The Berkeley Hills Tunnel is a

tunnel A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube cons ...

which carries

Bay Area Rapid Transit Bay Area Rapid Transit (BART) is a rapid transit system serving the San Francisco Bay Area in California. BART serves 50 stations along six routes on of rapid transit lines, including a spur line in eastern Contra Costa County which uses ...

(BART) through the

Berkeley Hills The Berkeley Hills are a range of the Pacific Coast Ranges that overlook the northeast side of the valley that encompasses San Francisco Bay. They were previously called the "Contra Costa Range/Hills" (from the original Spanish ''Sierra de la C ...

between

Rockridge station Rockridge station is a Bay Area Rapid Transit station located in the Rockridge district of Oakland, California. Located in the center median of the elevated State Route 24 west of the Caldecott Tunnel, the station has a single island platfor ...

and

Orinda station Orinda station is a Bay Area Rapid Transit station in Orinda, California. The station has an island platform in the center median of State Route 24. Service at the station began on May 21, 1973, following the completion of the Berkeley Hills T ...

Design

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 through a variety of rock strata, most of which are soft and porous. The earthquake-active Hayward Fault bisects the tunnel about inside the west portal (Oakland side). There are 2 bores, each in diameter, spaced apart. Pedestrian cross-tunnels are spaced every 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. By 2017, cumulative minor damage from fault creep had significantly reduced the tunnel's cross section, to the point where BART determined it was necessary to plan for repair and mitigation against future creep. The work, which includes excavating the tunnel walls and realigning the tracks, is expected to cost $60 million.

Construction

Construction of the tunnel began in early February, 1965. The bores were holed through by March, 1967, and construction completed in July, 1968. The tunnel was opened for revenue service on May 21, 1973, with the Concord line. Material removed in the construction of the tunnel was used as fill for a concurrent expansion of the

Port of Oakland The Port of Oakland is a major container ship facility located in Oakland, California, in the San Francisco Bay. It was the first major port on the Pacific Coast of the United States to build terminals for container ships. As of 2011 it was the f ...

Incidents

On December 4, 2013, a BART train suffered mechanical braking problems and made an emergency stop in the tunnel near

. Eleven people were treated for

smoke inhalation Smoke inhalation is the breathing in of harmful fumes (produced as by-products of combusting substances) through the respiratory tract. This can cause smoke inhalation injury (subtype of acute inhalation injury) which is damage to the respirator ...

References

Berkeley Hills Antioch–SFO+Millbrae line Railroad tunnels in California Tunnels in the San Francisco Bay Area Transportation buildings and structures in Alameda County, California Transportation buildings and structures in Contra Costa County, California Rail transportation in Oakland, California Tunnels completed in 1973 {{US-tunnel-stub

Design

Construction

Incidents

See also

References