Tone Bridge Tangier Way Taunton

Tied-arch design

Achieving shallow construction depth was a key driver. By placing a slender steel girder each side of the carriageway supported by feature arches overhead, the engineers were able to minimise the depth of the crossbeams, and use elegant tapering cantilevers to support the footways on each side. This also kept the deck edges very thin in line with the desired objective.

The arch has an open skeletal structure with solid chords separated by triangular crossframes. In order to achieve the desired lightness, delicacy and transparency, the engineers used a clever device with twin plates in the crossframes to create vierendeel action to restrain the arch chords and enable their diameter to be minimised. This also enabled the stainless steel hangers to fit neatly within the openings and form a fan-shaped array in elevation.¹

“We are very pleased that the whole operation went so smoothly this morning, said Morrison Construction site manager Bob Stevens. The fact that it took just an hour to perform such a complex manoeuvre is testament to the six months of careful planning by Galliford Try, Somerset County Council and Mabey Bridge Fabrication. It really is wonderful to see the new River Tone bridge in place, and to have been involved in leaving a lasting legacy to the improvement of transport in Taunton.” Consultant Flint & Neill designed the bridge, and the highway design was carried out by Atkins.

opened by Transport Minister Norman Baker, September 27th 2011

The Taunton Third Way bridge, with its distinctive bowstring arches, won best Civil Engineering Project (costing up to £3 million).

The principal contractor was Galliford Try, the designers were Flint & Neil, and Moxon Architects.

The bridge spans 36 metres over the River Tone in the centre of Taunton, designed for road traffic, pedestrians and cyclists. The entire 220 tonne structure was assembled alongside the river and lifted into place in a single operation by one of Europes largest cranes.