HS2 'superstructure' to be erected over listed bridge in Birmingham, under plans

Two large viaducts will sail over part of the bridge which extends from Curzon Street Station, and was built in 1838.

The viaducts, measuring 300 metres in length, will stretch from the station, across the Digbeth Branch Canal and over Ladywood Middleway. The construction has been approved but design elements are awaiting the go-ahead.

Plans propose the viaduct will split into four decks extending from the station, before merging into a single deck made of concrete above the canal. The deck covering the road will be made from steel.

The viaducts will be supported by 35 concrete piers. It is proposed that an extra four bespoke piers will intersect with the Digbeth Branch Canal.

These four piers are to be made from weathered steel, a design element intended to recall historic, canalside cranes. The bespoke steel piers will sit on top of concrete plinths.

The parapets along the side of the railway decks which will cross the canal will “include a pattern which references motifs found in the ironwork of historic bridges in Birmingham”, plans state.

They continue: “Where the proposed deck is split into 4 sections a lighter parapet is proposed on the inside edge of each section of the deck (shown in figure 4). These parapets would be made with a combination of pre-cast concrete and steel.

“This approach has been adopted to seek to increase the natural light under the deck. There is an ambition to maximise the opportunities to create usable and flexible public space under the Curzon viaduct structure.”

CGI photos show what the space could look like but plans for designing this space have not yet been submitted. However, the design of the viaducts has been considered with this use in mind.

The piers are designed in a way which reduces their visual mass. The plans also state: “Recesses on the outside faces of the V-piers have also been designed to allow for future services integration with drainage downpipes visually concealed on the inside faces of the V.”

Historic England was consulted on the plans and has confirmed it has no objections on historic grounds. This is because the plans avoid causing direct harm to the grade II listed bridge.

The Digbeth Branch Canal opened in 1799 and was built by the Birmingham Canal Navigations Company. The historic railway bridge is part of the first railway line connecting London and Birmingham, built between 1837 and 1838.

The proposed designs will be considered for approval by council chiefs on Thursday.