A small stone-built dock adjacent to Crockherbtown lock, no.50, (NPRN 85381) immediately north of the Queen Street tunnel (NPRN 85380) on the Glamorganshire Canal (NPRN 34425).

From 1850, this dock was a site of the forty-ton capacity boat weighing machine constructed in 1836 by Brown, Lenox & Co of Pontypridd and originally sited at Ton Lock in Tongwynlais. The machine consists of six round pillars with plain capitals supporting a structure from which hangs a cast-iron cradle suspended on four radial rods. In 1894 it was moved to a site on North Road (NPRN 85404. It was dismantled in 1955 and re-erected in 1963 at the Waterways Museum, Stoke Bruerne, Northamptonshire. It is currently (2018) on display in the garden of the National Waterfront Museum, Swansea.

(Sources: Rowson and Wright, The Glamorganshire and Aberdare Canals, vol. II, ch. 9 `The Boat Weighing Machine? (2004); National Waterfront Museum, Swansea)
A.N. Coward, RCAHMW, 02.07.2018