Dent Head Viaduct
between Blea Moor Tunnel and Artengill Beck, Dentdale, Cumbria
John Sydney Crossley
1870 - 1875
Railway Viaduct |
ICE reference number
photo Paul Dunkerley / ICE R&D Fund
The southern section of the Settle & Carlisle Railway — the only mainline mountain railway in the country — features some major engineering works. Among these are two major viaducts that lie close together between the Blea Moor Tunnel and Dent Station: Dent Head Viaduct and Arten Gill Viaduct.
Dent Head Viaduct is 350.5m above sea level. It takes the rail line across the head of Dentdale just north of Blea Moor Tunnel. Crossley designed it as part his work on the whole railway. He was chief engineer to the Midland Railway, the builders of the line.
The 183m-long viaduct is constructed in masonry, on a slight curve in plan, and consists of 10 arches. These are segmental (almost semi-circular) and span 13.7m each. They have stepped arch quoins. The rails are 30.5m above ground level at the highest point. Sold masonry parapets run either side.
Crossley wanted to minimize the chance of progressive collapse should disaster befall the viaduct, so the arches are arranged in two sets of five separated by a wide pier in the centre. All the piers are tapered, with prominent arch springings. The abutments and central pier are hollow — the abutments having four chambers, the central pier two.
Work on Dent Head Viaduct was begun by John Ashwell (who also worked on Ribblehead Viaduct) but his financial difficulties meant that the Midland Railway had to take over in 1871. They completed the work using men they hired directly.
Repairs were made to the viaduct in 2003. Work included the replacement of shattered masonry with coloured concrete, pressure grouting work, the installation of tie bars and pattress plates to match those already there, the installation of scour protection to the pier adjacent to Fell End Gill, and the replacement of asbestos cement rainwater items with cast iron. Further repairs were carried out to the pier just south of the central pier in 2006.
Eleven-span Arten Gill Viaduct lies a little further north.
Contractor: initially John Ashwell, then Midland Railway direct labour
Architect (2003): Potts Parry Ives & Young
Contractor (2003): Edmund Nuttall Ltd
Research: PD and AJD