Tunnel No. 6 (Coast Line)

Tunnel Number 6
Overview
Other name(s)Summit Tunnel
LineUP Coast Subdivision[1]
LocationSanta Margarita, California
Coordinates35°21′06″N 120°38′06″W / 35.3517°N 120.6351°W / 35.3517; -120.6351
CrossesCuesta Pass
Operation
Constructed1893–1894
OwnerUnion Pacific Railroad
TrafficFreight and passenger trains
Technical
Length3,610 ft (1,100 m)
No. of tracks1
Track gauge4 ft 8+1⁄2 in (1,435 mm) standard gauge
Highest elevation1,323 ft (403 m)

Tunnel Number 6, or the Summit Tunnel, is a railway tunnel between Santa Margarita, California and San Luis Obispo, California.[2] It is the longest tunnel along the Union Pacific Railroad Coast Line at 3,610 feet (1.10 km) in length and is wide enough to carry a single track.[3] The tunnel under the Cuesta Pass represents the highest point along the line at 1,323 feet (403 m) above sea level.[4]

The tunnel was constructed between 1893 and 1894 by the Southern Pacific Railroad. It was enlarged between 1940 and 1959.[3] One daily passenger train, the Coast Starlight, operates through the tunnel.

  1. ^ SMA Rail Consulting (April 2016). "California Passenger Rail Network Schematics" (PDF). California Department of Transportation. p. 6.
  2. ^ Rice, Walter; Echeverria, Emiliano (2008). Rails of California's Central Coast. Arcadia Publishing. p. 87. ISBN 9780738555911.
  3. ^ a b Middlecamp, David (October 4, 2013). "Tales from the tunnels, the railroad and the Cuesta Grade". The Tribune. Retrieved September 11, 2023.
  4. ^ Highest Elevations (PDF) (Map). Union Pacific Railroad. Retrieved November 12, 2020.