The area near the Castro Muni Metro Station is expected to be affected by construction work on the Twin Peaks Tunnel, with lane closures on Market Street and some loss of parking. (Kevin N. Hume/S.F. Examiner)

The area near the Castro Muni Metro Station is expected to be affected by construction work on the Twin Peaks Tunnel, with lane closures on Market Street and some loss of parking. (Kevin N. Hume/S.F. Examiner)

Construction on Twin Peaks Tunnel to begin November 30

Area around Castro Muni Station will see greatest impacts including lane closures on Market Street

Yet another round of construction will begin on the beleaguered Twin Peaks Tunnel November 30, less than two weeks after supervisors slammed the San Francisco Municipal Transportation Agency’s leadership for failing to successfully bring capital projects to fruition.

Construction is expected to run through February 2021 with work taking place six days a week from 7:30am to 8pm.

Crews will work for the next three months to replace the splice connections and lines overhead, upgrade the switch machine and subway lights, make trackway adjustments and perform critical maintenance to infrastructure.

“These are the key elements that keep our trains running,” the SFMTA wrote in a blog post last week.

Perhaps the largest undertaking, though, will be the replacement of the ballast, the rocky bed beneath the tracks that stabilizes the rail and facilitates proper maintenance.

The rocky underbedding was supposed to be replaced in the 2018 overhaul of the Twin Peaks Project, which was itself shrouded in tragedy and scandal including the death of a worker who was killed when a crane operator knocked over a steel beam, the failure of the contractor to disclose previous safety violations and an agency-wide operator shortage that caused significant bus service gaps during construction.

SFMTA officials first revealed in October to the agency’s board of directors that the old ballast had not been replaced as planned and, instead, was simply reused in order to “save time and money.”

Without new ballast, the trackway’s life expectancy will quickly erode as the rock degrades, so the agency has determined it must spend tens of millions of dollars to partially redo the project.

“Looking back, we acknowledge these choices were an oversight,” the agency wrote on its website.

The agency has yet to release estimate, saying only it will have more details “in the coming weeks” once it hammers out a task order with a contractor.

Work will predominantly take place on the Eureka Curve, the connector between downtown San Francisco and West Portal.

As such, the area surrounding the Castro Station is expected to see the greatest impacts to parking access and traffic lanes. One lane will be closed in each direction along Market Street between Diamond and Castro streets during active construction hours, and parking will be restricted in the same section.

Additionally, access to Market Street from Collingwood and 18th streets will be limited.

SFMTA told the Examiner it reached out to the Castro Merchant Association, West Portal Merchants, the Greater West Portal Neighborhood Association, the Duboce Triangle Neighborhood Association and the Eureka Valley Neighborhood Association with details on local impact.

Muni Metro shut down March 30 in the wake of the coronavirus pandemic, and it’s been closed ever since save for a short-lived relaunch in August that lasted only three days due to splice failures.

The Twin Peaks Tunnel project is part of the transit agency’s Subway Renewal Program, designed to target “critical subway systems and infrastructure for strategic overhauls” to improve reliability, resilience and longevity of the system once it reopens.

Subway Renewal will also attempt to rectify the “culture of fear” that permeates the workforce, which SFMTA head Jeffrey Tumlin has described as a key part of the agency’s legacy of botched capital projects.

“We are committed to promoting a more open workplace that supports our staff raising challenging questions during the course of projects to make sure the choices we make are in the best interest of the system and of the public,” according to the press release.

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