New steel decks for multi-span viaduct

More than 2,400t of steelwork is currently being delivered by Fairfield-Mabey to south Cumbria for the refurbishment of the Leven rail viaduct.

Taking place during a 16 week line closure, main contractor Carillion is replacing all of the 49 spans’ walkways and decks.

The viaduct was orignally built in 1857 and carries the Carnforth to Barrow-in-Furness railway across the Leven Estuary. The old structure consists of an iron/steel deck supported on brick/reinforced concrete piers, with spans varying in length from 9m to 12m, and a navigational span of 20m.

Matt Wylde, Carillion Project Manager said the importance of steel being delivered promptly is paramount as the Viaduct is scheduled to re-open on 17 July 2006.

“Steelwork for the new walkways was first to be erected and by the end of April we were halfway through installing them,” Mr Wylde said. “Then during May our ten-week deck replacement programme got into full swing.”

Apart from the widening of the Viaduct to a twin-track structure in 1863, and some pier encasement works carried out in 1915, this is the first time the decks and walkways have been completely replaced.

Dr Peter Lloyd, Fairfield-Mabey Managing Director said most of the 49 spans are around 9m in length, with the exception of the central navigational span, two 7m, a 10m and a single 12m span.

“After a detailed survey we discovered a total of 16 different deck geometries, all requiring unique 3D models, were needed,” Dr Lloyd explained.

“Our use of automation and robot welding based directly on 3D modeling means we are able to fabricate and deliver girders within a tight schedule,” Dr Lloyd said.