With about three-quarters of the U.K. high-speed rail’s 2.1-mile-long Colne Valley Viaduct complete, concrete deck segment placing crossed the country’s longest canal—the 137-mile Grand Union, about 20 miles from central London. The Align joint venture of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick will place about 1,000 of the 140-metric-ton segments to carry the London-to-Birmingham HS2 high-speed rail route. The contractor has completed all 56 piers and 39 spans of what is planned to be the U.K.’s longest railroad viaduct. About 9.3 miles of elevated structures are planned along the HS2 line, as well as 65 miles of twin tunnels.