Westinghouse’s train air brakes: adopted by industry or legislation?

Factual Questions
1

Around the end of the 19th century, brakemen used to risk their lives by going over every wagon and turn the break wheels to stop the train. Many lives were being lost but then Westinghouse invented a pneumatic system to break trains without the need for brakemen.

This is where the history gets murky: some history textbooks I read said that the industry quickly adopted the brakes. The Modern Marvels History Channel documentary on trains was not exactly the same: railway companies decided that the new system, while practical, was deemed more expensive than the old way, so workers continued to die, but so did many passengers. So, people pressed congress and a law was passed to mandate the use of the new brakes. While expensive, the rail companies benefited because a train with pneumatic brakes could be much longer and more profitable, not to mention safer.

Did railway companies adopt the breaks or were they forced to?

2

WAG -

the brake came before the “muckraking” of the early 20[sup]th[/sup] century - safety laws were unknown at the time.

I’d guess market dynamics - paying passengers would shy away from less safe cars.

3

The air brake was widely accepted before it was made mandatory on US trains by the Railway Safety Act of 1893 (Britannica)

4

I was under the impression that brakemen hand-operating carriage brakes were obsolete well before the end of the 19th century. The Westinghouse system didn’t replace them, it replaced the first steam-powered brakes operated from the locomotive. These used steam pressure to apply the brakes, but were dangerous as they’d become inoperative if the train became separated from the locomotive. Westinghouse brakes are fully on in their default position, and use steam to keep the brakes off. An unattached train will automatically go into an emergency stop.

I’ll try to find a cite.