This article was taken from the April 2015 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.
How do you dismantle 51,000 tonnes of highly strung steel? With some careful forward planning. For the demolition of the old San Francisco-Oakland Bay Bridge, currently blocking the view of its new earthquake-proof replacement, California Department of Transportation engineers built a 3D computer model calculating the tensions across the bridge's different sections. Then they worked out the precise sequence in which it had to be demolished to avoid the steel springing back in their faces.
One problem: the carefully planned sequence has been interrupted by 500 stubborn -- and protected -- cormorants who call the bridge home.
Tricks to lure the birds to the new bridge include using mirrors and amplified bird calls to fool them into thinking there's a new colony nearby. But the cormorants won't move -- and work has stalled. Dealing with the birds could cost up to $17 million (£11.2m). "Since humans can't approach their nests by foot, they don't have a lot to be afraid of," says Barbara Callahan of the International Bird Rescue Centre in California, which is providing advice. Construction schedule? It's for the birds.
This article was originally published by WIRED UK
