When I come across a tough door during conventional forcible entry, the NY Roof Hook saves me. The NY Roof Hook is 6ft long (72 inches), and it acts as a big leaver to increase my force.
For example, the effort arm on this lever would be 72”, and if I divide that by the resistance arm of 2”, we would get a 36:1 mechanical advantage with this tool (72/2=36). Let’s say I can put 100 pounds of force into the roof hook… it would multiply that into 3600 pounds of force! (approximately). Try it out and see for yourself!