Metra trains will slow down during heat wave
Temperatures going up mean Metra trains will be slowing down during the heat wave.
Forecasts for Friday call for weather in the mid-90s with high humidity, which puts extra stress on the steel tracks, switches and signals, Metra officials said.
To remedy that problem, engineers will reduce speeds, exerting less pressure on the hot steel, which means riders could run into delays of 10 to 15 minutes in the next few days. The tipping point is usually 95 degrees.
Steel expands when it warms up, but continuous rails that are welded together are constrained. The rail "is put in place in such a way it can't expand," spokesman Michael Gillis said. "It's done as a precaution against sun kink developments."
Sun kinks occur when tracks buckle in extreme heat.
In 2012, buckling track brought on by temperatures of 103 degrees was determined to be the likely cause of a coal train derailment that led to a railway bridge crashing down onto a road near Northbrook. A Glenview couple was killed.
For more information on delays, go to https://metrarail.com/.