Operation of longer, heavier trains
Published: March 17th 2010
Source: The Transportation Safety Board of Canada (TSB)
The Problem
Inappropriate handling and marshalling can compromise the safe operation of longer, heavier trains.
Background
Freight trains cross the country every day. The length of each train, as well as the manner in which its cars are marshalled, or put together, affects the forces involved during train handling. Lighter cars, for example, slow down and speed up more quickly than heavier ones, generating disruptive push/pull forces that can derail the train. This effect is more pronounced in longer trains, particularly when empty cars are located at the front. Since 2000, the TSB has investigated at least 12 derailments where these in-train forces have been a causal or contributing factor, and the problem is growing. Not only are trains involved in main-track derailments heavier than ever, they are longer, too—over 25 per cent from just 15 years ago. Some of today's longer, heavier trains stretch over three kilometres in length and contain 150 cars or more. These trains are seeing expanded use across Canada, including into the country's busiest traffic corridors. The consequences of any derailment, therefore, can become magnified, and it is important that those who identify and monitor the risks be able to mitigate them.
Solution
Following the 2007 derailment of a freight train near Cobourg, Ontario, the TSB once again drew attention to train configuration and braking, expressing concern that effective measures have not been taken to reduce the continued risks of derailment.
The TSB has issued four other safety communications since 2001 all dealing with the safe operation of longer, heavier trains. Despite these efforts, some railways have not taken sufficient steps required to safely manage these in-train forces.
