BASE OF THE NEW BAY BRIDGE TOWER

THE NEW ICONIC BAY BRIDGE TOWER.

A self-anchored suspension, the longest span of its kind in the world, and it has a tower that reaches 525 feet above the bay.

bay bridge tower

When it is a high profile job and it has to be done right the first time, C. H. Bull is the “A Team”. C. H. Bull Company was asked to supply a jacking system for lowering the 3500 ton base (that is 7,000,000 pounds) of the main Bay Bridge tower 28 feet to the bottom of the San Francisco Bay.

noun: A-team; 1.a group of elite soldiers or the top advisers or workers in an organization.

Pictured is the east end of the new bridge approaching the base of the tower. Two of the twenty – 500 ton jacks in position with the threaded rod on each side of the jacks attached to the 3,500 ton base.

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C.H. Bull worked with the design engineers and came up with a system using threaded rod to safely lower the base. Each corner had four 500 ton jacks and eight threaded rods which were attached to the base.

One side of the base each corner with 4 jacks

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3 of the 4 jacks on one corner

3 of the 4 jacks

A closer look at the jack arrangement

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To equal the load a 3 point jacking system was used. Two sets of jacks were connected to one port on the manifold. With a 3 point system the load was always equal on all 4 groups of jacks. The base was safely lowered to the bottom of the Bay and then filled with another 3500 tons of concrete.

This is the base lowered to the bay bottom. You are able to see 3 of the 4 corners with the threaded rod extending skyward.

lowered base