In the San Francisco Bay Area, a Bechtel joint venture designed and built the world's largest and most advanced rapid-transit system.
A first-of-a-kind effort, the Bay Area Rapid Transit System (BART) enabled riders to leave their motor vehicles at home, cutting down on street, bridge, and highway traffic; speeding travel time; reducing air pollution; and promoting commerce as well as recreation.
In the decades since its debut, BART has transformed the daily lives of Bay Area residents—for the better.
It has been honored with designation as a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers. BART is in the company of the Golden Gate Bridge, Panama Canal, and Hoover Dam as one of the "Top Ten Public Works Projects of the 20th Century" as cited by the American Public Works Association.
Inside the project
The Bay Area Rapid Transit District asked a Bechtel joint venture to develop engineering data, a preliminary design, and estimates for a radically new rapid-transit system. The plans were approved in 1962 and the joint venture was given the green light to perform detailed engineering and manage construction.
The project team constructed the 3.6-mile- (5.8-kilometer-) long underwater passage in 57 sections. Fabricated above ground, the concrete-and-steel modules were floated into place, immersed—with their ends sealed—into a trench spanning the bottom of San Francisco Bay, between San Francisco and Oakland. Crews made watertight connections between the sections, removed the end caps, and secured the entire tube.
The BART project's most dramatic feat, the Transbay Tube, a submerged tube across San Francisco Bay, was completed in 1969. The project also included a hard-rock tunnel through the Berkeley hills.
Bechtel delivered more than 70 miles (115 kilometers) of wide-gauge, double-track, ballast-free, fully automated electric railway—which later extended to 104 miles (167 kilometers). The original system proved so effective that the length of BART railway has grown by nearly 50 percent. BART now operates nearly 700 revenue-producing vehicles.
Our continued role
Bechtel continued its role with BART as general engineering consultant on a $2.7 billion extension program in four different counties, including service to and from San Francisco International Airport. We later served as general engineering consultant for a $1.5 billion seismic retrofit program.
Experts grappled with a high water table, seismic considerations, buried ships and other artifacts, and a tangle of underground utilities—many of them uncharted, owing to their installation during the course of the previous century building the tunnels and cavernous stations below Market Street in downtown San Francisco.
To deal with the wet, muddy environment beneath San Francisco's busy Market Street, crews did their excavation work entirely under compressed-air conditions.