BC Transit – Air Brake Course

Combining mechanical advantage to achieve force multiplication.
Air
pressure
at 100 psi.
3000 lbs
of force
Slack adjuster - 6 ins. in length
100 psi
Brake chamber - 30 sq. in. diameter
18,000 ft.-lbs.
of force
here!
“S” cam
1 inch in
length
100 psi is exerted against a diaphragm 30 sq. ins. in area inside the brake chamber
pictured here. 30 X 100 = 3000 lbs. of force! Times that by the length of the slack
adjuster (lever) and the total force is… 18,000 ft-lbs. of force.
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