Merit: Scarborough Footbridge, York
Reminiscent of Viking longboats, a new weathering steel pedestrian and cycle bridge has improved access between York railway station and the city centre.
Architect: Network Rail
Structural engineer: AECOM
Main contractor: AmcoGiffen
Client: City of York CouncilSpanning the River Ouse in York, Scarborough Footbridge provides a new pedestrian and cycle link between the city centre and main railway station.
The scheme comprised the replacement of the existing narrow lattice u-frame superstructure and steep step access with a widened architectural weathering steel pedestrian bridge with step-free approaches.
The overall structure and approach parapets are said to be reminiscent of Viking longships, providing a fitting aesthetic appearance for the centre of York, which was once the main stronghold of the Norsemen’s British possessions.
The bridge comprises two 22m-long main river spans, which are formed of prefabricated box girders with integral curved parapets and cantilevered deck plates. Meanwhile, two 10m-long side spans cross over the existing river footpath and are formed of prefabricated u-troughs with integral parapets and deck plates to match the main river spans.
Stability of the cantilevered main spans was achieved with mechanical uplift bearings. Tensioned straining wires run through integral eyelets on the parapets, which are anchored into masonry clad anchor blocks at either end of the structure.
The approach ramps and stairs at either end of the structure are flanked by bespoke fabricated painted steel curved parapet panels with a stainless steel top rail and integrated handrail lighting. The steelwork elements of the scheme are said to complement the masonry blocks and stone cladding to provide a mix of modern and historic elements to enhance the local conservation area.
The architectural and outline structural design was developed by Network Rail on behalf of City of York. AmcoGiffen were appointed as main contractor for the scheme and they selected AECOM as lead designers to develop the project through detailed design.
Early engagement and implementation of a ‘safety by design’ philosophy led to the project team developing the outline reference scheme to deliver a safe, economical and innovative solution, which greatly enhanced buildability and minimised risks, not only during construction, but with future inspection and maintenance operations in mind.
AECOM Regional Director, Transportation, Peter Robinson says: “To minimise weight and maximise prefabrication, steel was the obvious choice for the scheme.
“Steelwork was also beneficial as it helped form a lightweight, aesthetic structure that required minimal work at height over water and therefore caused minimal disruption to the operational railway.”
The main spans were modified to a fully prefabricated box girder with integral parapet posts and a cantilevered deck plate to simplify construction, limit lifting operations, remove joints and potential hidden critical elements, reduce time spent working at height over the river and improve durability.
The judges say, the project used its location, adjacent to Scarborough Rail Bridge, to enable delivery and installation of large preassembled units using the railway. The bridge wholly fulfils the brief, promoting sustainable transport for all users through the city.