George Westinghouse Jr. patents the automatic railroad air brake.
Before the air brake, railroad engineers stopped trains by cutting power, braking their locomotives, and using whistles to signal their brakemen. The brakemen turned the brakes in one car, jumped to the next to set the brakes there, then jumped to the next, and so on. The system was dangerous (many brakemen died or were maimed), imprecise (the train might stop before or after the station), and unreliable (the train sometimes didn’t stop until it ran into another train or something else on the tracks). Accidents were frequent and deadly (see here).
Westinghouse’s first version of the device, the straight or direct air brake, used air hoses to connect the cars. When the engineer applied the brakes, air pressure turned the brakes on in each car of the train. Of course, if the hoses leaked or were disconnected, the train lost braking power.
With air brake 2.0, Westinghouse turned things around. Air pressure kept the brakes off. The engineer reduced pressure to apply the brakes. This built-in safeguard meant the brakes’ losing pressure stopped the train automatically. That held true whether pressure dropped due to leakage or to cars coming unhitched; loose cars would brake to a stop. The system debuted in 1872 on the Pennsylvania Railroad. Automatic air brakes were soon adopted around the world. They were safer and more precise, and now that trains could be reliably stopped, railroads could operate at higher speeds. Air brakes are also used today on trucks, buses, and even amusement-park rides.
Westinghouse also invented electrical signals that saved lives by keeping two trains from occupying the same block of track. He bought Nikola Tesla’s patents for alternating current and demonstrated its superiority over Thomas Edison’s direct current (see here). And he founded the Westinghouse company.—RA