Incredible time-lapse footage shows a 12,600-ton bridge being slid into place across a highway in a world-record-setting engineering feat.

Around 450 people spent 40 hours over the Christmas week slowly positioning the gigantic structure over the M42 in Warwickshire, England, at a speed of around 15 feet per hour.

The method involved building the entire 282 feet (86 meter) bridge on land next to the motorway over a six month period. During the planning period, civil and structural engineers then designed a sliding mechanism that allowed it to be pushed into place—like a 21st century version of the wooden rollers of the ancients.

The operation took place during a 10-day closure of the roadway (between Junctions J9 and J10) which is on-schedule to reopen tomorrow, January 3rd. The new Marston Box Bridge will carry a high-speed railway towards Birmingham and London.

"This is the first box slide of its kind over a motorway in the UK, and we believe it's also the world's longest slide, so it's a great achievement for HS2 as we quickly approach peak construction," said Mike Lyons, the civil delivery director of the firm behind this genius feat, HS2 Ltd.

"It's fantastic to celebrate another big milestone for a project that is already providing work for almost 30,000 people today, and in the future, it will encourage people to use zero carbon public transport."

HS2 claims the construction method, which allowed it to be moved into place in one movement, dramatically reduced disruption for drivers, compared with building the bridge in place.

"We're extremely proud to have successfully delivered the world's longest box slide," said Sasan Ghavami, one of the construction directors with Balfour Beatty VINCI, the contracting firm that, along with HS2, worked with National Highways to deliver the ‘intricate' operation to the West Midlands region.

WATCH the time-lapse below… 

SHARE This Incredible Feat Of Engineering With Your Friends…