View source for Sunset Tunnel

{{Short description|Streetcar tunnel in San Francisco, California, U.S.}}
{{For|the Oregon highway tunnel formerly known as the Sunset Tunnel|Dennis L. Edwards Tunnel}}
{{Use American English|date=September 2025}}
{{Use mdy dates|date=July 2018}}
{{Infobox tunnel
|name        = Sunset Tunnel
|image       = Sunset Tunnel West-1.jpg
|caption     = The western portal of the Sunset Tunnel
|line        = {{MUNI legend|N}}
|location    = [[San Francisco]], California
|coordinates = East portal: {{Coord|37|46|09|N|122|26|04|W|format=dms|display=inline|type:landmark_region:US-CA}}<br/>West portal: {{Coord|37|45|59|N|122|26|55|W|format=dms|display=inline|type:landmark_region:US-CA}}
|system      = [[Muni Metro]]
|crosses     = [[Buena Vista Park]] and nearby areas between [[Duboce Park]] and Richard Gamble Memorial Park
|status      = 
|start       = Duboce Ave & Noe St ([[Duboce Park]])
|end         = Carl St & Cole St (Richard Gamble Memorial Park)
|stations    = None
|opened      = {{start date and age|1928|10|21}}
|owner       = [[San Francisco Municipal Transportation Agency]]
|operator    = [[San Francisco Municipal Railway]]
|character   = Tunnel for [[light rail]]/[[tram|streetcar]] line
|linelength  = {{convert|4232|ft|m mi|abbr=on}}
|tracklength = 
|notrack     = 2
|gauge       = {{RailGauge|ussg|allk=on}}
|el          = {{600 V DC|conductor=overhead}}
|speed       = 
|hielevation = 
|lowelevation= 
|height      = {{convert|23|ft|m|abbr=on}}<ref name="sfgenealogy"/>
|grade       =
}}

The '''Sunset Tunnel''', originally known as the '''Duboce Tunnel''', is a {{convert|4232|ft|m|abbr=on}}-long<ref name="sfgenealogy"/> [[light rail]]/[[streetcar]] tunnel in [[San Francisco]], [[California]]. The tunnel runs under the steep hill adjacent to [[Buena Vista Park]] and is used exclusively by the [[N Judah]] [[Muni Metro]] line.

The eastern entrance is located at Duboce and Noe streets on the south side of [[Duboce Park]] in the [[Duboce Triangle, San Francisco|Duboce Triangle]] neighborhood, and the western portal is located in Richard Gamble Memorial Park near the intersection of Carl and Cole streets in the [[Cole Valley, San Francisco|Cole Valley]] neighborhood.

==History==
[[File:Sunset-Tunnel-east.jpg|thumb|left|The [[N Judah]] entering the eastern portal of the Sunset Tunnel, by [[Duboce Park]]]]

===Initial proposals===
[[Bion J. Arnold]] proposed a Mission–Sunset Tunnel in his ''Report on the Improvement and Development of the Transportation Facilities of San Francisco'' of March 1913.<ref name=Bion>{{cite report |url=https://archive.org/details/reportonimprovem1913arno |title=Report on the Improvement and Development of the Transportation Facilities of San Francisco |chapter=11. Market Street extension tunnel under Twin Peaks |pages=225–270 |author=Arnold, Bion J. |date=March 1913 |access-date=17 April 2018}}</ref> In Arnold's scheme, the Mission–Sunset Tunnel would start at [[Eureka Valley station]], which was proposed as the transfer station for passengers needing service through the [[Twin Peaks Tunnel]]. The Mission–Sunset Tunnel would serve as a feeder bringing rail, automobile, and pedestrian traffic from the [[Panhandle (San Francisco)|Panhandle region]] to the planned [[Market Street subway]].<ref name=Bion />{{rp|228}} It would also improve service to the [[Sunset District, San Francisco|Sunset District]] from the [[Mission District, San Francisco|Mission]] and other areas [[South of Market, San Francisco|south of Market]], as existing routes were circuitous or limited.<ref name=Bion />{{rp|239}}

Arnold's plan called for a two-level tunnel, with a road and pedestrian tunnel similar in cross-section to the [[Stockton Street Tunnel]] above a two-track rail tunnel.<ref name=Bion />{{rp|267–269}} Depending on the planned alignment and portal locations, the length of the Mission–Sunset Tunnel proposed by Arnold would have been {{convert|3720|–|4720|ft|abbr=on}}.<ref name=Bion />{{rp|239–240}}

[[File:Arnold (1913) pg 234 - Perspective sketch of Eureka Valley (cropped).jpg|thumb|left|upright|Sketch of Arnold's proposed Market Street extension (1913), with a Mission–Sunset Tunnel portal near Eureka & Market, per Plan 3]]
{|class=wikitable style="font-size:85%;text-align:center;"
|+ style="font-size:135%;" |Mission–Sunset Tunnel proposals (1913)<ref name=Bion />{{rp|239–240}}
|-
| scope="col" style="width:22%;" |&nbsp;
! scope="col" style="width:26%;" |Plan No. 1
! scope="col" style="width:26%;" |Plan No. 2
! scope="col" style="width:26%;" |Plan No. 3
|-
! West portal
| Carl & Cole
| colspan=2 | Frederick & Cole
|-
! East portal
| 16th & Noe
| 17th & Castro
| [[Market Street (San Francisco)|Market]] & Eureka<br/>(extension)
|-
! Length
| {{convert|4720|ft|abbr=on}}
| {{convert|4400|ft|abbr=on}}
| {{convert|3720|ft|abbr=on}}
|}
{{OSM Location map
 |coord={{Coord|37.765|-122.441}}
 |float=right
 |zoom=14
 |width=280 |height=220
 |scalemark=20
 |shape1=n-square
  |shape-color1=#f00
  |shape-outline1=#fff
  |mark-size1=20
 |mark-coord1 ={{Coord|37|46|09|N|122|26|04|W}}
 |mark-title1 =East Portal ([[Duboce and Noe station|Duboce & Noe]])
 |mark-coord2 ={{Coord|37|45|59|N|122|26|55|W}}
 |mark-title2 =West Portal ([[Carl and Cole station|Carl & Cole]])
 |mark-coord3 ={{Coord|37.761864|-122.438654}} |shape-color3 =#080
 |mark-title3 =Proposed East Portal (1913, at [[Eureka Valley station]] as a transfer point for traffic through the [[Twin Peaks Tunnel]])
 |fullscreen-option=1
 |caption=Sunset Tunnel locations
 |auto-caption=1
}}
However, further work on a tunnel to the Sunset District was postponed in favor of completing the Twin Peaks Tunnel, which opened to revenue service in June 1918.<ref name=Ring-MA71>{{cite thesis |chapter-url=http://ignacio.usfca.edu/articles/1074771.13617/1.PDF |title=Tunnels and Residential Growth in San Francisco, 1910 - 1930 |author=Ring, Vincent D. |date=May 1971 |type=M.A. |chapter=V. A Second Tunnel for the Sunset |pages=118–141 |publisher=University of San Francisco |access-date=6 August 2018}}</ref>{{rp|119}} Soon afterwards, in July 1918, a Sunset Tunnel alignment matching the as-completed route along Duboce Avenue was proposed.<ref name=Ring-MA71 />{{rp|120}}

After the [[San Francisco Board of Supervisors]] appropriated funds for a tunnel into the Sunset in September 1921,<ref>{{cite journal |url=https://archive.org/stream/journalofproceed1921sanfrich#page/796/mode/1up |title=Appropriation, $500,000, Sunset Extension, Municipal Railway |date=19 September 1921 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=16 |number=38 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |page=796}}</ref><ref>{{cite journal |url=https://archive.org/stream/journalofproceed1921sanfrich#page/832/mode/1up |title=Appropriation, $500,000, Sunset Extension, Municipal Railway |date=26 September 1921 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=16 |number=39 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |page=832}}</ref> City Engineer [[Michael O'Shaughnessy|M.M. O'Shaughnessy]] was tasked with recommending a final alignment. He considered four routes, of which two relied on surface routes (one of these would run north from [[Forest Hill station (Muni Metro)|Laguna Honda]]), one was based on Arnold's 1913 proposed routing from the Eureka Valley station, and one matched the proposed Duboce route from 1918; of these four, O'Shaughnessy preferred the Duboce route<ref name=Ring-MA71 />{{rp|121–122}} as noted in a November 1921 Board meeting.<ref>{{cite journal |url=https://archive.org/stream/journalofproceed1921sanfrich#page/994/mode/1up |title=Sunset District Extension |date=21 November 1921 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=16 |number=47 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |page=994}}</ref> The Board approved the Duboce alignment in a resolution passed on May 31, 1922 which also established the special assessment district.<ref>{{cite journal |url=https://archive.org/stream/journalofproceed1922sanfrich#page/454/mode/1up |title=Tunnel Construction Resolution of Intention |date=31 May 1922 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=17 |number=22 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |pages=454–458}}</ref> The route was opposed by several supervisors, who favored surface routes, but those were over the objections of Sunset residents, who preferred "the shorter and most direct [Duboce] route".<ref>{{cite journal |url=https://archive.org/stream/journalofproceed1922sanfrich#page/502/mode/1up |title=Reconsideration–Duboce Tunnel |date=5 June 1922 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=17 |number=23 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |page=502}}</ref>

[[File:Six Alternative Routes to the Sunset District (1924) (5190406390).jpg|thumb|left|upright=2|October 1921 study by City Engineer's office showing six proposed routes for a Sunset District Extension, including the selected Duboce alignment. Also note surface alignment along Grove, which included a short tunnel under [[Alamo Square]].]]

===Construction and opening===
Funds for test bores were set aside in June 1922<ref>{{cite journal |url=https://archive.org/stream/journalofproceed1922sanfrich#page/544/mode/1up |title=Appropriation, $1,500, Test Borings, Duboce Tunnel |date=3 July 1922 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=17 |number=27 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |page=544}}</ref> and the City Engineer's report, including detailed plans and estimated costs, were filed three months later in September. As planned, the tunnel would be {{convert|4250|ft}} long and would cost {{USD|1500000|1922|round=-4}}.<ref>{{cite journal |url=https://archive.org/stream/journalofproceed1922sanfrich#page/742/mode/1up |title=Presentation of Proposals: Duboce Tunnel |date=18 September 1922 |journal=Journal of Proceedings: Board of Supervisors, City and County of San Francisco |volume=17 |number=38 |publisher=The Recorder Printing and Publishing Company |access-date=6 August 2018 |pages=742–743}}</ref> The final route was not approved until April 6, 1925, due to "protracted political discussion."<ref name=BOE-1925 />{{rp|16}}

The contract for the Sunset Tunnel was awarded on May 10, 1926 for the low bid of {{USD|1247592|1925|round=-4}}, submitted by the Youdall Construction Company, who broke ground on the project on June 10, 1926.<ref name=BOE-1925>{{cite report |url=https://archive.org/stream/reportofbureauof19241925s#page/6/mode/1up |title=Report of the Bureau of Engineering |author=O'Shaughnessy, Michael M. |date=1924–1925 |publisher=Department of Public Works, City and County of San Francisco |access-date=6 August 2018 |pages=6; 16–17}}</ref>{{rp|6}}&nbsp;<ref>{{cite report |url=https://archive.org/stream/reportofbureauof19251926s#page/20/mode/1up |title=Report of the Bureau of Engineering |author=O'Shaughnessy, Michael M. |date=1925–1926 |publisher=Department of Public Works, City and County of San Francisco |access-date=6 August 2018 |page=20}}</ref> As designed, the Sunset Tunnel was {{convert|4232|ft}} long including approaches with a grade of 3%; inside, the width was {{convert|25|ft}} and the vertical clearance was {{convert|18|ft|9|in|abbr=on}} above the top of the rail.<ref name=BOE-1925 />{{rp|17}} The total length of the two open cuts for the approaches was {{convert|261|ft}}; the tunnel was driven largely through [[serpentite|serpentine rock]].<ref name=BOE-1927 /> The tunnel was constructed using three drifts: a pilot drift at the crown, and two at the side walls. The pilot drift was accelerated in order to provide ventilation and to explore the geologic formations, and that crown drift was "holed-through" less than a year after groundbreaking, on March 11, 1927.<ref>{{cite report |url=https://archive.org/stream/reportofbureauof19261927s#page/19/mode/1up/ |title=Report of the Bureau of Engineering |author=O'Shaughnessy, Michael M. |date=1926–1927 |publisher=Department of Public Works, City and County of San Francisco |access-date=6 August 2018 |pages=19–22}}</ref> Construction of the tunnel was completed on February 4, 1928 for a total cost of {{USD|1477618|1928|round=-4}}.<ref name=BOE-1927>{{cite report |url=https://archive.org/stream/reportofbureau19271928san#page/26/mode/1up |title=Report of the Bureau of Engineering |author=O'Shaughnessy, Michael M. |date=1927–1928 |publisher=Department of Public Works, City and County of San Francisco |access-date=6 August 2018 |pages=26–28}}</ref> After the tunnel was nearly complete, a contract was awarded to build the rail line, but work was halted under an injunction that lasted from October 1927 to May 1928.<ref>{{cite magazine |url=https://archive.org/stream/municipalemploye219271928sanf#page/n447/mode/1up |title=New Tunnel an Engineering Feat |author=Ost, Paul J. |date=October 1928 |magazine=The Municipal Employee |pages=12; 54 |access-date=6 August 2018 |volume=II |number=10}}</ref>

The tunnel was opened for revenue service on October 21, 1928 in a ceremony presided over by Mayor [[James Rolph]].<ref name="sfgenealogy">{{cite news
 |url = http://www.sfgenealogy.com/sf/history/hgtun.htm
 |title = San Francisco History - City's Tunnels
 |access-date = July 14, 2008
 |last = Wallace
 |first = Kevin
 |date = March 27, 1949
 |newspaper = [[San Francisco Chronicle]]
 }}</ref> The new "N" line recorded the second-highest gross revenues of all streetcar lines shortly after opening.<ref>{{cite report |url=https://archive.org/stream/reportofbureau19281929san#page/52/mode/1up |title=Report of the Bureau of Engineering |author=O'Shaughnessy, Michael M. |date=1928–1929 |publisher=Department of Public Works, City and County of San Francisco |access-date=6 August 2018 |page=52}}</ref> Both the Twin Peaks and Sunset tunnels were credited with spurring development in the Sunset District, with many of the homes built by [[Henry Doelger]] in the 1930s and 1940s.<ref>{{cite news |url=https://www.sfgate.com/bayarea/article/Visionary-s-ticky-tacky-landmarks-S-F-seeks-2762393.php |title=Visionary's 'ticky-tacky' landmarks / S.F. seeks to honor little homes' designer |author=Garcia, Ken |date=October 15, 2002 |newspaper=San Francisco Chronicle |access-date=3 August 2018}}</ref><ref>{{cite news |url=https://www.sfgate.com/travel/article/Growth-of-city-neighborhoods-3217001.php |title=Growth of city neighborhoods |author=Nolte, Carl |date=25 September 2009 |newspaper=San Francisco Chronicle |access-date=3 August 2018}}</ref>

===Intrusion===
Access to the tunnel is restricted to [[San Francisco Municipal Railway]] [[light rail]] trains only. Despite the access limitations, this tunnel is not well protected, and has been [[vandalism|vandalized]], copper cable has been stolen,<ref>{{cite news |url=https://www.sfgate.com/bayarea/article/N-Judah-running-again-through-Sunset-Tunnel-3192340.php |title=N-Judah running again through Sunset Tunnel |author=Cabanatuan, Michael |date=April 17, 2010 |newspaper=San Francisco Chronicle |access-date=3 August 2018}}</ref> and [[graffiti]] has been painted on the surfaces.<ref>{{cite news |url=https://www.sfgate.com/news/article/Tunnel-death-ties-up-Muni-line-3100710.php |title=Tunnel death ties up Muni line |author1=Glover, Malcolm |author2=Brazil, Eric |date=11 March 1998 |newspaper=San Francisco Examiner |access-date=3 August 2018}}</ref> From time to time, automobile drivers manage to drive their cars into the tunnel,<ref>{{cite web
 |url         = https://abc7news.com/archive/6054206/
 |archive-url  = https://web.archive.org/web/20120826082657/http://abclocal.go.com/kgo/story?id=6054206&section=news%2Flocal
 |archive-date = August 26, 2012
 |title       = Drunk drives 2 miles through train tunnel
 |work        = ABC 7 Local News
 |date        = April 1, 2008
 |author      = Terry McSweeney
 |url-status     = live
}}</ref><ref>{{cite news|last1=Chinn|first1=Jerold|title=Problems persist with drivers attempting to enter Muni tunnels|url=https://sfbay.ca/2016/09/30/problems-persist-with-drivers-attempting-to-enter-muni-tunnels/|access-date=October 4, 2016|publisher=SFBay.ca|date=September 30, 2016}}</ref> including four separate incidents in February 2017 alone.<ref>{{cite news |url=http://www.ktvu.com/news/cars-drive-in-munis-sunset-tunnel-4-times-in-the-past-month |title=Cars drive in Muni's Sunset Tunnel 4 times in the past month |date=2 February 2017 |work=KTVU |access-date=3 August 2018}}</ref>

===Trackway Improvement Project===
The Sunset Tunnel Trackway Improvement Project replaced tracks and repaired key equipment inside the tunnel, including a new [[overhead line|overhead contact system]], fire sprinkler valve refurbishment, seismic upgrades, and rebuilt platforms at [[Judah and 28th Avenue station|28th Avenue]].<ref>{{cite web |url=https://www.sfmta.com/projects/sunset-tunnel-trackway-improvement-project |title=Sunset Tunnel Trackway Improvement Project |date=December 16, 2013 |publisher=San Francisco Municipal Transportation Agency |access-date=2 August 2018}}</ref> The work, which started in November 2014, was originally planned to finish by June 2015,<ref>{{cite news |url=https://www.sfgate.com/news/article/Noise-complaint-halts-work-on-Sunset-Tunnel-in-6036238.php |title=Noise complaint halts work on Sunset Tunnel in S.F. |author=Cabanatuan, Michael |date=24 January 2015 |newspaper=San Francisco Chronicle |access-date=3 August 2018}}</ref> but was not completed until October 2017.<ref>{{cite news |url=https://www.sfmta.com/project-updates/sunset-tunnel-weekend-construction-completed |title=Sunset Tunnel Weekend Construction Completed |date=20 October 2017 |publisher=SFMTA |access-date=2 August 2018}}</ref> During some weekends, the tunnel was closed and N Judah was short-turned at [[Duboce and Church station|Church & Duboce]]. Buses were used to continue service to [[Ocean Beach, San Francisco|Ocean Beach]].<ref>{{cite web |url=https://www.sfmta.com/project-updates/sunset-tunnel-weekend-construction-resumes-july-10-13 |title=Sunset Tunnel Weekend Construction Resumes on July 10–13 |date=July 2015 |publisher=SFMTA |access-date=2 August 2018}}</ref> A combination of additional needed work that was discovered during construction, plus nearby residents challenging a night work permit, resulted in delays to the project and an additional $4 million cost for a total of $23.3 million.<ref>{{cite news |url=https://www.sfgate.com/bayarea/article/Costs-to-upgrade-Muni-s-Sunset-Tunnel-soar-12502863.php |title=Costs to upgrade Muni's Sunset Tunnel soar — partly thanks to neighbors |newspaper=San Francisco Chronicle |date=January 16, 2018 |first=Michael |last=Cabanatuan}}</ref>

==References==
{{Reflist}}

==External links==
{{Commons category}}
{{Attached KML |display=title,inline}}
* {{cite web |url=https://www.flickr.com/photos/walkingsf/8199708921 |title=Tentative Plan, Buena Vista Station, Sunset Tunnel, Duboce Avenue Route (1926) |date=10 July 1926 |publisher=City and County of San Francisco, Department of Public Works, Bureau of Engineering |website=flickr |access-date=2 August 2018}}
* {{cite magazine |url=https://archive.org/stream/municipalemploye219271928sanf#page/n447/mode/1up |title=Sunset Tunnel a Reality |author=Swanson, Walter Gaines |date=October 1928 |magazine=The Municipal Employee |page=12 |access-date=6 August 2018 |volume=II |number=10}}
* {{YouTube |id=AecezmFchg4 |title=Judah's Prius}}. Video showing N Judah train towing Toyota Prius out of Sunset Tunnel.

{{Sunset District, San Francisco}}
{{Western Addition, San Francisco}}
{{Muni}}
{{Bay Area tunnels}}

[[Category:Muni Metro]]
[[Category:Railroad tunnels in California]]
[[Category:Tunnels in San Francisco]]
[[Category:Tunnels completed in 1928]]
[[Category:Sunset District, San Francisco]]
[[Category:Western Addition, San Francisco]]
[[Category:1928 establishments in California]]