CHICAGO (CBS) — The Chicago Transit Authority is stepping up inspections of track, using special trains that spray water on overheated rails and is working aggressively to keep air conditioning working aboard its trains and in its trackside switch houses to deal with the extreme heat.

As WBBM Newsradio’s Bob Roberts reports, Some of the steps are being taken to prevent the same type of “sun kink” believed responsible for the fatal July 4 freight train derailment on the Glenview-Northbrook border. The rails can kink when they have no place else to expand.

LISTEN: WBBM Newsradio’s Bob Roberts reports

So CTA spokesman Brian Steele said inspection of track is stepped up, and speeds in some 55-mph zones have been dropped to 35 mph, particularly on the south Red Line, which is about to undergo another track reconstruction.

The water trains typically run off-hours and are pulled by one of the CTA’s handful of diesel locomotives, after power to the electrified third rail has been turned off temporarily.

Metra and the CTA have both been battling “sun kinks,” or misaligned track, in the past couple of weeks. Neither has sustained a derailment because of the kinks, although CTA staff told board members Wednesday that the heat of recent weeks has “stressed the fleet.”

The Union Pacific railroad freight train derailment July 4 killed Glenview attorney Burton Lindner and his wife, Zorine, who were driving through the Shermer Road underpass when the bridge collapsed beneath the weight of freight cars derailing atop it. The bridge will be rebuilt; UP freight trains are using a temporary right-of-way laid across Shermer Road while that is done.

Inspectors look for loose rail fasteners and spikes, visible movement of the ties that hold the rails in place and rails that don’t appear to sit securely on the right of way. Steele said that most of the extra precautions take effect when the mercury hits 95 degrees for three consecutive days, without rain.

Steele said most of the CTA’s heat-related problems are far less spectacular — failed air conditioners aboard train cars. Steele says the CTA does its best to detach the sweatbox train cars and replace them at terminals with cars that have working air conditioning.

The CTA has more than 1,200 ‘L’ cars in its fleet for the first time in decades, because of the arrival of new 5000-series cars.

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