Selby Canal, Tankard's Culvert

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

MATERIALS: limestone and gritstone headwalls, wing walls, waterway channel walls, and culverts, built on timber foundations.

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 two culvert tunnels beneath the canal bed. The waterway channel walls have depressed angled U-plans, with straight lengths of wall that are splayed out at either end.

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 two courses of large ashlar limestone blocks; below this level the inner face of the sump is battered by stepped stone courses, which terminate either side of a recessed vertical central panel set at the internal apex of the sump, with two 1.75m high segmental stone arch culverts at its base. The two culvert tunnels pass beneath the canal channel to the opposite sump. The upper surface of the two sumps have a grass surface and the western surface acts as the towpath. The headwalls above the wing wall sections of the west sump rise one course in height before their termination on the landward ends. The open rear ends of the sumps are blocked by silt and changes in ground levels and do not have drainage channels. The opposing parallel masonry waterway channel walls form a 5.77m wide passage through which the canal passes; the ends of the channel walls splay back and the terminations of the wall ends abut lengths of dry-stone bank revetments, marking the junction with the adjacent canal banks.