Union Pacific’s failure to maintain track and equipment led to the June 3 derailment of a crude oil train, a fire, and a 1,100-bbl spill near the town of Mosier, Ore., the Federal Railway Administration (FRA) said in a June 23 preliminary finding (OGJ Online, June 8, 2016).
A preliminary investigation determined that broken lag bolts, leading to wide track gauge, caused the derailment, the US Department of Transportation’s FRA said. The loosened tie plates allowed the rails to be pushed outward as trains moved across them, eventually resulting in a wide gauge area that made the train derail, it explained.
“Broken and sheared lag bolts, while difficult to detect by high-rail, are more detectable by walking inspection combined with indications of movement in the rail or track structure and/or uneven rail wear, and are critically important to resolve quickly,” it added.
FRA said that following the derailment, it:
• Conducted walking inspections of all the curves in the Columbia River Gorge to inspect for additional track, fastener, or bolt issues.
• Conducted similar inspections of Burlington Norther Santa Fe track on the Washington side of the Columbia River.
• Searched its databases for tie fastener trends across the rail industry.
• Commissioned Volpe, one of DOT’s research centers, to test the broken bolts’ metallurgy.
• Ran a geometry car with a Gage Restraint Measurement System on UP track to rule out wide gauge on the railroad’s Portland, Ayer, and Spokane subdivisions.
• Confirmed that nine UP temporary speed restrictions remain in place in the railroad’s Portland subdivision, including a 10-mph speed restriction in Mosier.
• Evaluated potential enforcement actions, including violations, and other actions to ensure UP’s compliance with applicable safety regulations.
FRA said the train originated in New Town, ND, and was bound for Tacoma, Wash. It 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. The train was operating with conventional air brakes. Dakota Plains, which loaded the crude, said it had a 9.2 psi vapor pressure at the North Dakota loading facility.
“During the derailment, a coupler struck one tank car, mechanically puncturing it,” FRA said. “This puncture allowed crude oil to come into contact with an ignition source, leading to a fire that burned for approximately 14 hr. Four cars were eventually involved in the fire.”
The four tank cars involved in the fire were the punctured car, and three additional tank cars—two that had their bottom outlet valves sheared off in the derailment, and one car with the gasket melted out from under the manway cover, it said.
Oregon’s Department of Transportation asked its federal counterpart to temporarily halt movement of trains carrying crude oil in the state until ways are found to prevent a track bolt failure that led to the derailment and crude oil spill near Mosier (OGJ Online, June 17, 2016).
Contact Nick Snow at firstname.lastname@example.org.