Patent No. 124,405: Automatic Railroad Air Brake
Before the Westinghouse's patent for the air brake, railroad engineers would stop trains by cutting power, braking their locomotives and using the whistle to signal their brakemen. The brakemen would manually turn the brakes in one car at a time - jumping from one car to the next until all the brakes were set. The system was dangerous. Brakemen often died or were maimed by the imprecise system. The train might stop too soon or too late for the station. The system was so unreliable that the train wouldn't stop at all or would stop by literally running into another train or anything else left on the tracks. Before air brakes, railroad accidents were frequent and deadly.
Straight or Direct Air Brake
Westinghouse's 1869 version, the straight or direct air brake, used air hoses to connect the cars. When the engineer turned on the brakes, air pressure turned the brakes on in each car of the train. Of course, if the hoses leaked or disconnected, the train lost braking power.
Automatic Railroad Air Brake
With the 1872 version, Westinghouse changed the entire industry. Air pressure kept the brakes off. The engineer reduced pressure to put the brakes on. This built-in safeguard meant a loss of pressure would stop the train automatically. That applied to leakage and to the situation where cars came unhitched: Loose cars would brake to a stop. The system went into use in 1872 on the Pennsylvania Railroad.
Automatic air brakes soon gained widespread adoption around the world. They made braking safer and more precise and allowed railroads to operate at higher speeds, now that trains could be reliably stopped.
Still In-use Today
Air brakes are used today not only on railroads, but for large trucks, buses and even amusement-park rides.
About George Westinghouse Jr. (1846-1914)
Westinghouse was one of the great inventors of the 19th century. He also created life-saving electrical signals for railroads that kept two trains from occupying the same "block" of track, a rotary steam engine and devices for transporting natural gas. He bought Nikola Tesla's patents for alternating current, electrified hundreds of towns and demonstrated the superiority of AC over the direct current favored by Thomas Edison. And, of course, he founded the company that bears his name.