[Cvengr]

I had been under the impression that such brakes were “Normally Closed” systems, where lack of air pressure resulted in the railroad car applying it’s brakes automatically. That way, if a RR car is decoupled and loose, it naturally brakes. Am I mistaken.

(Never worked as a Friction Engineer.)

[MasterGunner01]

My point is when you secure a train on an incline, it does not make sense to rely totally on the air brakes to work. Instead, I would have set the brakes on other cars in the train and chocked the wheels so the train could not move. Securing the train means SECURE the train so that you cannot have a runaway. Obviously, the train was not secured, what brakes that were applied could not keep the train from rolling down the incline, and this terrible accident happend when the runaway derailed.