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Ironworkers make adjustments as the final deck section of new self-anchored suspension span of the Bay Bridge is lowered into place Oct. 28, 2011 in Oakland

The section is the 28th and final piece of the deck for the self-anchored suspension span, which has a total length of 2,047 feet, making it the longest span of its kind in the world, according to Caltrans.

Marking what bridge officials said was a milestone in the $6.3 billion project, crews used a large custom-built floating crane to place the section. Deck sections vary in weight — from about 560 tons to 1,670 tons — and length, from 64 feet to 229 feet.

The last two sections of the road deck — one for each of the parallel roadways — could only be installed after crews completed constructing the 525-foot tower earlier this year.

The project is expected to be finished in 2013.