Switch determined to be cause of derailment

DEXTER, Mo. -- A team of Union Pacific investigators has determined the cause of a train derailment July 24 was defective components in a switching mechanism on the tracks east of Dexter.

Fourteen railroad cars on a southbound Union Pacific train derailed within the city limits that day, one of which contained a hazardous material -- liquid petroleum gas. The contents of the 14 cars that derailed included four cars of nut oil, four cars of railroad ties, one car of corn, one car of frozen vegetables and one car of nonhazardous lubricating oil. Two cars were empty.

There were no injuries as a result of the accident.

Information officer Mark Davis of Union Pacific said investigators concluded that a switching device that moves the train from one track to another malfunctioned and caused the derailment.

The exact nature of the defect in the switching mechanism was not known. Davis said it was not the movement of the switching device, but the part itself that caused the derailment.

Investigators will continue to test the metal and other components to determine if the problem was caused by the age of material, the way it was manufactured or any other reason.

Davis said roughly 42 trains a day travel the track that was involved. UP inspectors routinely inspect the track, including inspection twice annually by electronic devices that test the inside of the track.

The derailment damaged 1,500 feet of track, which had to be replaced. Other tracks along the line were used with a reduced speed limit until the derailed cars were removed and the track repaired.

Davis said four teams investigated the derailment, looking at different aspects of what might have caused it. Team members reviewed the mechanical components of the train, including rail cars and the locomotive as well as the actions of the two employees on the train, in addition to other factors, Davis said.

The findings will be reported to the Federal Railroad Administration.

Pertinent address:

Dexter, Mo.