SEPTA trolley tunnel will stay closed until next week
The Center City trolley tunnel remains shut for repairs to the overhead power system.
Philadelphia’s trolley tunnel has been closed for most of the last two weeks as SEPTA contends with glitches in the connection between the overhead catenary wires and the pole that conducts electricity to the vehicle.
The tunnel will remain closed at least until next week for repairs, and city trolleys will operate from West Philadelphia. Riders can take the Market-Frankford El to get to and from Center City to 40th and Market Streets.
At issue is a U-shaped brass part called a slider that carries carbon, which coats the copper wires above that carry electricity.
“There’s a lot of friction and heat. The carbon acts as a lubricant,” said John Frisoli, deputy chief engineer for SEPTA.
Earlier in the fall, SEPTA replaced 3-inch sliders with 4-inch models in an effort to reduce maintenance costs, but the carbon in the longer units wore out sooner than they should have, causing metal-on-metal contact between the trolley and the copper wires.
Soon after, there were two major incidents when trolleys were stranded in the tunnels. On Oct. 14, 150 passengers were evacuated from one vehicle and 300 were evacuated from a stalled trolley on Oct. 21.
SEPTA went back to the 3-inch sliders.
On Nov. 7, SEPTA shut down the tunnel to deal with the issue, which had cropped up again, then reopened it on the morning of Nov. 13, thinking it was solved. But it discovered further damage to the catenary system and the tunnel was closed at the end of the day.
“It’s just unfortunate that we’re dealing with the damage that decision caused,” said Kate O’Connor, assistant general manager for engineering, maintenance, and construction.
The transit agency is running test trolleys and has found minimal wear of the wires rather than the extensive wear earlier, O’Connor said. Her department is working on a plan to replace wires by sections and will continue test runs until it’s determined the tunnel is safe for passenger traffic again, she said.
“We have far more traffic in the tunnel than on the street — all five routes use it — and the overhead system there is more rigid,” O’Connor said.
Trolleys have been unaffected traveling on the street. Jason Tarlecki, acting chief deputy engineer for power, said that the wires have “a lot more upward flexibility to absorb the shock,” he said, leading to less friction.
The Federal Transit Administration on Oct. 31 ordered SEPTA to inspect the overhead catenary system along all its trolley routes.
The directive came in response to four failures of the catenary system in September and October, including the tunnel evacuations.