SFMTA blames construction damage for West Portal slowdown

On Wednesday, the SFMTA published a public message that opened with the phrase, “Muni Metro riders have been stuck in significant delays” in the Twin Peaks tunnel.

Admittedly, the city’s transit overseers could have made that statement pretty much any week—according to SFTMA’s own Muni performance measurement app, the M, L, and K metro lines had a combined on-time rating of just 40 percent in June.

This week is a special case, however, as trains entering West Portal Station on the inbound route have ended up mysteriously stalled.

The statement was meant to provide some explanation to frustrated riders; according to the transit agency, it has to do with ongoing work in the Twin Peaks tunnel:

This past weekend, the contractor for the Twin Peaks project completed the first of two nightly weekend shutdowns (the second will occur this weekend) to perform some routine tasks as part of the project requirements.

It appears that the equipment the construction crews were using damaged some of the components that make the automatic train control system work correctly. [...] Early Saturday morning we began to experience anomalies in our train control system that randomly stopped some trains from entering West Portal station

It’s still possible for trains to enter the tunnel, but only at “significantly reduced speed” between West Portal and Forest Hill.

Even worse, the city still isn’t sure why this keeps happening, and right now they are “currently gathering data” and hoping for a fix soon.

The Twin Peaks tunnel has been undermining SFMTA’s credibility for months now. Although the 60-day tunnel closure and renovation that ran from the end of June to the beginning of August finished on schedule, the delays it created did such a number on Muni’s always grim on-time numbers that it provoked a mayoral rebuke and a public apology.

Even worse, 51-year-old signal technician Patrick Ricketts died after a temporary support beam fell on him in the tunnel in August.

The tunnel job contractor, Shimmick Construction, did not disclose the entirety of its safety record when applying for the job, and SFMTA did not discover Shimmick’s unreported past violations at the time.

Photo by Sheila Fitzgerald

• Update: Slow Subway Service [SFMTA]
• On-Time Performance [SFMTA]
• Twin Peaks Tunnel Closes [Curbed SF]
• Mayor Drags SFMTA [Curbed SF]
• Muni Apologizes To Riders [Curbed SF]