Bay Area Rapid Transit System

San Francisco’s Bay Area Rapid Transit (BART) system was like nothing attempted before. When BART began service in 1972, it was the first fully automated transit system in the world. Bechtel’s work to complete the original BART system received a dozen major engineering awards and set a new standard for mass transit, inspiring similar systems in Caracas; Washington, D.C.; and São Paulo, all of which Bechtel helped build. 

Bechtel continued its role with BART as general engineering consultant on a $2.7 billion BART extension program. The extensions were constructed from 1993 to 2003 in four different counties and included an extension to San Francisco International Airport.

Today, Bechtel serves as general engineering consultant for the $1.5–billion BART Seismic Retrofit Program, a long-term program to upgrade the original system to the latest seismic standards. The program has been ongoing since 2000, and is slated for completion in 2009.

BART remains an engineering achievement of immeasurable importance. It has been honored with designation as a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers and is in the company of the Golden Gate Bridge, Panama Canal, and Hoover Dam as one of the American Public Works Association’s “Top Ten Public Works Projects of the 20^th Century.”

Details

The San Francisco Bay Area Rapid Transit (BART) system took the 19^th century concept of mass transportation and vaulted it into the 20^th century. BART was among the first systems designed to be fully automated and computer controlled, right down to the fare collection.

The BART system originally spanned three counties, including 123 kilometers (74 miles) of track and 34 stations, and presented numerous challenges for the Bechtel joint venture. A primary challenge was building a 6-kilometer (3.6-mile) tube along the floor of San Francisco Bay. The tube was built in 330-foot-long sections that would rest in a trench at the bottom of the Bay, requiring exacting design and seismic studies before construction could begin. For excavation of subway tunnels 80 to 100 feet below downtown San Francisco, sandhogs operated under compressed-air conditions to hold back mud and water. They had to work in the midst of a hundred years’ worth of underground infrastructure and in areas once part of San Francisco’s harbor that were rich with buried ships and other artifacts. Construction of underground stations and cut-and-cover railway boxes employed slurry walls and other shoring systems. In addition, planning for BART’s aboveground portions included landscape architecture and right-of-way beautification to ensure that the railroad would be aesthetically pleasing.

As general engineering consultant for BART’s extensions program, Bechtel led a joint venture in increasing the system to a total of 172 kilometers (103 miles) and 43 stations. The extensions connected BART with East Bay cities including Pittsburg and Pleasanton and connected the Bay Area’s major economic centers with San Francisco International Airport. Bechtel provided program management services as well as engineering design and design support during construction.

For the Seismic Retrofit Program, Bechtel is applying state-of-the-art upgrades to improve BART’s ability to safely withstand a major earthquake and expedite return to service. Bechtel leads a team of consultants and convened an independent panel of world-renowned experts. The first milestones for the program have been completion of a comprehensive study of the system’s vulnerability, development of retrofit concepts, and prioritization of retrofit work. Current work entails development of design criteria and retrofit strategies for the structural elements of the system along with support through final design and construction of retrofits.