Working for a railroad in train operations as an engineer, I know how trains work. Several things are wrong with this movie and personally it surpasses what I know as being just plain stupid to reach a new plateau of stupidity and retardation of normal people which I've never known before. For example:
a - when a brake pipe hose between two cars breaks its connection, the rapid drop in break pipe pressure will cause a train to immediately go into emergency and stop. (in the movie they were trying to put it back together to try to stop the train)
b - when a train has electrical problems, such as even a weak battery, safety systems will cause an emergency application of the brakes. This did not happen in the movie.
c - I have never in all my railroading days seen a boxcar with railings on the side and extruding steel for a footwalk to gain access to the door.
d - when the train was creeping at walking speed at the top of the mountain, the people could have EASILY walked to the cars and tied hand brakes stopping the train. Even if all the hand brakes failed (which is an impossibility due to required initial terminal testing on the trains brakes before departure from a yard) a large limb from a nearby tree could have been used to stop the train. *I've done it while working in the yards using a 2x4*
e - when the engine was attached to the rear end and trying to pull the train to a stop, use of dynamic brakes couldn't create so much "strain" as to break a knuckle (the coupling mechanism in a coupler) as depicted in the movie. The knuckle part of a coupler is solid steel, and given the circumstances would be EXTREMELY difficult to break.
f - the crew on the caboose had control of the emergency brake valve on the caboose, and could have placed the train into emergency from the rear.
