Sensor-Aided Stress Tests Aim to Resolve Railcar Safety Concerns

The Southeastern Pennsylvania Transportation Authority is outfitting trains with sensors and sandbags to determine where and when fatigue cracks occur.

by Jason Laughlin, The Philadelphia Inquirer / July 25, 2016

(TNS) — More than a dozen men bustled around the elevated railcar, attaching wires and sensors to it like doctors placing monitors on a heart patient.

And like a heart patient undergoing a stress test, the Southeastern Pennsylvania Transportation Authority (SEPTA) is going to push the railcar to the max. "This is exceptional," said SEPTA senior project engineer Greg Buzby of the tests he and other engineers are performing on a Silverliner V, one of 120 cars pulled from service due to a faulty part.

Over Independence Day weekend, SEPTA found a fatigue crack in one of the Silverliner V's equalizer beams, a piece that transfers the car's weight to its axles. The same flaw, the result of a shoddy weld, the train's maker Hyundai says, was found in all but five of the cars. Pulling them from service for safety reasons has meant a scheduling nightmare on the transportation agency's Regional Rail service.

Buzby is working through his normally free weekend for the third straight week, he said. So are the other engineers at the Overbrook Maintenance Facility in Philadelphia, part of the team trying to find out how to best solve SEPTA's train travails.

The car up on the elevated platform is one of the Silverliner Vs, but none of the equalizer beams on this one have cracks in them.

The three different types of sensors attached to an equalizer beam measure how the metal flexes and the beam shifts while the car is in motion.

The testers will be taking readings Monday as the car travels full round trips on the Norristown, Marcus Hook and Trenton lines. Then the car will repeat the trip, this time with 36,900 pounds of sandbags on board — about the weight of 230 passengers. The trips will give SEPTA an idea of the stresses its routes place on the equalizer beam, from high speeds to stopping at platforms to passing across switches. The data collected will create a map of track conditions SEPTA will use to test two types replacement beams that should arrive for testing early next month.

One type of beam will be forged, completely lacking the welding that was the focal point of the cracks. The other will have welded pieces, but the welds will be done in a different manner than the original welds.

SEPTA's general manager Jeff Knueppel said beams with welded parts can work safely, though a forged piece is intrinsically better at handling the long-term strains of railroad operations.

SEPTA still has a lengthy process ahead. When the new beams arrive, they're going to be subjected in a lab to simulations of the conditions recorded in Monday's test runs. There will also be fatigue tests that will replicate stresses the beam would be subjected to over about 15 years of use, engineers said.

The problems with the Silverliner Vs will also likely change how SEPTA tests and inspects new vehicles, said Ron Hopkins, general manager for operations.

"This will get a lot of attention," he said, referring to a planned procurement of 45 new railcars. "We'll do an addendum to make sure there's extensive testing."

The engineers working Sunday aren't oblivious to the frustration passengers have been venting since the rail fleet lost a third of its cars. One of them, Bob Lawless, project designer for new rail vehicles, rides the West Trenton Line to work and is regularly questioned by friends about when the trains will be back in service.

"We're working on it," is his stock answer.

Buzby said his friends don't always understand what his job involves. For better or worse, his work, usually behind the scenes, is now drawing the region's attention.

"It's been easier to explain what I do. This is what I do," he said, then added, "Usually on a much smaller scale."

©2016 The Philadelphia Inquirer. Distributed by Tribune Content Agency, LLC.

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