The Santa Susana Tunnel is a railroad tunnel that connects the Simi and San Fernando valleys in Southern California. The tunnel is credited with saving considerable time and distance between

San Francisco San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17t ...

and

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world ...

. The tunnel is long and runs through the

Simi Hills The Simi Hills are a low rocky mountain range of the Transverse Ranges in eastern Ventura County and western Los Angeles County, of southern California, United States. Geography The Simi Hills are aligned east-west and run for , and average aro ...

and

Santa Susana Mountains The Santa Susana Mountains are a transverse range of mountains in Southern California, north of the city of Los Angeles, in the United States. The range runs east-west, separating the San Fernando and Simi valleys on its south from the Santa C ...

. The tunnel is located beneath the

Santa Susana Pass The Santa Susana Pass, originally Simi Pass, is a low mountain pass in the Simi Hills of Southern California, connecting the San Fernando Valley and Los Angeles neighborhood of Chatsworth, to the city of Simi Valley and eponymous valley. It h ...

History

Before the construction of the Montalvo Cutoff, the most direct rail line between San Francisco and Los Angeles ran (from north to south) to Ventura, through the Santa Clara River Valley, to Saugus, California, through the

San Fernando Tunnel Newhall Pass is a low mountain pass in Los Angeles County, California. Historically called Fremont Pass and San Fernando Pass, with Beale's Cut, it separates the Santa Susana Mountains from the San Gabriel Mountains. Although the pass was visite ...

and then to Burbank, for a distance of . Construction of the tunnel began in 1900 by the

Southern Pacific Transportation Company The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...

and was completed in 1904. The first train to use the tunnel was on March 20, 1904. With the completion of the tunnel, the distance between Montalvo and Burbank was reduced to . In 1903 the railroad opened the

Santa Susana Depot Santa Susana Depot is a train station building located near the Santa Susana Pass The Santa Susana Pass, originally Simi Pass, is a low mountain pass in the Simi Hills of Southern California, connecting the San Fernando Valley and Los Angeles ...

Rancho Simi Rancho Simi, also known as Rancho San José de Nuestra Señora de Altagracia y Simí, was a Spanish land grant in what is now eastern Ventura and western Los Angeles counties granted in 1795 to Santiago Pico, founder of the Pico family of Cal ...

providing farmers an easier method of transferring their crops and livestock to market. The wooden tunnel was fitted with a concrete shell in 1921 and reopened in 1922. In 1972, the tunnel underwent minor renovations. In 1997, officials began seeking options to restore the tunnel due to its deterioration over time. Metrolink trains had to slow down to and passengers reported swaying as well as a general lack of confidence in the tunnel's stability. Due to the separation of rock from the tunnel's concrete shell over time, the tunnel was considered vulnerable in the event of a serious earthquake. Local officials attempted to secure in federal funds to fix the tunnel but ultimately failed. In 1998, an initial was invested into the tunnel's restoration. Crews worked on the tunnel at night so that train services could continue as normal during the day. By 2000, the project's cost rose to as wooden

railroad tie A railroad tie, crosstie (American English), railway tie ( Canadian English) or railway sleeper ( Australian and British English) is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties tran ...

s were replaced with steel ones, new water pumps were installed, loose soil was excavated, and the tunnel's shell was secured with new support bolts. Crews completed maintenance on the tunnel in October 2000. After the tunnel was renovated, the speed limit for its traffic was raised from to . The tunnel is still used today as part of the

Union Pacific Railroad The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Paci ...

Coast Line. Freight service is provided by Union Pacific, and passenger services include the Metrolink's

Ventura County Line The Metrolink Ventura County Line is a commuter rail line serving Ventura County and the San Fernando Valley in Los Angeles County and the City of Los Angeles, in the Southern California system. The line is the successor of the short lived CalTr ...

and

Amtrak The National Railroad Passenger Corporation, doing business as Amtrak () , is the national passenger railroad company of the United States. It operates inter-city rail service in 46 of the 48 contiguous U.S. States and nine cities in Canada. ...

's ''

Coast Starlight The ''Coast Starlight'' is a passenger train operated by Amtrak on the West Coast of the United States between Seattle and Los Angeles via Portland and the San Francisco Bay Area. The train, which has operated continuously since Amtrak's format ...

'' and ''

Pacific Surfliner The ''Pacific Surfliner'' is a passenger train service serving the communities on the coast of Southern California between San Diego and San Luis Obispo. The service carried 2,924,117 passengers during fiscal year 2016, a 3.4% increase from F ...

''.

References

Railroad tunnels in California Simi Hills Tunnels in Los Angeles County, California Transportation buildings and structures in Ventura County, California Chatsworth, Los Angeles Santa Susana Mountains Tunnels completed in 1904 1904 in California Underground commuter rail Southern Pacific Railroad Union Pacific Railroad tunnels {{California-transport-stub