As much as I HATE conspiracy theories, there is the fact that the Westinghouse Air Brake employed on rail car designs requires pressurization to remove the brakes and allow the wheels to turn. If, as reports indicate, the engine had been shut off, the air within the main brake line would have bled off, the brakes would have been applied, and the wheels would have been unable to turn.
Somehow, the main brake line remained pressurized, or was re-pressurized, and the train rolled downhill.
Wikipedia wrote:
An air brake is a conveyance braking system actuated by compressed air. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on March 5, 1868. The Westinghouse Air Brake Company (WABCO) was subsequently organized to manufacture and sell Westinghouse's invention. In various forms, it has been nearly universally adopted.
The Westinghouse system uses air pressure to charge air reservoirs (tanks) on each car. Full air pressure signals each car to release the brakes. A reduction or loss of air pressure signals each car to apply its brakes, using the compressed air in its reservoirs.
Each car has its own reservoir, so that it would take not only the pressure in the main brake line to bleed off,
but the air pressure in each one of the rail cars that went rolling down the line.
The only other scenario that I can think of is that either each reservoir was deliberately drained, or that the entire brake system was in such disrepair that the reservoirs could not maintain pressure to hold the brakes. In either case, someone either failed to manually set the brakes, or they were set, and someone deliberately un-set them.
Occam's Razor would indicate poor maintenance and general stupidity, rather than a conspiracy, so I'm hoping that I'm wrong.
Would someone PLEASE prove me wrong?
Last edited by Fnord on 09 Jul 2013, 2:45 pm, edited 2 times in total.