For the second time in a year, welds appear to be the root cause of railcar problems that are forcing the vehicles off the tracks, SEPTA officials said.
In July, the problems were on the Regional Rail. This time, Market-Frankford Line riders are facing delays and an uncertain repair timeline. The vehicles from the two lines are different ages, used in different kinds of services, and are from different manufacturers, but in both cases cracks appear to have formed at a welded point on the car.
"Welding is absolutely a great thing," Jeff Knueppel, SEPTA's general manager, said in a Monday news conference, "but it absolutely has to be done well."
In the case of the M4 El cars, it apparently wasn't. Vent boxes that allow air to pass into the motors to cool them were welded to the body bolster, the 94-inch long beam that connects the body of the car to the wheel truck beneath. Those vent boxes have less strength than the bolster, and it appears, Knueppel said, that cracks formed there. So far, SEPTA has identified 58 cars with cracks in the vent boxes, and in two of those cars the fissures extended into the bolsters. It appears the welds drew stress to the larger beams when the vent boxes began fracturing, causing the cracks to extend into the bolster.
"It's a complicated area," Knueppel said, "and it's the highest stress area of that beam."
All 58 cars with cracks in the vent boxes have been pulled from service. About 40 other cars were out of service for maintenance or an unrelated overhaul, leaving SEPTA with 108 cars operable Tuesday morning.
The El carries more than 187,000 people each weekday between the Frankford Transportation Center and 69th Street in Upper Darby. Stops include City Hall and 30th Street Station; the line typically requires 144 cars to handle rush-hour traffic during the week.
The shortage on Monday resulted in 6-minute intervals between trains; 4 is the norm. Despite the shortage, congestion wasn't as bad as anticipated, SEPTA officials said. It's possible that conditions will be more difficult Tuesday, they said, and SEPTA will again have buses available to carry El passengers between Girard Avenue and 15th Street and also between 52nd and 15th Streets.
The two cars with the cracked bolsters likely weren't damaged to the point that there was danger of the beam giving way, Knueppel said. One crack was eight inches long in a 23-inch-wide beam. Other problems would have been noticed before the cracks developed to the point where a car failure was possible, he said.
How the cracks will be fixed, and when, remains unknown. It will likely involve welding, but members of the union responsible for maintaining the cars, Transportation Workers Union Local 234, noted the cracks that extend into the body bolsters have created a fissure in a part that can't simply be replaced.
"Anything can be fixed, but there's no way this is going to be an easy fix," said Joe Coccio, treasurer for the local and a vehicle mechanic. "This is not made to be removed. Everything is built around this piece."
SEPTA has been engaged in a comprehensive evaluation of all its vehicles since the Regional Rail cars failed in July, Knueppel said. About a third of those cars, 120 Silverliner V's, were pulled from service after a faulty weld was found in load-bearing beams. All Silverliner V's are back in service, Knueppel said. The similarities between the flawed parts is coincidental, though. The Silverliners were built by Hyundai Rotem from 2010 to 2013. Adtranz, now a part of Bombardier Inc., a Canadian company, built 220 M4s on a $285 million contract and delivered them to SEPTA from 1997 to 1999.
Knueppel did not know whether a warranty still existed on the M4s, he said.
The cracks were found unexpectedly only after mechanics conducting an overhaul of the El cars pulled up floor panels. SEPTA used a less-complicated procedure, which involved lowering a scope into the vent box, to confirm that the cars going into service Tuesday did not have cracks, Knueppel said.