05/28/2012 11:49 EDT | Updated 07/28/2012 05:12 EDT

Trains delayed as heat warps railroad tracks

Warped railroad tracks are already causing delays for train passengers travelling between Ottawa and Montreal due to the warm temperatures.

The phenomenon is called "sun-kinking" where railroad tracks get hot, expand or contract, and warp slightly. It often happens in July and August but both Canadian National Railway (CN) and Via Rail have received go-slow orders for two track sections owned by CN.

Go-slow orders are temporary but they force train engineers to slow to half the usual speed at times. They are implemented in both hot and cold temperatures.

Newer alloys do reduce the “sun-kinking” but there are still older tracks that fall victim. This leads to longer trips and delays and the issue could get worse in the coming months.

"This is the type of occurrence that is a bit more prevalent in the hotter months," said Malcolm Andrews, spokesman for Via Rail.

The CN track going eastbound between Montreal and Halifax has also seen go-slow orders the past two years.

In Europe, kinking is not an issue because tracks for high-speed trains, which travel at about 300 km/h, are set in concrete. In Canada, tracks are set over gravel.