Selby Canal, Brayton Tunnel

The Selby Canal Brayton Tunnel is a canal culvert built in 1778, designed by engineer William Jessop for the Aire and Calder Navigation Company. It features limestone and gritstone headwalls, wing walls, waterway channel walls, and a culvert, all constructed on timber foundations. The upper surface of the north sump headwall is paved with stone setts.

The structure has a pair of inverted horse-shoe plan walled sumps, lined by headwalls with open backs on either side of a walled waterway channel, connected by a culvert beneath the canal bed. The waterway channel walls have a depressed U-plan; the northern wall has straight sides with a gently curved central section, while the southern wall is more angular with a straight central section.

Each sump headwall is topped with a course of gritstone blocks, featuring recesses for timber railing posts secured by wrought-iron straps fixed in lead. Below the capstones are three courses of large ashlar limestone blocks resting on a band of five courses of blue engineering bricks encircling the structure. Below the water level, each wing wall of the sump is battered with stepped stone courses that end in large ashlar quoins beside a slightly recessed vertical central panel, which has a 1.75-meter high segmental stone arch culvert at its base. The culvert floor is made of timber and extends beneath the canal channel to the opposite sump. The upper surface of the north sump serves as a 3.73-meter wide towpath paved with stone setts, while the south sump is grassed. The parallel waterway channel walls create a 5.77-meter wide passage for the canal. The open rear of the north sump connects to a stream running parallel to the towpath, while the south sump is fed by a stream from the southeast that drains the land of Henwick Hall Farm.