Railway accommodation bridge BIF/11 at NZ 225 310

This is a railway accommodation overbridge, built in 1885 as part of the Spennymoor Branch of the North Eastern Railway Company. The bridge carries the railway line over a cutting. It is constructed primarily of snecked sandstone, with much of the masonry rock-faced and margined, and has ashlar dressings. The arch itself is formed of red brick.

The bridge has a single segmental arch, 25.1 metres wide, with a 7.9-metre span and a height of 4.42 metres at the crown. The arch sits between abutments that curve outwards to form wing walls, which blend into the sides of the cutting. The eastern side of the cutting is slightly higher, and the bridge deck slopes gently towards the west.

The masonry of the bridge is largely laid in irregular horizontal courses, with the elevations rock-faced and margined, except for the parapets, which are rock-faced only. The stepped voussoirs of the arch rings and the quoins of the abutments are emphasised by chamfering, creating a V-grooved effect that continues through the underside of the voussoirs. The soffit of each arch ring is simply tooled. The abutment walls under the arch barrel are rock-faced but not margined. The arch rings spring from skewback stones set above impost bands; individual voussoirs have stepped ends that key directly into the spandrels.

The parapets are distinguished from the spandrels by a near-horizontal string course at deck level, and the stonework here appears darker than elsewhere on the bridge. The impost bands and string coursing are ashlar, featuring a concave lower moulding that transitions to a square middle and angled upper section. The pilaster strips on the abutments extend upwards through the parapets as piers, with the parapets continuing beyond these piers as curving wing walls, terminating in end piers. All piers are rectangular, break forward on their external faces, and have pyramidal caps that project slightly above the coping stones of the adjoining parapets and wing walls, due to the slight downward angle of the latter to facilitate rainwater runoff.