River Lock and attached bridges at Red Jacket Pill

Cadw's description

Location

Beside a footpath on the E side of the Tennant Canal, S of the Jersey Marine Gas Works and W of the M4.

History

A barge lock constructed in 1817-18 by the engineer William Kirkhouse. It allowed vessels of up to 61 tonnes to lock out of the River Neath and reach Swansea by means of a canal cut in the 1780s that was superseded by the Tennant Canal, which opened in 1824.

Exterior

The lock chamber is composed of coursed rubble stone with large dressed coping stones. At the narrower NE (river) end are rebates for the lock gates, that survive partly in situ. Beyond the gates the walls curve outwards and terminate, with a later copper-slag wall added on the S side. The SW (canal) end of the lock chamber is similar, with rebates and the partial survival of the lock gates. Beyond the lock gates is a 2-span rubble-stone bridge with segmental arch ring above the entrance to the lock and a second arch on the S side over the canal built in the 1780s, of which a canal-side wall survives in part. Beyond the lock gates the lock walls curve outwards as they do on the NE side. A later rubble stone revetment is on the N side. The bridge retains its parapet with copper-slag coping only partly on the N side. On the SE side the parapet, with copper-slag coping, curves outwards and uphill. The deck is missing from the bridge and is covered with vegetation.

Reason for designation

Listed for industrial archaeological interest as a well-preserved early river lock.