Railway accommodation bridge BIF/11 at NZ 225 310

Railway accommodation overbridge, 1885 for the Spennymoor Branch of the North Eastern Railway Company.

MATERIALS: snecked sandstone, mostly rock-faced and margined, with ashlar dressings; red brick arch

PLAN: single arched between abutments with curving wing walls

DESCRIPTION: the railway runs through a cutting, and the bridge comprises a single segmental arch, 25.1m wide by 7.9m span by 4.42m high at the crown. It is set between abutments that curve out in the form of wing walls to merge in to the cutting’s sides. The eastern side of the cutting is marginally higher and the bridge deck slopes down slightly towards the west. Apart from the barrel of the arch which is red brick, the bridge is constructed from squared masonry laid in irregular horizontal courses. On the elevations, all masonry is rock-faced and margined apart from the parapets which are rock-faced only. The stepped voussoirs in the arch rings and quoins in the pilaster strips of the abutments are emphasised by chamfering to create the effect of V-grooving. The grooving continues through the underside of the voussoirs, but the soffit of each arch ring is simply tooled rather than rock-faced. The abutment walls under the arch barrel are rock-faced but not margined. The arch rings spring from skewback stones set above impost bands, and individual voussoirs have stepped ends that key directly in to the spandrels. The parapets are differentiated from the spandrels by a near-horizontal string course at deck level; the stonework of both parapets and string course appears darker than that in the rest of the bridge. Impost bands and string coursing are ashlar and have a smooth, concave lower moulding, rising to a square middle and angled upper section. The pilaster strips on the abutments continue through the parapets as piers, and the parapets continue beyond these piers as curving wing walls that terminate in additional end piers. All piers are rectangular and break forward on their external faces only, and all have pyramidal caps that rise slightly proud of the coping stones on the adjoining parapets and wing walls, largely because the upper surfaces of the latter are angled down slightly to assist the shedding of rainwater.