The Reasons Behind Link Outages
Two reports on the causes of Link's many unplanned outages ($) were released on Thursday, as Mike Lindblom at the Seattle Times writes. One report is by engineering consultant HNTB; the other is a Sound Transit internal review. The reports identify 432 hours (10 workweeks) of unplanned 1 Line disruptions, delays, and shutdowns between January and November 2024. This is separate from the planned maintenance periods where ST announced reductions, single-tracking, or bus shuttles in advance.
Many of the delays are caused by failures in the electrical infrastructure: station power outages, substations struggling as extensions come online, grounding via the return wire, stray current corroding the rails. Other disruptions are caused by signal failures, mechanical breakdowns, dispatch issues, contaminants in hydraulic brake fluid causing train stalls, pressure leaks causing stalls, inadequate HVAC systems leading to unnecessarily high or low temperatures for equipment, and overcustomization of facilities to satisfy political and community requests and reduce property takings. A lack of spare parts delayed repairs at UW Station. (The UW Station wires were finally repaired in February.)
Breakdowns suddenly increased in mid-2024 because new station and track openings added electrical and other stress to the system, according to Moises Guterriez, deputy CEO for agency oversight." (Lindblom)
The HNTB report contains 79 recommendations to fix the problems, including shoring up the electrical systems, adding crossover tracks to bypass blockages, improving governance, using maintenance crews more efficiently, and better coordination between Sound Transit and King County Metro. (Sound Transit owns Link but Metro operates it.) ST is also looking at more monitoring devices for the infrastructure.
The report specifically recommends crossover tracks at Symphony or Pioneer Square station, so that ST can single-track a shorter segment downtown when a blockage occurs on either the northbound or southbound track. This has been a repeated suggestion by several STB commentators, so it's good to see Sound Transit considering it. It also recommends a crossover just south of Lynnwood City Center station, although ST's Russ Arnold, Deputy CEO for service delivery, says modifying elevated tracks would be harder than modifying the unused center lane in downtown tunnel stations.
Since improvement efforts started in November, hours of disrupted service were lowered by half, to 2.5 hours per month, but more gains are needed, Gutierrez reported Thursday to a transit board committee. Trains are stalling more often but workers are restarting them quicker, he said." (Lindblom)
We're glad progress is being made and solutions are being identified. We hope the majority of disruptions will be fixed somehow, so that we can get a reliable subway circulation system like we expected.
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