Twin Peaks Tunnel

Twin Peaks Tunnel

Twin Peaks Tunnel at Forest Hill Station
Overview
Line	K Ingleside  L Taraval  M Ocean View  T Third Street  S Castro Shuttle
Location	San Francisco, California
Coordinates	East portal: 37°45′43″N 122°26′13″W / 37.76194°N 122.43694°W / 37.76194; -122.43694 West portal: 37°44′29″N 122°27′56″W / 37.74139°N 122.46556°W / 37.74139; -122.46556
System	Muni Metro
Start	Eureka Station (closed)
End	West Portal Station
No. of stations	3 (2 open, 1 closed)
Operation
Opened	February 3, 1918; 99 years ago (1918-02-03)
Owner	San Francisco Municipal Transportation Agency
Operator	San Francisco Municipal Railway
Character	Underground subway tunnel for light rail/streetcar system
Technical
Line length	2.27 mi (3.65 km)
No. of tracks	2
Track gauge	4 ft 8 1⁄2 in (1,435 mm) (standard gauge)
Electrified	Overhead lines, 600 V DC
Tunnel clearance	25 ft (7.6 m)
Route map
Market Street Railway original portal demolished c. 1970s Market Street portal never used to Market Street Subway Eureka closed 1972 Twin Peaks Forest Hill West Portal Inbound : sign changes to This diagram: This diagram:

The Twin Peaks Tunnel is a 2.27-mile (3.65 km)-longlight rail/streetcar tunnel in San Francisco, California. The tunnel runs under the Twin Peaks and is used by the K Ingleside, L Taraval, M Ocean View, and T Third Street Muni Metro lines. The S Castro Shuttle also uses the tunnel for AT&T Park game day runs.

The tunnel was opened on February 3, 1918. The eastern entrance to the tunnel is located near the intersection of Market and Castro streets in the Castro neighborhood, and the western entrance is located at West Portal Avenue and Ulloa Street in the West Portal neighborhood.

The service through the tunnel has evolved from streetcars into light rail, and while there are longer light-rail tunnels elsewhere (such as Portland's Robertson Tunnel), the Twin Peaks Tunnel remains one of the world's longest streetcar or light-rail tunnels. There are two stations along the tunnel, Forest Hill Station, near the western end, and the now disused Eureka Station, near the eastern end.

When the Muni Metro system and Market Street Subway were built, they were connected to the Twin Peaks Tunnel to be used by the K Ingleside, L Taraval and M Ocean View lines. The Eureka Station was closed, and the Metro lines stop at the nearby Castro Street Station instead.