From CBC Website: http://www.cbc.ca/canada/story/2008/06/05/train-wheels.html Last Updated: Thursday, June 5, 2008 | 11:44 AM ET Comments20Recommend31The Canadian Press The Transportation Safety Board of Canada says 12,000 wheel sets still in use by Canadian Pacific Railway, Canadian National Railway and other North American railroads "have a high susceptibility to loosen" and should be replaced. They were among 43,000 suspect wheel sets produced at the Canadian National Transcona shop in Winnipeg, many of which have already been removed from service. The Canadian Press originally reported that all 43,000 wheel sets were susceptible to loosening and should be replaced, but later revised the figure to 12,000. The board says its finding arose from an investigation into a January 2006 derailment of a Canadian Pacific train near Buckskin, Ont., when a wheel became loose on a curve and shifted inboard on its axle. The board says at least 18 wheel sets made with the modified pressure-fit technique have been involved in derailments in Canada. It says the risk of failure for the remaining wheel sets increases the longer they remain in service. The Buckskin derailment damaged 18 kilometres of track as the train continued on its way until the loose wheel set hit a switch, causing 11 additional cars to derail and 130 metres of track to be destroyed. There were no hazardous goods involved and no injuries resulted.