Selby Canal, Brayton Tunnel

Canal culvert, 1778, designed by William Jessop engineer for the Aire and Calder Navigation Company.

MATERIALS: limestone and gritstone headwalls, wing walls, waterway channel walls, and a culvert, built on timber foundations. The upper surface of the north sump headwall is paved in stone setts.

PLAN: a pair of inverted horse-shoe plan walled sumps lined by headwalls with open backs to either side of a walled waterway channel, linked by a culvert beneath the canal bed. The waterway channel walls have a depressed U-plan; the northern wall has straight side lengths with a gently curved central section, and the southern wall is more angular and the central section is also straight.

DESCRIPTION: each sump headwall is capped by a course of gritstone blocks, into which recesses have been cut to receive timber railing posts that were retained by wrought-iron straps fixed in lead. Below the capstones are three courses of large ashlar limestone blocks laid on a band of five courses of blue engineering bricks, which runs the circumference of the structure. Below this level (the water-level) each side or wing wall of the sump is battered by stepped stone courses that terminate in large ashlar quoins either side of a slightly recessed vertical central panel, with a 1.75m high segmental stone arch culvert at its base. The culvert floor is laid in timber and it passes beneath the canal channel to the opposite sump. The upper surface of the north sump forms a 3.73m wide towpath paved with stone setts, while the upper surface of the south sump is grassed. The opposing parallel waterway channel walls form a 5.77m wide passage through which the canal passes. The open rear of the north sump feeds into a stream that runs parallel to the towpath, while that of the south sump is fed by a stream from the south-east that drains the land of Henwick Hall Farm.