Re: Transportation Safety Board [TSB] of Canada Report on the fatal 2006 WP&Y Runaway & Derailment

I would say the primary factor in the runaway was the overloaded cars, regardless of their construction.

Depending on how bad they were actually overloaded, it was about the same as if the brakes were completely cut out on several of the cars.

Bottom line, there was insufficient braking force available to keep the train under control due to:

1. Overloaded cars resulting in insufficient available braking effort
2. Improper use of and all cars not equipped with retainers
3. Failure of the RR employees (including MOW crews) to recognize the overload condition, and runaway potential (due to lack of training and supervision?).

IMHO, the train was doomed as soon as it started down the grade.