CHICAGO (CBS) — The Chicago Transit Authority is having a few teething problems with its newest ‘L’ cars.

As WBBM Newsradio’s Bob Roberts reports, when an ‘L’ train broke down last week at the height of the morning rush at the northwest corner of the Loop — the busiest junction on the rapid transit system, and one of the busiest in the world — one of the CTA’s newly-delivered cars was to blame.

LISTEN: WBBM Newsradio’s Bob Roberts reports

The reason for the mishap is still being determined by mechanical engineers from both the CTA and Bombardier Transit Corp., the firm that is manufacturing the 706-car order.

CTA President Forrest Claypool winces when reminded of the breakdown, which took 38 minutes to remove but had ripple effects that lasted much longer. Nonetheless, he said he believes the new cars are performing well overall.

“I think it’s consistent with the introduction of a new generation of rail cars,” he said. “Bombardier’s been very responsive to correcting any defects or flaws that we’ve encountered.”

Claypool said the new cars “are a completely different animal” from the rest of the CTA’s ‘L’ fleet, and said train operators and repair personnel are still getting acquainted with the cars and how to troubleshoot what goes wrong.

The uncertainties are why the cars are being broken in on its most lightly-patronized lines. The cars first entered service on the Pink Line, and by late January, should begin to appear on the Green Line.

Claypool said that way, any glitches the cars have won’t tie up the much more heavily-used Red, Blue and Brown Lines — unless they occur at a location similar to last week’s breakdown.

In fact, the Red Line is slated to get the cars last, in 2013 and 2014. Not all riders like the new cars, especially the “bowling-alley” seats which face each other, in an attempt to make room for more standing passengers, and some regular Red Line riders tell WBBM Newsradio they are perfectly content to be last.

One change being made to the cars that is not mechanical in nature deals with its destination signs. The 40 new cars now in service have yellow LED signs on a black background, which can be confusing to riders who have become accustomed for the past 20 years of destination signs that identified the line on which a train operated by color.

Cars already in the CTA’s possession will be retrofitted, and the rest built, with full-color LED signs. A CTA spokesman said the technology was not commercially available when specifications were drawn up for the cars, but has advanced.

Claypool said the system’s oldest ‘L’ cars are being retired if they need any major repair. But he said the last of the 2200-series cars, built in 1969-70 and the last on the system to have “accordion-style” blinker doors, won’t be removed from service for another year. As of Thursday, 130 of the 40-year-old cars remained in service.

The 2200s are not being removed from service one-for-one as new cars are delivered, though. CTA is growing is rapid transit fleet from 1,190 cars to 1,400 cars.

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