the frame around the sign prevents people from walking up behind the sign, and spray painting / putting graffiti on it.

@fostermatt80

8 жыл бұрын

Came to say the same thing. You beat me to it.

@PracticalEngineeringChannel

8 жыл бұрын

Didn't even think of that. Thanks!

@AIM54A

8 жыл бұрын

Beat me to it. You can see the paint patch marks on the frame work where taggers where painted over.. They work well. Though I think an electric cow fence wire wrapped around the pole might be more effective.

@howardwhite9773

8 жыл бұрын

Lot's of highway signs in SoCal with razor wire wrapped strategically to deter would be artists.

@PlasmaHH

8 жыл бұрын

not at all, those people know how to use sidecutters...

"about as good as it can feel to find out your life calling is talking about infrastructure to people on the internet" - that's one of the most honorable callings I can think of. This is stuff we rely on everyday and if you don't teach us about it in a fun, well communicated way, who will? Already in love with this series, don't stop!

@PracticalEngineeringChannel

8 жыл бұрын

Haha thanks Jon! I'm really glad that so many people find this stuff interesting.

Look up Davis California Frog Tunnel. We built a great tunnel to help frogs get under a freeway. The issue became that birds are smart. They quickly figured out that the tunnel was like a food dispenser. All the frogs got eaten but we still have the toy village at the entrance by the post office.

@PracticalEngineeringChannel

8 жыл бұрын

Hilarious. Sometimes even projects with the best intentions have unintended consequences.

@oogrooq

8 жыл бұрын

+Practical Engineering An LED stoplight got installed in Idaho to save energy but failed to melt the accumulated snow once winter hit.

@raffriff42

8 жыл бұрын

In Florida, the Cross Land Bridge over Interstate 75 is mostly for wildlife migration but also used by hikers and mountain bikers. From below it looks like a bridge, but from above you can see it's landscaped like a park.

@lukeyluke9637

6 жыл бұрын

chumbuckery777 taking care to make sure the nature wildlife isn’t crushed to death by cars isn’t being a “wacko”. These animals need to more freely too, and if we can do it at a minimum cost using under-road culverts, Why not?

@NicholasLittlejohn

5 жыл бұрын

@@PracticalEngineeringChannel Check out the Vancouver Washington land bridge that includes a museum and nature.

The pistons that lock up are called hydraulic snubbers. They move easily with small slow displacements but they lock up with large and fast ones

@TF2BackburnerNoob

6 жыл бұрын

No, they use a damper-rod style damper. This means that a piston basically forces oil through a small orifice. Since the flow of oil is relative to the v^2 of the piston, with flow being reduced at higher velocities, faster movement is "locked out". No need for a non-Newtonian fluid.

@KenDunnUSNA87

5 жыл бұрын

So, @@TF2BackburnerNoob, this isn't different in principle from an ordinary shock absorber in a car, i.e. force is merely resistive & proportional to speed? If so, it's the same "dashpot" model many engineers used & learned about in modeling classes. That'd make it simple to engineer as well as cheap (relatively) to make.

@TF2BackburnerNoob

5 жыл бұрын

@@KenDunnUSNA87 Yes you are absolutely correct. That's the whole point of engineering right? Make the most suitable solution for the lowest possible cost. Actually, these fixed orifice dampers are bad for handling in cars; they will always be either overdamped or underdamped due to the relationship between damping and velocity. Low (shock) velocity events such as braking will have a lower damping force, causing brake dive and sometimes a "pogo stick" effect. On the other extreme, high velocity shock movements caused by potholes and the like result in overdamping, leading to a harsh ride and even loss of traction. High performance vehicles get around this by having compression and rebound controlled by different valves, and these valves vary their diameter based on the shock velocity via springs and clever plumbing. Till the day of driving bridges though, I don't think it matters, and the fixed orifice dampers are more than sufficient :)

the 11foot8 bridge has laser over-height indicators as well

@christophervanerp1133

7 жыл бұрын

not that it works, though.

@lukeyluke9637

6 жыл бұрын

Sir Arch Duke Reginald The Fourth a sign saying “overweight must turn” is activated, as well as the green light turning red, when an over height vehicle is detected. This happens way before it hits the bridge.

@Twee877

4 жыл бұрын

They actually fixed it now by digging down and lowering the road

@MonkeyJedi99

4 жыл бұрын

I have seen a couple places in Massachusetts where there will be a hanging sign before a low bridge and the sign reads, "I you hit this sign, you will hit that bridge"

@Jehty_

4 жыл бұрын

@@Twee877 since they "fixed" it there were already 3 accidents in 3 months.

I would love to see a time lapse of bridges moving over the day.

I don't have anything constructive (hahaha) to add to the information in the video, because I'm a biomedical/mechanical engineer and not a civil engineer, but I just want to say I find these videos fascinating. I'm so glad someone has taken it upon themselves to make really well produced and digestible videos about engineering. Before college I really didn't know that I wanted to be an engineer, and I took a huge chance going to an engineering school. I got lucky and found out that it was perfect for me, but I would have loved to watch videos like this beforehand to give me a sense for the type of thinking that goes into engineering. Thanks again, and keep it up! Videos like these may not get the same attention as those awful drama videos that go around youtube, but you're doing a real service to your viewers by creating educational and entertaining content like this!

@PracticalEngineeringChannel

7 жыл бұрын

Thanks this is really kind. I was in the same boat as you. Never exposed to engineering when I was a kid. It took me a while to find my way to it.

@arthas640

4 жыл бұрын

i love these videos since nobody ever pays attention to this sort of stuff. As someone who's been in construction since they were 14 and from a family who's been in construction since at least the 1800s I can say that if we do our job right the average Joe never has to think about any of it. Like you never notice lights in a building unless they dont work, you only notice roads if they're too small or have potholes, and you only notice a million other things by their absence.

@2:43, my guess is to prevent hoodlums from climbing up to the sign and spraying graffiti on it. living in SoCal i've seen other preventative measures like this along the lines of barbed wire blocking access to the sign.

@brianmangan2459

8 жыл бұрын

yup, antigrafiti barriers.

@coledarr

8 жыл бұрын

Yep, graffiti deterrent. I've heard from law enforcement that the taggers will work in a group and hang people over the ledges by holding onto them.. nice way to fall into the road.

@dylanmckeithen4281

7 жыл бұрын

That was my first thought too, but I've seen many other signs without any kind of protection and others that do have the angled guards that are no where near any kind of pedestrian access. So if it is graffiti protection, then it's definitely not very consistent.

@shannontheblack

7 жыл бұрын

glare protectors. glare between signs from sun is a pain in the ass

@The1Helleri

7 жыл бұрын

That's probably because it would be costly to do this to all signs. They probably only do it to the signs that they have had problems with in the past. And taggers that go to this extreme are part thrill seeker. It makes sense that a group of taggers who want a challenge would target something hard to access and highly visible.

Its nice to see that you enjoy making these videos and are rewarded for all the work you put into them. I have nothing to do with engineering, yet i really enjoy learing new information from someone who sounds like hes constantly smiling. Keep up the good work.

Thank @TomScott for the support. I've been waiting for a channel like this.

I've been waiting for this next episode forever

@srenkaas4654

8 жыл бұрын

yes

The shades around signs are indeed hoodlum guards. They've put a few up here in Phoenix where signs have been vandalized repeatedly.

@user-ky6vw5up9m

5 жыл бұрын

I love the description “hoodlum guards” so American 😀

@knockhello2604

5 жыл бұрын

What?...

@58209

4 жыл бұрын

@@user-ky6vw5up9m if by "american" you mean "racist"

@anonymoususer638

3 жыл бұрын

@@58209 american isn't a race, but i do agree their reply is ignorant as all hell since "americans" litteraly consist of thousands of different cultures

@spambot7110

3 жыл бұрын

also known as "a challenge"

I used to work for a company that made and installed parking garage systems (gates, ticket machines, software, etc), and also installed the vehicle-detecting loops in the concrete which worked like the detection loops for stoplights. They sense metal near the loop to trigger the control electronics. I remember being told that the best place to trigger them is on the corner of the loop, so that might help with motorcycle detection. An interesting problem is that these loops sense metal above or below them... so in multi-level parking ramps, a loop in the concrete could be triggered by a tall vehicle driving by on the floor below. If this is a problem they can add a metal grate/mesh to minimize detection on that side.

4:19 A thin sheet of lead were oftentimes found under the rocker assembly during bridge restorations. The lead was removed & isomeric bearing pads of laminated steel plates housed in hard rubber were welded to the beam's upper flange, while the lower plate below received a Teflon coated surface slide, mounted to the top of the concrete abutment cap... which was blast cleaned & receive a 10 mil. coating of type X white epoxy coating to insure no moisture would penetrate the re-bar below it. TXDOT Inspector of new const. '86 - '96 9417

We have a number of tunnels here in LA where they vary the artificial lighting. Numerous bright lights in the beginning, fading into sparse lighting by the end to aid the transtion

@arthas640

4 жыл бұрын

They do that alot in stores too, it's called daylight dimming or photosensor dimming or about a million other things. Basically theres a photocell (a light sensor) that has built in dimmer and when they sense light they dim the lights in different zones accordingly. In some cities like Seattle they're making it required for areas around windows to have them so that way they reduce power consumption and they often have multiple zones near each window or door or similar areas. It also helps reduce eye strain and light pollution to a degree.

@Milosz_Ostrow

2 жыл бұрын

Are the lights near the tunnel portals reduced in intensity at night when drivers' eyes are dark-adapted? Having tunnel lights that are too bright could cause safety issues at night, just like having tunnels that are too dark can cause issues in daylight.

I never been interested in civil engineering before but since I discovered your channel few months ago, I am really in love with the ingenuity that exist in this field.

totally love the 11foot8 channel. warning sign, red light and they still go through. the best are the RVs that have their air conditioning units just scraped off the top.

In Colorado, we run different intensity lighting, sometimes as simple as just different spacing of the lights, as you enter and exit the tunnel to try to help the drivers' eyes adjust. There's even a second set of lights specifically for nighttime driving in a few of the tunnels with newer lighting systems.

This series is like my dream. One of my friends and I like to geek out on the HVAC systems in buildings. I'll dig through my phone photos for interesting infrastructure to send in!

Rollers and rockers on bridges allow the bridge to adapt to dynamic loads in additon to dealing with thermal expansion. As vehicles move across, the bridge will flex and move in the rollers. Thanks for the videos, I look forward to the next one!

The angled shield around the sign gantry is there to stop people tagging the sign. They generally get used when signs are mounted on bridges, particularly if said bridge has a footpath.

I wish more people were fascinated with the underlying engineering that literally drives our world. I stopped this video every few seconds to show my girlfriend all the ways bridges are designed to cope with expansion. She enjoys some science and engineering but I think I just bothered her more than fascinated her 🤷🏻‍♂️ As a Network Engineer I particularly enjoyed your wireless infrastructure video (my only complaint is that I wish it was longer to be more in depth!) but I love all engineering that supports and enables our man made world. As a fellow nerd I’d love to see more “What’s that Infrastructure” videos!

I drive through that tunnel in Sweden almost daily. I've never considered the sun-shade thingie...

@1978rockon

4 жыл бұрын

Finns tex även före och efter Gårdstenstunneln på Angeredsbron.

Another awesome video, Grady. I love your channel and have watched pretty much every video you have uploaded. You have a gift for explaining things in an insightful and entertaining way. You make me proud to be an engineering student and I hope that one day I'll have half as many awesome projects going on in my life as you do. Please keep up the good work and stay out of the heat!

@PracticalEngineeringChannel

8 жыл бұрын

+Smatt1996 Thanks! This is really kind.

from some one who stumbled on to your channlea few years ago, who liked the topic but was clueless... well ive learned a lot and that all thanks to you. cant wait to get my hands o na copy of yoru book . thnaks.

so excited that you decided to do this series. keep it up.

Actually, the 11foot8 bridge (now 11 foot 8 inches plus 8 inches) has a laser-detection system for overheight vehicles approaching the bridge, and then triggers a red light and flashing "overheight" sign at the intersection, giving the overheight vehicle time to go around. The sacrifical steel beam is only used as a last resort.

this is the first of your videos I have just seen, I have to admit that I found that truly fascinating! I'm subscribing purl because I love learning about technical and mechanical engineering!

I'm studying​ civil engineering in Sweden and you just reminded me why I made that choice. I literally have goosebumps from your videos! Thank you for making these videos!

From one Civil PE to another (hoping you passed your exam), I love your videos... and the quirky humor! Your's is the first youtube channel to which I've subscribed. Keep the cool videos coming!

waaaaaau, great idea and series, keep it up, love to see more from viewers with your commentary...

This scene brings back some bittersweet memories. This stretch of highway is about eight miles north of Sylmar (Los Angeles), California, and winds around down into the San Fernando Valley, turning into the "Golden State Freeway". In 1971, a massive earthquake in this area caused violent shaking and widespread damage to the communities of Sylmar and San Fernando. The powerful M6.6 temblor was felt as far away as Bakersfield and San Diego.

Big win. I hope this series goes for many seasons.

OMG, I love infrastructure documentaries and vids. I'm gonna binge tomorrow on day off.

awesome content, I was never interested in civic engineering, but you make it so accessible I'm a huge fan.

This is the coolest series I've encountered! :D I'd love to watch something about submarine cables and cable landing points.

Another interesting video, I always enjoy seeing the 'hidden' side of every day modern infrastructure and the creative ways people solve problems like these. For some reason I find it incredibly inspiring and it gives me hope for the future. Good luck on your exam and I look forward to seeing the next video when you get a chance!

@PracticalEngineeringChannel

8 жыл бұрын

Thanks!

I live in Grand Forks where the Sorlie bridge is. That bridge from MN to ND is extremely old (30's) and takes a brutal temperature (-40 to 105) and flood currents yearly. I have seen the thing completely submerged several years. I cannot believe it is still around.

@arthas640

4 жыл бұрын

I feel the same way about some bridges in the Pacific Northwest. I drove over a no-name bridge awhile back near the Hoh Rainforest in Washington and it has to contend with an acidic environment from the soil and nearby cedar trees (the sap is worse than salt), regular floods, minor earth quakes, snow/ice, and annual rainfall that averages around 140 inches but a few miles away (upriver) it rains over 180 inches a year and I've heard of it getting as much as 260 inches in a year.

What a neat series! Please make more.

Best of luck on the PE! That's a huge commitment

In my city, theres a "warning system" (if you can call it that) thats a sheet metal with yellow and black paint suspended about 3m before the bridge. if you hit it with the truck, it makes a very loud noise but causes no actual damage to it, as is suspended by chains, but its heavy and big enough for them to feel the impact aside from the loud noise. Its on a low speed street tho.

@arthas640

4 жыл бұрын

there are similar system in rural areas where i live, simialr to what you see in some drive through fast food places they'll suspend a brightly colored pipe by chains so if your vehicle is too tall it will clank against your vehicle to let you know your about to lose your roof.

Your supercool and I love your passion towards engineering! It’s freaking Osum! I wish I found your Channel 2 Years ago and participated in this series anyways you rock 🤙🏻🙌🏻❤️

3:11 It's funny how much that magnet costs just because it's called a "Red Light Changer."

@IamR3D88

4 жыл бұрын

I guess other places may vary, but here a motorcycle can run a red light after 2 mins. Otherwise there are many around town I would get trapped at during nighttime.

@IamR3D88

4 жыл бұрын

@@Bashfulvideos1 yea, it's in the Illinois rules of the road book. You must wait 2 mins, if it doesnt change by then, you proceed with caution.

@LaserFur

4 жыл бұрын

But the sensors are not magnet detectors. they are AC induction detectors. so a loop of heavy copper would be better.

@KuraIthys

4 жыл бұрын

Makes sense. since I have an interest in it and have tried to get such jobs in the past, I know some trains follow the same logic. The wait time is longer though. I believe in germany if a train has been at certain kinds of red signals for 45 minutes you can pass it, but only at very low speeds...

As others have said, the guard around the freeway sign is to prevent graffiti artists from reaching it. It is more expensive than barbed wire, but more effective, and that is a major interchange entering the LA basin, so probably has been a favorite target for graffiti, so they invested in the guard after years of the sign being obliterated. I will be driving under it tomorrow, and will try to remember to look at it lol

The way you described the pistons (4:56) sounds like a shock transmission unit, which is designed to allow some motion, but work to tie the pieces of the structure together from large motions. A similar looking technology used in the same place for a similar purpose is a viscous damping piston for dissipating earthquake energy. They are designed to move during the strong motion event and the internals deform plastically converting a lot of the motion energy to heat. Those have been used in a lot of bridge retrofits in California, for example.

@PracticalEngineeringChannel

8 жыл бұрын

Very cool. Thanks for sharing more info. I'm not a seismic guy so I do my best on that stuff ;)

This video is great! It inspired me to do the small research project I had to do for school on bridge expansion joints. I'm loving this series, keep up the great work:)

@PracticalEngineeringChannel

7 жыл бұрын

Awesome. I hope you got a 100! Thanks for watching.

I love this series! Thank you for doing this

Infrastructure is definitely something we should be more aware of. Thanks for sharing your passion.

This is the first time seeing this vid or any of your vids but it was fun to watch. An interesting structure I had always been fascinated with is the island airport off the coast of Japan. Extremely ingenious how they have utilized the available tech to not only keep the buildings stationary and earthquake resistance but also the airport's support system to stay above water and not sink.

great work as always keep it up!

I was wicked excited when I saw the curved freeway sign because its the sign and highway to my hometown.😁 Amazing Video without a doubt.

You could do a video on the millennium bridge in London. A footbridge (atually an interesting suspension bridge design IIRC) that resonated at the same frequeny as pedestrians walk (not good!). They had to install dampers. The pistons on a bridge in your video reminded me of that.

I'm a CWI Certified Welding Inspector, I really enjoy your videos

I work for a transportation engineering firm and we use these things regularly in our designs. It's cool to know so many people are curious about them.

What a cool and original idea for a series

I love your dry sense of humor. I am constantly laughing through your videos.

Love this channel Brady !

awesome! love this series

Absolutely AWESOME Video 👍

Love the new series! Keep it up

I really enjoy these videos! Keep it up ☺

I love your videos. Keep up the good work.

I believe the angled frame in the California one is to keep people from getting up there and tagging the road sign

looove this series!

We have a few "bat bridges" in the county of Cornwall, England. The bridges are made out of suspended steel wire and netting stretched in a V-shape across the road. According to local media, they were built as part of the bypass project to stop the bats from becoming confused as a result of the hedges' removal.

love your videos great education for those not in the industry

how about putting a coin under one of the roller or rocker supports when there's a temperature extreme approaching, then returning to retrieve it when temperatures reverse? A bit slower than the "coin on the tracks" option, but perhaps no less entertaining.

@TheAechBomb

4 жыл бұрын

I wonder how flat it would get?

@alanowa123

4 жыл бұрын

@@TheAechBomb lets try and check :D

@DANT98

4 жыл бұрын

I was totally thinking the same thing. You'd want to set it down and then come check it a year later I think.

@user-fp4dm6od1b

4 жыл бұрын

It would probably wedge the roller to a stop and the bridge would get damaged because it can`t expand/contract anymore and then collapse. Then in proper American fashion, you would be sued by the people that died, bridge maker, and the US Mint for destroying the coin.

@alanowa123

4 жыл бұрын

@@user-fp4dm6od1b yeah, the same thing is with derailing trains that ran over an coin ;)

I hope you continue to post civil engineering things ,so students persuing degree can take benefit from your practical videos and understand it very clearly . Thank you sir for all efforts that you make, we are getting benfit from your videos.

I can't believe I just randomly stumbled accross a video saying what those giant wheels were for on that Sorlie bridge in Grand Forks, ND. I used to walk under that bridge all the time as a kid and wondered what the hell those wheels were for. I should have guessed they were just for expansion movement. Thanks for the video!

I saw a pivot on an L line bridge the other day and wondered why it would need to pivot there. Thank you for answering my question

I absolutely love your thesis statement “where we divulge and discuss the world around us”

love this series!

Another really cool episode!

I'm late to the party, but i really love this stuff. hated high school but then worked as a machinist for oil and im really interested in all this now. started riding motorcycles and now question how everything works. really wish i had started to get into this stuff before 25, but never to late to learn something new.

the durham nc one has lasers and warnings for over height on multiple blocks, not only that but it changes the light to red while large signs flash warnings above the light for the truck driver to see.

The beveled border around the freeway sign are to dissuade vandals from climbing up behind the sign and reaching over to tag it with paint.

@Nevir202

6 жыл бұрын

lohphat That was what I figured. I started seeing them all over my city and finally realized they were on the signs I’d seen tagged before. But I still wasn’t certain

Keep up the good work. Love the videos.

Infrastructure is fascinating; especially the building of roadways! A hillside is being cut and a bridge built over the river near my town. Generally, six excavators and many dump trucks work at it all day. It's been going on for months! Townsfolk have repeatedly told each other, "If there was a place to sit and watch this process, I'd be there all day." I've teased that I would open a snack stand for everyone's enjoyment. Lol!

Ooooh, PE exam time! I teach an SE exam review course so it's definitely that busy time of year. Good luck!

Another great video! I thought of several things that I’ve seen and wondered… “What in the world is going on there???” Seeing this video answered some of my questions. You should totally keep making videos! I’m from the future and I just saw that your most recent video hit at least #35 on Trending… I don’t think your KZread has trending yet, but it will and you will make the top 50 videos :)

Great video and great idea, I hope to see more episodes

Good luck on the PE! I just graduated as a ME and took it as soon as possible. I'm sure you can attest to all sorts of stuff you totally forgot since you went to school and now have to learn all over again. Definitely the hardest test I've ever taken.

@PracticalEngineeringChannel

7 жыл бұрын

Thanks. In Texas, they just decoupled the experience requirement with the exam, so I _had_ to wait 4 years :/ Lots of studying

Nice job! I subscribed. The thumb nail got me, as I thought it looked like the one one the sorlie bridge in downtown Grand Forks, ND. lol. Next to it is the reminder, center support, of an old train bridge that would pivot to let steam boats go by when the river was flooding. ( That's a story on itself ) they still have one by Oslo MN. On the Red River of the North.

Thanks for that video! It's interesting and I WANT MOAR!!!!

The 11' 8" bridge was raised to 12' 4" and there are videos of the work being done in NOV.2019. It still get a few trucks though!

Interesting. Montréal also has a shade system just before a long tunnel, and wildlife over/underpasses are frequent in Canada. we also have unidirectional moose/deer gates : if a moose/deer happens to reach the highway, they can get back in the forest through a turnstile-type gate, but these gates do not allow them back on the highway.

@4:58 That's actually a Light Rail elevated guideway. Part of the Link Light Rail system here in Seattle. Those pistons are on the opposite ends of a segment of guideway that is fixed (either cast in place or a transition from elevated to ground level) the other end. That specific picture is a segment north of the Seatac/Airport Station.

Great video! A truly interesting series, keep it up!

@PracticalEngineeringChannel

8 жыл бұрын

+Philipp Klein Herrero Thanks!

I need to check where exactly it is but in Germany there's at least one big wildlife crossing above the highway, it's full of grass/plants/trees and the sides are painted with stylized forest and animals. Very cool idea

The angled frame bounced headlights to light up the sign at night. Here in Phoenix, we are using them more often and removing all lights from freeway signs as these make the sigh more visible without the need for lights.

There is a concrete tunnel (culvert) on the side of an expressway in NW Georgia, that allows water to escape from a cave (Hurricane Cave). It doubles as an entrance to the cave for cavers.

There are a lot of those inductive loops in use around central Iowa. When I am riding I have found If I stop my bike right on or very near one of the side lines in the road the light will change. If I sit in the middle I could sit there for hours and the light wouldn't change.

2:40 im a truck driver and ive driven on this particular road several times. That thing around the outside of the sign is a sun shade i believe, this road runs east/west and as you can see behind the sign there is a valley which in certain months of they year the sun can sign straight down. California has a lot of weird signs and things like that.

You can also flash your lights at the sensors next to red lights to get them to change. They look for flashing emergency lights and change the traffic lights when they detect them. Flashing your lights in the correct orientation will set it off and change the lights.

3:07 Ottawa, Canada has 3 yellow dots at some intersections to note the most sensitive spot of an induction loop. Very important for cyclists that don't have dedicated infrastructure.

That broken rebar on the bridge, at 0:18, concerns me. It is in a critical zone that suffers tensile stress, precisely where rebar is most needed. But I digress. As always, a nicely done video. Thumbs up!

The sunshade entrances are pretty standard in Europe. Another solution is a gradual reduction in lighting at the tunnel start to give your eyes time to accomodate. Here in Norway that system is mostly used, because it doesn't need a long extra length to the tunnel ( we have a shitload of short tunnels

I live in Cambridge UK, which is perhaps the cycling centre of the UK. I have put a neodymium magnet on the front fork of my bicycle so that I can trigger traffic lights and it really works.

I believe the LA sign shield at 2:45 is to make it difficult for graffiti vandals to climb out there.

@TechNiVoltisgr3at

8 жыл бұрын

That makes total sense

train tracks on the london underground, they have varying tyes some of which have shock absorbers and vibration dampeners so that passing trains are a) quieter and b) their vibrations dont cause buildings to move.