Why trains are 2 minutes slower at UW Station

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Thousands of travelers on Sound Transit’s light rail trains are being delayed two minutes northbound near University of Washington Station, until a damaged overhead power wire can be replaced in early December.

Operators for about the last month have been ordered not to exceed 10 mph for “several hundred feet” along and near the station platform, as a precaution against worsening the wire damage, said spokesperson John Gallagher. Trains would normally travel closer to 30 mph in those spots, while they approach or leave UW Station.

The overhead wire supplies electric power to light rail trains through a pantograph, shaped like an inverted triangle atop each railcar. On Sept. 17, a bent pantograph damaged the wire at UW Station, officials have said. That train stalled just north of the boarding platforms, and was left there all day while other trains shared a single track.

Sound Transit will postpone wire repairs until after Thanksgiving and weekend sports crowds have come and gone — and there’s already a weekend shutdown of five downtown stations planned Nov. 9-10, when crews resume trackwork connecting the 1 Line to a future I-90 corridor reaching the Eastside.

During the December fixes at UW Station, crews will close the northbound tunnel there, and trains going north and south will “single track,” by taking turns in the southbound tunnel. No schedule is announced yet, but single-tracking typically reduces the usual 10-minute frequency to arrivals 25 or 30 minutes apart.

During the 9 a.m. hour Wednesday most riders barely looked up, as trains crawled near walking speed for 50 to 65 seconds arriving at UW Station, and again departing the platform. Trips from UW to U District Station lasted three minutes, compared with two minutes along that stretch in the southbound tunnel.

Over the 33-mile line from Lynnwood to Angle Lake, the lost time can be made up, Gallagher said. An average 82,300 daily passengers rode the 1 Line as of July, while 5,800 rode the starter 2 Line segment on the Eastside.

An investigation is underway to find out why the single pantograph became misaligned or damaged, but transit staff believe it’s an isolated incident, Gallagher said.

This UW Station wire problem is unrelated to a two-hour train stall in the same area Friday, where technicians restarted a stuck railcar after finding an electronics problem inside the train.

Sound Transit has struggled with both onboard and off-board power interruptions that caused train stalls, causing frustration as ridership grows, and 12 new stations opened along two lines this year.

On-time performance this year has trended at or slightly below Sound Transit’s minimum 90% goal. In addition, about 5.4% of scheduled 1 Line trains missed their entire trips in August, according to the agency.

CEO Goran Sparrman ordered an independent engineering report to solve multiple electronic problems causing stalls in several places: circuitry sequences that halted power in Bellevue’s Spring District twice this spring; the all-day outage Aug. 1 at a tunnel portal near Northgate Station; and stoppages when on-train alarms displayed a loss of braking power.