Federal Railroad Administration, Office of Safety Headquarters Assigned Accident Investigation Report HQ-2006-46, Union Pacific (UP), Morrison, Montana, June 10, 2006

摘要

Eastbound Union Pacific Railroad Company (UP) freight Train Symbol MKCAS 09 derailed on June 10, 2006, at 7 a.m., near Morrison, Missouri, on Main Track No. 2, at UP Milepost (MP) 94.2, on the St. Louis Division, Jefferson City Subdivision. Morrison is located about 100 miles west of St. Louis, Missouri. Timetable directions used for this report are east and west. There were no injuries. Three rail tank cars were derailed without release of product. There was no evacuation. Damages were $68,761 to equipment and $156,730 to track. At the time of the accident it was daylight and clear. The temperature was 80 DGF. The eastbound train stopped to wait for a westbound train to clear single main track at Morrison Junction. Locomotive event recorder data indicates the use of dynamic braking was improper due to rapid adjustment, causing the slack to run in. The run-in caused the leading end of the 32nd head car, Car No. EEC1406, to derail. There was no inspection of the train conducted after the stop by the crew. The train was pulled about 1,200 feet east, resulting in the derailment of the 29th through 48th head cars. All derailed rail cars remained in the upright position. The crew was required to submit to UP Reasonable Cause testing. All results were negative. The primary cause is Train Handling, cause code H519 - Use of Dynamic Brake, too rapid adjustment. The Train Simulator revealed that maximum steady-state buff forces were excessive, in the range of 500,000 to 700,000 lbs., although train make-up was in compliance with UP System Special Instructions. A contributing factor should be recorded as H504 - buffing action excessive, train make-up.