Mile Rock Tunnel

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Mile Rock Tunnel
INSPECTION PARTY IN AUTO DRIVEN THROUGH MILE ROCK TUNNEL, AUG. 26, 1915. Department of Public Works, Map and Plan Room, photo -2545. - Mile Rock Tunnel, Under Forty-eighth HAER CAL,38-SANFRA,196-14.tif
Inspection party: August 26, 1915
Location map San Francisco County.png
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Location Map San Francisco Bay Area.png
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Overview
Coordinates 37°46′24″N122°30′32″W / 37.773356°N 122.508984°W / 37.773356; -122.508984 (south portal)
StatusActive
Operation
Opened1915 (1915)
Charactersewer tunnel (currently used for storm drain overflow)
Technical
Length4,233 feet (1,290 m) long

Mile Rock Tunnel is a utility tunnel in San Francisco, in the U.S. state of California that was originally constructed as the storm sewer outfall draining the Sunset, West Mission, Richmond, and Ingleside districts.

Contents

The tunnel travels from Cabrillo Street northward under 48th Ave to its outfall near Mile Rock Beach. [1]

History

The Mile Rock Tunnel started construction in 1914 and was completed by 1915. [2] The contract was initially awarded to Edward Malley, but he stopped work after five months because of the high cost of insurance; R.C. Storrie and Company, who were responsible for other large tunneling projects including the Twin Peaks Tunnel, assumed responsibility for the work in January 1915. [2]

Mayor 'Sunny Jim' Rolph and other officials, including City Engineer M.M. O'Shaughnessy performed an inspection of the completed tunnel using a car on August 26, 1915. The tunnel was fitted with temporary structures and lighting to allow the car to enter without the threat of flooding from the outlet, but as it was not wide enough to allow the car to turn around, the return trip was conducted in reverse gear. [2]

In 1995, the outfall portion of the Mile Rock Tunnel was connected to the new Richmond Transport tunnel, to be used as an emergency combined sewer overflow. [3]

Design

The tunnel was constructed by a combination of cut-and-cover (through soil) and boring (through rock) methods. [2]

See also

References

  1. ↑ O'Shaughnessy, Michael (December 1913). 17. PLAN AND PROFILE. SHEET 1 OF 3. CASE A, DRAWING 782. - Mile Rock Tunnel, Under Forty-eighth Avenue from Cabrillo Street to San Francisco Bay at Point Lobos, San Francisco, San Francisco County, CA (Report). Department of Public Works, City and County of San Francisco, California. Retrieved 2025-02-04.
  2. 1 2 3 4 Maniery, Mary L. (February 1995). Historic American Engineering Record: Mile Rock Tunnel (PDF) (Report). National Park Service, Western Region, Department of the Interior. Retrieved 27 July 2018.
  3. ↑ Maiolini, Steven; Klein, Steve; Essex, Randy (January 1995). "Policies influencing the design of the Richmond transport project" (PDF). Tunnelling and Underground Space Technology - TUNN UNDERGR SPACE TECHNOL. 10: 37–44. doi:10.1016/0886-7798(94)00063-Q . Retrieved 2025-02-05.
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