UPDATE 1-CP Rail derailment caused by broken wheel -watchdog
(Adds comment from CP Rail)
Dec 11 (Reuters) - A Canadian Pacific Railway Ltd train carrying crude and other cargo derailed in April 2013 because of a broken wheel, which Canada's transport safety watchdog said could have been replaced but was not due to differing guidelines on when repairs should be made.
Four days before the incident the wheel exceeded the American Association of Railroads' (AAR) removal threshold in a trackside test, but under CP's higher threshold, which is similar to that of other major railways, it remained in service, said the Transportation Safety Board (TSP).
After the test, "... CP could have set the car out immediately, replaced the No. 1 wheel set and charged the car owner for the work in accordance with AAR rules," said the TSB in its report, released on Thursday.
A CP spokesman said the railway is reviewing the report, adding that CP safely moves millions of carloads every year. "Safety is the highest priority in our company for employees, customers and communities," the spokesman said.
Regulations do not force railways to replace wheels based on trackside tests in Canada or the United States, an issue the Canadian watchdog raised in a 2011 advisory. Transport Canada promised a "comprehensive review," but on Thursday the TSB said "to date, there have been no tangible developments."
The TSB said AAR rules are based on technical studies done in the early 1990s. It said CP's thresholds were "established primarily by industry practice and in order to manage the volume of wheels removed," not an engineering analysis.
Wheel Impact Load Detectors, installed along train tracks, can catch problems with wheels before they fail, but railways decide which readings merit a repair.
CP said it has "steadily tightened" thresholds as it gains more experience with the detectors, which it called a relatively new technology. Continued...