The weight of a fully loaded light-rail train triggered the post-Apple Cup stall Nov. 26, when inadequate communications led stranded passengers to walk out along the underground tracks, Sound Transit said Wednesday.
Sound Transit CEO Peter Rogoff called the stall a “preventable mechanical failure.”
When the new Siemens train filled with riders, its coil suspension sagged, providing less clearance over trackway devices than usual, the inquiry found.
A power cable between railcars was sliced when it struck a metal rod (meant to reduce electromagnetic interference under UW laboratory buildings) that was protruding from the trackway, the investigation found. Rows of rods below campus each extend upward, like a bolt end.
“Those rods were higher than they were supposed to be,” Rogoff told members of a transit board committee Wednesday. They should have been cut long before train service north of UW opened last fall. And because of the crush-loaded train, the cable was hanging lower than usual, he said.
A 52-page investigative report sheds more light on the stall at 8:19 p.m. on a Friday night, some 1,000 feet north of University of Washington Station, inside the new tunnel to Northgate Station.
Despite extensive testing before the line opened Oct. 2, key personnel didn’t understand that train cables were at risk of hitting the rods, said Sound Transit internal auditor Patrick Johnson.
Testing and maintenance staff logged 16 work orders related to protruding rods in September, October and November, he said. They found oak boards beneath the railcars — called “safety boards” to knock debris or people aside — were getting cracked, the draft audit says.
Some 200 rods needed to be cut to improve clearance, based on records by King County Metro, which operates the trains, he said. But the problem wasn’t elevated to either Metro or Sound Transit’s safety team, the report found. The bolt-like rods are only supposed to stick out only two threads above the concrete track bed.
In addition, the project’s “dynamic envelope” tests, which assure a moving train clears all obstacles, measured the sides and overhead but not the underside of trains, the report said.
Since then, the rods have been trimmed, and under-train exams will be part of the tests for Sound Transit’s 2023 line from International District/Chinatown Station to Bellevue and Overlake, the agency said.
The post-stall review also explored communication lapses.
In a train with no lights or ventilation, riders coming from the UW-Washington State football game pulled open the doors of the darkened railcars and walked through the concrete tunnel. Some used an emergency passage door into the southbound tunnel where they could have been struck by a train. These cross-passages, required every 800 feet by federal law, are meant as fire escapes, but transit agencies consider it safer to remain aboard in most stalls.
Fortunately, an operator of a train moving in the southbound tunnel was moving slowly and saw the passengers in time to stop safely, radio traffic shows. Others walked along an edge in the northbound tube, back to UW Station.
The first passenger walked out four minutes after the train stopped. After 11 minutes, many passengers were walking through tunnels. The intercom system worked but wasn’t used in the first few minutes, while the train operator was preoccupied trying to restart service. Transit staff had trouble coordinating, surrounded by another 800 people crowding the UW Station platform, the report says.
“We don’t blame the passengers for self-evacuating, given the crowded conditions onboard, without any communication from us,” said Suraj Shetty, executive operations director.
After 26 minutes, transit supervisors began loading people onto a rescue train, which was the southbound train whose operator paused earlier. Its trip to UW Station was delayed in part because some people yanked on its doors, Shetty said.
If communications had been clear, “The rescue train could have been available within 15 minutes, and the entire process would have been shorter and less severe,” he said.
Even an hour later, Sound Transit staff had not been notified and not issued rider alerts. Officials missed a two-hour deadline, at 10:20 p.m., to notify state and federal regulators of what Sound Transit classified as an emergency evacuation.
“It’s clear that all emergency communication protocols must be improved and enhanced,” Rogoff said.
Sometime in 2023, as the Eastside line opens, train control will move into a new dispatch center, with communication staff on-site, as in Vancouver, B.C. That will help make public information faster, said Russ Arnold, rider experience officer.