This is a video showing a derailment of a coal train taken by the guy who maintains the track. You can watch the video which shows all the damage as he gives a detailed explanation of what happened and why.
I believe this carrier uses locomotives on either end of their shuttle trains of about 40 cars. The railroad DOES NOT connect to the national network. There was a article about the operation in Trains last year.
Breaking the brake line should have put the locomotive into emergency…
Believe the engine shown derailed was at the rear end of the train. I don’t know if it was being operated as a DPU or being handled just like another car in the train.
Apparently that is the DPU and the derailed cars are at the rear of the train. I see comments asking the guy to confirm whether the engine was the DPU. So they suspect it was.
Cumberland Mine Railroad operates in push-pull per Wikipedia