Accident Report Detail

This report describes and analyzes a derailment which occurred when a train separation resulted in unequal deceleration of the two parts of the train. Unusual lateral forces at the rear of the third locomotive unit canted the outside rail of a 3 30' curve outward enough to allow the wheels to drop inside. A tank car of propane was punctured and the ensuing fire impinged other tank cars and caused the violent rupture of three of them. Fifty-four person were injured by the fire and rocketing parts of tank cars.

The National Transportation Safety Board determines that the probable cause of this accident was the inability of the track to resist the lateral forces which canted the outside rail outward and widened the gage of the track. These forces which were induced at the third locomotive unit resulted from the emergency application of the brakes when the train was separated between the third and fourth cars as it entered the 3 30' curve. The train separated as a result of the broken center sill on the fourth car.