This article was first published in the March 2016 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
This supercrane is strong enough to lift entire sections of a bridge, so they don't have to be assembled in the air. The Left Coast Lifter sits atop a 117-metre barge powered by three diesel generators, and it can lift 1,750 tonnes.
It is being used to build the 4,881-metre Tappan Zee Bridge in New York state, putting prefab sections, including 106-metre pieces of steel, into place. "It takes a project of this grand scale to use a crane like this," says Ron Crockett, who commissioned the crane's construction. Not only because its size prevents it from being used in most locations, but also because a smaller-scale project might not benefit economically. "The project needs to be designed around the crane, not the other way around."
The floating crane's movements are planned months in advance, down to the finest details. All eight anchors are positioned so that they can be used for multiple operations. "With the anchoring system you can turn the entire crane," says Crockett. "The anchor winches are electronically controlled by a master console, so you can turn this crane just about any way you want." The crane can be pulled into different positions by relaxing and tightening anchor lines. Then a GPS system tracks the precise location of the crane and the load, so that each manoeuvre can be executed exactly.
What about the name -- isn't New York on the east coast? The Left Coast Lifter was built for the San Francisco Bay Bridge project. "There is no other crane of this size qualified to work in US waters," says Crockett, who was the technical director on the Bay Bridge project.
This article was originally published by WIRED UK
