In a five-hour operation Aug. 10, the team building the U.K.'s HS2 high-speed railroad slid a more-than-1,700-ton steel and concrete highway bridge over four existing tracks northeast of Birmingham.

The contractor on that section of track, Balfour Beatty VINCI, hired heavy-lift specialist Mammoet to roll the 276-ft-long, 69-ft-wide bridge into place on two 128-wheeled self-propelled modular transporters. The contractor temporarily covered the tracks with fill topped with aluminum sheeting to form runways for the transporters. 

Designed for the contractor by Mott MacDonald and Systra, the composite bridge's concrete deck was cast over steel girders into glass reinforced plastic permanent formwork. It was completed on a 97,000-sq-ft piled platform near its final position. 

The new structure will replace the existing adjacent brick arch bridge, which is too short to allow the new high-speed tracks beneath.