13 December 2004
Californian's transport authorities have recommended development of a simpler option for the main span of the San Francisco-Oakland Bay Bridge in parallel with rebidding the original design.
A single bid was received earlier this year for the self-anchored suspension bridge (SAS) contract. Soaring steel prices were largely responsible for the price being nearly double the original budget. The California Business, Transportation & Housing Agency and California Department of Transportation rejected the bid and looked at six alternatives for completing the bridge. A report published on Friday narrows the options to two which should be considered further, but says that neither stands out as the obvious choice. The options are to:
- repackage and re-advertise the SAS
- extend the Skyway Bridge (currently under construction) to Yerba Buena.
A package of modifications is recommended to make the SAS contract more suitable for bidding. Measures include waiving the requirement to use domestic steel and developing alternative strategies for insurance and bonding. The SAS is seen as giving a high likelihood of achieving the seismic safety requirements but has potential for cost increases.
Extending the Skyway Bridge would mean abandoning plans for a "signature" main span in favour of a simpler box girder structure. This has the potential to reduce costs and construction risks, says the report, but savings could be lost due to delays in obtaining consensus and permits.
The report dismissed the other four options. These included three different cable-stayed designs and a modification of the SAS design to have concrete towers and decks.