Deck erection on the U.K.'s longest train viaduct formally started on May 31 with the launch of a 770-ton sliding girder that will place around 1,000 concrete elements along the 2.1-mile-long Colne Valley Viaduct on the emerging London-Birmingham high speed railroad, known as HS2.
First used nearly two decades ago on Hong Kong's 0.8-mile-long East Tsing Yi viaduct, the refurbished 525-ft-long launch girder will travel over the Colne Valley's 56 piers to erect the deck as balanced cantilevers, with approximately 150-, 200- and 260-ft spans.