In 1858, the Derwent Iron Company lobbied the newly-formed North Eastern Railway to establish a link between Consett and the River Tyne at Gateshead. Original known as the Lanchester Railway Extension, this took three years to build, opening on 2nd December 1867 following a Board of Trade inspection by Colonel Hutchinson.

Climbing 730 feet, the engineering was severe, demanding four substantial viaducts and a 60-feet deep, half-mile long cutting for which quarter-of-a-million tonnes of earth had to be excavated.

Opposition from the Earl of Strathmore, who refused to allow an alignment through his Gibside Estate, drove the construction of Lockhaugh Viaduct which propelled the single track across the valley of the River Derwent. Comprising nine segmental arches each 60 feet in span, the structure extends for 210 yards and reaches a height of 85 feet. Built mostly in sandstone, the arches were faced with unusual yellow brick. Adjacent to the river, the piers are protected by cutwaters. Beneath the ashlar parapet is a rounded oversail.

Traffic levels were significant, with timber, bricks and coal being transported northwards to the Tyne whilst iron ore went the other way. Half-a-million passengers travelled the route in 1914. Such success brought with it the need for additional capacity, resulting in the provision of a second track. This necessitated the viaduct being widened, with a second structure erected and tied to the original one on its southern side. The newer piers still exhibit the projecting stone supports for the arch centring.

Although the passenger stations were closed piecemeal, the route survived intact for freight purposes until 11th November 1963 when the section north of Blackhill closed. The remainder survived until 1982. Durham County Council has since developed the route into the Derwent Walk Railway Path whilst the section within Gateshead is now a country park. It all forms part of the coast-to-coast (C2C) route of Sustrans’ National Cycle Network.