Great Documentaries's video: Westinghouse - Chapter 21 - Union Switch and Signal

(NARRATOR) Westinghouse made tremendous advances in the areas of railroad signaling and interlocking. The Union Switch and Signal Company, regarded as one of his least glamorous but most important companies, was founded in 1881. (SKRABEC) A lot of people remember the air brake. They don't remember all the work that Westinghouse did with switching and signaling. You had trains on the same track. They had to pick up signals. They had to make switches. The tracks had to be manually switched a lot of times so the trains wouldn't collide. (NARRATOR) Signals tell a train when to reduce speed, when to stop, and when to start, when to proceed under control, and when to go ahead at full speed. (SKRABEC) The railroads weren't too interested in it. It was a safety issue, you know, and they weren't really -- just like the brakes. They didn't come on stream with that. Westinghouse sort of pushed that. He saw a need. (NARRATOR) Interlocking provided control and operation of switches and signals so that they moved in certain sequences. It was said that if a man were blindfolded and pulled levers at random, he could stop traffic, but he could not produce a collision. (REIS) So they were using air to switch tracks. It was new at the time. They were also using electric current down the railroad tracks so they could tell where the trains were without having an observer in a tower, which had a major impact on the ability to move lots of trains through heavy traffic areas. So those two items alone had a major impact on the railroad industry. (NARRATOR) Another of his lesser-known inventions was the steam heater, which used steam from the locomotive to warm train cars in the dead of winter.