Berkeley Hills Tunnel
|This article needs additional or better citations for verification. (June 2012) (Learn how and when to remove this template message)|
|Location||Alameda County, California|
|System||Bay Area Rapid Transit|
|Crosses||Berkeley Hills, Hayward Fault|
|Start||Rockridge Station, Oakland|
|End||Orinda Station, Orinda|
|No. of stations||None|
|Opened||May 21, 1973|
|Owner||San Francisco Bay Area Rapid Transit District|
|Operator||San Francisco Bay Area Rapid Transit District|
|Line length||3.1 mi (5.0 km)|
|No. of tracks||2|
|Track gauge||5 ft 6 in (1,676 mm)
|Electrified||Third rail, 1000 V DC|
|Tunnel clearance||16.8 feet (5.1 m)|
|Grade||1.2% (2% max)|
While the tracks run in the median of California State Route 24 on both sides of the tunnel, the Berkeley Hills Tunnel allows the tracks to take a straighter alignment offset to the north of the Caldecott Tunnel.
The tunnel bores through the Berkeley Hills east of Berkeley and Oakland a distance of 3.1 miles (5.0 km) through a variety of rock strata, most of which are soft and porous. The earthquake-active Hayward Fault bisects the tunnel about 900 feet (270 m) inside the west portal (Oakland side). There are 2 bores, each 17.5 feet (5.3 m) in diameter, spaced 50 feet (15 m) apart. Pedestrian cross-tunnels are spaced every 1,000 feet (300 m) for emergency evacuation in case of fire, etc. There is a ventilation structure at the east portal with roll-down doors that can close off the tunnel end to allow air to be sucked out or blown in.
Boring was completed in February 1967 after 465 work days. The tunnel was opened for revenue service in 1973.
On December 4, 2013, a BART train suffered mechanical braking problems and made an emergency stop in the Berkeley Hills Tunnel near Rockridge station. Eleven people were treated for smoke inhalation.
- Caldecott Tunnel — motor vehicle tunnels (4 bores), running approximately parallel to the Berkeley Hills Tunnel
- List of tunnels in the United States
- "Figure 12".
- Rogers & Peck. "Engineering Geology of the Bay Area Rapid Transit (BART) System, 1964-75". Index of /~mly/www.geolith.com. Geolith Engineering. Retrieved 22 June 2017.
- Berkeley Gazette, October 24, 1966, p.13
- Shields, Brian (December 4, 2013). "BART Brake Smoke Causes Injuries in Caldecott Tube". KRON4. Retrieved 2013-12-05.
|This article relating to rapid transit systems in San Francisco is a stub. You can help Wikipedia by expanding it.|
|This United States tunnel–related article is a stub. You can help Wikipedia by expanding it.|