CN Rail has been ordered by the federal government to remove potentially faulty wheels mounted on trains at the company's Transcona wheel shop.
The directive was issued in response to a railway investigation report released by the Transportation Safety Board on June 5, 2008.
Ottawa has given CNR just over four months to identify and remove any potentially faulty train wheels.
As many as 12,000 sets are still being used by Canadian Pacific Railway (CPR), CNR and other North American railroads, the TSB said in its report.
"The safety and security of Canadians is our number one priority, and our government is acting to make our railways as safe as possible," Transport Minister Lawrence Cannon said in a press release Friday.
"By issuing this emergency directive, I want to ensure every possible measure is taken to prevent potential derailments related to faulty wheels."
The report identified loose wheels as the cause of a CPR freight train derailment near Buckskin, Ont. on Jan. 31, 2006.
After the engine derailed, it continued moving forward until it hit a switch. That caused 11 more cars to go off the rails.
More than 18 kilometres of track were damaged but no hazardous materials were spilled and no one was injured.
The faulty wheels were mounted on the CPR car at CNR's Transcona wheel shop in Winnipeg.
The shop sent out 43,000 suspect wheel sets in question between April 1998 and February 2001.
Many of the sets, which were made with the modified pressure-fit technique, have already been removed.
"Our government is taking decisive action to improve rail safety in Canada," Cannon said.
"We continue to take significant enforcement actions to help address derailments and other safety issues by issuing notices and orders, increasing physical inspections and performing audits of railway safety management practices."
