Philadelphia – CBTC Glitches Jam Streetcar Tunnel

Rail Transit Online, December 2008

A 10-year program to install communications-based train control to prevent rear-end collisions in SEPTA's downtown streetcar tunnel has instead slowed traffic and created rush-hour snarls causing long delays for passengers. With headways as low as 50 sec. during peak periods, the tunnel is used by five Subway-Surface routes where cars run without signals above ground.

The CBTC equipment, which will stop a car if the operator fails to respond to a red cab signal, appears to work well during base periods but can't seem to cope during heavy traffic. Apparently, the system has trouble promptly identifying a car entering or leaving the tunnel portals at 36th Street and 40th Street, reducing speed or forcing cars to stop even though a crash is not imminent.

"We're still having failures several times a day," Patrick Nowakowski, SEPTA's Assistant General Manager of Operations, told The Philadelphia Inquirer. "It's too much." Bombardier engineers have reportedly been sent to Philadelphia once again to eliminate the glitches.

The CBTC system has a long history dating back to 1993, when SEPTA placed a $285-million contract with Adtranz, formerly ABB Traction, for 220 subway cars to equip its Market-Frankford Line. The first two prototype vehicles finally arrived in January 1997, approximately 21 months late, and each car was 1,200 lb. (544.3 kg) heavier than specified. Liquidated damages of up to $400 per day per car could have been imposed plus $25 for each extra pound.

Instead of risking a long legal battle for compensation in cash, SEPTA in late 1997 negotiated a unique deal with Adtranz, since acquired by Bombardier. The company agreed to supply a $23.6-million CBTC system for the 2.5-mi. (4 km) downtown tunnel, replacing wayside signals, at no cost to the transit agency. In addition, an order for a $1.9-million work car was cancelled.

The system was activated in May 2005 but only during off-peak periods, with manual operation continuing during rush hours because of ongoing technical problems. However, after a collision involving three streetcars in the tunnel last July that injured 11 people, SEPTA placed CBTC into full-time operation.

Nowakowski says the only way to make the technology work is to use it in revenue service. "You've got to see the bugs so you can deal with them," he told The Philadelphia Inquirer. "We can't find these problems if we don't turn it on full-time." Meanwhile, equipment that supposedly was to be free has so far cost SEPTA several million dollars.

SEPTA's Subway Surface streetcar routes.