Crossing solution

Construction of concrete piers to support a new road bridge across the river Swale in Kent, UK has been fast tracked through use of mast climbing work platforms from Alimak Hek supplied by access rental specialist Adastra Access The work forms part of a UK£ 100 million (€ 150 million) project to replace the existing lift bridge with a permanent link with sufficient headroom for shipping. The 1,25 km long bridge will be supported by 18 pairs of tapered reinforced concrete piers – five within the tidal estuary and 13 over land – which vary in height up to 30 m. The diameter of the columns tapers from a maximum of 3,85 m at the base to a uniform 3 m at the top, which meant that a bespoke solution was needed.

Adastra's Peter Hoare said, “The changing profile was an unusual problem. Scaffolding was an option but would have been extremely time consuming, as the framework would have needed to be extended with each lift and would have limited access.”

Alimak Hek proposed using two independently operated mast climbing platforms with a specially profiled 7,5 m long deck, which could be adjusted to meet the varying column dimensions. Contractor Edmund Nuttall used eight of the platforms, working in pairs to give unobstructed access and achieve a 7 m column lift per day. The platforms can carry payloads of up to 1200 kg to allow transportation of personnel and materials.