Conisbrough Viaduct

Railway viaduct, 1906 to 1909, of brick construction, with a lattice girder river span.

MATERIALS: the main structure has a core of red bricks faced by two courses of Staffordshire blue engineering bricks, and the river-span is a lattice girder bridge.

PLAN: a double track, narrow rectangular plan 482.8m long viaduct, aligned west-by-north-west to east-by-south-east.

DESCRIPTION: the viaduct spans the River Don Valley, approximately 1.08km north-east of Conisbrough Castle, set between Foulsyke Wood and Nearcliff Wood, with the abutments blended into the valley sides. The viaduct is 482.8m (528yds) long and comprises 21 x 16.76m (55ft) round arches, ranging from 12.19m (40ft) to 35.05m (115ft) in height. There is a seven-arch arcade to the south of the river and two seven-arch arcades to the north, separated by a large double-pier, along with a double-pier situated to either side of the River Don. The arches rest on tapering rectangular section piers, with plain projecting impost bands and projecting drip moulds above. The parapet walls are carried on brick corbel tables and are copped with flat coping stones; refuges project out from the face of the wall above each of the piers, giving the appearance of brick posts. A pair of decorative brick buttresses project from the sides of each of the double-piers and are carried up to form posts, crowned by ashlar capstones that rise above the parapet wall; similar brick posts are situated at each end of the parapet walls. The double-piers to either side of the River Don have a projecting bedstones that support a 20-bay 45.72m (150ft) long Warren truss bridge, built of two parallel lattice girders, linked by transverse cross-bracing, beneath a metal bridge deck laid in concrete. The central six bays of each girder have longitudinal cross-bracing, while the six bays to either side have inclined bracing and the two end bays have double canted bracing. The sides of the open bridge deck are cantilevered out from the track bed and are protected by tall moulded cast-iron posts with flared bases, supporting three-bar tubular railings.