Westinghouse Automatic Air Brakes George Westinghouses Automatic By William Fischer, Jr., September 6, 2010 2.

Railroad Brakes, also, Westinghouse Automatic Air Brakes...

Railroad Brakes. Early railroad cars had hand-operated brakes.

A lever (and later a brake wheel) near the top of each car applied the brakes only on that individual car.

The engineer directed brakemen to apply or release brakes by whistle signals; crewmen scrambled from rooftop to rooftop, leaping the gap between cars.

An untold number of railroaders died during this terribly hazardous process...

George Westinghouse demonstrated the first practical air brake system in 1868.

A locomotive supplied compressed air to pistons on each car, forcing brake shoes against the wheels.

Westinghouses later Automatic Air Brake was far more fail-safe, as the loss of air pressure due to a system failure, uncoupling, or derailment applied the brakes on all cars automatically.

Cars still have hand-operated brakes, but only for use when cars are not coupled to a trains air line...,,,,,,..

Westinghouse Automatic Air Brakes.

George Westinghouses Automatic Air Brake system, developed in 1872, was railroadings most significant safety advance...

A compressor on the locomotive supplies compressed air to a brake pipe running beneath each car and through flexible hoses between cars.

When the engineer uses his brake valve to reduce pressure in the brake pipe, a valve on each car senses the pressure change and uses the air in the cars reservoir to apply the brakes proportionately.

A 5-10 psi reduction in the brake pipe pressure applies the brakes lightly, while a 20 psi or larger reduction applies the brakes heavily...

The engineer can also make an emergency brake application by moving his brake valve to the emergency, or big hole, position...,,,,,,..

Modern Train Braking Systems.

Trains use two separate air brake systems.

Both use compressed air from the locomotive, and are controlled from the cab...

The engineers automatic air brake valve controls the brakes on both the locomotive(s) and cars.

The automatic brake valve reduces the pressure in the brake pipe connected to each cars air reservoir, applying the locomotives and cars brakes in proportion to that pressure reduction.

On heavy downhill grades, a retainer valve on each car can be manually set to keep the brakes applied...

The independent air brakes are controlled by a separate valve in the cab.

The independent valve only applies the brakes on the locomotive(s), not the cars...

This historical marker was erected by Illinois Railway Museum.

An untold number of railroaders died during this terribly hazardous process.

Cars still have hand-operated brakes, but only for use when cars are not coupled to a trains air line.

Railroad Air Brakes