Articulated Double Stack Car Effects on Bridges
(Room 200 C)
24 Sep 19
3:30 PM
-
4:00 PM
Tracks:
AREMA Technical Sessions By Date- Structures, AREMA Technical Sessions By Functional Group- Structures, Technical Sessions By Day- Tuesday
Transportation Technology Center, Inc.’s (TTCI) research on the effects of articulated double-stack cars on railroad bridges indicates they can apply greater loads to short bridge spans and floor system members as compared to typical bulk commodity cars. Most articulated double-stack cars have a nominal maximum truck weight of 157,500 lbs., which is higher than the nominal truck weight of 143,000 lbs. for a coal car. An analytical investigation indicates that double-stack cars should cause larger maximum moments only on spans shorter than approximately 15 feet. To compare nominal loads to real-world conditions, actual net truck vertical forces were collected and analyzed from four wheel impact load detectors (WILD) located on different intermodal corridors in North America. To confirm the analytical studies, strain gage data was collected from a short bridge on a line carrying both intermodal and coal trains. The results from this research indicate the following preliminary conclusions: • Depending on location, 5 to 12 percent of all articulated truck loads exceeded the maximum allowable truck load for four-axle interchange cars (143 kips). • The collected data shows that articulated double-stack cars often are not loaded to full capacity; and therefore, their load effect is often comparable to or less than the load effect due to coal cars. • In terms of fatigue, the equivalent stress range was about 10 percent lower under a typical intermodal train compared to a coal train. The number of accumulative stress cycles was about 80 percent lower. *Missed this Session or want to view it again? Stop by the VirtualAREMA kiosk located in the Registration area to purchase this product today!