HS2 pushes 4,600-tonne bridge over M6 in UK first

The HS2 railway project has successfully deployed a 4,600-tonne bridge section over the M6 motorway using innovative "fully restrained" technology, marking a UK first for motorway bridge installation.

Engineers on the HS2 project have achieved a UK first by sliding a massive 4,600-tonne bridge section across the M6 motorway without closing it to traffic. The 4,600-tonne structure was maneuvered into place during a 17-hour operation over the weekend.

This marks the first time the so-called “fully restrained” technique has been used on a British motorway. The method was developed in close collaboration between main contractor Balfour Beatty VINCI and National Highways to minimize disruption to road users.

In practice, this means the 315-meter-long eastern section of the M6 South bridge was pushed forward using winches at a speed of 13 meters per hour. Meanwhile, the structure glided across special pads made from the same material used in non-stick frying pans to reduce friction.

“We are pioneering new approaches to deliver more efficiently and with less impact on our neighbors. Most importantly, we’ve been able to cut in half the number of times we’ve had to close the motorway,” says Caroline Warrington, Head of Delivery at HS2 Ltd.

The project has now reached the halfway point. In 2026, the process will be repeated when a parallel western section is installed to carry trains heading south.

Furthermore, the bridges’ hollow double-box construction is built from weathering steel that develops a protective rust layer, which in turn eliminates the need for maintenance painting. Each bridge is supported by four pairs of concrete piers, the tallest measuring 9.9 meters.