hull design, especially for vessels operating in demanding environments or carrying hazardous cargo. A double bottom provides an additional layer of protection against water ingress in case of damage to the outer hull. A double hull design creates multiple barriers to prevent water from reaching the cargo compartments.
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AUX MACH Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situation. Procedures for emergency steering includes; 1. Establish communication with the bridge 2. Switch over to local control on all starter cabinets 3. Control the rudder on command from the bridge by operating the pilot valves on the main valve block 4. Activate the pilot for main spool, the the pilot for idling valve 5. When the rudder is given order, release the pilot for idling valve and then the pilot for main valve Give 3 examples of the applications of refrigeration system and briefly discuss each 1. Preservation of Perishable Goods: One of the primary applications of refrigeration systems on ships is to preserve perishable goods during transportation. Refrigerated cargo holds or containers are used to store items such as fruits, vegetables, seafood, and dairy products at controlled temperatures. This helps to maintain the quality and freshness of the goods, extending their shelf life and preventing spoilage. 2. Air Conditioning and HVAC Systems: Refrigeration systems play a crucial role in providing air conditioning and ventilation on ships. They cool and dehumidify the air inside cabins, crew quarters, control rooms, and public areas, ensuring a comfortable and healthy environment for passengers and crew members. HVAC (Heating, Ventilation, and Air Conditioning) systems on ships rely on refrigeration technology to regulate temperature, humidity, and air quality. 3. Provisioning and Galley Equipment: Refrigeration systems are used in the ship's galley (kitchen) and provisioning areas to store and preserve food supplies. Refrigerators, freezers, and cold rooms are utilized to store ingredients, prepared meals, and other perishable items. These systems help to maintain food safety and quality standards, ensuring that an adequate supply of fresh food is available during the voyage. 4. Refrigerated Tanks and Containers: Some ships transport temperature-sensitive cargo in specialized refrigerated tanks or containers. Examples include the transportation of chemicals, pharmaceuticals, and certain types of gases that require specific temperature control. Refrigeration systems are employed to maintain the desired temperature range and prevent spoilage or degradation of the cargo. 5. Medical and Laboratory Facilities: Certain ships, such as research vessels or hospital ships, may have onboard medical facilities or laboratories that require refrigeration. Refrigeration systems are used to store medical supplies, vaccines, blood samples, and other temperature-sensitive materials, ensuring their integrity and viability. How does the thermostatic valve work in the refrigeration system? - A thermostatic valve, also known as an expansion valve, is a critical component in a refrigeration system that plays a vital role in regulating the flow of refrigerant into the evaporator. The valve operates by utilizing a sensing bulb, which is connected to the suction line of the evaporator. Inside the sensing bulb, there is a temperature-sensitive substance, such as a refrigerant or gas, that expands or contracts based on the temperature of the refrigerant vapor in the suction line. As the temperature changes, the substance in the sensing bulb expands or contracts, causing the pressure within the bulb to increase or decrease accordingly.
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LO2.5: Ship's hydrostatic table • Introduction to Hydrostatic Table -also known as a hydrostatic data sheet or hydrostatic curve, is a tabular or graphical representation of a ship's hydrostatic properties. It provides essential information about the ship's buoyancy, stability, and load conditions. The table typically includes data such as drafts, displacements, centers of gravity, freeboard, and other relevant parameters. • Drafts and Trim - Draft refers to the vertical distance between the waterline and the deepest point of a ship's hull. Trim refers to the longitudinal balance of a ship, specifically the difference in draft between the forward and aft ends of the ship. It is a measure of how level or inclined the ship is along its length. Trim is expressed as a positive or negative value, indicating whether the bow or stern is lower in the water. • Buoyancy and Displacement - Buoyancy is the upward force exerted on the ship by the water, keeping it afloat. Displacement is the weight of the water displaced by the ship's hull and represents the mass of the ship. • Centers of Gravity - refers to a key reference point that plays a crucial role in assessing a ship's stability and equilibrium. It represents the average location of the ship's weight distribution in three dimensions: longitudinally, transversely, and vertically. The position of the center of gravity influences the ship's stability, trim, and response to external forces. • Freeboard and load conditions - Freeboard refers to the vertical distance between the waterline and the upper deck of the ship. The hydrostatic table may provide data on the ship's freeboard in various load conditions, such as full load, ballast condition, or any other specific configuration. • Soundings Drafts - are drafts measured at specific points along the length of the ship. These soundings help in assessing the ship's trim and overall weight distribution • Tank Soundings - tank soundings refer to the measurements of liquid levels in various tanks on the ship, such as fuel tanks or ballast tanks LO2.6: Stress-calculating equipment • Strain Gauges - are sensors that measure the strain or deformation in a material. They are often attached to the surface of a structure and change their electrical resistance in response to strain, allowing for the calculation of stress. • Load Cells - are devices used to measure force or load. They can be employed to determine the magnitude of external forces acting on a structure, which is important for stress analysis. • Accelerometers - are sensors used to measure acceleration or vibration. They are commonly used to assess dynamic loads and vibrations in structures, which can impact stress levels. • Pressure Transducer - are utilized to measure fluid or gas pressure. They can be employed to determine the internal pressure within a structure, which is relevant for stress analysis in pressurized systems. • Inclinometers - or tilt sensors, are used to measure the angle or tilt of an object with respect to gravity. They can be used to assess the inclination or deflection of a structure. • Vibration Sensors - are used to monitor and measure vibrations in structures. Excessive vibrations can induce stress and fatigue in materials. • Ultrasonic Testing Equipment - utilizes high-frequency sound waves to inspect the internal structure of materials. It can be used to detect defects, cracks, or variations in material properties that may affect stress levels. • Strain Monitoring System - typically consists of multiple strain gauges or sensors strategically placed on a structure to continuously monitor strain levels. It provides real-time data for stress analysis and structural health monitoring. • Finite Element Analysis (FEA) Software - is a computer-based tool used to simulate and analyze the behavior of structures under various loading conditions. It uses numerical methods to solve complex equations, allowing engineers to calculate stress distributions and evaluate structural integrity LO2.7: Intact Buoyancy Intact Buoyancy - refers to the buoyancy characteristics of a ship in its undamaged and intact condition. It represents the ability of the ship to remain afloat and stable without any structural damage or breaches. • Components of Intact Buoyancy - The components of intact buoyancy include the buoyant force exerted on the ship by the surrounding water, the shape and design of the ship's hull, and the distribution of weight and cargo on board. These factors collectively determine the ship's ability to displace water and maintain its stability. • Buoyancy Calculation • Freeboard and Reserve Buoyancy - Freeboard refers to the vertical distance between the waterline and the uppermost continuous deck of the ship. It provides a margin of safety by ensuring that the ship remains above the waterline under normal operating conditions. Reserve buoyancy refers to the additional volume of water that the ship can displace without compromising its stability. It acts as a safety buffer against unexpected flooding or damage. Effects of Breach on Ship Stability: • Immediate Impact on Stability - A breach can cause a sudden loss of intact buoyancy, leading to a decrease in the ship's overall buoyant force. This can result in a loss of stability, causing the ship to list or capsize. • Down flooding and Ingress of Water - Downflooding refers to the entry of water into the ship through openings caused by a breach. This can lead to the ingress of large volumes of water, affecting the ship's stability and buoyancy. The location and size of the breach can determine the extent of downflooding and its impact on stability. • Free Surface Effect - When water enters the ship due to a breach, it can create a free surface effect. This occurs when the water is free to move within the ship, causing shifts in weight distribution. The free surface effect can reduce stability and increase the risk of capsizing, especially if the water accumulates on one side of the ship. LO2.8: Watertight Integrity • Importance of Watertight Integrity o Safety: Maintaining watertight integrity ensures the safety of the crew and passengers by preventing water from entering critical areas of the ship, which could lead to instability, flooding, or sinking. o Damage Control: Watertight integrity plays a vital role in damage control efforts during emergencies. It helps limit the spread of flooding and compartmentalizes the ship, allowing for effective containment and control of water ingress. o Stability: Watertight compartments contribute to the overall stability of the ship. By preventing water from freely flowing throughout the vessel, they help maintain the ship's buoyancy and stability, even in the event of localized flooding. • Hull Construction and Watertight Compartments • Watertight Doors and Hatches - Watertight doors and hatches are installed in bulkheads and decks to allow access between different compartments while maintaining watertight integrity. These doors and hatches are designed to provide a watertight seal when closed, preventing water from passing through. • Sealing Mechanisms - Watertight doors and hatches employ various sealing mechanisms to ensure a watertight seal. These mechanisms may include rubber gaskets, compression seals, dogs or clamps, and locking mechanisms. When properly engaged, these mechanisms create a tight seal that resists the passage of water. • Maintenance of Watertight Seals - Regular maintenance is necessary to ensure the effectiveness of watertight seals. This includes inspections, testing, and maintenance of sealing mechanisms, gaskets, and associated components. Any damaged or worn-out seals should be promptly repaired or replaced to maintain watertight integrity. • Watertight Penetrations - Watertight penetrations refer to openings that pass through watertight boundaries, such as bulkheads or decks. Examples include pipes, cables, ventilation ducts, and other systems that need to cross from one compartment to another. These penetrations are designed with appropriate sealing mechanisms to maintain watertight integrity. • Emergency Closure and Damage Control - In emergency situations, when flooding or water ingress occurs, emergency closure procedures are followed to quickly isolate affected compartments and prevent the spread of water. This involves closing watertight doors and hatches, activating remote-operated valves, and implementing damage control measures to mitigate the effects of flooding and ensure the safety and stability of the ship.
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AUXMACH STEERING GEAR SYSTEM - The main function of a steering gear system on a ship is to control the direction of the vessel by changing the angle of the rudder. This system plays a crucial role in maneuvering the ship safely in various conditions, such as navigating through narrow channels, avoiding obstacles, and maintaining course during rough seas.This system allows the ship's operator, usually the helmsman, to change the ship's course by turning the rudder. The steering gear system converts the rotational motion from the steering wheel or control device into a linear movement that moves the rudder left or right, thereby steering the ship in the desired direction. Principle/concept How: telemotor-control unit-power unit-transmission What: steer/navigate/move rudder Why: safely move/maneuver the ship Telemotor Loc: bridge below steering wheel - receive signal from the bridge and transmit this to the control unit Type: electrical, mechanical, pneumatic, hydraulic Control Unit Loc: between telemotor and power unit - commands the Power unit depending on the telemotor command Power Unit - provides force to move the actuator or the rudder Transmission system - the actuator or the action maker of the S.G. system Common types of S.G. system 1. Fully Hydraulic 2. Electro-Hydraulic *Ram - hydraulic cylinder *Vane- rotating vanes 3. Fully Electric COMMON FAULTS Loc: Alarm indicator/panel *Overload - when electric motor draws large current than normal *Phase Failure - if one or two E.Motor (3 phase) phase have high or low current than normal *Hydraulic Lock - when the directional valve does not follow the given command *Low oil level - oil service tank level below normal *High temp - oil temp on service tank above normal *Clogged Filter - return line filter dirty resulting to high pressure *Short Circuit - unintentional touching of electrical components *Control Power Failure - remote to local control switch malfunction or switching *No power - steering gear system power loss/failure EMERGENCY STEERING DRILL Occur: Once a month Involve: All crew Purpose: - familiarization to emergency steering - SOLAS Requirement STEPS: 1. Establish a clear/good communication with bridge 2. Switch to Local Control (No.2 system pump) 3. Wait for bridge command while standing near the emergency directional valve operating level 4. Execute the command or preferred rudder angle then continue having a clear communication SAFETY DEVICES 1. Relief valve - remove excess pressure 2. Pressure regulating valve - control pressure Safematic System - isolate leaking components of steering gear system and maintain its normal operation it involves the isolation valves and solenoid valves. Alarm panel - shows the alarms, malfunctions and current condition of the steering gear system. Indicates system status and alarm condition. Loc: ECR BRIDGE STEERING GEAR ROOM Control Panel - for system control Loc: - bridge - Steering Gear Room SOLAS REQUIREMENT 10 000 Gross Tonnage tanker 70 000 Gross Tonnage non tanker - should have at least two (2) power unit
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AUTO LO2.2 PLC Fundamentals • Introduction to PLCs • Basic Components of a PLC Central Processing Unit (CPU): The CPU is the brain of the PLC. It executes the control program, communicates with other devices, and coordinates the operation of the PLC system. Memory: PLCs have different types of memory, including program memory (stores the control program), data memory (stores variables and I/O values), and retentive memory (retains data even after power loss). Input/Output (I/O) Modules: These modules interface with the external world, receiving inputs from sensors and providing outputs to actuators. They convert electrical signals between the PLC and the connected devices. Power Supply: The power supply unit provides electrical power to the PLC system. • PLC ProgrammingLanguages • PLC Scan Cycle • I/O (Input/Output) Configuration • PLC Program Execution • Relays and Timers in PLCs • Data handling and Processing • Troubleshooting and Debugging LO2.3 PLC Programing Language • Ladder Logic (LAD) - is a graphical programming language that mimics the appearance of electrical relay circuits. It uses ladder-like rungs to represent logical control circuits. Ladder Logic is particularly suited for representing discrete logic operations and is widely used in industries where relay-based control systems are prevalent. It is easy to understand for those with a background in electrical wiring and control circuits. • Structured Text (ST) - is a high-level programming language that follows a structured programming approach and uses statements and expressions to define control logic. It allows for complex calculations, mathematical operations, and conditional branching. ST is particularly suited for mathematical computations, data manipulation, and complex control algorithms. • Function Block Diagram (FBD) - is a graphical programming language that represents control logic as a network of interconnected function blocks. These function blocks encapsulate specific control functions and can be interconnected to create complex control algorithms. FBD is visually similar to electronic circuit diagrams and is useful for designing and representing control systems in a modular and structured manner. It is commonly used for systems with complex interconnections and for implementing reusable control modules. • Instruction List (IL) • Sequential Function Chart (SFC) • Structured Control language (SCL) LO2.4: PLC application on board • PLC Alarm Annunciator System - An alarm annunciator system is used to monitor and display alarms from various ship systems and equipment. A PLC can be employed to collect alarm signals from different sensors and control devices, process the signals, and activate visual and audible alarms on the annunciator panel. The PLC can also log alarm events, provide alarm prioritization, and facilitate remote monitoring and control. • PLC Boiler Startup System - A PLC-based boiler startup system can automate and sequence the startup process, ensuring proper procedures are followed. The PLC can control boiler parameters such as fuel supply, air flow, water level, and safety interlocks. It can monitor and regulate the boiler operation, including ignition, fuel firing rate, and water level control. • PLC Separator Control System - Separators are used on ships to remove impurities and separate different components from fluids, such as fuel oils and lubricating oils. A PLC-based separator control system can monitor and control the operation of the separator, including flow rates, temperatures, pressures, and discharge conditions. The PLC can adjust valve positions, monitor levels, and provide alarms or shut down the system in case of abnormal conditions. • PLC Main Engine Remote Control System - . A PLC-based remote control system for the main engine allows for centralized control and monitoring from a control room or bridge. The PLC can receive commands from the control station and control the engine's speed, direction, fuel supply, cooling water flow, and other parameters. It can also monitor engine performance, collect data, and provide alarms and safety interlocks. LO2.5 Typical DCS on board • Distributed Control System Architecture (DCS) - refers to the arrangement and structure of a control system that is distributed across multiple components and locations within a process. A DCS is designed to provide centralized control, monitoring, and operation of complex processes or systems. • Difference between DCS and PLC o System Scope: DCS is generally used for larger, complex systems that require centralized control and monitoring of multiple processes, whereas PLC is often used for smaller, standalone control tasks. o Scalability: DCS is highly scalable and can handle a large number of I/O points and complex control strategies, making it suitable for extensive plant-wide control. PLC, on the other hand, is typically limited in terms of scalability and is more suitable for discrete control tasks. o Communication: DCS systems rely on a distributed architecture with multiple controllers communicating over a network, allowing for seamless integration and data sharing. PLC systems are often standalone units that communicate with each other, but not to the same extent as a DCS. • Sample DCS System Application On board Ships o Engine Room Control: The DCS can monitor and control various parameters of the ship's engines, such as fuel flow, temperature, pressure, and speed. It can also provide alarms and alerts for abnormal conditions. o Power Management System: The DCS can manage the ship's electrical power generation, distribution, and load shedding. It can monitor power consumption, control generators and switchboards, and optimize power usage. o Cargo Management: In ships carrying cargo, the DCS can oversee the loading, unloading, and monitoring of cargo holds. It can control cargo handling equipment, monitor tank levels, and manage ballast systems. o Environmental Control: The DCS can regulate and monitor environmental systems on board, including HVAC (Heating, Ventilation, and Air Conditioning) systems, fire detection and suppression, and safety systems. o Navigation and Communication: The DCS can integrate with navigation and communication systems, providing centralized control and monitoring of radar, GPS, AIS (Automatic Identification System), and communication equipment. LO2.6: SCADA Systems Used in Maritime Industry SCADA - SCADA, which stands for Supervisory Control and Data Acquisition, is a system used to monitor and control industrial processes and operations. It is a centralized system that collects real-time data from various sensors, instruments, and devices, and allows operators to control and manage the processes remotely. • Vessel Automation - SCADA systems are used to automate and control various ship systems, including propulsion, steering, and auxiliary systems. They enable centralized monitoring and control, allowing operators to efficiently manage vessel operations. • Tank Gauging and Cargo Management - SCADA systems are employed to monitor tank levels, temperatures, and pressure in cargo tanks. They provide accurate measurements and facilitate effective cargo management, including loading, unloading, and transfer operations. • Navigation and Dynamic Positioning System - SCADA systems integrate with navigation equipment to provide real-time monitoring and control of the ship's position, course, and speed. They ensure precise navigation and support dynamic positioning systems, which are critical for offshore operations. • Power Management - SCADA systems play a vital role in managing electrical power generation, distribution, and load shedding on ships. They monitor power consumption, control generators, switchboards, and optimize power usage to ensure efficient and reliable power management. • Weather Monitoring and Reporting - SCADA systems can integrate weather monitoring sensors and instruments to provide real-time weather data to ship operators. This information assists in making informed decisions related to route planning, safety, and optimizing vessel performance. • Security and Surveillance - SCADA systems are utilized for security and surveillance purposes on ships. They integrate with CCTV cameras, access control systems, and intrusion detection systems, allowing operators to monitor and manage security aspects of the vessel. • Emergency Response and Alarm Management - SCADA systems enable efficient management of alarms and emergency response procedures. They provide real-time notifications and alerts for critical events, allowing operators to take appropriate actions promptly. LO3.1: Boiler Drum Level Control System • Introduction to Boiler Drum Level Control • Boiler Drum Level Measurement • Single-Element Control System • Two-Element Control System • Three-Element Control System • Control Algorithms (PID Control) • Control Valve Operation • Alarm and Trip Systems • Control System Integration
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Advantages of Electrical Control Systems on Ships: Faster response times and precise control Lower maintenance requirements More compact and lightweight Easier integration with modern automation systems Better compatibility with digital communication protocols Higher energy efficiency Disadvantages of Electrical Control Systems on Ships: High initial installation costs Vulnerable to electrical faults and power supply disruptions Requires skilled technicians for maintenance and troubleshooting Limited suitability for high-power applications Greater complexity in terms of wiring and circuitry Advantages of Pneumatic Control Systems on Ships: Simplicity in design and operation Good resistance to harsh environments (e.g., moisture, heat) Reliable and robust performance Ability to handle high-pressure applications Lower risk of electrical hazards Disadvantages of Pneumatic Control Systems on Ships: Slower response times compared to electrical systems Limited precision and accuracy Larger and bulkier equipment Higher maintenance requirements (e.g., air compressors, pneumatic valves) More prone to leakage and loss of pressure.
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Explain the production, conditioning and distribution of compressed air on board ships - PRODUCTION: Compressed air is typically produced on ships using air compressors. These compressors are driven by electric motors or diesel engines and are responsible for compressing atmospheric air to a higher pressure. The compressed air is generated in the compressor and stored in air receivers or air storage tanks. - CONDITIONING: The compressed air produced by the compressors needs to undergo conditioning before it can be used in various shipboard systems. Conditioning involves removing impurities, moisture, and oil from the compressed air to ensure its quality and prevent damage to machineries onboard. The air may go through air filters, moisture separators, or air dryers. - DISTRIBUTION: Once the compressed air is conditioned, it is distributed throughout the ship to various systems and equipment. Air distribution is achieved through a network of pipelines and valves. The distribution system is designed to deliver the necessary pressure and flow rate to different points of use. Control valves and regulators may be installed to adjust the pressure and control the flow of compressed air to different equipment and systems. LO1.3. Explain the operations of pneumatic and electro pneumatic devices used in electro-pneumatic Pneumatic Actuators: 1. Cylinders: Pneumatic cylinders are devices that convert compressed air energy into linear motion. They consist of a piston and cylinder arrangement. When compressed air enters the cylinder, it pushes the piston, generating linear force and motion. 2. Rotary Actuators: Rotary actuators convert compressed air energy into rotational motion. They are used when rotary movement is required instead of linear motion. Rotary actuators can turn valves, drive rotating machinery, or control the movement of robotic arms. Valves in Pneumatics: 1. Directional Control Valves: These valves determine the direction of airflow in a pneumatic system. They can be manually or electrically actuated and control the flow of compressed air to different actuators or exhaust air from them. 2. Pressure Control Valves: Pressure control valves regulate the pressure within the pneumatic system. They maintain the desired pressure level by relieving excess pressure or supplying additional air when the pressure drops below the set point. 3. Flow Control Valves: Flow control valves adjust the flow rate of compressed air in a pneumatic system. They regulate the speed of actuator movement by controlling the rate at which air flows into or exhausts from the actuator. Pneumatic Sensors: 1. Pressure Sensors: Pressure sensors are used to measure the pressure of compressed air within the pneumatic system. They provide feedback on system pressure and can trigger actions based on pressure thresholds. 2. Position Sensors: Position sensors are used to detect the position of pneumatic actuators or other moving components in a system. They provide feedback on the position of the actuator, enabling precise control and positioning. Air Preparation Units: 1. Filters: Filters are used to remove contaminants, such as dust, dirt, moisture, and oil, from the compressed air. They ensure that the air supplied to the pneumatic system is clean and suitable for reliable operation. 2. Regulators: Regulators control and maintain the desired pressure level in the pneumatic system. They adjust the output pressure of the compressed air to a specified set point, regardless of upstream pressure variations. 3. Lubricators: Lubricators introduce a small amount of oil or lubricant into the compressed air stream. They provide lubrication to pneumatic components, such as cylinders and valves, reducing friction, wear, and extending their lifespan. LO1.4. Describe the various application of electro pneumatic circuits on board 1. Control Systems: Electro-pneumatic circuits are extensively used in control systems for precise and reliable control of various processes. They can be found in industrial automation systems, manufacturing plants, and machinery control systems. Electro-pneumatic circuits incorporate electrical control signals to actuate pneumatic components, such as valves and actuators, enabling control over fluid flow, pressure, and other parameters. 2. Engine Control: Electro-pneumatic circuits play a crucial role in engine control systems, particularly in large marine engines and industrial engines. They utilize electrical control signals to actuate pneumatic valves and actuators, regulating fuel flow, air intake, exhaust, and other engine parameters. Electro-pneumatic circuits ensure precise and efficient control of engine operations, optimizing performance and fuel consumption. 3. Cargo Handling: Electro-pneumatic circuits are utilized in cargo handling systems on ships and in warehouses. They control the operation of pneumatic actuators and valves in cranes, hoists, winches, and conveyor systems. Electro-pneumatic circuits provide accurate control over the movement, positioning, and lifting of cargo, ensuring efficient and safe handling. 4. Braking Systems: Electro-pneumatic circuits are commonly used in braking systems, both in automotive and industrial applications. They incorporate electrical control signals to actuate pneumatic valves, controlling the application and release of pneumatic brakes. Electro-pneumatic braking systems offer responsive and reliable braking control, essential for safe operation and maneuvering of vehicles and machinery. 5. Pneumatic Tools: Electro-pneumatic circuits are employed in pneumatic tool systems, such as impact wrenches, drills, and grinders. They utilize electrical control signals to actuate pneumatic valves, regulating the air supply to the tools. Electro-pneumatic circuits enable precise and controlled operation of the pneumatic tools, providing efficient and versatile tooling solutions. 6. Emergency Systems: Electro-pneumatic circuits are integrated into emergency systems to ensure quick and reliable response during critical situations. They can be found in emergency shutdown systems, fire suppression systems, and emergency venting systems. Electro-pneumatic circuits enable rapid actuation of pneumatic components, allowing for immediate actions in emergency scenarios. 7. Tensioning Systems: Electro-pneumatic circuits are applied in tensioning systems used in cable laying, towing operations, and mooring operations. They control the operation of pneumatic tensioners, maintaining accurate and controlled tension in cables, wires, or ropes. Electro-pneumatic circuits enable precise adjustment and monitoring of tensioning forces, ensuring safe and efficient operations. 8. Hatch Cover Operations: Electro-pneumatic circuits are utilized in hatch cover systems on cargo ships. They control the operation of pneumatic actuators and valves, enabling the opening, closing, and securing of hatch covers. Electro-pneumatic circuits ensure reliable and synchronized operation of hatch covers, maintaining cargo compartments' integrity and safety. 9. Automation and Control Systems: Electro-pneumatic circuits are integral to automation and control systems across various industries. They combine electrical control signals with pneumatic components to achieve precise control and automation of processes. Electro-pneumatic circuits can include sensors, programmable logic controllers (PLCs), and feedback devices, enabling advanced control, sequencing, and coordination of pneumatic operations with other electrical and mechanical systems. LO2.1. Explain the functions of the four main parts of a programmable logic controller (PLC). 1. Input: The input section of a PLC is responsible for receiving signals from various input devices such as sensors, switches, and other field devices. It converts these signals into digital data that the PLC's processor can interpret. The input section ensures that the PLC can monitor and react to changes in the external environment. 2. Processor: The processor, also known as the central processing unit (CPU), is the core component of the PLC. It executes the control program stored in the memory and performs various operations, including arithmetic calculations, logical decisions, and data manipulation. The processor continuously scans the input signals, processes them based on the programmed instructions, and generates appropriate output signals. 3. Memory: The memory in a PLC stores the control program, data, and variables required for operation. It is typically divided into two main types: o Program Memory: This non-volatile memory holds the user-defined control program. It contains the ladder logic, function block diagrams, or other programming languages used to implement the control logic. The program memory is retained even when the PLC loses power. o Data Memory: This volatile memory stores data and variables used during program execution. It includes input and output values, internal registers, timers, counters, and other temporary data. Data memory is cleared when the PLC loses power. 4. Output: The output section of a PLC is responsible for sending control signals to external devices such as motors, actuators, solenoid valves, and other output devices. It converts the digital data generated by the processor into appropriate electrical or pneumatic signals that actuate the output devices. The output section allows the PLC to control and manipulate the physical processes in the external world.
@user-lq9vc5zf2u5 ай бұрын
AUTO 2 LO1.1. Explain the various components and sub-system in machine automation per industry standards 1. Automation System: The automation system encompasses all the components and subsystems working together to automate a machine or process. It includes the control system, sensors, actuators, and other elements necessary for automation. 2. Control System: The control system manages and regulates the operation of the machine. It can be categorized into open-loop and closed-loop control. • Open-loop Control: In open-loop control, the system operates without feedback. Control commands are sent to the actuators based on predetermined inputs, without monitoring the output. This type of control is suitable for simple, predictable processes. • Closed-loop Control: Closed-loop control, also known as feedback control, incorporates sensors to measure the output and provides feedback to the control system. The control system compares the actual output with the desired setpoint and adjusts the control signals accordingly. This enables precise control and compensation for disturbances. • PID Controllers and Tuning: Proportional-Integral-Derivative (PID) controllers are commonly used in closed-loop control systems. They continuously analyze the feedback and adjust the control signals based on proportional, integral, and derivative actions. Tuning involves optimizing the PID controller parameters to achieve stable and responsive control. 3. Sensors and Actuators: Sensors are devices that detect physical variables such as temperature, pressure, position, and proximity. They provide feedback to the control system. Actuators, on the other hand, are devices that convert control signals into physical actions. They can include motors, solenoid valves, pneumatic cylinders, and more. 4. Programmable Logic Controllers (PLCs): PLCs are specialized digital computers used for industrial automation. They receive input signals from sensors, execute the control program, and generate output signals to control the actuators. PLCs provide a flexible and reliable control platform and can integrate with various devices and systems. 5. Pneumatic Components: Pneumatic components utilize compressed air to perform mechanical work. They are commonly used in machine automation due to their simplicity, low cost, and high power-to-weight ratio. Some key pneumatic components include: • Compressor and Air Preparation Unit: Compressors are used to generate compressed air, which is then passed through an air preparation unit. The air preparation unit typically consists of filters to remove contaminants, regulators to control air pressure, and lubricators to provide lubrication to pneumatic components. • Pneumatic Valves: Pneumatic valves control the flow of compressed air to actuate various pneumatic devices. They can be categorized into directional control valves, pressure control valves, and flow control valves. These valves enable precise control of the pneumatic system. • Pneumatic Cylinders and Actuators: Pneumatic cylinders, also known as pneumatic actuators, convert compressed air energy into linear or rotary motion. They are commonly used to move and control machine components, such as grippers, slides, and clamps.
@user-lq9vc5zf2u5 ай бұрын
NAV ARCH Identify the principal dimensions and the main structural members of the ship. -PRINCIPAL DIMENSION - Length Overall (LOA): The Length Overall, often abbreviated as LOA, is the maximum length of a ship from its forward-most point to its aft-most point. It represents the overall length of the vessel and is usually measured in meters or feet. LOA provides an indication of the size and scale of the ship. - Beam: The Beam of a ship refers to its maximum width or breadth at the widest point. It is measured perpendicular to the longitudinal axis (centerline) of the vessel. The beam is typically measured in meters or feet and is an important measurement for determining the ship's stability and interior space. - Draft: The Draft of a ship is the vertical distance between the waterline and the lowest point of the ship's hull, such as the keel or the bottom of the hull. It indicates the depth of the ship's immersion in the water. Draft is measured in meters or feet and affects the ship's maneuverability, stability, and the amount of cargo it can carry. - Freeboard: Freeboard refers to the vertical distance between the waterline and the main deck of the ship. It represents the height of the ship's side above the waterline. Freeboard is an important safety consideration as it helps to prevent water from entering the ship during normal operation and in rough sea conditions. It is measured in meters or feet and is regulated by maritime authorities to ensure the ship's stability and seaworthiness. -MAIN STRUCTURAL MEMBERS OF THE SHIP - Hull: The hull is the main body or shell of the ship that provides buoyancy and structural integrity. It consists of various components such as plates, frames, and bulkheads. - Keel: The keel is the central structural member running along the bottom of the ship from bow to stern. It provides stability and serves as a foundation for the rest of the ship's structure. - Frames: Frames are vertical structural members that run perpendicular to the keel and provide support to the hull. They help maintain the shape and strength of the ship's structure. - Bulkheads: Bulkheads are vertical walls or partitions that divide the interior space of the ship into separate compartments. They provide structural strength, support, and help maintain the ship's stability and watertight integrity. - Decks: Decks are horizontal structural members that provide platforms or floors within the ship. They contribute to the overall strength and rigidity of the ship's structure. - Superstructure: The superstructure refers to the part of the ship above the main deck, including cabins, bridge, and other functional spaces. It is typically made up of various structural elements and components. Explain the functions of the different ship types in reference to its cargo and construction. 1.General cargo - or dry cargo ships are designed to carry different types of dry cargoes. Thanks to their built-in cargo loading equipment, their flexibility in loading and unloading is increased. 2.Oil, Chemical and Gas Tanker - Liquids are transported by means of tanker vessels. These liquids include crude oil, gases, and chemicals. 3.Bulk Carrier - This type of merchant vessel is designed to carry large amounts of cargoes that do not need packaging or are carried in bulk such as coal, grains, ore, cement and etc. 4.Combination Carrier - A combination carrier, also known as OBO (Ore-Bulk-Oil), is designed to carry dry and wet cargoes, on different voyages, or at the same time. 5.Container Ship - It is a type of cargo ship that transports goods inside a container unit with nominal dimensions of lengths of 20 or 40 feet, and widths of 8 or 9 feet respectively. 6.Roll On/Roll Off - These “car carriers” are types of ships used to transport wheeled cargo. Their cargoes are loaded and unloaded by means of an inclined ramp. 7.Passenger Ship - This nature of merchant vessel has two types: the cruise ships, which transport passengers with high standards of accommodation and leisure facilities, and ferries, which are combinations of ro-ro and passenger vessels. Identify common steel sections used in modern shipbuilding 1.Plates - a steel section level, without curvature. Used for the construction of the ship's hull, decks, bulkheads, and other structural components. 2.Angles - are L-shaped steel sections that are used for reinforcing corners, edges, and joints of the ship's structure. They provide additional strength and rigidity. 3.Channels - are C-shaped steel sections that are commonly used for structural support, such as in frames, stringers, and other load-bearing members of the ship's structure. 4.Bulb Flats - are specialized steel sections with a flat surface and a bulbous shape on one edge. 5.T-sections - also known as T-bars, are steel sections that have a T-shaped cross-section. They are used for framing, bracing, and supporting deck structures. 6.I-Beams - also known as H-beams, are steel sections with an I-shaped cross-section. They are commonly used for commonly used as main structural members, such as keel beams and longitudinal stiffeners. 7.Hollow Sections - Hollow sections, such as rectangular or circular tubes, are used for specific applications in shipbuilding, including piping systems, masts, and cranes. They offer strength and stiffness while reducing the weight of the structure. 8.Z-Sections - also known as Z-bars, are steel sections that have a Z-shaped profile. They are often used for secondary structural components, such as brackets, supports, and stiffeners. 9.Pipe Sections - Steel pipes and tubes are used extensively in shipbuilding for various purposes, including piping systems for fuel, water, and other fluids, as well as for the construction of masts, booms, and other structural elements. 10.Bars and Rounds - Steel bars and rounds are used for various applications, including reinforcing smaller structural components, such as hatches, doors, and handrails. 11.Transition Pieces - are specialized steel sections used to connect different types of structural members or sections, ensuring a smooth transition and proper load transfer between them. 12.Fitting - such as flanges, elbows, tees, and reducers, are used in piping systems to connect and control the flow of fluids within the ship's structure. Identify the structural components of the ship's hull. 1.Shell Plating: The shell plating forms the outer skin of the ship's hull. It consists of large metal plates that are welded or riveted together to create a watertight barrier. Shell plating provides structural strength and helps to maintain the integrity of the hull. 2.Frames: Frames, also known as ribs or bulkheads, are vertical or transverse structural members that run across the ship's hull. They provide structural support and help distribute the loads and stresses throughout the hull. Frames are typically made of steel and are spaced at regular intervals along the length of the ship. 3.Keel: The keel is the central longitudinal structural member that runs along the bottom of the ship's hull. It is often a large, heavy beam or plate that provides strength and stability to the ship. The keel is usually located at or near the lowest point of the hull and serves as the foundation for the entire vessel. 4.Deck: The deck is the horizontal structure that forms the top surface of the ship's hull. It provides a working platform and separates the different levels or compartments within the ship. Decks are typically made of steel and can be reinforced to support heavy equipment, cargo, or structures on the ship. 5.Bulkheads: Bulkheads are vertical walls or partitions that divide the ship's interior into separate compartments. They provide structural strength, help maintain the vessel's stability, and contribute to its watertight integrity. Bulkheads are often made of steel and extend from the bottom of the ship's hull to the deck. 6.Stringers: Stringers are longitudinal structural members that run parallel to the ship's keel. They provide additional support and reinforcement to the hull, especially in areas where localized loads or stresses are expected. Stringers are typically located on the inside of the hull and are connected to the frames and other structural components.
@user-lq9vc5zf2u5 ай бұрын
AUXMACH LO1- Describe the operating principles of a purifier system with the use of a manufacturer’s manual. A purifier system, also known as a centrifugal separator or purifier clarifier, is a device used to separate solid impurities and water from a liquid, typically oil or fuel, through the principles of centrifugal force and gravity separation. A fuel oil purifier is a device used onboard ships to remove sediments, sludges, and water content on HFO. This is achieved by using an electric motor as means of the prime mover to rotate the bowl at a very high speed, thus generating a centrifugal force for separating two liquids with different densities. Describe the faults in a purifier system with the use of a manufacturer’s manual: - High Vibration: Excessive vibration in the purifier system can indicate misalignment of components, worn out bearings, or unbalanced parts. This can also indicate that the motor is not functioning. This can lead to reduced separation efficiency and potential damage to the system if not addressed promptly. - Oil Leakage: Oil leakage from the purifier system can occur due to worn-out seals, gaskets, or damaged connections. It can lead to a loss of oil, environmental pollution, and compromise the system's operation. - Low Separation Efficiency: If the purifier system fails to achieve the desired separation efficiency, it may indicate issues such as inadequate bowl speed, incorrect adjustment of gravity discs, or clogging of the centrifuge. This can result in poor-quality purified oil and increased maintenance requirements. - Heater Failure: Leaks in the heat exchanger cause inadequate heating, thus affecting the purification of oil since the required temperature and viscosity of the oil are not met. - Water transducer failure - can lead to inaccurate measurement of water content in the fuel oil, compromising the efficiency of the water separation process. It can result in increased water content in the purified fuel oil, potentially causing corrosion, combustion issues, and reduced equipment performance.
@anniel30136 ай бұрын
AUXMACH Emergency Steering Gear Operation: Emergency steering gear is crucial in situations where the primary steering system fails. It typically involves activating an auxiliary mechanism, often a hydraulic or mechanical system, that directly controls the rudder's movement. This backup system allows the vessel to maintain directional control and navigate safely in emergencies. The steering of the vessel can be operated from the steering gear room. Emergency steering can be done by pressing the push buttons on the hydraulic valve blocks, see Figure 3.2. The buttons on the starter cabinet, see Figure 3.3, may also be used for emergency steering. However, then an unrestricted view to the Rudder Angle Indicator on the actuator is required. Procedure for emergency steering is: 1. Establish communication with the bridge. 2. Switch over to local control on all starter cabinets. 3. Control the rudder on command from the bridge by operating the pilot valves on the main valve block, see Figure 3.2. 4. Activate the pilot for main spool, then the pilot for idling valve. 5. When rudder is at given order, release the pilot for idling valve and then the pilot for main valve. The pressure will increase to relief valve setting if only the idling valve is activated. Applications of Refrigeration Systems on Board Ships: 1. Food Preservation. Refrigeration systems are vital for preserving perishable food items during long voyages. They maintain low temperatures in onboard refrigerated rooms or containers, preventing food spoilage and ensuring fresh provisions for the crew. 2. Cargo Preservation. Refrigeration is also used to maintain specific temperature conditions for certain cargo types, such as pharmaceuticals, chemicals, or perishable goods like fruits and vegetables. This ensures the quality and integrity of the cargo throughout the voyage. 3. Air Conditioning. Refrigeration systems provide air conditioning for various areas onboard, including crew cabins, control rooms, and passenger lounges. They regulate indoor temperatures and humidity levels, enhancing crew comfort and ensuring optimal conditions for equipment operation. Thermostatic Valve Operation in Refrigerating Systems: A thermostatic valve regulates the flow of refrigerant in the system based on temperature variations. It contains a temperature-sensitive element, such as a bulb filled with gas or liquid, connected to the valve mechanism. When the temperature deviates from the setpoint, the element expands or contracts, modulating the valve opening to adjust refrigerant flow accordingly. This maintains the desired temperature within the system by controlling the amount of cooling capacity delivered. AUTO Offset: Offset refers to the difference between a setpoint and the actual value of a controlled variable in a control system. It indicates the deviation that needs correction for the system to reach the desired operating condition. Proportional Band (PB): Proportional band defines the range of error values within which proportional control action occurs in a control system. If the PB is too wide, the system may exhibit sluggish response and overshoot, leading to oscillations or instability. Conversely, if the PB is too narrow, the system may be overly sensitive, causing frequent adjustments and potential instability due to excessive control action. Reverse Power Relay: A reverse power relay is a protective device used onboard ships to prevent damage to generators in case of reverse power flow. It monitors the direction of power flow between a generator and the power grid. If the generator starts consuming power instead of supplying it (indicating abnormal conditions like a blackout), the relay trips to disconnect the generator from the grid, preventing potential damage. Preferential Trip: Preferential trip settings prioritize the isolation of specific electrical circuits or equipment during fault conditions to maintain critical services or prevent cascading failures. They are programmed to trip selected circuit breakers or disconnect switches based on predefined criteria such as system importance, safety considerations, or operational requirements. NAV ARCH Elevation and Plan View: In naval architecture and engineering, elevation refers to a view of an object or structure as seen from one side, showing its height and width but not depth. Plan view, on the other hand, shows the object or structure as seen from above, illustrating its length and width but not height. These views are essential for designing and visualizing ship structures and systems. Main Types of Longitudinal Stress: The two main types of longitudinal stress experienced in ships are tensile stress and compressive stress. Tensile stress occurs when forces act to stretch or elongate the material, while compressive stress occurs when forces act to compress or shorten the material along its longitudinal axis. Both types of stress can affect the structural integrity of the ship, particularly in areas subjected to bending or axial loading. Types of Stresses Experienced Onboard: Onboard ships, various types of stresses are experienced, including: 1. Structural Stresses. These include loads and forces acting on the hull, superstructure, and other components, such as bending, torsion, shear, and hydrostatic pressure. 2. **Operational Stresses. These result from the ship's motion, propulsion, loading conditions, environmental factors (e.g., waves, wind), and operational activities (e.g., cargo handling, maneuvering). They affect equipment, systems, and crew performance. Difference Between Flare and Tumblehome: - Flare refers to the outward curvature or widening of a ship's hull towards the upper sections above the waterline. It enhances stability and buoyancy, especially in rough seas, by providing more reserve buoyancy and preventing excessive rolling. - Tumblehome, in contrast, describes the inward curvature or narrowing of a ship's hull towards the upper sections above the waterline. It can reduce the ship's resistance to waves and improve hydrodynamic performance but may sacrifice some stability compared to a flared hull design.
@user-lq9vc5zf2u8 ай бұрын
ELECTRO Possible causes if the Direct-on-line circuit is not turning on (troubleshoot) If a Direct-On-Line (DOL) starter circuit is not turning on, there could be several possible causes: Power Supply Issues: Check if there is proper power supply to the circuit. This includes verifying the voltage levels and phase connections. Overload or Short Circuit: The overload relay might have tripped due to an overload or short circuit in the motor or wiring. Faulty Contactor: The contactor could be faulty or damaged. Inspect for physical damage or signs of burning. Wiring Errors: Incorrect or loose wiring connections can prevent the circuit from functioning. Ensure all connections are secure and correct. Faulty Motor: The motor itself might be faulty. Check for signs of damage or wear. Control Circuit Issues: Problems in the control circuit, such as a faulty start button, stop button, or control relay, can prevent operation. Thermal Overload Relay Tripped: The thermal overload relay might have tripped due to excessive heat or overload conditions. Fuses or Circuit Breakers: Blown fuses or tripped circuit breakers can cut off the power supply to the circuit. Emergency Stop Activated: If there's an emergency stop button in the system, ensure it hasn't been activated. Environmental Factors: Extreme environmental conditions like moisture, dust, or temperature can affect circuit components. TROUBLESHOOTING: - Use Personal Protective Equipment. - Use Lock-in/ tag-out to isolate the system. -Power Supply: Check the power supply to the circuit. Ensure that there is a stable and sufficient voltage supply. - Overcurrent Protection: If there is tripped or blown fuse or circuit breaker, investigate the cause of the overcurrent and replace the fuse or reset the circuit breaker. - Inspect the contactor, which is responsible for making and breaking the power circuit. - Check the motor windings for any faults or short circuits. Use a multimeter to measure the resistance across the motor terminals. - Examine the wiring connections throughout the circuit. Look for loose connections, damaged insulation, or incorrect wiring. - Use a multimeter to check the continuity of various components in the circuit. - Check the health of the motor separately by connecting it to a known good power source. Possible causes if the Wye-Delta circuit turns on but turns off shortly thereafter (troubleshoot) If a Wye-Delta (or Star-Delta) starter circuit turns on but then turns off shortly thereafter, several issues could be at play: Timer Issues: The timer that controls the transition from the Wye (Star) to the Delta configuration might be malfunctioning, causing the circuit to turn off prematurely. Incorrect Wiring or Connection: If the wiring or connections between the Wye and Delta configurations are incorrect, it can cause the circuit to fail after initiation. Overload Protection Tripping: The overload protection might be tripping due to an actual overload or a fault in the protection system itself. Faulty Contactor: If any of the contactors (for Wye or Delta) are faulty, they might not be able to maintain the circuit after the initial start. Phase Imbalance or Loss: A loss or imbalance in one of the phases can cause the system to shut down after starting. Motor Issues: Problems with the motor, such as winding faults or mechanical issues, can lead to an automatic shutdown after start. Control Circuit Problems: Issues within the control circuit, including faulty relays or switches, can disrupt operation. Thermal Overload Relay: If the thermal overload relay is overly sensitive or faulty, it might trip unnecessarily. Environmental Factors: Excessive heat, moisture, or dust can impact the components, leading to malfunctions. Voltage Fluctuations: Significant fluctuations in supply voltage can affect the performance and stability of the starter circuit. TROUBLESHOOTING: - Use Personal Protective Equipment. - Use Lock-in/ tag-out to isolate the system. - Check if the motor is overheating. Overheating can trigger thermal overload protection, causing the motor to shut down. - Verify the stability and adequacy of the power supply to the motor. - Examine all wiring connections in the Wye-Delta circuit. Check the wiring against the circuit diagram to ensure correct connections. - Check the control circuit components, including relays, timers, and contactors. - If the circuit includes timers for transitioning between the Wye and Delta configurations, check the timer settings. - Isolate the motor from the control circuit and test it independently. - Ensure that the setup and configuration align with the specifications provided by the manufacturer. AUXMACH Purpose of Ballast System The ballast system on a ship serves several crucial purposes: Stability: The primary function of a ballast system is to provide stability to the ship. By adjusting the amount and distribution of ballast water, the center of gravity is lowered, which enhances the ship's stability, especially when it is not carrying cargo or is lightly loaded. Trim and List Adjustment: Ballast water can be adjusted in different tanks to change the ship's trim (its longitudinal inclination) and list (its lateral inclination). This is essential for optimal navigation and maneuverability, and to ensure the propeller and rudder are adequately submerged. Structural Integrity: Maintaining proper ballast helps to avoid excessive stress on the ship's structure. Without proper ballast, the ship could bend or suffer structural damage, especially when sailing through rough seas. Safety: Proper ballasting contributes to the overall safety of the vessel, reducing the risk of capsizing in adverse conditions and ensuring safe operation. Operational Efficiency: Correct ballasting can improve the hydrodynamic efficiency of the ship, reducing resistance through water and thus saving fuel. Loading and Unloading Operations: During loading and unloading, ballast water is adjusted to keep the ship stable and at the correct height relative to the dock or loading equipment. Draft Management: Ballast water is used to maintain or alter the ship's draft (the vertical distance between the waterline and the bottom of the hull). This is particularly important when navigating through shallow waters or entering and leaving ports with depth restrictions. Q and H in a Pump Head In the context of pump performance, "Q" and "H" are critical parameters: Q - Flow Rate: - Definition: "Q" stands for the flow rate, which is the volume of fluid that the pump can move in a given period of time. "Q" stands for the pump flow rate and is typically measured in units such as gallons per minute (GPM) or cubic meters per hour (m³/h). It represents the volume of fluid (liquid) that the pump can move through the system in a given amount of time. - Units: It is typically measured in cubic meters per hour, gallons per minute (GPM), or liters per second. H - Head - Definition: "H" represents the head, which is a measure of the energy or pressure imparted to the fluid by the pump. - Concept: The head determines how high the pump can lift the fluid and is a key indicator of the pump's ability to overcome resistance (caused by gravity, friction, etc.). - Units: It is usually measured in meters or feet. - "H" stands for pump head and is measured in units such as meters or feet. Pump head is the energy imparted to the fluid by the pump, resulting in the elevation or pressure of the fluid. It represents the height to which the pump can raise the fluid or the pressure it can generate. The relationship between flow rate (Q) and head (H) in a pump is often depicted by a pump performance curve. This curve, commonly known as a pump characteristic curve, illustrates how the pump performs at different operating points.
@user-lq9vc5zf2u8 ай бұрын
AUTO In marine engineering, "MC" and "ME" refer to two types of marine diesel engines, each with distinct features related to automation and control: MC Engine (MAN B&W MC Series) Type: These are two-stroke diesel engines. Control: MC engines are mechanically controlled. Their fuel injection and exhaust valve operation are driven by traditional mechanical systems. Characteristics: They are known for robustness and reliability. The mechanical systems, while less sophisticated than electronic controls, are easier to maintain and repair, especially in remote or harsh marine environments. Automation Level: While they incorporate some level of automation for essential functions, they rely heavily on mechanical processes and manual intervention for operation and adjustments. ME Engine (MAN B&W ME Series) Type: These are also two-stroke diesel engines. Control: ME engines are electronically controlled. They use an electronic control system to manage fuel injection and valve timing. Characteristics: These engines offer greater fuel efficiency, lower emissions, and improved operational flexibility compared to mechanically controlled engines. The electronic control allows for precise timing adjustments, optimizing performance. Automation Level: They have a higher degree of automation, with sophisticated systems for monitoring and adjusting engine parameters. This results in better performance management, diagnostic capabilities, and ease of integration with other shipboard automated systems. Importance of Calibration Accuracy and Consistency: Calibration ensures that sensors, controllers, and other measuring instruments in automated systems provide accurate and consistent results. This is crucial for maintaining the quality of the output and for ensuring that processes run as intended. Safety: In automated systems, especially in industries like chemical, oil and gas, and manufacturing, accurate measurements are critical for safety. Misreadings due to uncalibrated equipment can lead to hazardous situations, including accidents or system failures. Process Efficiency: Well-calibrated instruments ensure that processes are running at optimal efficiency. For example, in an automated production line, calibration of sensors ensures that the right amount of material is used, temperatures are maintained correctly, and timings are adhered to, which saves time and resources. Compliance and Standards: Many industries are governed by strict regulatory standards that require precise measurements. Regular calibration is necessary to comply with these regulations and to pass audits and inspections. Data Integrity: In an automated system, decisions and adjustments are often made based on data from sensors and instruments. Calibration ensures the integrity of this data, which is vital for maintaining the reliability of the entire system. Extended Equipment Life: Regular calibration can help in identifying potential issues in instruments before they turn into major faults, extending the lifespan of these devices.
@kiancharlescostuya32689 ай бұрын
A DC (direct current) motor is an electromechanical device used on ships for various functions. It converts electrical energy into mechanical energy and finds applications in propulsion systems, thrusters for maneuvering the ship, winches and cranes for lifting and handling tasks, pumping systems for fluid transfer, ventilation systems for airflow, and hydraulic systems for power generation. DC motors offer advantages such as high starting torque, good speed control, compact size, and robustness. However, they require a DC power source. It's worth noting that modern ships may also employ alternative propulsion systems like AC motors or hybrid systems based on specific requirements and efficiency considerations.
@AstarothGX79 ай бұрын
1:09 why do i suddenly find his SHUT UP so funny 😭☠☠☠
@12kidcat Жыл бұрын
I thought this was Japanese dub not Japanese speedrun through battle dialogue dub
@WolfgangBrozart Жыл бұрын
"Should I restart the recording after that siren ruined it? Nah its ok I'm sure they can barely hear it."
@AL_EVOz Жыл бұрын
This was interesting. I only got ending A and I was like screw it. Haha I just want to watch all the endings. So turns out it's no happy ending for them. 😢
@yadoshite Жыл бұрын
w w w
@user-ny9lq4hg7n Жыл бұрын
thanks Lappy!
@nkksx9898 Жыл бұрын
Kaneki???
@unskillfullymasterful Жыл бұрын
i hope we get a sequel soon. it would be lame if they left us in this cliffhanger of an ending. i wanna see what else they can do with 2b, 9s and A2
@lane297211 ай бұрын
We wont the nier series is officially over although now the cannon sequel is Ff xiv yoRHa dark apocalypse cuz yoko taro liked it that he made it cannon lol
@morgonfr33m4n1337z23 күн бұрын
There is a sequel, it's a mobile game and an audio drama in an orchestra concert And if they double down on the timeloop theory, then the anime adapatation is a "sequel" too
@westdu5961 Жыл бұрын
best game ever, the story and epiphany behind is absolutely profound it's like i have read a book instead of a game, and the design of E end is fking epic, unifying players around the world to fight alongside each other is just the ultimate human fable
@S3metalsymphony Жыл бұрын
I know everyone is 2B this, 9S that... but I'm just happy for A2.
@myzfytmayhem7057 Жыл бұрын
Shit don't work now. Tried several times
@ricochet8104 Жыл бұрын
what?
@user-dd9cg7zc1c Жыл бұрын
the best game.. Masterpiece of art
@kingdohe2 жыл бұрын
Randomly checking out your videos 😂 barret always loud
@lappy75372 жыл бұрын
Walking megaphone
@lunajoyxiv2 жыл бұрын
What is with the sirens? Lmao. Is crime getting bad in Gridania???
@kingdohe2 жыл бұрын
I HEAR THEEEEEEEEEEE
@kordoroy75622 жыл бұрын
Yours is the only video that actually helped my smooth brain out. Appreciate you👌🏽
@pomegranatewarfare2 жыл бұрын
kaneki-kunnn !!
@handlessuck5892 жыл бұрын
LOL TANJIRO
@afinoxi2 жыл бұрын
Is it bad that it felt good for me to see 9S die ? God I hated him.
@ddyiotdyi2 жыл бұрын
You don't understand him, you probably haven't had any traumatic experiences in your life or have experienced the loss of a very important person in your life.
@afinoxi2 жыл бұрын
@@ddyiotdyi "yOu DoNT UndErstAnd HiM" No I do, doesn't change the fact that he's still fucking annoying and I hate his character and it felt good to see him die.
@ddyiotdyi2 жыл бұрын
@@afinoxi Are you fucking serious? No you don't understand him and you don't understand how you hurt me and all of other people who suffer from PTSD by calling him "annoying" stfu bitch you're probably 11
@fatetastarossa2 жыл бұрын
Did she have long hair or short one? I’m confused @_@
@strmwvealpha11402 жыл бұрын
She had long hair but then cut it after killing 2B
@fatetastarossa2 жыл бұрын
@@strmwvealpha1140 I thought so too but look at 2:44 . I guess they forgot about that A2 cut her hair.
@shaotihk64452 жыл бұрын
@@fatetastarossa You can customize the hair in the game
Пікірлер
Doesn't work anymore
6:27 oh fucking hell this line... my heart can only take so much
Here are 3 reasons why a centrifugal purifier might not reach its intended bowl speed: Mechanical Issues: Bowl Imbalance: A worn bearing, loose internal components, or foreign object contamination within the bowl can cause it to become imbalanced. This imbalance creates vibrations and resistance that the motor needs to overcome, hindering it from reaching the desired speed. Drive System Problems: Faulty belts, couplings, or gears in the power transmission system between the motor and the bowl can slip or wear, reducing the rotational force transferred to the bowl. Process Issues: Excessive Feed Rate: If the purifier is overloaded with influent exceeding its processing capacity, the motor might struggle to maintain speed due to the increased load on the bowl. Control System Malfunction: Faulty Speed Sensor: A malfunctioning sensor might provide inaccurate speed readings to the control system, causing it to misinterpret the actual speed and not provide enough power to the motor to reach the target speed. Control System Failure: In some cases, the control system itself might malfunction, preventing it from sending the correct signals to the motor to achieve the desired speed.
Nav Arch 1. Explain the following • Bow - The bow is the forward part of the hull, serving as the leading edge that cuts through the water as the vessel moves. Its design is critical for the ship's hydrodynamics, affecting factors such as resistance, stability, and seaworthiness. Different bow designs, like the traditional clipper bow or the modern bulbous bow, are used to optimize the vessel's performance for specific operating conditions and requirements. The bow also houses important features like the anchor and anchor windlass. • Hull - The hull is the main body of the ship, providing the structural integrity and buoyancy. It is the watertight shell that supports the weight of the vessel, its cargo, and equipment. The hull design, including its length, width, depth, and shape, influences the ship's stability, speed, and maneuverability. Different hull types, such as displacement hulls, planing hulls, or catamaran hulls, are used for various applications and operating environments. The hull also includes features like the keel, bilge, and stern, which all contribute to the overall performance and handling of the vessel. • Keel - The keel is a central structural component that runs along the bottom of the hull, from the bow to the stern. It acts as the backbone of the ship, providing longitudinal strength and stability. The keel helps to prevent the ship from drifting sideways and aids in keeping the vessel on course. It also helps to resist the lateral forces generated by the wind and waves, contributing to the vessel's stability and seaworthiness. The keel design can vary, with some vessels having a flat keel, a V-shaped keel, or a bulbous keel, depending on the specific requirements and intended use of the ship. 2. Explain the following types of ships according to its design • General Cargo -or dry cargo ships are designed to carry different types of dry cargoes. Thanks to their built-in cargo loading equipment, their flexibility in loading and unloading is increased. • Oil Tanker - Liquids are transported by means of tanker vessels. These liquids include crude oil, gases, and chemicals. • Bulk Carrier - This type of merchant vessel is designed to carry large amounts of cargoes that do not need packaging or are carried in bulk such as coal, grains, ore, cement and etc. 3. What is Intact and Damage Stability • Intact Stability: Passenger cruise ships must maintain intact stability to ensure passenger comfort and safety. Stability criteria such as GM and range of stability are rigorously evaluated during design and must comply with regulatory standards. (Additional you may or may not add) • Intact stability ensures the ship can withstand external forces like wind, waves, or shifting cargo without tipping over excessively. Imagine a seesaw - intact stability makes sure the ship recovers quickly from a tilt, just like a well-balanced seesaw bouncing back after a dip. This is achieved through careful design considerations like the center of gravity (weight distribution) and the center of buoyancy (upward water pressure acting against the hull). • Damage Stability: In addition to intact stability, cruise ships are required to demonstrate adequate damage stability. This involves assessing the vessel's ability to remain afloat and upright in the event of damage to the hull, such as from a collision or grounding. (Additional you may or may not add) • Damage stability considers what happens if the hull is breached, perhaps due to a collision or grounding. Here, the focus is on how well the ship can stay afloat even with flooding in certain compartments. Imagine multiple watertight compartments within the hull, like separate rooms in a house. Damage stability analyzes how flooding in one compartment might affect the ship's overall balance (trim) and how deep it sits in the water (draft). Ships are designed with these watertight compartments to minimize flooding and improve survivability in case of damage. 4. Construction of watertight doors according SOLAS. 5. What is Archimedes principle? • The Archimedes principle states that the buoyant force exerted on an object that is submerged partially or completely in a fluid is equal to the weight of the fluid that is displaced by the object. Buoyant Force - refers to the upward-directed force that a fluid (either a liquid or a gas) exerts on an object that is partially or completely immersed in the fluid. Displacement of Fluid - Displacement is the general term used to indicate the mass of the vessel. A ship's displacement is the volume of water it displaces when it is floating, and measured in cubic meters. 6. Forces that leads to stress and strains on ships • Waves - As a ship moves through the water, the wave-induced motion can cause bending and torsional stresses, leading to hogging (the middle of the ship bending upwards) and sagging (the middle of the ship bending downwards) of the hull. • Tensile Force - which acts to pull the ship's structure apart, causing it to stretch or elongate. These tensile forces can be experienced in the ship's hull, superstructure, and other structural elements. • Compression - act to push the ship's structure together, causing it to shorten or buckle. Compression can be experienced in the ship's hull, especially in the bottom and sides, as well as in the superstructure. • Shear Force - These forces act to slide one part of the ship's structure relative to another, causing the material to experience distortion. Shear stresses can be particularly problematic in areas where the ship's structure changes, such as at the transitions between the hull and the superstructure • Torsional Force - can twist the ship's structure, causing it to experience rotational stresses. These forces can be experienced in the ship's hull, especially in the midship section, as well as in the superstructure and other structural elements.
AUX MACH 1. What is interface and how does it affect the separation efficiency? • On board ships, the term "interface" refers to the boundary between the two immiscible liquid phases, such as oil and water, within a separator. This interface plays a critical role in determining the separation efficiency of the system. Firstly, the position of the interface, or phase boundary, needs to be properly maintained at the correct level within the separator. If the interface is too high, it can lead to carry-over of water into the oil stream, while a too low interface can result in oil being carried over into the water stream. Maintaining the optimal interface level is crucial for achieving the desired separation outcomes. 2. Explain Follow up and Non-Follow up controls on steering gear. 2. Explain how operating water in purifiers work • Purifiers, especially those used for oil treatment on ships, rely on a clever system of pressurized water called operating water to open and close the centrifuge bowl. Imagine this water acting like a powerful hydraulic fluid. To seal the bowl for purification, high-pressure water fills the "closing water" chamber. This pressure pushes a piston or cylinder upwards, creating a tight seal with a ring on the bowl. This pressurized state might be constant or pulsed depending on the system. When it's time to expel waste, the water flow is diverted to the "opening water" chamber. This opposing pressure pushes another piston or cylinder down, overcoming the closing force. This slight downward movement opens ports in the bowl, allowing accumulated waste like sludge to be discharged. Some purifiers might even have a dedicated "conditioning water" line for flushing or cleaning tasks within the bowl or pipes. In essence, operating water is the hidden powerhouse that precisely controls the opening and closing of the centrifuge bowl throughout the purification and waste removal cycles. 3. working principle of rotary steering gear - A rotary vane steering gear is a mechanism on ships specifically designed to control the rudder's direction, influencing the vessel's course. It uses a rotating cylindrical housing with fixed and movable vanes to achieve this. In a rotary vane steering system, the helmsman's turn of the steering wheel translates into an electrical signal via the telemotor. This signal is amplified and sent to the power unit, which uses electric motors and pumps to generate high-pressure hydraulic fluid. The transmission system, comprised of valves and pipes, channels this fluid to the rotary vane. Here, specific chambers are pressurized based on the signal, causing the vanes within the housing to rotate. This rotational force is transferred to the rudder stock, ultimately turning the rudder blade and steering the ship. Additional components like the rudder angle indicator provide feedback on the rudder's position, while the hydraulic reservoir stores fluid, filters keep it clean, and safety relief valves protect the system from pressure overload. 4. common faults found in steering gear • Oil Leaks: Leaks in the hydraulic system can reduce pressure and hinder the steering's effectiveness. It's crucial to address leaks promptly to avoid complete system failure. • Discrepancy Between Rudder and Helm: Sometimes, the actual turn of the rudder doesn't match the angle indicated on the ship's wheel (helm). This can be due to issues with linkages, adjustments, or faulty sensors. • Steering Difficulty: Difficulty turning the wheel or sluggish response can indicate problems like friction in the system, pump issues, or low hydraulic pressure. • Excessive Noise: Unusual noises coming from the steering gear can signify internal wear, malfunctioning pumps, or air trapped in the hydraulic system. • High Oil Temperatures: Overheating oil can damage components and reduce lubrication. This might be caused by excessive use, blocked filters, or malfunctioning coolers. • Rudder Movement Beyond Limits: The rudder should only turn within a specific range. Uncontrolled or excessive movement can occur due to mechanical failures or faulty limit switches. • No Remote Control Steering: Modern ships often have remote steering options from the bridge. Failure of these systems could be due to problems with pumps, valves, or the control system itself. • Rudder Angle Transmitter or Tiller Link Issues: These components are crucial for translating helm input into rudder movement. Faulty sensors or damaged linkages can disrupt this communication 5. Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situations. Procedures for emergency steering includes; • Establish communication with the bridge • Switch over to local control on all starter cabinets • Control the rudder on command from the bridge by operating the pilot valves on the main valve block • Activate the pilot for main spool, and the pilot for idling valve • When the rudder is given order, release the pilot for idling valve and then the pilot for main valve 6. Operating Principles of Refrigeration System The operating principles of a refrigeration system, which is composed of the main components of a compressor, condenser, expansion valve, and evaporator, are as follows: The refrigeration cycle begins with the compressor, which is the heart of the system. The compressor takes in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it, increasing its pressure and temperature. This high-pressure, high-temperature refrigerant vapor is then sent to the condenser. In the condenser, the hot refrigerant vapor transfers its heat to the surrounding air or water, causing the refrigerant to condense into a high-pressure, high-temperature liquid. As the refrigerant condenses, it releases the latent heat of vaporization, which is carried away by the air or water flowing through the condenser. The high-pressure, high-temperature liquid refrigerant then flows through the expansion valve, which is a metering device. As the refrigerant passes through the expansion valve, its pressure and temperature drop dramatically due to the Joule-Thomson effect. This low-pressure, low-temperature liquid refrigerant is then fed into the evaporator. In the evaporator, the low-pressure, low-temperature refrigerant absorbs heat from the surrounding environment, such as the air or water being cooled. As the refrigerant absorbs heat, it undergoes a phase change from a liquid to a vapor, becoming a low-pressure, low-temperature refrigerant vapor. This vapor is then drawn back into the compressor, completing the refrigeration cycle. The continuous cycling of the refrigerant through these four main components (compressor, condenser, expansion valve, and evaporator) is what allows the refrigeration system to remove heat from the desired space and transfer it to the surrounding environment, effectively cooling the target area.
AUX MACH 1. What is interface and how does it affect the separation efficiency? • On board ships, the term "interface" refers to the boundary between the two immiscible liquid phases, such as oil and water, within a separator. This interface plays a critical role in determining the separation efficiency of the system. Firstly, the position of the interface, or phase boundary, needs to be properly maintained at the correct level within the separator. If the interface is too high, it can lead to carry-over of water into the oil stream, while a too low interface can result in oil being carried over into the water stream. Maintaining the optimal interface level is crucial for achieving the desired separation outcomes. 2. Explain Follow up and Non-Follow up controls on steering gear. 2. Explain how operating water in purifiers work • Purifiers, especially those used for oil treatment on ships, rely on a clever system of pressurized water called operating water to open and close the centrifuge bowl. Imagine this water acting like a powerful hydraulic fluid. To seal the bowl for purification, high-pressure water fills the "closing water" chamber. This pressure pushes a piston or cylinder upwards, creating a tight seal with a ring on the bowl. This pressurized state might be constant or pulsed depending on the system. When it's time to expel waste, the water flow is diverted to the "opening water" chamber. This opposing pressure pushes another piston or cylinder down, overcoming the closing force. This slight downward movement opens ports in the bowl, allowing accumulated waste like sludge to be discharged. Some purifiers might even have a dedicated "conditioning water" line for flushing or cleaning tasks within the bowl or pipes. In essence, operating water is the hidden powerhouse that precisely controls the opening and closing of the centrifuge bowl throughout the purification and waste removal cycles. 3. working principle of rotary steering gear - A rotary vane steering gear is a mechanism on ships specifically designed to control the rudder's direction, influencing the vessel's course. It uses a rotating cylindrical housing with fixed and movable vanes to achieve this. In a rotary vane steering system, the helmsman's turn of the steering wheel translates into an electrical signal via the telemotor. This signal is amplified and sent to the power unit, which uses electric motors and pumps to generate high-pressure hydraulic fluid. The transmission system, comprised of valves and pipes, channels this fluid to the rotary vane. Here, specific chambers are pressurized based on the signal, causing the vanes within the housing to rotate. This rotational force is transferred to the rudder stock, ultimately turning the rudder blade and steering the ship. Additional components like the rudder angle indicator provide feedback on the rudder's position, while the hydraulic reservoir stores fluid, filters keep it clean, and safety relief valves protect the system from pressure overload. 4. common faults found in steering gear • Oil Leaks: Leaks in the hydraulic system can reduce pressure and hinder the steering's effectiveness. It's crucial to address leaks promptly to avoid complete system failure. • Discrepancy Between Rudder and Helm: Sometimes, the actual turn of the rudder doesn't match the angle indicated on the ship's wheel (helm). This can be due to issues with linkages, adjustments, or faulty sensors. • Steering Difficulty: Difficulty turning the wheel or sluggish response can indicate problems like friction in the system, pump issues, or low hydraulic pressure. • Excessive Noise: Unusual noises coming from the steering gear can signify internal wear, malfunctioning pumps, or air trapped in the hydraulic system. • High Oil Temperatures: Overheating oil can damage components and reduce lubrication. This might be caused by excessive use, blocked filters, or malfunctioning coolers. • Rudder Movement Beyond Limits: The rudder should only turn within a specific range. Uncontrolled or excessive movement can occur due to mechanical failures or faulty limit switches. • No Remote Control Steering: Modern ships often have remote steering options from the bridge. Failure of these systems could be due to problems with pumps, valves, or the control system itself. • Rudder Angle Transmitter or Tiller Link Issues: These components are crucial for translating helm input into rudder movement. Faulty sensors or damaged linkages can disrupt this communication 5. Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situations. Procedures for emergency steering includes; • Establish communication with the bridge • Switch over to local control on all starter cabinets • Control the rudder on command from the bridge by operating the pilot valves on the main valve block • Activate the pilot for main spool, and the pilot for idling valve • When the rudder is given order, release the pilot for idling valve and then the pilot for main valve 6. Operating Principles of Refrigeration System The operating principles of a refrigeration system, which is composed of the main components of a compressor, condenser, expansion valve, and evaporator, are as follows: The refrigeration cycle begins with the compressor, which is the heart of the system. The compressor takes in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it, increasing its pressure and temperature. This high-pressure, high-temperature refrigerant vapor is then sent to the condenser. In the condenser, the hot refrigerant vapor transfers its heat to the surrounding air or water, causing the refrigerant to condense into a high-pressure, high-temperature liquid. As the refrigerant condenses, it releases the latent heat of vaporization, which is carried away by the air or water flowing through the condenser. The high-pressure, high-temperature liquid refrigerant then flows through the expansion valve, which is a metering device. As the refrigerant passes through the expansion valve, its pressure and temperature drop dramatically due to the Joule-Thomson effect. This low-pressure, low-temperature liquid refrigerant is then fed into the evaporator. In the evaporator, the low-pressure, low-temperature refrigerant absorbs heat from the surrounding environment, such as the air or water being cooled. As the refrigerant absorbs heat, it undergoes a phase change from a liquid to a vapor, becoming a low-pressure, low-temperature refrigerant vapor. This vapor is then drawn back into the compressor, completing the refrigeration cycle. The continuous cycling of the refrigerant through these four main components (compressor, condenser, expansion valve, and evaporator) is what allows the refrigeration system to remove heat from the desired space and transfer it to the surrounding environment, effectively cooling the target area.
Nav Arch 1. Explain the following • Bow - The bow is the forward part of the hull, serving as the leading edge that cuts through the water as the vessel moves. Its design is critical for the ship's hydrodynamics, affecting factors such as resistance, stability, and seaworthiness. Different bow designs, like the traditional clipper bow or the modern bulbous bow, are used to optimize the vessel's performance for specific operating conditions and requirements. The bow also houses important features like the anchor and anchor windlass. • Hull - The hull is the main body of the ship, providing the structural integrity and buoyancy. It is the watertight shell that supports the weight of the vessel, its cargo, and equipment. The hull design, including its length, width, depth, and shape, influences the ship's stability, speed, and maneuverability. Different hull types, such as displacement hulls, planing hulls, or catamaran hulls, are used for various applications and operating environments. The hull also includes features like the keel, bilge, and stern, which all contribute to the overall performance and handling of the vessel. • Keel - The keel is a central structural component that runs along the bottom of the hull, from the bow to the stern. It acts as the backbone of the ship, providing longitudinal strength and stability. The keel helps to prevent the ship from drifting sideways and aids in keeping the vessel on course. It also helps to resist the lateral forces generated by the wind and waves, contributing to the vessel's stability and seaworthiness. The keel design can vary, with some vessels having a flat keel, a V-shaped keel, or a bulbous keel, depending on the specific requirements and intended use of the ship. 2. Explain the following types of ships according to its design • General Cargo -or dry cargo ships are designed to carry different types of dry cargoes. Thanks to their built-in cargo loading equipment, their flexibility in loading and unloading is increased. • Oil Tanker - Liquids are transported by means of tanker vessels. These liquids include crude oil, gases, and chemicals. • Bulk Carrier - This type of merchant vessel is designed to carry large amounts of cargoes that do not need packaging or are carried in bulk such as coal, grains, ore, cement and etc. 3. What is Intact and Damage Stability • Intact Stability: Passenger cruise ships must maintain intact stability to ensure passenger comfort and safety. Stability criteria such as GM and range of stability are rigorously evaluated during design and must comply with regulatory standards. (Additional you may or may not add) • Intact stability ensures the ship can withstand external forces like wind, waves, or shifting cargo without tipping over excessively. Imagine a seesaw - intact stability makes sure the ship recovers quickly from a tilt, just like a well-balanced seesaw bouncing back after a dip. This is achieved through careful design considerations like the center of gravity (weight distribution) and the center of buoyancy (upward water pressure acting against the hull). • Damage Stability: In addition to intact stability, cruise ships are required to demonstrate adequate damage stability. This involves assessing the vessel's ability to remain afloat and upright in the event of damage to the hull, such as from a collision or grounding. (Additional you may or may not add) • Damage stability onsiders what happens if the hull is breached, perhaps due to a collision or grounding. Here, the focus is on how well the ship can stay afloat even with flooding in certain compartments. Imagine multiple watertight compartments within the hull, like separate rooms in a house. Damage stability analyzes how flooding in one compartment might affect the ship's overall balance (trim) and how deep it sits in the water (draft). Ships are designed with these watertight compartments to minimize flooding and improve survivability in case of damage. 4. Construction of watertight doors according SOLAS. 5. What is Archimedes principle? • The Archimedes principle states that the buoyant force exerted on an object that is submerged partially or completely in a fluid is equal to the weight of the fluid that is displaced by the object. Buoyant Force - refers to the upward-directed force that a fluid (either a liquid or a gas) exerts on an object that is partially or completely immersed in the fluid. Displacement of Fluid - Displacement is the general term used to indicate the mass of the vessel. A ship's displacement is the volume of water it displaces when it is floating, and measured in cubic meters. 6. Forces that leads to stress and strains on ships • Waves - As a ship moves through the water, the wave-induced motion can cause bending and torsional stresses, leading to hogging (the middle of the ship bending upwards) and sagging (the middle of the ship bending downwards) of the hull. • Tensile Force - which acts to pull the ship's structure apart, causing it to stretch or elongate. These tensile forces can be experienced in the ship's hull, superstructure, and other structural elements. • Compression - act to push the ship's structure together, causing it to shorten or buckle. Compression can be experienced in the ship's hull, especially in the bottom and sides, as well as in the superstructure. • Shear Force - These forces act to slide one part of the ship's structure relative to another, causing the material to experience distortion. Shear stresses can be particularly problematic in areas where the ship's structure changes, such as at the transitions between the hull and the superstructure • Torsional Force - can twist the ship's structure, causing it to experience rotational stresses. These forces can be experienced in the ship's hull, especially in the midship section, as well as in the superstructure and other structural elements.
AUTO 1. What is Reverse Power Relay and how it works The reverse power relay is a vital protective device used in electrical power generation systems, particularly in generators, to prevent reverse power flow. Its primary function is to detect when the generator is operating in a reverse power condition and take appropriate action to safeguard the generator and the electrical system. During normal generator operation, the power flows from the generator towards the grid or load, which is the intended direction. However, a reverse power condition can occur when the power flow reverses, and the generator starts to consume power instead of generating it. This can happen due to various reasons, such as a failure in the prime mover (e.g., turbine, engine), a loss of load, or a fault in the electrical system. The reverse power relay monitors the direction of the active power flow (real power) in the generator circuit. When the relay detects a reverse power flow, it senses that the generator is operating in a reverse power condition. In response, the relay will initiate a trip signal to the generator's circuit breaker, causing the generator to be quickly disconnected from the electrical system. This rapid disconnection helps prevent damage to the generator, such as mechanical stress, overheating, or potential backfeeding into the prime mover. 2. What is preferential trip and how does it work in generator system The preferential trip is a crucial protective feature in generator systems that prioritizes the tripping or disconnection of specific equipment or components in the event of a fault or abnormal condition. The primary purpose of this mechanism is to ensure that the most critical or sensitive elements within the generator system are isolated and protected first, minimizing the overall impact and potential damage to the entire system. When a fault or an abnormal condition occurs in the generator system, such as an overload, short circuit, or any other type of disturbance, the protective relays and devices within the system detect the issue. The preferential trip mechanism is then activated, and it prioritizes the tripping or disconnection of the most critical components based on their importance and the potential consequences of their failure. For example, in a generator system, the preferential trip might prioritize the disconnection of the generator itself, followed by the disconnection of other auxiliary equipment, such as transformers, switchgear, or feeders. This selective tripping helps to contain the impact of the fault or abnormal condition and prevent it from spreading to the entire generator system. 3. What are the advantages and disadvantages of electrical and pneumatic control Electrical Control Advantages: • Faster response times compared to pneumatic systems • More precise and accurate control • Easier to integrate with other electronic systems on the ship • Require less maintenance and fewer moving parts • Allow for remote monitoring and control of systems Electrical Control Disadvantages: • Susceptibility to electrical failures and power outages • Potential safety concerns with high voltage/current • Require specialized maintenance and repair expertise • Can be more complex and costly to install initially Pneumatic Control Advantages: • Intrinsically safe operation, no risk of electrical sparks • Can operate reliably even with power failures • Simple and robust design with fewer moving parts • Can provide good force and torque for actuating valves/dampers • Lower installation and maintenance costs Pneumatic Control Disadvantages: • Slower response times compared to electrical controls • Less precise and accurate control • Require compressed air supply system to be maintained • Potential for air leaks in the piping network • Limited ability to integrate with digital control systems 4. PLC programming languages • Ladder Logic (LAD) - is a graphical programming language that mimics the appearance of electrical relay circuits. It uses ladder-like rungs to represent logical control circuits. Ladder Logic is particularly suited for representing discrete logic operations and is widely used in industries where relay-based control systems are prevalent. It is easy to understand for those with a background in electrical wiring and control circuits. • Structured Text (ST) - is a high-level programming language that follows a structured programming approach and uses statements and expressions to define control logic. It allows for complex calculations, mathematical operations, and conditional branching. ST is particularly suited for mathematical computations, data manipulation, and complex control algorithms. • Function Block Diagram (FBD) - is a graphical programming language that represents control logic as a network of interconnected function blocks. These function blocks encapsulate specific control functions and can be interconnected to create complex control algorithms. FBD is visually similar to electronic circuit diagrams and is useful for designing and representing control systems in a modular and structured manner. It is commonly used for systems with complex interconnections and for implementing reusable control modules. 5. three application of PLC onboard • PLC Alarm Annunciator System - An alarm annunciator system is used to monitor and display alarms from various ship systems and equipment. A PLC can be employed to collect alarm signals from different sensors and control devices, process the signals, and activate visual and audible alarms on the annunciator panel. The PLC can also log alarm events, provide alarm prioritization, and facilitate remote monitoring and control. • PLC Boiler Startup System - A PLC-based boiler startup system can automate and sequence the startup process, ensuring proper procedures are followed. The PLC can control boiler parameters such as fuel supply, air flow, water level, and safety interlocks. It can monitor and regulate the boiler operation, including ignition, fuel firing rate, and water level control. • PLC Separator Control System - Separators are used on ships to remove impurities and separate different components from fluids, such as fuel oils and lubricating oils. A PLC-based separator control system can monitor and control the operation of the separator, including flow rates, temperatures, pressures, and discharge conditions. The PLC can adjust valve positions, monitor levels, and provide alarms or shut down the system in case of abnormal conditions. • PLC Main Engine Remote Control System - . A PLC-based remote control system for the main engine allows for centralized control and monitoring from a control room or bridge. The PLC can receive commands from the control station and control the engine's speed, direction, fuel supply, cooling water flow, and other parameters. It can also monitor engine performance, collect data, and provide alarms and safety interlocks. 6. Basic Components of PLC 1. Input: The input section of a PLC is responsible for receiving signals from various input devices such as sensors, switches, and other field devices. It converts these signals into digital data that the PLC's processor can interpret. The input section ensures that the PLC can monitor and react to changes in the external environment. 2. Processor: The processor, also known as the central processing unit (CPU), is the core component of the PLC. It executes the control program stored in the memory and performs various operations, including arithmetic calculations, logical decisions, and data manipulation. The processor continuously scans the input signals, processes them based on the programmed instructions, and generates appropriate output signals. 3. Memory: The memory in a PLC stores the control program, data, and variables required for operation. It is typically divided into two main types: o Program Memory: This non-volatile memory holds the user-defined control program. It contains the ladder logic, function block diagrams, or other programming languages used to implement the control logic. The program memory is retained even when the PLC loses power. o Data Memory: This volatile memory stores data and variables used during program execution. It includes input and output values, internal registers, timers, counters, and other temporary data. Data memory is cleared when the PLC loses power. 4. Output: The output section of a PLC is responsible for sending control signals to external devices such as motors, actuators, solenoid valves, and other output devices. It converts the digital data generated by the processor into appropriate electrical or pneumatic signals that actuate the output devices. The output section allows the PLC to control and manipulate the physical processes in the external world.
AUX MACH 1. What is interface and how does it affect the separation efficiency? • On board ships, the term "interface" refers to the boundary between the two immiscible liquid phases, such as oil and water, within a separator. This interface plays a critical role in determining the separation efficiency of the system. Firstly, the position of the interface, or phase boundary, needs to be properly maintained at the correct level within the separator. If the interface is too high, it can lead to carry-over of water into the oil stream, while a too low interface can result in oil being carried over into the water stream. Maintaining the optimal interface level is crucial for achieving the desired separation outcomes. 2. Explain Follow up and Non-Follow up controls on steering gear. 2. Explain how operating water in purifiers work • Purifiers, especially those used for oil treatment on ships, rely on a clever system of pressurized water called operating water to open and close the centrifuge bowl. Imagine this water acting like a powerful hydraulic fluid. To seal the bowl for purification, high-pressure water fills the "closing water" chamber. This pressure pushes a piston or cylinder upwards, creating a tight seal with a ring on the bowl. This pressurized state might be constant or pulsed depending on the system. When it's time to expel waste, the water flow is diverted to the "opening water" chamber. This opposing pressure pushes another piston or cylinder down, overcoming the closing force. This slight downward movement opens ports in the bowl, allowing accumulated waste like sludge to be discharged. Some purifiers might even have a dedicated "conditioning water" line for flushing or cleaning tasks within the bowl or pipes. In essence, operating water is the hidden powerhouse that precisely controls the opening and closing of the centrifuge bowl throughout the purification and waste removal cycles. 3. working principle of rotary steering gear - A rotary vane steering gear is a mechanism on ships specifically designed to control the rudder's direction, influencing the vessel's course. It uses a rotating cylindrical housing with fixed and movable vanes to achieve this. In a rotary vane steering system, the helmsman's turn of the steering wheel translates into an electrical signal via the telemotor. This signal is amplified and sent to the power unit, which uses electric motors and pumps to generate high-pressure hydraulic fluid. The transmission system, comprised of valves and pipes, channels this fluid to the rotary vane. Here, specific chambers are pressurized based on the signal, causing the vanes within the housing to rotate. This rotational force is transferred to the rudder stock, ultimately turning the rudder blade and steering the ship. Additional components like the rudder angle indicator provide feedback on the rudder's position, while the hydraulic reservoir stores fluid, filters keep it clean, and safety relief valves protect the system from pressure overload. 4. common faults found in steering gear • Oil Leaks: Leaks in the hydraulic system can reduce pressure and hinder the steering's effectiveness. It's crucial to address leaks promptly to avoid complete system failure. • Discrepancy Between Rudder and Helm: Sometimes, the actual turn of the rudder doesn't match the angle indicated on the ship's wheel (helm). This can be due to issues with linkages, adjustments, or faulty sensors. • Steering Difficulty: Difficulty turning the wheel or sluggish response can indicate problems like friction in the system, pump issues, or low hydraulic pressure. • Excessive Noise: Unusual noises coming from the steering gear can signify internal wear, malfunctioning pumps, or air trapped in the hydraulic system. • High Oil Temperatures: Overheating oil can damage components and reduce lubrication. This might be caused by excessive use, blocked filters, or malfunctioning coolers. • Rudder Movement Beyond Limits: The rudder should only turn within a specific range. Uncontrolled or excessive movement can occur due to mechanical failures or faulty limit switches. • No Remote Control Steering: Modern ships often have remote steering options from the bridge. Failure of these systems could be due to problems with pumps, valves, or the control system itself. • Rudder Angle Transmitter or Tiller Link Issues: These components are crucial for translating helm input into rudder movement. Faulty sensors or damaged linkages can disrupt this communication 5. Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situations. Procedures for emergency steering includes; • Establish communication with the bridge • Switch over to local control on all starter cabinets • Control the rudder on command from the bridge by operating the pilot valves on the main valve block • Activate the pilot for main spool, and the pilot for idling valve • When the rudder is given order, release the pilot for idling valve and then the pilot for main valve 6. Operating Principles of Refrigeration System The operating principles of a refrigeration system, which is composed of the main components of a compressor, condenser, expansion valve, and evaporator, are as follows: The refrigeration cycle begins with the compressor, which is the heart of the system. The compressor takes in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it, increasing its pressure and temperature. This high-pressure, high-temperature refrigerant vapor is then sent to the condenser. In the condenser, the hot refrigerant vapor transfers its heat to the surrounding air or water, causing the refrigerant to condense into a high-pressure, high-temperature liquid. As the refrigerant condenses, it releases the latent heat of vaporization, which is carried away by the air or water flowing through the condenser. The high-pressure, high-temperature liquid refrigerant then flows through the expansion valve, which is a metering device. As the refrigerant passes through the expansion valve, its pressure and temperature drop dramatically due to the Joule-Thomson effect. This low-pressure, low-temperature liquid refrigerant is then fed into the evaporator. In the evaporator, the low-pressure, low-temperature refrigerant absorbs heat from the surrounding environment, such as the air or water being cooled. As the refrigerant absorbs heat, it undergoes a phase change from a liquid to a vapor, becoming a low-pressure, low-temperature refrigerant vapor. This vapor is then drawn back into the compressor, completing the refrigeration cycle. The continuous cycling of the refrigerant through these four main components (compressor, condenser, expansion valve, and evaporator) is what allows the refrigeration system to remove heat from the desired space and transfer it to the surrounding environment, effectively cooling the target area.
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15. Power Management Systems (PMS) ● Automatic Synchronizing - PMS enables automatic synchronization of multiple generators or power sources to ensure a smooth and stable transition during power transfer or parallel operation. It synchronizes the frequency, phase, and voltage of the sources before connecting them to the grid or load. ● Automatic Load Sharing - PMS facilitates the automatic sharing of electrical loads among multiple generators in a synchronized system. It distributes the load based on the capacity and availability of each generator, ensuring efficient utilization and preventing overloading. ● Automatic Start/Stop/Stby Generators according to Load Demand - PMS monitors the load demand and automatically starts, stops, or puts standby generators into operation as required. It ensures that the available generators match the load demand, optimizing fuel consumption and minimizing downtime. ● Large Motors Automatic - PMS includes features to automatically block or unblock the starting of large motors based on system conditions. This prevents excessive starting currents, voltage drops, or other undesirable effects that may occur during motor startup. ● Blocking Load Analysis and Monitoring - PMS continuously monitors and analyzes the load profile, voltage, current, and other parameters to identify abnormalities or deviations from the desired operating conditions. It provides real-time information and alerts to operators for effective load management. ● Three (3) Phase Management and Voltage Matching - PMS manages the three-phase power distribution, ensuring balanced loads across all phases. It also maintains voltage matching between generators and loads to prevent voltage imbalances and equipment damage. ● Redundant Power Distribution - PMS incorporates redundancy in power distribution to ensure uninterrupted power supply. It monitors the status of multiple power sources and automatically switches to an alternative source in case of a failure or outage. ● Frequency Control - PMS regulates and stabilizes the frequency of the power system within acceptable limits. It adjusts the engine speed or the load sharing among generators to maintain the desired frequency and prevent frequency deviations that can affect sensitive equipment. ● Blackout Start - PMS enables automatic starting of standby generators in the event of a blackout or loss of main power supply. It ensures a seamless transition to backup power and minimizes disruption to critical operations. ● Selection of Generators Pioit(fist - PMS provides intelligent algorithms for selecting the most appropriate generators based on factors like load demand, generator capacity, fuel efficiency, and maintenance requirements. It optimizes generator selection to achieve the best performance and cost-effectiveness. 16. M.E. Fresh Water Cooling System ● Introduction to Fresh Water Cooling System - The Fresh Water Cooling System is an essential component of marine engines (M.E.) that helps maintain the temperature of the engine within optimal operating limits. It utilizes fresh water as a cooling medium to remove excess heat generated during engine operation. ● Component of Fresh Water Cooling System ● Fresh Water circulating pump - The circulating pump is responsible for circulating the fresh water through the cooling system. It ensures a continuous flow of water to carry away heat from the engine components. ● Heat exchanger - The heat exchanger transfers the heat from the engine coolant to a separate cooling medium, such as seawater or air. It consists of tubes or plates that facilitate the exchange of heat between the coolant and the cooling medium. ● Expansion Tank - The expansion tank, also known as the header tank or surge tank, provides a reservoir for the coolant. It accommodates the expansion and contraction of the coolant due to temperature variations and helps maintain the proper coolant level in the system. ● Thermostat -The thermostat regulates the flow of coolant within the cooling system. It opens or closes based on the engine temperature, allowing the coolant to flow through the system when the engine reaches the desired operating temperature. ● Piping and fittings -The piping and fittings connect various components of the cooling system, allowing the flow of coolant. They are designed to withstand the temperature and pressure requirements of the system. ● Cooling Medium - The cooling medium in a fresh water cooling system is typically fresh water, which is circulated through the engine to remove heat. The fresh water absorbs the thermal energy generated by the engine and carries it to the heat exchanger for dissipation. ● Circulation System - The circulation system comprises the pump, piping, and fittings that facilitate the movement of the coolant through the cooling system. It ensures a continuous flow of fresh water to regulate the engine temperature effectively. ● What is OFFSET and what does it signify? - "offset" refers to the difference between the desired setpoint and the actual process variable value when the control loop is in a steady state. It signifies the deviation that remains even when the control loop is supposed to be maintaining the process variable at the setpoint. For example, if our control system held the temperature at 100.5°C consistently (even though the set point was 100.0°C), then an offset of 0.5°C exists. ● What is "proportional band" and what happens if the proportional band is too wide and too narrow - The proportional band determines the range of error values over which the control output will change in proportion to the error. If the proportional band is too wide, it means that the control output will change gradually even for small errors. This can result in slow response and sluggish control. It may take longer for the control system to bring the process variable back to the setpoint, leading to larger deviations and potentially prolonged instability. - On the other hand, if the proportional band is too narrow, the control output will change rapidly for even small errors. This can result in overshoot and oscillations around the setpoint. The control system may become overly sensitive to small disturbances, leading to instability and erratic behavior. Finding the right proportional band is crucial for achieving a well-tuned control system. It depends on the dynamics of the process being controlled and the desired response characteristics. A properly tuned proportional band allows the control system to respond quickly to errors while avoiding excessive oscillations or overshoot, leading to stable and accurate control of the process variable. ● What is a reverse power relay and how does it work onboard a ship? - Is a protective device used to detect and respond to reverse power flow. Reverse power flow occurs when power flows from a generator to its prime mover (usually an engine) instead of from the prime mover to the generator, which is the normal operating condition. Onboard ships, the reverse power relay is typically installed in the generator circuit to protect the prime mover (such as a diesel engine) from damage caused by reverse power flow. The relay monitors the power flow direction and activates when it detects reverse power flow beyond a preset threshold. When reverse power flow is detected, the reverse power relay operates to disconnect the generator from the electrical system. This action prevents further power flow in the reverse direction, protecting the prime mover from potential damage. The relay may also activate an alarm or provide a signal to indicate the reverse power condition. - ● What is a preferential trip and how do they apply onboard? - Preferential trip, also known as selective tripping or selective shutdown, is a technique used in electrical systems to prioritize the disconnection of specific loads or equipment during fault conditions. It is implemented to ensure that critical or essential equipment remains operational while non-critical loads are selectively disconnected. - Onboard ships, preferential trip schemes are used to protect essential systems and equipment. For example, in the event of a fault or overload, the preferential trip system will first disconnect non-essential loads or equipment, such as lighting circuits or non-essential machinery. This allows the electrical system to prioritize the supply of power to critical systems, such as navigation equipment, communication systems, propulsion machinery, and safety systems. - The implementation of preferential trip systems involves setting up a hierarchical arrangement of protective devices, such as circuit breakers or relays, with different time-delay settings and coordination characteristics. These devices are coordinated to selectively trip or isolate specific circuits or equipment based on their priority level during fault conditions. By doing so, the preferential trip system helps maintain the availability of critical systems while minimizing the impact of faults on non-essential loads.
AUTO 12. Boiler Drum Level Control System ● Introduction to Boiler Drum Level Control - Boiler drum level control is crucial for several reasons, including safety and efficiency. Maintaining the correct water level in the drum ensures an adequate supply of water for steam generation, preventing overheating or flooding. It also promotes optimal steam quality and thermal efficiency, avoiding energy losses and reducing overall boiler efficiency. ● Boiler Drum Level Measurement - Accurate measurement of the drum level is essential for effective control. Common methods of drum level measurement include float-operated devices, differential pressure transmitters, and guided wave radar. These instruments provide real-time feedback on the water level in the drum, which is used by the control system to make adjustments. ● Single-Element Control System - A single-element control system utilizes only the drum level measurement to control the boiler feedwater flow. It is a basic control strategy that adjusts the feedwater flow based on the drum level deviation from the desired setpoint. However, this approach may not account for variations in steam demand and can lead to instability or improper control. ● Two-Element Control System - A two-element control system incorporates an additional measurement, typically steam flow or feedwater flow, along with the drum level. This additional input helps account for variations in steam demand and provides better control. The control system adjusts the feedwater flow based on both the drum level and the secondary measurement. ● Three-Element Control System - A three-element control system further enhances control accuracy by adding a measurement of the steam flow rate. It considers the rate of change of the drum level, along with the drum level and steam flow, to make more precise adjustments to the feedwater flow. This system provides faster response and improved stability. ● Control Algorithms (PID Control) - Proportional-Integral-Derivative (PID) control algorithms are commonly used in boiler drum level control systems. PID controllers calculate the control output based on the error (difference between the desired setpoint and the measured value), the integral of the error over time, and the rate of change of the error. These algorithms help fine-tune the control response and maintain stability. ● Control Valve Operation - Control valves are used to regulate the flow of feedwater into the boiler drum. The control system sends signals to the control valve to open or close based on the desired drum level. The valve position determines the flowrate of feedwater, which affects the water level in the drum. ● Alarm and Trip Systems -Boiler drum level control systems incorporate alarm and trip systems to ensure safety. Alarms are activated when the drum level deviates from the desired range, indicating potential issues. Trip systems initiate automatic shutdown or protective actions if the drum level reaches critical levels, preventing damage to the boiler and associated equipment. ● Control System Integration - Boiler drum level control systems are typically integrated into a larger control system that oversees the overall operation of the boiler. Integration includes communication with other control loops, monitoring of critical parameters, and coordination with safety systems. 13. Basic Boiler drum level and combustion control system ● Importance of Drum Level Control - Drum level control in boilers is essential for safe and efficient operation. Maintaining the correct water level ensures an adequate supply of water for steam generation, preventing overheating or flooding. It enhances safety and optimizes steam quality and thermal efficiency, avoiding energy losses and reducing overall boiler efficiency. ● Components of Drum Level Control System ● Level Measuring Device: It is used to measure the water level in the steam drum. Commonly used devices include float-operated devices, capacitance probes, and differential pressure transmitters. ● Level Controller: The level controller compares the measured drum level with the desired setpoint and calculates the error. It generates an output signal to adjust the water flow into the drum based on the error. ● Control Valve: The control valve regulates the flow of feedwater into the boiler drum. It is modulated by the level controller to maintain the desired drum level. ● Feedwater Pump: The feedwater pump supplies water to the boiler drum based on the control signal from the level controller. ● Combustion Control - Combustion control in a boiler system involves maintaining the proper ratio of fuel and air for efficient and safe combustion. It aims to achieve complete combustion while minimizing the emission of pollutants. ● Components of Combustion Control System ● Fuel Flow Control: This component regulates the flow rate of fuel into the combustion chamber. It can be achieved using control valves or variable speed drives for pumps or fans, depending on the type of fuel. ● Air Flow Control: The air flow control system adjusts the supply of combustion air to the burner. It ensures that the correct amount of air is available for efficient combustion. Control dampers or variable speed drives for fans are commonly employed for air flow control. ● Oxygen Trim System: An oxygen trim system measures the oxygen content in the flue gas and adjusts the air-fuel ratio accordingly. This helps to optimize combustion efficiency and reduce emissions. ● Burner Management System (BMS): The BMS ensures the safe and reliable operation of the burner. It includes safety interlocks, flame detection systems, and fuel trip systems to prevent hazards such as flame failure, high or low gas pressure, or ignition failures. ● Air-Fuel Ratio Control - Maintaining the proper air-fuel ratio is crucial for efficient combustion. The air-fuel ratio control system adjusts the flow rates of fuel and combustion air to achieve the desired ratio. It typically utilizes feedback control loops to monitor and regulate the air and fuel flows based on measurements such as oxygen content in the flue gas or analysis of combustion products. ● Flame Monitoring and Safety Systems - Flame monitoring and safety systems are essential to ensure safe and reliable boiler operation. These systems include flame detectors that continuously monitor the presence and stability of the flame. If the flame is lost or unstable, the safety system initiates appropriate actions, such as shutting off the fuel supply and activating alarms or safety interlocks to prevent hazardous conditions. 14. Basic Main Engine Remote Control Starting System ● Introduction to Main Engine Starting - The Main Engine Remote Control Starting System is responsible for initiating the starting sequence of the main engine in a marine vessel. It allows for the remote control and monitoring of the starting process, ensuring safe and efficient engine operation. ● Components of Remote Control Starting System ● Starting air distributor - the starting air distributor is a device that distributes compressed air to the engine cylinders during the starting process. It ensures that the correct amount of air is supplied to each cylinder for combustion. ● Air compressors - Air compressors supply the compressed air required for starting the engine. They compress atmospheric air and store it in starting air receivers. ● Starting air receivers - Starting air receivers are vessels that store the compressed air from the air compressors. They provide a reservoir of air for the starting process and ensure a continuous supply of air during engine starting. ● Control valves - Control valves regulate the flow of starting air from the starting air receivers to the engine cylinders. They open and close according to the commands from the control system, allowing the precise timing and distribution of air to the cylinders. ● Safety interlocks - Safety interlocks are mechanisms that ensure the starting process can only be initiated under safe conditions. They may include prerequisites such as proper fuel supply, sufficient lubrication, and correct engine parameters before allowing the starting sequence to begin. ● Starting Air Distribution System - The starting air distribution system consists of the starting air receivers, control valves, and piping network. Compressed air from the receivers is directed to the engine cylinders through the control valves. The distribution system ensures that the starting air reaches each cylinder at the right time and in the correct quantity for reliable combustion. ● Control Valves and Timing Devices - Control valves in the starting system are responsible for regulating the flow of starting air to the engine cylinders. They open and close based on signals from the control system to ensure precise timing and synchronization of the starting process. Timing devices may also be incorporated to control the duration of air supply to each cylinder. ● Safety Interlocks and Protections - Safety interlocks play a crucial role in the remote control starting system. They prevent the starting process from being initiated if certain safety conditions are not met. For example, the interlocks may check for proper fuel supply, lubrication, or engine parameters to ensure safe starting operations. Protections are in place to safeguard against abnormal conditions, such as high cylinder temperatures or abnormal engine speed. ● Control Panel Operation - The control panel is the interface for operating the remote control starting system. It allows the operator to start, stop, and monitor the main engine starting process. The control panel provides indicators, alarms, and controls for the various components, facilitating safe and efficient engine starting.
What is the difference between plan view and elevation view? - A plan view in navigational architecture is a top-down representation of a ship or vessel, providing a bird's-eye view of the layout and arrangement of decks, compartments, and structures. It offers a two-dimensional perspective and is commonly used to illustrate the horizontal distribution of spaces, such as navigation equipment, cargo holds, accommodation areas, and deck layouts. On the other hand, an elevation view shows the ship's profile from a side view, offering a two-dimensional representation of the ship's height and structure. It focuses on the vertical arrangement of decks, superstructures, masts, funnels, and other features, providing insights into the ship's external appearance and proportions. Both plan view and elevation view are essential in understanding the spatial organization and design of a ship. - Give at least two examples of longitudinal force acting on ships - Longitudinal forces refer to forces that act along the length or longitudinal axis of a ship. These forces can affect the ship's motion, stability, and performance during navigation. Some common longitudinal forces includes: 1. Propulsive Force: The propulsive force is generated by the ship's propulsion system and acts in the direction of the ship's motion. It propels the ship forward or astern, driving it through the water. The magnitude of the propulsive force depends on factors such as the power of the propulsion system, the efficiency of the propellers or thrusters, and the ship's speed. 2. Resistance Force: Resistance force is the opposing force experienced by a ship as it moves through the water. It acts in the opposite direction to the ship's motion and is caused by various factors, including water friction, wave resistance, and form drag. The resistance force depends on the ship's hull shape, speed, displacement, and environmental conditions. Minimizing resistance is crucial for optimizing fuel efficiency and improving the ship's performance. 3. Wind Force: Wind force can exert a longitudinal force on a ship when the wind blows parallel or nearly parallel to the ship's longitudinal axis. Depending on the wind direction, it can act as a driving force, pushing the ship forward, or as a retarding force, opposing the ship's motion. The magnitude of the wind force depends on factors such as wind speed, ship's profile area exposed to the wind, and wind angle relative to the ship's heading. 4. Current Force: Current force refers to the force exerted by water currents on a ship. If the current flows in the same direction as the ship's intended course, it can act as a driving force, aiding the ship's propulsion. Conversely, if the current flows in the opposite direction, it can act as a retarding force, opposing the ship's progress. The magnitude of the current force depends on the speed and direction of the water current. Two types of stresses experienced onboard 1. Tensile Stress: Tensile stress is a type of stress that occurs when a force is applied to stretch or elongate a material. Onboard a ship, tensile stress can arise in components such as cables, ropes, and chains that are subjected to pulling or tension forces. For example, mooring lines or towing cables experience tensile stress when supporting the weight and forces exerted on the ship during docking, anchoring, or towing operations. 2. Compressive Stress: Compressive stress is the opposite of tensile stress and occurs when a material is subjected to forces that tend to compress or shorten it. In a ship's structure, compressive stress can occur in columns, pillars, or support structures that bear the weight and loads of the ship's decks, superstructures, or cargo. It is important to ensure that these structural elements can withstand the compressive forces and maintain their stability. 3. Shear Stress: Shear stress refers to the stress that occurs when parallel forces act in opposite directions, causing one layer of a material to slide or deform relative to another layer. Onboard a ship, shear stress can be experienced in components such as hull plating, beams, or connections subjected to lateral or transverse forces, such as those caused by waves or ship motions. Shear stress analysis is crucial to ensure the structural integrity and resistance to deformation of these components. 4. Bending Stress: Bending stress occurs when a material is subjected to a combination of tension and compression forces, resulting in bending or flexure. In a ship's structure, bending stress can be present in components such as beams, girders, or keels, which are subjected to loads that cause them to bend or deflect. Proper design and analysis are essential to ensure that these components can withstand the bending stress without experiencing excessive deformation or failure. 5. Fatigue Stress: Fatigue stress is a type of stress that occurs over time due to repeated or cyclic loading. Ships often experience cyclic loads from wave impacts, vibration, or machinery operations, leading to fatigue stresses. Fatigue stress can gradually weaken the ship's structure or components, potentially leading to cracks, fractures, or failures. Proper inspection, maintenance, and fatigue analysis techniques are employed to manage and mitigate fatigue stress onboard ships. What are the differences between Flare and Tumblehome? ● Flare: Flare refers to the outward curvature or widening of the ship's hull as it moves from the waterline towards the upper portions of the ship's sides. In other words, the hull gradually angles outward or expands in width. Flare is often seen in vessels that operate in rough sea conditions, such as offshore supply vessels, fishing boats, or ships designed for icebreaking. The flare helps to deflect waves and spray away from the ship, improving stability and reducing the likelihood of water coming over the sides. ● Tumblehome: Tumblehome, on the other hand, refers to the inward curvature or narrowing of the ship's hull as it moves from the waterline towards the upper portions of the ship's sides. In contrast to flare, the hull gradually angles inward or tapers in width. Tumblehome was a common design feature in older ship designs and is occasionally seen in yachts and sailboats. Tumblehome can help reduce a ship's beam (the width of the ship) and potentially improve maneuverability. However, it may also lead to a reduction in stability and interior space.
Watertight Doors and Openings: Install watertight doors and openings in bulkheads to allow access between compartments while maintaining watertight integrity. Ensure that watertight doors are properly designed, constructed, and maintained to withstand water pressure. Implement appropriate sealing mechanisms, such as rubber gaskets or hydraulic systems, to achieve water tightness. Week 12 The free surface effect is a crucial consideration in the stability of vessels, particularly those containing liquid cargo or with partially filled tanks. When a vessel experiences motion, the liquid within its tanks tends to slosh around, creating what is known as a free surface effect. This effect can have significant implications for the vessel's stability and overall safety. Here's how: Shift in Center of Gravity (CG): The movement of liquid within the tanks alters the vessel's center of gravity. As the liquid sloshes from one side to another, the center of gravity of the vessel shifts accordingly. If the liquid moves to one side, it effectively raises the center of gravity on that side, potentially leading to instability. This shift in the center of gravity can make the vessel more prone to listing or capsizing. Reduction in Metacentric Height (GM): The metacentric height (GM) is a measure of a vessel's stability. It represents the distance between the center of gravity (CG) and the metacenter (M), which is a point of intersection of the centerline of the vessel with the centerline of the buoyancy force. When liquid sloshes around in partially filled tanks, it can reduce the metacentric height. A lower GM makes the vessel less stable and more susceptible to rolling motions, especially in rough seas. Increased Rolling Motion: The presence of a free surface amplifies the rolling motion of the vessel. As the liquid sloshes from side to side, it generates momentum that can cause the vessel to roll more violently. This increased rolling motion not only affects the comfort of those on board but also poses a safety risk, particularly if the rolling becomes severe enough to lead to a capsize. Dynamic Stability: The free surface effect also affects the dynamic stability of the vessel. Dynamic stability refers to the vessel's ability to return to an upright position after being inclined by external forces, such as waves or wind. The presence of a free surface can dampen the vessel's dynamic stability, making it more difficult for the vessel to recover from heeling moments. The effects of a liquid's free surface inside a tank are complex and encompass various principles in fluid dynamics, hydrostatics, and tank design. Here's a breakdown of how each of these factors influences the behavior of the liquid and consequently impacts vessel stability: Fluid Dynamics: Free Surface Flows: Fluid dynamics govern the movement of liquids within a tank, especially when the liquid surface is free. The sloshing and wave-like motion of the liquid can occur due to the vessel's movement or external forces. Understanding these flows is essential for predicting the behavior of the liquid cargo and its impact on the vessel's stability. Wave Propagation: The free surface of the liquid can propagate waves within the tank, which can interact with the vessel's structure and contribute to dynamic loads. These waves can amplify if resonance conditions are met, leading to potentially hazardous situations. Hydrostatics: Hydrostatic principles determine the pressure distribution within the liquid and its equilibrium state. The weight of the liquid exerts hydrostatic pressure on the tank walls and bottom. Changes in liquid level or distribution affect this pressure distribution, which in turn influences the vessel's stability characteristics. Buoyancy: Buoyancy forces act on the immersed portion of the tank, exerting an upward force counteracting the weight of the liquid. Changes in the liquid's distribution alter the buoyant force distribution, affecting the vessel's overall buoyancy and stability. Tank Design and Stability: Tank design plays a crucial role in mitigating the effects of the liquid's free surface. Baffles, anti-sloshing devices, and other structural features are incorporated to minimize sloshing and dampen the impact of wave propagation. Proper tank design is essential to maintain the vessel's stability under various operating conditions. Stability calculations take into account the dynamic effects of the liquid cargo within the tanks. Stability criteria, such as the metacentric height and the range of stability, are evaluated considering the free surface effect to ensure the vessel remains safe and stable during its operations. Capillary and Surface Tension: Capillary action and surface tension phenomena can influence the behavior of the liquid at the free surface. These effects may be minor compared to other factors but can contribute to the overall dynamics of the liquid and its interaction with the tank walls. Stability requirements for different types of ships vary depending on their intended purpose, design, and operational characteristics. Here's an overview of stability considerations for various types of ships: General Stability Concepts: Metacentric Height (GM): GM is a fundamental concept in ship stability. It represents the distance between the center of gravity (G) and the metacenter (M), which is a point of intersection of the centerline of the vessel with the centerline of the buoyancy force. A larger GM typically indicates greater stability, as the vessel will have a stronger tendency to return to its upright position after being heeled by external forces. Cargo and Container Ships: Stowage and Loading: Cargo and container ships must adhere to strict stowage and loading procedures to maintain stability. Proper distribution of cargo weight and securing of containers are critical to prevent excessive list or trim. Freeboard Requirement: Freeboard is the distance between the waterline and the main deck of the ship. Cargo and container ships are subject to international regulations governing minimum freeboard requirements, which ensure adequate reserve buoyancy and stability, especially in rough seas. Tankers: Liquid Dynamics: Tankers transport liquid cargo, which introduces unique stability challenges due to the dynamic behavior of the liquid within the tanks. Sloshing and free surface effects can significantly impact stability, requiring careful consideration during design and operation. Ballast Systems: Tankers often utilize ballast systems to control stability by adjusting the distribution of weight within the vessel. Ballasting and deballasting operations help optimize stability depending on cargo load and environmental conditions. Passenger Cruise Ships: Intact Stability: Passenger cruise ships must maintain intact stability to ensure passenger comfort and safety. Stability criteria such as GM and range of stability are rigorously evaluated during design and must comply with regulatory standards. Damage Stability: In addition to intact stability, cruise ships are required to demonstrate adequate damage stability. This involves assessing the vessel's ability to remain afloat and upright in the event of damage to the hull, such as from a collision or grounding.
NAV ARCH Week 9 Propulsion System: This includes the main engines, propellers, shafting, and any thrusters. Typically, the main engines are located in the engine room, with propellers at the stern. The shafting connects the engine to the propeller, usually passing through the ship's hull. Thrusters, if present, are often positioned at the bow and/or stern for improved maneuverability. Fuel Systems: Fuel tanks are strategically placed to ensure stability and weight distribution. They are commonly located in the lower part of the ship's hull to maintain stability, with piping systems running to the engine room. Fuel filters, pumps, and other equipment are usually installed nearby for efficient fuel delivery. Cooling Systems: Heat exchangers, pumps, and piping are arranged to cool the engines and other machinery. Heat exchangers are often placed near the engines to transfer heat to the ship's cooling water system or to separate cooling systems for various machinery. Exhaust Systems: Exhaust pipes from the engines lead to funnels or stacks above the ship's deck to release exhaust gases safely. These are often located aft to minimize interference with crew areas and to prevent exhaust from affecting navigation. Air Systems: Air intakes for engine combustion and ventilation are positioned to ensure a steady flow of fresh air. Ventilation systems throughout the ship maintain a comfortable environment for crew and prevent the buildup of hazardous gases. Electrical Systems: Generators, switchboards, and distribution panels are placed in the engine room or a dedicated electrical room. Wiring runs throughout the ship to provide power to various systems and equipment. Emergency backup systems are also incorporated for critical functions. Automation and Control Systems: Control panels and instrumentation are located in the engine control room for monitoring and controlling the propulsion and auxiliary systems. These systems often include advanced automation for optimal performance and fuel efficiency. In terms of stability, the arrangement of these systems must be carefully considered to maintain the ship's center of gravity and stability characteristics. The weight distribution of equipment and machinery, along with fuel and cargo, must be balanced to ensure the ship remains stable in various sea conditions. Additionally, modern ships often employ stability management systems that monitor and adjust ballast and trim to optimize stability throughout the voyage. Week 10 "Compartmentation" refers to the division of a ship's interior into separate compartments or sections. This is a fundamental principle in ship design aimed at enhancing safety, particularly in the event of flooding or damage. Each compartment is typically bounded by watertight bulkheads, floors, and ceilings, creating a barrier that prevents water from freely flowing throughout the vessel. Watertight integrity, therefore, relies heavily on the effectiveness of compartmentation. Here's how it affects the ship's safety: Damage Containment: If a ship suffers damage, whether from a collision, grounding, or other mishap, compartmentation limits the spread of water to the affected area. By confining flooding to a single or a few compartments, the ship can maintain stability and buoyancy, reducing the risk of sinking. Stability: Compartmentation helps maintain the ship's stability by preventing water from accumulating unevenly. Even if one compartment floods, the rest of the vessel remains relatively unaffected, allowing the ship to maintain its proper trim and stability. Safety: Compartmentation enhances the safety of passengers and crew by providing time for evacuation or for addressing the source of flooding. It slows down the rate of flooding, giving responders more time to mitigate the situation. Redundancy: Large ships often feature redundant compartments, meaning that even if one compartment is compromised, there are multiple backup compartments to maintain buoyancy and stability. This redundancy adds an extra layer of safety. Regulatory Compliance: Compartmentation is typically subject to international maritime regulations, such as those outlined by the International Maritime Organization (IMO). These regulations specify standards for the construction, placement, and maintenance of watertight bulkheads and doors to ensure adequate compartmentation and watertight integrity. However, while compartmentation is a crucial aspect of ship safety, it's not foolproof. Compromises in compartmentation due to factors like structural weaknesses, inadequate maintenance, or improper sealing of doors and hatches can undermine watertight integrity. Additionally, modern ships often have complex systems running through bulkheads, such as piping and cabling, which may introduce vulnerabilities if not properly managed. Overall, compartmentation remains a cornerstone of ship design and safety, providing a critical defense against the hazards of flooding and damage at sea. Week 11 Watertight bulkheads are structural divisions within a ship's hull designed to prevent the ingress of water in case of damage to the vessel's hull. These bulkheads play a crucial role in maintaining the ship's stability and integrity, particularly in the event of a flooding incident. According to SOLAS Regulation, the construction of watertight bulkheads in ships must adhere to several key requirements: Integrity: Watertight bulkheads should be constructed with materials and design that ensure their structural integrity and prevent water penetration. They must be capable of withstanding the pressure exerted by water and should not deform or collapse under such pressure. Watertightness: Bulkheads should be constructed to be watertight, meaning they should prevent the passage of water under normal operating conditions as well as during flooding situations. Proper sealing mechanisms, such as gaskets, welds, or other approved methods, must be employed to maintain the watertight integrity of the bulkheads. Extent and Location: SOLAS specifies the minimum number and location of watertight bulkheads based on the ship's length, type, and purpose. The objective is to divide the ship into compartments to minimize the risk of progressive flooding and maintain the ship's stability even in the event of damage to one or more compartments. Penetrations and Openings: Watertight bulkheads should have limited or no openings, and any penetrations through the bulkheads, such as pipes, cables, or ventilation ducts, must be properly sealed to maintain their watertightness. Penetrations should be minimized, and if necessary, they should have appropriate watertight closures or fittings. Doors and Hatches: Bulkhead doors and hatches must also meet specific watertightness criteria. They should be designed and constructed to resist water pressure and remain watertight under various conditions. Additionally, these doors and hatches should have a means of securing them in the closed position to prevent unintentional opening during flooding situations. Inspection and Maintenance: Regular inspection and maintenance of watertight bulkheads are crucial to ensure their ongoing effectiveness. Ship operators and owners are responsible for maintaining the structural integrity and watertightness of the bulkheads, including conducting inspections, testing seals, and promptly addressing any identified issues or deficiencies. It's important to note that while SOLAS provides guidelines and regulations for watertight bulkheads, the specific requirements may vary depending on the ship's size, type, and intended operations. Ship designers, builders, and operators should consult the relevant SOLAS regulations, classification societies, and other applicable standards to ensure compliance with the specific requirements for their vessels. To ensure the construction of watertight bulkheads, here are some recommended guidelines and considerations: Bulkhead Construction Standards: Follow industry standards and regulations for shipbuilding and maritime engineering, such as those set by classification societies like the International Association of Classification Societies (IACS) or national regulatory bodies. Refer to specific guidelines and requirements for bulkhead construction provided by the regulatory authorities. Placement and Arrangement: Determine the locations of bulkheads based on the ship's design, purpose, and intended use. Consider factors such as the ship's stability, structural integrity, and the potential impact of water ingress on different compartments. Place bulkheads at appropriate intervals to create separate watertight compartments throughout the ship. Watertight Integrity Criteria: Ensure that bulkheads meet specific watertight integrity criteria, which may include pressure and leakage tests. Use suitable materials for construction that are resistant to corrosion, fatigue, and deformation. Implement proper welding or joining techniques to maintain watertightness. Strength and Stability Requirements: Design bulkheads to withstand hydrostatic and hydrodynamic pressures, as well as potential impacts from cargo, environmental forces, or accidents. Consider the strength and stability requirements outlined by the classification societies or regulatory bodies. Use appropriate structural reinforcements, such as stiffeners or girders, to enhance the strength of bulkheads. Double Bottom and Double Hull Design: Consider incorporating a double bottom or double hull design, especially for vessels operating in demanding environments or carrying hazardous cargo. A double bottom provides an additional layer of protection against water ingress in case of damage to the outer hull. A double hull design creates multiple barriers to prevent water from reaching the cargo compartments.
AUX MACH Discuss emergency steering operation Emergency steering operation on a ship refers to the procedures and systems in place to control and steer the vessel in case of a failure or malfunction of the primary steering system. It ensures that the ship remains maneuverable and can be safely navigated even in emergency situation. Procedures for emergency steering includes; 1. Establish communication with the bridge 2. Switch over to local control on all starter cabinets 3. Control the rudder on command from the bridge by operating the pilot valves on the main valve block 4. Activate the pilot for main spool, the the pilot for idling valve 5. When the rudder is given order, release the pilot for idling valve and then the pilot for main valve Give 3 examples of the applications of refrigeration system and briefly discuss each 1. Preservation of Perishable Goods: One of the primary applications of refrigeration systems on ships is to preserve perishable goods during transportation. Refrigerated cargo holds or containers are used to store items such as fruits, vegetables, seafood, and dairy products at controlled temperatures. This helps to maintain the quality and freshness of the goods, extending their shelf life and preventing spoilage. 2. Air Conditioning and HVAC Systems: Refrigeration systems play a crucial role in providing air conditioning and ventilation on ships. They cool and dehumidify the air inside cabins, crew quarters, control rooms, and public areas, ensuring a comfortable and healthy environment for passengers and crew members. HVAC (Heating, Ventilation, and Air Conditioning) systems on ships rely on refrigeration technology to regulate temperature, humidity, and air quality. 3. Provisioning and Galley Equipment: Refrigeration systems are used in the ship's galley (kitchen) and provisioning areas to store and preserve food supplies. Refrigerators, freezers, and cold rooms are utilized to store ingredients, prepared meals, and other perishable items. These systems help to maintain food safety and quality standards, ensuring that an adequate supply of fresh food is available during the voyage. 4. Refrigerated Tanks and Containers: Some ships transport temperature-sensitive cargo in specialized refrigerated tanks or containers. Examples include the transportation of chemicals, pharmaceuticals, and certain types of gases that require specific temperature control. Refrigeration systems are employed to maintain the desired temperature range and prevent spoilage or degradation of the cargo. 5. Medical and Laboratory Facilities: Certain ships, such as research vessels or hospital ships, may have onboard medical facilities or laboratories that require refrigeration. Refrigeration systems are used to store medical supplies, vaccines, blood samples, and other temperature-sensitive materials, ensuring their integrity and viability. How does the thermostatic valve work in the refrigeration system? - A thermostatic valve, also known as an expansion valve, is a critical component in a refrigeration system that plays a vital role in regulating the flow of refrigerant into the evaporator. The valve operates by utilizing a sensing bulb, which is connected to the suction line of the evaporator. Inside the sensing bulb, there is a temperature-sensitive substance, such as a refrigerant or gas, that expands or contracts based on the temperature of the refrigerant vapor in the suction line. As the temperature changes, the substance in the sensing bulb expands or contracts, causing the pressure within the bulb to increase or decrease accordingly.
LO2.5: Ship's hydrostatic table • Introduction to Hydrostatic Table -also known as a hydrostatic data sheet or hydrostatic curve, is a tabular or graphical representation of a ship's hydrostatic properties. It provides essential information about the ship's buoyancy, stability, and load conditions. The table typically includes data such as drafts, displacements, centers of gravity, freeboard, and other relevant parameters. • Drafts and Trim - Draft refers to the vertical distance between the waterline and the deepest point of a ship's hull. Trim refers to the longitudinal balance of a ship, specifically the difference in draft between the forward and aft ends of the ship. It is a measure of how level or inclined the ship is along its length. Trim is expressed as a positive or negative value, indicating whether the bow or stern is lower in the water. • Buoyancy and Displacement - Buoyancy is the upward force exerted on the ship by the water, keeping it afloat. Displacement is the weight of the water displaced by the ship's hull and represents the mass of the ship. • Centers of Gravity - refers to a key reference point that plays a crucial role in assessing a ship's stability and equilibrium. It represents the average location of the ship's weight distribution in three dimensions: longitudinally, transversely, and vertically. The position of the center of gravity influences the ship's stability, trim, and response to external forces. • Freeboard and load conditions - Freeboard refers to the vertical distance between the waterline and the upper deck of the ship. The hydrostatic table may provide data on the ship's freeboard in various load conditions, such as full load, ballast condition, or any other specific configuration. • Soundings Drafts - are drafts measured at specific points along the length of the ship. These soundings help in assessing the ship's trim and overall weight distribution • Tank Soundings - tank soundings refer to the measurements of liquid levels in various tanks on the ship, such as fuel tanks or ballast tanks LO2.6: Stress-calculating equipment • Strain Gauges - are sensors that measure the strain or deformation in a material. They are often attached to the surface of a structure and change their electrical resistance in response to strain, allowing for the calculation of stress. • Load Cells - are devices used to measure force or load. They can be employed to determine the magnitude of external forces acting on a structure, which is important for stress analysis. • Accelerometers - are sensors used to measure acceleration or vibration. They are commonly used to assess dynamic loads and vibrations in structures, which can impact stress levels. • Pressure Transducer - are utilized to measure fluid or gas pressure. They can be employed to determine the internal pressure within a structure, which is relevant for stress analysis in pressurized systems. • Inclinometers - or tilt sensors, are used to measure the angle or tilt of an object with respect to gravity. They can be used to assess the inclination or deflection of a structure. • Vibration Sensors - are used to monitor and measure vibrations in structures. Excessive vibrations can induce stress and fatigue in materials. • Ultrasonic Testing Equipment - utilizes high-frequency sound waves to inspect the internal structure of materials. It can be used to detect defects, cracks, or variations in material properties that may affect stress levels. • Strain Monitoring System - typically consists of multiple strain gauges or sensors strategically placed on a structure to continuously monitor strain levels. It provides real-time data for stress analysis and structural health monitoring. • Finite Element Analysis (FEA) Software - is a computer-based tool used to simulate and analyze the behavior of structures under various loading conditions. It uses numerical methods to solve complex equations, allowing engineers to calculate stress distributions and evaluate structural integrity LO2.7: Intact Buoyancy Intact Buoyancy - refers to the buoyancy characteristics of a ship in its undamaged and intact condition. It represents the ability of the ship to remain afloat and stable without any structural damage or breaches. • Components of Intact Buoyancy - The components of intact buoyancy include the buoyant force exerted on the ship by the surrounding water, the shape and design of the ship's hull, and the distribution of weight and cargo on board. These factors collectively determine the ship's ability to displace water and maintain its stability. • Buoyancy Calculation • Freeboard and Reserve Buoyancy - Freeboard refers to the vertical distance between the waterline and the uppermost continuous deck of the ship. It provides a margin of safety by ensuring that the ship remains above the waterline under normal operating conditions. Reserve buoyancy refers to the additional volume of water that the ship can displace without compromising its stability. It acts as a safety buffer against unexpected flooding or damage. Effects of Breach on Ship Stability: • Immediate Impact on Stability - A breach can cause a sudden loss of intact buoyancy, leading to a decrease in the ship's overall buoyant force. This can result in a loss of stability, causing the ship to list or capsize. • Down flooding and Ingress of Water - Downflooding refers to the entry of water into the ship through openings caused by a breach. This can lead to the ingress of large volumes of water, affecting the ship's stability and buoyancy. The location and size of the breach can determine the extent of downflooding and its impact on stability. • Free Surface Effect - When water enters the ship due to a breach, it can create a free surface effect. This occurs when the water is free to move within the ship, causing shifts in weight distribution. The free surface effect can reduce stability and increase the risk of capsizing, especially if the water accumulates on one side of the ship. LO2.8: Watertight Integrity • Importance of Watertight Integrity o Safety: Maintaining watertight integrity ensures the safety of the crew and passengers by preventing water from entering critical areas of the ship, which could lead to instability, flooding, or sinking. o Damage Control: Watertight integrity plays a vital role in damage control efforts during emergencies. It helps limit the spread of flooding and compartmentalizes the ship, allowing for effective containment and control of water ingress. o Stability: Watertight compartments contribute to the overall stability of the ship. By preventing water from freely flowing throughout the vessel, they help maintain the ship's buoyancy and stability, even in the event of localized flooding. • Hull Construction and Watertight Compartments • Watertight Doors and Hatches - Watertight doors and hatches are installed in bulkheads and decks to allow access between different compartments while maintaining watertight integrity. These doors and hatches are designed to provide a watertight seal when closed, preventing water from passing through. • Sealing Mechanisms - Watertight doors and hatches employ various sealing mechanisms to ensure a watertight seal. These mechanisms may include rubber gaskets, compression seals, dogs or clamps, and locking mechanisms. When properly engaged, these mechanisms create a tight seal that resists the passage of water. • Maintenance of Watertight Seals - Regular maintenance is necessary to ensure the effectiveness of watertight seals. This includes inspections, testing, and maintenance of sealing mechanisms, gaskets, and associated components. Any damaged or worn-out seals should be promptly repaired or replaced to maintain watertight integrity. • Watertight Penetrations - Watertight penetrations refer to openings that pass through watertight boundaries, such as bulkheads or decks. Examples include pipes, cables, ventilation ducts, and other systems that need to cross from one compartment to another. These penetrations are designed with appropriate sealing mechanisms to maintain watertight integrity. • Emergency Closure and Damage Control - In emergency situations, when flooding or water ingress occurs, emergency closure procedures are followed to quickly isolate affected compartments and prevent the spread of water. This involves closing watertight doors and hatches, activating remote-operated valves, and implementing damage control measures to mitigate the effects of flooding and ensure the safety and stability of the ship.
AUXMACH STEERING GEAR SYSTEM - The main function of a steering gear system on a ship is to control the direction of the vessel by changing the angle of the rudder. This system plays a crucial role in maneuvering the ship safely in various conditions, such as navigating through narrow channels, avoiding obstacles, and maintaining course during rough seas.This system allows the ship's operator, usually the helmsman, to change the ship's course by turning the rudder. The steering gear system converts the rotational motion from the steering wheel or control device into a linear movement that moves the rudder left or right, thereby steering the ship in the desired direction. Principle/concept How: telemotor-control unit-power unit-transmission What: steer/navigate/move rudder Why: safely move/maneuver the ship Telemotor Loc: bridge below steering wheel - receive signal from the bridge and transmit this to the control unit Type: electrical, mechanical, pneumatic, hydraulic Control Unit Loc: between telemotor and power unit - commands the Power unit depending on the telemotor command Power Unit - provides force to move the actuator or the rudder Transmission system - the actuator or the action maker of the S.G. system Common types of S.G. system 1. Fully Hydraulic 2. Electro-Hydraulic *Ram - hydraulic cylinder *Vane- rotating vanes 3. Fully Electric COMMON FAULTS Loc: Alarm indicator/panel *Overload - when electric motor draws large current than normal *Phase Failure - if one or two E.Motor (3 phase) phase have high or low current than normal *Hydraulic Lock - when the directional valve does not follow the given command *Low oil level - oil service tank level below normal *High temp - oil temp on service tank above normal *Clogged Filter - return line filter dirty resulting to high pressure *Short Circuit - unintentional touching of electrical components *Control Power Failure - remote to local control switch malfunction or switching *No power - steering gear system power loss/failure EMERGENCY STEERING DRILL Occur: Once a month Involve: All crew Purpose: - familiarization to emergency steering - SOLAS Requirement STEPS: 1. Establish a clear/good communication with bridge 2. Switch to Local Control (No.2 system pump) 3. Wait for bridge command while standing near the emergency directional valve operating level 4. Execute the command or preferred rudder angle then continue having a clear communication SAFETY DEVICES 1. Relief valve - remove excess pressure 2. Pressure regulating valve - control pressure Safematic System - isolate leaking components of steering gear system and maintain its normal operation it involves the isolation valves and solenoid valves. Alarm panel - shows the alarms, malfunctions and current condition of the steering gear system. Indicates system status and alarm condition. Loc: ECR BRIDGE STEERING GEAR ROOM Control Panel - for system control Loc: - bridge - Steering Gear Room SOLAS REQUIREMENT 10 000 Gross Tonnage tanker 70 000 Gross Tonnage non tanker - should have at least two (2) power unit
AUTO LO2.2 PLC Fundamentals • Introduction to PLCs • Basic Components of a PLC Central Processing Unit (CPU): The CPU is the brain of the PLC. It executes the control program, communicates with other devices, and coordinates the operation of the PLC system. Memory: PLCs have different types of memory, including program memory (stores the control program), data memory (stores variables and I/O values), and retentive memory (retains data even after power loss). Input/Output (I/O) Modules: These modules interface with the external world, receiving inputs from sensors and providing outputs to actuators. They convert electrical signals between the PLC and the connected devices. Power Supply: The power supply unit provides electrical power to the PLC system. • PLC ProgrammingLanguages • PLC Scan Cycle • I/O (Input/Output) Configuration • PLC Program Execution • Relays and Timers in PLCs • Data handling and Processing • Troubleshooting and Debugging LO2.3 PLC Programing Language • Ladder Logic (LAD) - is a graphical programming language that mimics the appearance of electrical relay circuits. It uses ladder-like rungs to represent logical control circuits. Ladder Logic is particularly suited for representing discrete logic operations and is widely used in industries where relay-based control systems are prevalent. It is easy to understand for those with a background in electrical wiring and control circuits. • Structured Text (ST) - is a high-level programming language that follows a structured programming approach and uses statements and expressions to define control logic. It allows for complex calculations, mathematical operations, and conditional branching. ST is particularly suited for mathematical computations, data manipulation, and complex control algorithms. • Function Block Diagram (FBD) - is a graphical programming language that represents control logic as a network of interconnected function blocks. These function blocks encapsulate specific control functions and can be interconnected to create complex control algorithms. FBD is visually similar to electronic circuit diagrams and is useful for designing and representing control systems in a modular and structured manner. It is commonly used for systems with complex interconnections and for implementing reusable control modules. • Instruction List (IL) • Sequential Function Chart (SFC) • Structured Control language (SCL) LO2.4: PLC application on board • PLC Alarm Annunciator System - An alarm annunciator system is used to monitor and display alarms from various ship systems and equipment. A PLC can be employed to collect alarm signals from different sensors and control devices, process the signals, and activate visual and audible alarms on the annunciator panel. The PLC can also log alarm events, provide alarm prioritization, and facilitate remote monitoring and control. • PLC Boiler Startup System - A PLC-based boiler startup system can automate and sequence the startup process, ensuring proper procedures are followed. The PLC can control boiler parameters such as fuel supply, air flow, water level, and safety interlocks. It can monitor and regulate the boiler operation, including ignition, fuel firing rate, and water level control. • PLC Separator Control System - Separators are used on ships to remove impurities and separate different components from fluids, such as fuel oils and lubricating oils. A PLC-based separator control system can monitor and control the operation of the separator, including flow rates, temperatures, pressures, and discharge conditions. The PLC can adjust valve positions, monitor levels, and provide alarms or shut down the system in case of abnormal conditions. • PLC Main Engine Remote Control System - . A PLC-based remote control system for the main engine allows for centralized control and monitoring from a control room or bridge. The PLC can receive commands from the control station and control the engine's speed, direction, fuel supply, cooling water flow, and other parameters. It can also monitor engine performance, collect data, and provide alarms and safety interlocks. LO2.5 Typical DCS on board • Distributed Control System Architecture (DCS) - refers to the arrangement and structure of a control system that is distributed across multiple components and locations within a process. A DCS is designed to provide centralized control, monitoring, and operation of complex processes or systems. • Difference between DCS and PLC o System Scope: DCS is generally used for larger, complex systems that require centralized control and monitoring of multiple processes, whereas PLC is often used for smaller, standalone control tasks. o Scalability: DCS is highly scalable and can handle a large number of I/O points and complex control strategies, making it suitable for extensive plant-wide control. PLC, on the other hand, is typically limited in terms of scalability and is more suitable for discrete control tasks. o Communication: DCS systems rely on a distributed architecture with multiple controllers communicating over a network, allowing for seamless integration and data sharing. PLC systems are often standalone units that communicate with each other, but not to the same extent as a DCS. • Sample DCS System Application On board Ships o Engine Room Control: The DCS can monitor and control various parameters of the ship's engines, such as fuel flow, temperature, pressure, and speed. It can also provide alarms and alerts for abnormal conditions. o Power Management System: The DCS can manage the ship's electrical power generation, distribution, and load shedding. It can monitor power consumption, control generators and switchboards, and optimize power usage. o Cargo Management: In ships carrying cargo, the DCS can oversee the loading, unloading, and monitoring of cargo holds. It can control cargo handling equipment, monitor tank levels, and manage ballast systems. o Environmental Control: The DCS can regulate and monitor environmental systems on board, including HVAC (Heating, Ventilation, and Air Conditioning) systems, fire detection and suppression, and safety systems. o Navigation and Communication: The DCS can integrate with navigation and communication systems, providing centralized control and monitoring of radar, GPS, AIS (Automatic Identification System), and communication equipment. LO2.6: SCADA Systems Used in Maritime Industry SCADA - SCADA, which stands for Supervisory Control and Data Acquisition, is a system used to monitor and control industrial processes and operations. It is a centralized system that collects real-time data from various sensors, instruments, and devices, and allows operators to control and manage the processes remotely. • Vessel Automation - SCADA systems are used to automate and control various ship systems, including propulsion, steering, and auxiliary systems. They enable centralized monitoring and control, allowing operators to efficiently manage vessel operations. • Tank Gauging and Cargo Management - SCADA systems are employed to monitor tank levels, temperatures, and pressure in cargo tanks. They provide accurate measurements and facilitate effective cargo management, including loading, unloading, and transfer operations. • Navigation and Dynamic Positioning System - SCADA systems integrate with navigation equipment to provide real-time monitoring and control of the ship's position, course, and speed. They ensure precise navigation and support dynamic positioning systems, which are critical for offshore operations. • Power Management - SCADA systems play a vital role in managing electrical power generation, distribution, and load shedding on ships. They monitor power consumption, control generators, switchboards, and optimize power usage to ensure efficient and reliable power management. • Weather Monitoring and Reporting - SCADA systems can integrate weather monitoring sensors and instruments to provide real-time weather data to ship operators. This information assists in making informed decisions related to route planning, safety, and optimizing vessel performance. • Security and Surveillance - SCADA systems are utilized for security and surveillance purposes on ships. They integrate with CCTV cameras, access control systems, and intrusion detection systems, allowing operators to monitor and manage security aspects of the vessel. • Emergency Response and Alarm Management - SCADA systems enable efficient management of alarms and emergency response procedures. They provide real-time notifications and alerts for critical events, allowing operators to take appropriate actions promptly. LO3.1: Boiler Drum Level Control System • Introduction to Boiler Drum Level Control • Boiler Drum Level Measurement • Single-Element Control System • Two-Element Control System • Three-Element Control System • Control Algorithms (PID Control) • Control Valve Operation • Alarm and Trip Systems • Control System Integration
Advantages of Electrical Control Systems on Ships: Faster response times and precise control Lower maintenance requirements More compact and lightweight Easier integration with modern automation systems Better compatibility with digital communication protocols Higher energy efficiency Disadvantages of Electrical Control Systems on Ships: High initial installation costs Vulnerable to electrical faults and power supply disruptions Requires skilled technicians for maintenance and troubleshooting Limited suitability for high-power applications Greater complexity in terms of wiring and circuitry Advantages of Pneumatic Control Systems on Ships: Simplicity in design and operation Good resistance to harsh environments (e.g., moisture, heat) Reliable and robust performance Ability to handle high-pressure applications Lower risk of electrical hazards Disadvantages of Pneumatic Control Systems on Ships: Slower response times compared to electrical systems Limited precision and accuracy Larger and bulkier equipment Higher maintenance requirements (e.g., air compressors, pneumatic valves) More prone to leakage and loss of pressure.
Explain the production, conditioning and distribution of compressed air on board ships - PRODUCTION: Compressed air is typically produced on ships using air compressors. These compressors are driven by electric motors or diesel engines and are responsible for compressing atmospheric air to a higher pressure. The compressed air is generated in the compressor and stored in air receivers or air storage tanks. - CONDITIONING: The compressed air produced by the compressors needs to undergo conditioning before it can be used in various shipboard systems. Conditioning involves removing impurities, moisture, and oil from the compressed air to ensure its quality and prevent damage to machineries onboard. The air may go through air filters, moisture separators, or air dryers. - DISTRIBUTION: Once the compressed air is conditioned, it is distributed throughout the ship to various systems and equipment. Air distribution is achieved through a network of pipelines and valves. The distribution system is designed to deliver the necessary pressure and flow rate to different points of use. Control valves and regulators may be installed to adjust the pressure and control the flow of compressed air to different equipment and systems. LO1.3. Explain the operations of pneumatic and electro pneumatic devices used in electro-pneumatic Pneumatic Actuators: 1. Cylinders: Pneumatic cylinders are devices that convert compressed air energy into linear motion. They consist of a piston and cylinder arrangement. When compressed air enters the cylinder, it pushes the piston, generating linear force and motion. 2. Rotary Actuators: Rotary actuators convert compressed air energy into rotational motion. They are used when rotary movement is required instead of linear motion. Rotary actuators can turn valves, drive rotating machinery, or control the movement of robotic arms. Valves in Pneumatics: 1. Directional Control Valves: These valves determine the direction of airflow in a pneumatic system. They can be manually or electrically actuated and control the flow of compressed air to different actuators or exhaust air from them. 2. Pressure Control Valves: Pressure control valves regulate the pressure within the pneumatic system. They maintain the desired pressure level by relieving excess pressure or supplying additional air when the pressure drops below the set point. 3. Flow Control Valves: Flow control valves adjust the flow rate of compressed air in a pneumatic system. They regulate the speed of actuator movement by controlling the rate at which air flows into or exhausts from the actuator. Pneumatic Sensors: 1. Pressure Sensors: Pressure sensors are used to measure the pressure of compressed air within the pneumatic system. They provide feedback on system pressure and can trigger actions based on pressure thresholds. 2. Position Sensors: Position sensors are used to detect the position of pneumatic actuators or other moving components in a system. They provide feedback on the position of the actuator, enabling precise control and positioning. Air Preparation Units: 1. Filters: Filters are used to remove contaminants, such as dust, dirt, moisture, and oil, from the compressed air. They ensure that the air supplied to the pneumatic system is clean and suitable for reliable operation. 2. Regulators: Regulators control and maintain the desired pressure level in the pneumatic system. They adjust the output pressure of the compressed air to a specified set point, regardless of upstream pressure variations. 3. Lubricators: Lubricators introduce a small amount of oil or lubricant into the compressed air stream. They provide lubrication to pneumatic components, such as cylinders and valves, reducing friction, wear, and extending their lifespan. LO1.4. Describe the various application of electro pneumatic circuits on board 1. Control Systems: Electro-pneumatic circuits are extensively used in control systems for precise and reliable control of various processes. They can be found in industrial automation systems, manufacturing plants, and machinery control systems. Electro-pneumatic circuits incorporate electrical control signals to actuate pneumatic components, such as valves and actuators, enabling control over fluid flow, pressure, and other parameters. 2. Engine Control: Electro-pneumatic circuits play a crucial role in engine control systems, particularly in large marine engines and industrial engines. They utilize electrical control signals to actuate pneumatic valves and actuators, regulating fuel flow, air intake, exhaust, and other engine parameters. Electro-pneumatic circuits ensure precise and efficient control of engine operations, optimizing performance and fuel consumption. 3. Cargo Handling: Electro-pneumatic circuits are utilized in cargo handling systems on ships and in warehouses. They control the operation of pneumatic actuators and valves in cranes, hoists, winches, and conveyor systems. Electro-pneumatic circuits provide accurate control over the movement, positioning, and lifting of cargo, ensuring efficient and safe handling. 4. Braking Systems: Electro-pneumatic circuits are commonly used in braking systems, both in automotive and industrial applications. They incorporate electrical control signals to actuate pneumatic valves, controlling the application and release of pneumatic brakes. Electro-pneumatic braking systems offer responsive and reliable braking control, essential for safe operation and maneuvering of vehicles and machinery. 5. Pneumatic Tools: Electro-pneumatic circuits are employed in pneumatic tool systems, such as impact wrenches, drills, and grinders. They utilize electrical control signals to actuate pneumatic valves, regulating the air supply to the tools. Electro-pneumatic circuits enable precise and controlled operation of the pneumatic tools, providing efficient and versatile tooling solutions. 6. Emergency Systems: Electro-pneumatic circuits are integrated into emergency systems to ensure quick and reliable response during critical situations. They can be found in emergency shutdown systems, fire suppression systems, and emergency venting systems. Electro-pneumatic circuits enable rapid actuation of pneumatic components, allowing for immediate actions in emergency scenarios. 7. Tensioning Systems: Electro-pneumatic circuits are applied in tensioning systems used in cable laying, towing operations, and mooring operations. They control the operation of pneumatic tensioners, maintaining accurate and controlled tension in cables, wires, or ropes. Electro-pneumatic circuits enable precise adjustment and monitoring of tensioning forces, ensuring safe and efficient operations. 8. Hatch Cover Operations: Electro-pneumatic circuits are utilized in hatch cover systems on cargo ships. They control the operation of pneumatic actuators and valves, enabling the opening, closing, and securing of hatch covers. Electro-pneumatic circuits ensure reliable and synchronized operation of hatch covers, maintaining cargo compartments' integrity and safety. 9. Automation and Control Systems: Electro-pneumatic circuits are integral to automation and control systems across various industries. They combine electrical control signals with pneumatic components to achieve precise control and automation of processes. Electro-pneumatic circuits can include sensors, programmable logic controllers (PLCs), and feedback devices, enabling advanced control, sequencing, and coordination of pneumatic operations with other electrical and mechanical systems. LO2.1. Explain the functions of the four main parts of a programmable logic controller (PLC). 1. Input: The input section of a PLC is responsible for receiving signals from various input devices such as sensors, switches, and other field devices. It converts these signals into digital data that the PLC's processor can interpret. The input section ensures that the PLC can monitor and react to changes in the external environment. 2. Processor: The processor, also known as the central processing unit (CPU), is the core component of the PLC. It executes the control program stored in the memory and performs various operations, including arithmetic calculations, logical decisions, and data manipulation. The processor continuously scans the input signals, processes them based on the programmed instructions, and generates appropriate output signals. 3. Memory: The memory in a PLC stores the control program, data, and variables required for operation. It is typically divided into two main types: o Program Memory: This non-volatile memory holds the user-defined control program. It contains the ladder logic, function block diagrams, or other programming languages used to implement the control logic. The program memory is retained even when the PLC loses power. o Data Memory: This volatile memory stores data and variables used during program execution. It includes input and output values, internal registers, timers, counters, and other temporary data. Data memory is cleared when the PLC loses power. 4. Output: The output section of a PLC is responsible for sending control signals to external devices such as motors, actuators, solenoid valves, and other output devices. It converts the digital data generated by the processor into appropriate electrical or pneumatic signals that actuate the output devices. The output section allows the PLC to control and manipulate the physical processes in the external world.
AUTO 2 LO1.1. Explain the various components and sub-system in machine automation per industry standards 1. Automation System: The automation system encompasses all the components and subsystems working together to automate a machine or process. It includes the control system, sensors, actuators, and other elements necessary for automation. 2. Control System: The control system manages and regulates the operation of the machine. It can be categorized into open-loop and closed-loop control. • Open-loop Control: In open-loop control, the system operates without feedback. Control commands are sent to the actuators based on predetermined inputs, without monitoring the output. This type of control is suitable for simple, predictable processes. • Closed-loop Control: Closed-loop control, also known as feedback control, incorporates sensors to measure the output and provides feedback to the control system. The control system compares the actual output with the desired setpoint and adjusts the control signals accordingly. This enables precise control and compensation for disturbances. • PID Controllers and Tuning: Proportional-Integral-Derivative (PID) controllers are commonly used in closed-loop control systems. They continuously analyze the feedback and adjust the control signals based on proportional, integral, and derivative actions. Tuning involves optimizing the PID controller parameters to achieve stable and responsive control. 3. Sensors and Actuators: Sensors are devices that detect physical variables such as temperature, pressure, position, and proximity. They provide feedback to the control system. Actuators, on the other hand, are devices that convert control signals into physical actions. They can include motors, solenoid valves, pneumatic cylinders, and more. 4. Programmable Logic Controllers (PLCs): PLCs are specialized digital computers used for industrial automation. They receive input signals from sensors, execute the control program, and generate output signals to control the actuators. PLCs provide a flexible and reliable control platform and can integrate with various devices and systems. 5. Pneumatic Components: Pneumatic components utilize compressed air to perform mechanical work. They are commonly used in machine automation due to their simplicity, low cost, and high power-to-weight ratio. Some key pneumatic components include: • Compressor and Air Preparation Unit: Compressors are used to generate compressed air, which is then passed through an air preparation unit. The air preparation unit typically consists of filters to remove contaminants, regulators to control air pressure, and lubricators to provide lubrication to pneumatic components. • Pneumatic Valves: Pneumatic valves control the flow of compressed air to actuate various pneumatic devices. They can be categorized into directional control valves, pressure control valves, and flow control valves. These valves enable precise control of the pneumatic system. • Pneumatic Cylinders and Actuators: Pneumatic cylinders, also known as pneumatic actuators, convert compressed air energy into linear or rotary motion. They are commonly used to move and control machine components, such as grippers, slides, and clamps.
NAV ARCH Identify the principal dimensions and the main structural members of the ship. -PRINCIPAL DIMENSION - Length Overall (LOA): The Length Overall, often abbreviated as LOA, is the maximum length of a ship from its forward-most point to its aft-most point. It represents the overall length of the vessel and is usually measured in meters or feet. LOA provides an indication of the size and scale of the ship. - Beam: The Beam of a ship refers to its maximum width or breadth at the widest point. It is measured perpendicular to the longitudinal axis (centerline) of the vessel. The beam is typically measured in meters or feet and is an important measurement for determining the ship's stability and interior space. - Draft: The Draft of a ship is the vertical distance between the waterline and the lowest point of the ship's hull, such as the keel or the bottom of the hull. It indicates the depth of the ship's immersion in the water. Draft is measured in meters or feet and affects the ship's maneuverability, stability, and the amount of cargo it can carry. - Freeboard: Freeboard refers to the vertical distance between the waterline and the main deck of the ship. It represents the height of the ship's side above the waterline. Freeboard is an important safety consideration as it helps to prevent water from entering the ship during normal operation and in rough sea conditions. It is measured in meters or feet and is regulated by maritime authorities to ensure the ship's stability and seaworthiness. -MAIN STRUCTURAL MEMBERS OF THE SHIP - Hull: The hull is the main body or shell of the ship that provides buoyancy and structural integrity. It consists of various components such as plates, frames, and bulkheads. - Keel: The keel is the central structural member running along the bottom of the ship from bow to stern. It provides stability and serves as a foundation for the rest of the ship's structure. - Frames: Frames are vertical structural members that run perpendicular to the keel and provide support to the hull. They help maintain the shape and strength of the ship's structure. - Bulkheads: Bulkheads are vertical walls or partitions that divide the interior space of the ship into separate compartments. They provide structural strength, support, and help maintain the ship's stability and watertight integrity. - Decks: Decks are horizontal structural members that provide platforms or floors within the ship. They contribute to the overall strength and rigidity of the ship's structure. - Superstructure: The superstructure refers to the part of the ship above the main deck, including cabins, bridge, and other functional spaces. It is typically made up of various structural elements and components. Explain the functions of the different ship types in reference to its cargo and construction. 1.General cargo - or dry cargo ships are designed to carry different types of dry cargoes. Thanks to their built-in cargo loading equipment, their flexibility in loading and unloading is increased. 2.Oil, Chemical and Gas Tanker - Liquids are transported by means of tanker vessels. These liquids include crude oil, gases, and chemicals. 3.Bulk Carrier - This type of merchant vessel is designed to carry large amounts of cargoes that do not need packaging or are carried in bulk such as coal, grains, ore, cement and etc. 4.Combination Carrier - A combination carrier, also known as OBO (Ore-Bulk-Oil), is designed to carry dry and wet cargoes, on different voyages, or at the same time. 5.Container Ship - It is a type of cargo ship that transports goods inside a container unit with nominal dimensions of lengths of 20 or 40 feet, and widths of 8 or 9 feet respectively. 6.Roll On/Roll Off - These “car carriers” are types of ships used to transport wheeled cargo. Their cargoes are loaded and unloaded by means of an inclined ramp. 7.Passenger Ship - This nature of merchant vessel has two types: the cruise ships, which transport passengers with high standards of accommodation and leisure facilities, and ferries, which are combinations of ro-ro and passenger vessels. Identify common steel sections used in modern shipbuilding 1.Plates - a steel section level, without curvature. Used for the construction of the ship's hull, decks, bulkheads, and other structural components. 2.Angles - are L-shaped steel sections that are used for reinforcing corners, edges, and joints of the ship's structure. They provide additional strength and rigidity. 3.Channels - are C-shaped steel sections that are commonly used for structural support, such as in frames, stringers, and other load-bearing members of the ship's structure. 4.Bulb Flats - are specialized steel sections with a flat surface and a bulbous shape on one edge. 5.T-sections - also known as T-bars, are steel sections that have a T-shaped cross-section. They are used for framing, bracing, and supporting deck structures. 6.I-Beams - also known as H-beams, are steel sections with an I-shaped cross-section. They are commonly used for commonly used as main structural members, such as keel beams and longitudinal stiffeners. 7.Hollow Sections - Hollow sections, such as rectangular or circular tubes, are used for specific applications in shipbuilding, including piping systems, masts, and cranes. They offer strength and stiffness while reducing the weight of the structure. 8.Z-Sections - also known as Z-bars, are steel sections that have a Z-shaped profile. They are often used for secondary structural components, such as brackets, supports, and stiffeners. 9.Pipe Sections - Steel pipes and tubes are used extensively in shipbuilding for various purposes, including piping systems for fuel, water, and other fluids, as well as for the construction of masts, booms, and other structural elements. 10.Bars and Rounds - Steel bars and rounds are used for various applications, including reinforcing smaller structural components, such as hatches, doors, and handrails. 11.Transition Pieces - are specialized steel sections used to connect different types of structural members or sections, ensuring a smooth transition and proper load transfer between them. 12.Fitting - such as flanges, elbows, tees, and reducers, are used in piping systems to connect and control the flow of fluids within the ship's structure. Identify the structural components of the ship's hull. 1.Shell Plating: The shell plating forms the outer skin of the ship's hull. It consists of large metal plates that are welded or riveted together to create a watertight barrier. Shell plating provides structural strength and helps to maintain the integrity of the hull. 2.Frames: Frames, also known as ribs or bulkheads, are vertical or transverse structural members that run across the ship's hull. They provide structural support and help distribute the loads and stresses throughout the hull. Frames are typically made of steel and are spaced at regular intervals along the length of the ship. 3.Keel: The keel is the central longitudinal structural member that runs along the bottom of the ship's hull. It is often a large, heavy beam or plate that provides strength and stability to the ship. The keel is usually located at or near the lowest point of the hull and serves as the foundation for the entire vessel. 4.Deck: The deck is the horizontal structure that forms the top surface of the ship's hull. It provides a working platform and separates the different levels or compartments within the ship. Decks are typically made of steel and can be reinforced to support heavy equipment, cargo, or structures on the ship. 5.Bulkheads: Bulkheads are vertical walls or partitions that divide the ship's interior into separate compartments. They provide structural strength, help maintain the vessel's stability, and contribute to its watertight integrity. Bulkheads are often made of steel and extend from the bottom of the ship's hull to the deck. 6.Stringers: Stringers are longitudinal structural members that run parallel to the ship's keel. They provide additional support and reinforcement to the hull, especially in areas where localized loads or stresses are expected. Stringers are typically located on the inside of the hull and are connected to the frames and other structural components.
AUXMACH LO1- Describe the operating principles of a purifier system with the use of a manufacturer’s manual. A purifier system, also known as a centrifugal separator or purifier clarifier, is a device used to separate solid impurities and water from a liquid, typically oil or fuel, through the principles of centrifugal force and gravity separation. A fuel oil purifier is a device used onboard ships to remove sediments, sludges, and water content on HFO. This is achieved by using an electric motor as means of the prime mover to rotate the bowl at a very high speed, thus generating a centrifugal force for separating two liquids with different densities. Describe the faults in a purifier system with the use of a manufacturer’s manual: - High Vibration: Excessive vibration in the purifier system can indicate misalignment of components, worn out bearings, or unbalanced parts. This can also indicate that the motor is not functioning. This can lead to reduced separation efficiency and potential damage to the system if not addressed promptly. - Oil Leakage: Oil leakage from the purifier system can occur due to worn-out seals, gaskets, or damaged connections. It can lead to a loss of oil, environmental pollution, and compromise the system's operation. - Low Separation Efficiency: If the purifier system fails to achieve the desired separation efficiency, it may indicate issues such as inadequate bowl speed, incorrect adjustment of gravity discs, or clogging of the centrifuge. This can result in poor-quality purified oil and increased maintenance requirements. - Heater Failure: Leaks in the heat exchanger cause inadequate heating, thus affecting the purification of oil since the required temperature and viscosity of the oil are not met. - Water transducer failure - can lead to inaccurate measurement of water content in the fuel oil, compromising the efficiency of the water separation process. It can result in increased water content in the purified fuel oil, potentially causing corrosion, combustion issues, and reduced equipment performance.
AUXMACH Emergency Steering Gear Operation: Emergency steering gear is crucial in situations where the primary steering system fails. It typically involves activating an auxiliary mechanism, often a hydraulic or mechanical system, that directly controls the rudder's movement. This backup system allows the vessel to maintain directional control and navigate safely in emergencies. The steering of the vessel can be operated from the steering gear room. Emergency steering can be done by pressing the push buttons on the hydraulic valve blocks, see Figure 3.2. The buttons on the starter cabinet, see Figure 3.3, may also be used for emergency steering. However, then an unrestricted view to the Rudder Angle Indicator on the actuator is required. Procedure for emergency steering is: 1. Establish communication with the bridge. 2. Switch over to local control on all starter cabinets. 3. Control the rudder on command from the bridge by operating the pilot valves on the main valve block, see Figure 3.2. 4. Activate the pilot for main spool, then the pilot for idling valve. 5. When rudder is at given order, release the pilot for idling valve and then the pilot for main valve. The pressure will increase to relief valve setting if only the idling valve is activated. Applications of Refrigeration Systems on Board Ships: 1. Food Preservation. Refrigeration systems are vital for preserving perishable food items during long voyages. They maintain low temperatures in onboard refrigerated rooms or containers, preventing food spoilage and ensuring fresh provisions for the crew. 2. Cargo Preservation. Refrigeration is also used to maintain specific temperature conditions for certain cargo types, such as pharmaceuticals, chemicals, or perishable goods like fruits and vegetables. This ensures the quality and integrity of the cargo throughout the voyage. 3. Air Conditioning. Refrigeration systems provide air conditioning for various areas onboard, including crew cabins, control rooms, and passenger lounges. They regulate indoor temperatures and humidity levels, enhancing crew comfort and ensuring optimal conditions for equipment operation. Thermostatic Valve Operation in Refrigerating Systems: A thermostatic valve regulates the flow of refrigerant in the system based on temperature variations. It contains a temperature-sensitive element, such as a bulb filled with gas or liquid, connected to the valve mechanism. When the temperature deviates from the setpoint, the element expands or contracts, modulating the valve opening to adjust refrigerant flow accordingly. This maintains the desired temperature within the system by controlling the amount of cooling capacity delivered. AUTO Offset: Offset refers to the difference between a setpoint and the actual value of a controlled variable in a control system. It indicates the deviation that needs correction for the system to reach the desired operating condition. Proportional Band (PB): Proportional band defines the range of error values within which proportional control action occurs in a control system. If the PB is too wide, the system may exhibit sluggish response and overshoot, leading to oscillations or instability. Conversely, if the PB is too narrow, the system may be overly sensitive, causing frequent adjustments and potential instability due to excessive control action. Reverse Power Relay: A reverse power relay is a protective device used onboard ships to prevent damage to generators in case of reverse power flow. It monitors the direction of power flow between a generator and the power grid. If the generator starts consuming power instead of supplying it (indicating abnormal conditions like a blackout), the relay trips to disconnect the generator from the grid, preventing potential damage. Preferential Trip: Preferential trip settings prioritize the isolation of specific electrical circuits or equipment during fault conditions to maintain critical services or prevent cascading failures. They are programmed to trip selected circuit breakers or disconnect switches based on predefined criteria such as system importance, safety considerations, or operational requirements. NAV ARCH Elevation and Plan View: In naval architecture and engineering, elevation refers to a view of an object or structure as seen from one side, showing its height and width but not depth. Plan view, on the other hand, shows the object or structure as seen from above, illustrating its length and width but not height. These views are essential for designing and visualizing ship structures and systems. Main Types of Longitudinal Stress: The two main types of longitudinal stress experienced in ships are tensile stress and compressive stress. Tensile stress occurs when forces act to stretch or elongate the material, while compressive stress occurs when forces act to compress or shorten the material along its longitudinal axis. Both types of stress can affect the structural integrity of the ship, particularly in areas subjected to bending or axial loading. Types of Stresses Experienced Onboard: Onboard ships, various types of stresses are experienced, including: 1. Structural Stresses. These include loads and forces acting on the hull, superstructure, and other components, such as bending, torsion, shear, and hydrostatic pressure. 2. **Operational Stresses. These result from the ship's motion, propulsion, loading conditions, environmental factors (e.g., waves, wind), and operational activities (e.g., cargo handling, maneuvering). They affect equipment, systems, and crew performance. Difference Between Flare and Tumblehome: - Flare refers to the outward curvature or widening of a ship's hull towards the upper sections above the waterline. It enhances stability and buoyancy, especially in rough seas, by providing more reserve buoyancy and preventing excessive rolling. - Tumblehome, in contrast, describes the inward curvature or narrowing of a ship's hull towards the upper sections above the waterline. It can reduce the ship's resistance to waves and improve hydrodynamic performance but may sacrifice some stability compared to a flared hull design.
ELECTRO Possible causes if the Direct-on-line circuit is not turning on (troubleshoot) If a Direct-On-Line (DOL) starter circuit is not turning on, there could be several possible causes: Power Supply Issues: Check if there is proper power supply to the circuit. This includes verifying the voltage levels and phase connections. Overload or Short Circuit: The overload relay might have tripped due to an overload or short circuit in the motor or wiring. Faulty Contactor: The contactor could be faulty or damaged. Inspect for physical damage or signs of burning. Wiring Errors: Incorrect or loose wiring connections can prevent the circuit from functioning. Ensure all connections are secure and correct. Faulty Motor: The motor itself might be faulty. Check for signs of damage or wear. Control Circuit Issues: Problems in the control circuit, such as a faulty start button, stop button, or control relay, can prevent operation. Thermal Overload Relay Tripped: The thermal overload relay might have tripped due to excessive heat or overload conditions. Fuses or Circuit Breakers: Blown fuses or tripped circuit breakers can cut off the power supply to the circuit. Emergency Stop Activated: If there's an emergency stop button in the system, ensure it hasn't been activated. Environmental Factors: Extreme environmental conditions like moisture, dust, or temperature can affect circuit components. TROUBLESHOOTING: - Use Personal Protective Equipment. - Use Lock-in/ tag-out to isolate the system. -Power Supply: Check the power supply to the circuit. Ensure that there is a stable and sufficient voltage supply. - Overcurrent Protection: If there is tripped or blown fuse or circuit breaker, investigate the cause of the overcurrent and replace the fuse or reset the circuit breaker. - Inspect the contactor, which is responsible for making and breaking the power circuit. - Check the motor windings for any faults or short circuits. Use a multimeter to measure the resistance across the motor terminals. - Examine the wiring connections throughout the circuit. Look for loose connections, damaged insulation, or incorrect wiring. - Use a multimeter to check the continuity of various components in the circuit. - Check the health of the motor separately by connecting it to a known good power source. Possible causes if the Wye-Delta circuit turns on but turns off shortly thereafter (troubleshoot) If a Wye-Delta (or Star-Delta) starter circuit turns on but then turns off shortly thereafter, several issues could be at play: Timer Issues: The timer that controls the transition from the Wye (Star) to the Delta configuration might be malfunctioning, causing the circuit to turn off prematurely. Incorrect Wiring or Connection: If the wiring or connections between the Wye and Delta configurations are incorrect, it can cause the circuit to fail after initiation. Overload Protection Tripping: The overload protection might be tripping due to an actual overload or a fault in the protection system itself. Faulty Contactor: If any of the contactors (for Wye or Delta) are faulty, they might not be able to maintain the circuit after the initial start. Phase Imbalance or Loss: A loss or imbalance in one of the phases can cause the system to shut down after starting. Motor Issues: Problems with the motor, such as winding faults or mechanical issues, can lead to an automatic shutdown after start. Control Circuit Problems: Issues within the control circuit, including faulty relays or switches, can disrupt operation. Thermal Overload Relay: If the thermal overload relay is overly sensitive or faulty, it might trip unnecessarily. Environmental Factors: Excessive heat, moisture, or dust can impact the components, leading to malfunctions. Voltage Fluctuations: Significant fluctuations in supply voltage can affect the performance and stability of the starter circuit. TROUBLESHOOTING: - Use Personal Protective Equipment. - Use Lock-in/ tag-out to isolate the system. - Check if the motor is overheating. Overheating can trigger thermal overload protection, causing the motor to shut down. - Verify the stability and adequacy of the power supply to the motor. - Examine all wiring connections in the Wye-Delta circuit. Check the wiring against the circuit diagram to ensure correct connections. - Check the control circuit components, including relays, timers, and contactors. - If the circuit includes timers for transitioning between the Wye and Delta configurations, check the timer settings. - Isolate the motor from the control circuit and test it independently. - Ensure that the setup and configuration align with the specifications provided by the manufacturer. AUXMACH Purpose of Ballast System The ballast system on a ship serves several crucial purposes: Stability: The primary function of a ballast system is to provide stability to the ship. By adjusting the amount and distribution of ballast water, the center of gravity is lowered, which enhances the ship's stability, especially when it is not carrying cargo or is lightly loaded. Trim and List Adjustment: Ballast water can be adjusted in different tanks to change the ship's trim (its longitudinal inclination) and list (its lateral inclination). This is essential for optimal navigation and maneuverability, and to ensure the propeller and rudder are adequately submerged. Structural Integrity: Maintaining proper ballast helps to avoid excessive stress on the ship's structure. Without proper ballast, the ship could bend or suffer structural damage, especially when sailing through rough seas. Safety: Proper ballasting contributes to the overall safety of the vessel, reducing the risk of capsizing in adverse conditions and ensuring safe operation. Operational Efficiency: Correct ballasting can improve the hydrodynamic efficiency of the ship, reducing resistance through water and thus saving fuel. Loading and Unloading Operations: During loading and unloading, ballast water is adjusted to keep the ship stable and at the correct height relative to the dock or loading equipment. Draft Management: Ballast water is used to maintain or alter the ship's draft (the vertical distance between the waterline and the bottom of the hull). This is particularly important when navigating through shallow waters or entering and leaving ports with depth restrictions. Q and H in a Pump Head In the context of pump performance, "Q" and "H" are critical parameters: Q - Flow Rate: - Definition: "Q" stands for the flow rate, which is the volume of fluid that the pump can move in a given period of time. "Q" stands for the pump flow rate and is typically measured in units such as gallons per minute (GPM) or cubic meters per hour (m³/h). It represents the volume of fluid (liquid) that the pump can move through the system in a given amount of time. - Units: It is typically measured in cubic meters per hour, gallons per minute (GPM), or liters per second. H - Head - Definition: "H" represents the head, which is a measure of the energy or pressure imparted to the fluid by the pump. - Concept: The head determines how high the pump can lift the fluid and is a key indicator of the pump's ability to overcome resistance (caused by gravity, friction, etc.). - Units: It is usually measured in meters or feet. - "H" stands for pump head and is measured in units such as meters or feet. Pump head is the energy imparted to the fluid by the pump, resulting in the elevation or pressure of the fluid. It represents the height to which the pump can raise the fluid or the pressure it can generate. The relationship between flow rate (Q) and head (H) in a pump is often depicted by a pump performance curve. This curve, commonly known as a pump characteristic curve, illustrates how the pump performs at different operating points.
AUTO In marine engineering, "MC" and "ME" refer to two types of marine diesel engines, each with distinct features related to automation and control: MC Engine (MAN B&W MC Series) Type: These are two-stroke diesel engines. Control: MC engines are mechanically controlled. Their fuel injection and exhaust valve operation are driven by traditional mechanical systems. Characteristics: They are known for robustness and reliability. The mechanical systems, while less sophisticated than electronic controls, are easier to maintain and repair, especially in remote or harsh marine environments. Automation Level: While they incorporate some level of automation for essential functions, they rely heavily on mechanical processes and manual intervention for operation and adjustments. ME Engine (MAN B&W ME Series) Type: These are also two-stroke diesel engines. Control: ME engines are electronically controlled. They use an electronic control system to manage fuel injection and valve timing. Characteristics: These engines offer greater fuel efficiency, lower emissions, and improved operational flexibility compared to mechanically controlled engines. The electronic control allows for precise timing adjustments, optimizing performance. Automation Level: They have a higher degree of automation, with sophisticated systems for monitoring and adjusting engine parameters. This results in better performance management, diagnostic capabilities, and ease of integration with other shipboard automated systems. Importance of Calibration Accuracy and Consistency: Calibration ensures that sensors, controllers, and other measuring instruments in automated systems provide accurate and consistent results. This is crucial for maintaining the quality of the output and for ensuring that processes run as intended. Safety: In automated systems, especially in industries like chemical, oil and gas, and manufacturing, accurate measurements are critical for safety. Misreadings due to uncalibrated equipment can lead to hazardous situations, including accidents or system failures. Process Efficiency: Well-calibrated instruments ensure that processes are running at optimal efficiency. For example, in an automated production line, calibration of sensors ensures that the right amount of material is used, temperatures are maintained correctly, and timings are adhered to, which saves time and resources. Compliance and Standards: Many industries are governed by strict regulatory standards that require precise measurements. Regular calibration is necessary to comply with these regulations and to pass audits and inspections. Data Integrity: In an automated system, decisions and adjustments are often made based on data from sensors and instruments. Calibration ensures the integrity of this data, which is vital for maintaining the reliability of the entire system. Extended Equipment Life: Regular calibration can help in identifying potential issues in instruments before they turn into major faults, extending the lifespan of these devices.
A DC (direct current) motor is an electromechanical device used on ships for various functions. It converts electrical energy into mechanical energy and finds applications in propulsion systems, thrusters for maneuvering the ship, winches and cranes for lifting and handling tasks, pumping systems for fluid transfer, ventilation systems for airflow, and hydraulic systems for power generation. DC motors offer advantages such as high starting torque, good speed control, compact size, and robustness. However, they require a DC power source. It's worth noting that modern ships may also employ alternative propulsion systems like AC motors or hybrid systems based on specific requirements and efficiency considerations.
1:09 why do i suddenly find his SHUT UP so funny 😭☠☠☠
I thought this was Japanese dub not Japanese speedrun through battle dialogue dub
"Should I restart the recording after that siren ruined it? Nah its ok I'm sure they can barely hear it."
This was interesting. I only got ending A and I was like screw it. Haha I just want to watch all the endings. So turns out it's no happy ending for them. 😢
w w w
thanks Lappy!
Kaneki???
i hope we get a sequel soon. it would be lame if they left us in this cliffhanger of an ending. i wanna see what else they can do with 2b, 9s and A2
We wont the nier series is officially over although now the cannon sequel is Ff xiv yoRHa dark apocalypse cuz yoko taro liked it that he made it cannon lol
There is a sequel, it's a mobile game and an audio drama in an orchestra concert And if they double down on the timeloop theory, then the anime adapatation is a "sequel" too
best game ever, the story and epiphany behind is absolutely profound it's like i have read a book instead of a game, and the design of E end is fking epic, unifying players around the world to fight alongside each other is just the ultimate human fable
I know everyone is 2B this, 9S that... but I'm just happy for A2.
Shit don't work now. Tried several times
what?
the best game.. Masterpiece of art
Randomly checking out your videos 😂 barret always loud
Walking megaphone
What is with the sirens? Lmao. Is crime getting bad in Gridania???
I HEAR THEEEEEEEEEEE
Yours is the only video that actually helped my smooth brain out. Appreciate you👌🏽
kaneki-kunnn !!
LOL TANJIRO
Is it bad that it felt good for me to see 9S die ? God I hated him.
You don't understand him, you probably haven't had any traumatic experiences in your life or have experienced the loss of a very important person in your life.
@@ddyiotdyi "yOu DoNT UndErstAnd HiM" No I do, doesn't change the fact that he's still fucking annoying and I hate his character and it felt good to see him die.
@@afinoxi Are you fucking serious? No you don't understand him and you don't understand how you hurt me and all of other people who suffer from PTSD by calling him "annoying" stfu bitch you're probably 11
Did she have long hair or short one? I’m confused @_@
She had long hair but then cut it after killing 2B
@@strmwvealpha1140 I thought so too but look at 2:44 . I guess they forgot about that A2 cut her hair.
@@fatetastarossa You can customize the hair in the game