But Homendy said that federal investigators would be looking at how Norfolk Southern uses and spaces wayside detectors, along with how train crews receive alerts from the detectors. The investigation has not discovered any operational issues with the wayside detectors. “But it’s absolutely critical for problems to be identified and addressed early so that these aren’t run until failure.” Federal investigators are still looking into the possible causes. Such wheel bearings can fail for a variety of reasons, including fatigue cracking, water or mechanical damage, a loose bearing or a wheel defect. The hot axle connected to the wheel bearing combined with the plastic pellets to start the initial fire that accompanied the derailment. The wheel bearing that failed was on a railcar with a load of plastic pellets, said Jennifer Homendy, chair of the National Transportation Safety Board, during a 23 February press briefing. Cassity describes railcar inspection times as having decreased from 3 to 4 minutes per car to about 30 to 60 seconds per car. “As an industry, railroads will use this initial report in shaping a thoughtful, fact-driven approach to prevent another similar accident before it can occur elsewhere,” said the Association for American Railroads, an industry organisation, in a prepared statement.īut train worker unions have voiced safety concerns over the major US freight railroad companies having implemented precision-scheduled railroading strategies that pressure crews to perform train inspections faster. Norfolk Southern said in a statement that its wayside detectors trigger at a temperature that is “among the lowest in the rail industry.” It also said that its all wayside detectors in the area of the incident and found they were operating as designed. The freight train was travelling at about 47 miles per hour (76 kilometres per hour) at the time of derailment. An automatic braking system also activated the train’s main air brakes – something that can be triggered when a derailment disconnects the air brake hose between railcars. “Bearings that increase in temperature as progressively as this one don’t usually get cooler.”Īfter getting the detector’s warning, the train engineer increased application of the dynamic braking system that uses the train’s motors as generators to slow the train and dissipate mechanical energy as heat. “This one appears to have gone about 30 miles before failure, which was plenty of time to set the car out at a siding,” says Quimby. Railcars with wheel bearing temperatures beyond that threshold are supposed to be separated from the train and put aside in rail sidings that branch off from the main track. Norfolk Southern typically requires train crews to stop and inspect warm wheel bearings if their temperatures are between 170 and 200☏ (76-93☌). Only the third detector located near the East Palestine derailment site sent a warning to the train crew after recording a temperature that was more than 253☏ (122☌) above ambient temperature. “Surprisingly, they are not required, nor are they regulated in any capacity,” says Jared Cassity, director of the transportation division at the International Association of Sheet Metal, Air, Rail, and Transportation Workers.Ĭassity also expressed concern about the fact that the temperature increased by 65☏ (36☌) between the first and second wayside detectors but no warning or information was sent to the train crew. The US Federal Railroad Administration, which creates and enforces US rail safety regulations, does not currently set standards for such detectors. Within the privatised US freight rail system, freight railroad companies set their own temperature thresholds for the wayside detectors, which are also known as hot box detectors.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |