摘要: |
In 2007, most revenue service experiments at the eastern and western mega sites continued. These two sites were established by the Association of American Railroads and the Federal Railroad Administration in late 2004 to consolidate various field experiments, which are designed to determine the effects of heavy axle load (HAL) traffic on track infrastructure and monitor new technologies intended to mitigate detrimental effects of HAL on the track structure and improve train operation safety. Premium test rails at both mega sites continue to show excellent wear resistance. Without preventive grinding, rolling contact fatigue (RCF) developed after 300-350 MGT on the low rails in the 2-degree test curves at the western mega site. Corrective grinding was required at 375 MGT to remove RCF. At the eastern mega site, wide gap welds continue to show good performance with no surface or internal defects identified for 123 MGT of traffic. |