Aberdulais Aqueduct

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

The monument consists of the remains of an impressive masonry aqueduct with contiguous lock and toll-house on the Tennant Canal. The canal was completed in 1824 as a private waterway 8.5 miles long linking Port Tennant harbour at Swansea with the Neath Canal at Aberdulais. It was promoted by George Tennant, and the engineer for the canal and the aqueduct was William Kirkhouse. The aqueduct, crossing the River Neath, was the largest structure on the whole main line, and the adjacent lock was the only one in its entire length. The aqueduct itself is just over 100m long with eleven low arches. The most easterly arch, near the junction basin, was of cast iron to maximise clearance over an early river navigation channel (of the 1740's) and tramroad which passed underneath. The other ten arches were masonry. The towpath was on the downstream side, with a stone parapet of which only a fragment now survives at its east end, the rest having been removed as a result of flooding. The lock abutted the aqueduct at its west end, and was of typical dimensions of the South Wales canals, taking boats 18m long by 2.65m beam. The constriction of traffic made this the most appropriate place for the toll house, which is a small stone structure with a pyramidal roof adjacent to the lock.

The monument is of national importance as one of the largest aqueducts on any South Wales canal, and as an impressive group of canal structures. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The structure itself may be expected to contain archaeological information concerning chronology and building techniques, together with a strong probability of environmental evidence. Aqueducts may be part of a larger cluster of monuments and their importance can further enhanced by their group value.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.