‘Marathon’ bridge build completed for HS2

HS2 has completed a ‘marathon’ construction operation near Lichfield to build and move a 2,600-tonne bridge. 

The operation involved excavating 14,000 tonnes of earth, building a 140 metre retaining wall and moving the bridge deck 130 metres into place under the South Staffordshire freight railway at Streethay.

The work was carried out during a 10-week blockade. It was completed by HS2’s civils contractor in the West Midlands, Balfour Beatty VINCI, and designers Mott MacDonald as part of a Design Joint Venture with SYSTRA (MMSDJV), together with teams from 18 specialist supply chain companies.

At the end of July the 2,600-tonne bridge deck, which had been cast on land adjacent to the railway, was moved 130 metres into position using self-propelled modular transporters. 

Since then each side of the bridge was backfilled, the rail tracks were reinstated, with the railway line successfully handed back to Network Rail on August 16. It has now reopened.

At 25 meters long and 18 metres wide, the Streethay overbridge sits within HS2’s Streethay cutting and will enable HS2 trains to travel under the existing railway between Birmingham and Crewe. 

Through design development, Mott MacDonald engineers were able to reduce the total length of wall structures for the railway at Streethay from 1.6 kilometres to 420 metres, meaning 80% less concrete is needed - saving around 420,000 tonnes of carbon, supporting HS2’s ambition to cut carbon on the project.

The Streethay bridge sits on top of the larger 420 metre long retaining wall structure which will have two additional bridges crossing it – the south bound A38 slip road bridge, and the Rykneld Bridge which carries the A38 north bound slip road and the A38 north and south bound carriageway.

At its peak, more than 150 people worked on the complex construction operation, with teams from 18 specialist companies, delivering design, surveys, piling works, bridge build, concrete pouring, crane operations, reinforcements, modular transportation, track and systems removal and reinstatement.

The work was delivered in parallel to the construction of the nearby Fulfen Wood bridge, which involved moving a giant 6,200-tonne single span structure under the West Coast Main Line - the UK’s heaviest drive to install an intersection bridge.

Caroline Warrington, senior project manager at HS2, said: “This is a fantastic example of a project within a project at HS2, pulling together teams from 18 specialist supply chain companies from the West Midlands as well as other regions, to deliver a complex construction operation. 

“These are some of the many companies that are helping to build Britain’s new zero carbon railway, supporting thousands of jobs right across the country.

“Unlike the Fulfen Wood bridge structure, which was constructed entirely off-site, the Streethay bridge walls under the railway embankment had to be constructed during the blockade. This required a 72 day blockade, making it more of a marathon than a sprint!"