Just after noon on Friday, June 3, 16 tank cars of a Union Pacific Train, ONETU 02, derailed near the town of Mosier Oregon. The train had been transporting Bakken crude oil for the US Oil & Refining Company and operating on UP’s Portland Subdivision and quickly caught fire, destroying four tank cars and burning for 14 hours. Now, a preliminary report points to broken lag bolts leading to wide track gauge and the use of conventional air brakes rather than newer electronic brakes as primary causes of the accident.
The train was traveling at a speed of approximately 25 miles per hour at the point of derailment – well within the 30-mph restriction in pace due to the track’s curvature, and operating with conventional air brakes. It originated in New Town, North Dakota, and was headed for Tacoma, Washington. The train consisted of two head-end locomotives, one distributed power locomotive at the rear, two buffer cars, and 94 tank cars loaded with Bakken crude oil, known for its volatility. The train’s cars were equipped with full-height head shields and metal jackets with insulation, but did not have thermal protection.
During the derailment, a coupler, is a mechanism for connecting rolling stock in a train, struck one tank car, mechanically puncturing it. This puncture allowed crude oil to come into contact with an ignition source, setting off the massive blaze. The four tank cars involved in the fire included the punctured car and three additional tank cars – two of which had their bottom outlet valves sheared off in the derailment, and one with the gasket melted out from under the manway cover.
A preliminary investigation by the Federal Railroad Administration determined that the derailment was caused by multiple broken and sheared lag bolts that led to tie plates loosening from ties, allowing the rails to be pushed outward as trains moved across them and ultimately resulting in an area of dangerously wide gauge. But an upgrade in the train’s brakes might well have reduced the intensity of the accident, investigators say.
The investigation involved multiple simulations conducted by the FRA’s Office of Research and Development. These simulations modeled a derailment similar to Train ONETU 02 and equipped with conventional breaks, distributive power and electronically controlled pneumatic (ECP) brakes. Distributive power provides power to the train from both ends of the consist (lineup of locomotive cars) and provides improved braking over air brakes, while ECP brakes use an electronic trainline signal to activate brakes on all cars throughout a train consist simultaneously.
Results of the simulations strongly suggest that brakes applied uniformly and instantaneously would have provided additional train control, potentially shortening the stopping distance and minimizing damage. Specifically, if Train ONETU 02 had been equipped with ECP brakes, two fewer tank cars may have derailed, and one less tank car may have been punctured, investigators say.
In train derailments and other accidents, multiple parties may be at fault. If you are injured in a train accident, or if you spot and report a potential safety issue that isn’t being addressed, call 888-519-RAIL (7245) to speak with a railroad injury lawyer with Jacksonville’s Rail Justice today.
