Clydach canal lock

Clydach canal lock

The lock on the Swansea Canal near the Vale Inco “Mond” nickel works was one of 36 locks that were built to lift the canal 120 metres (400 feet) between the docks in Swansea and Hen Neuadd, Abercraf.

The lock chamber was constructed just large enough to accommodate a horse-drawn Swansea “day boat”. Although this lock is typical in its layout and construction, there is a detail that makes it unique when compared with other locks on the canal. The road over-bridge just below the lock was widened in the late 1920s to allow for increasing road traffic. The bridge was widened on both sides of the road and the parapets were rebuilt.

As a result of this alteration the balance beams of the lower lock gates had to be shortened. This would have upset the equilibrium of the gates and reduced the leverage available to people opening or closing the gates. It appears that a system of ropes and pulleys may have been employed to assist in the opening and closing.

This lock and those in Trebanos and Ynysmeudwy are testament to the skill of the canal builders. The Swansea Canal Society aims to repair and reopen this lock to allow small water craft to travel again from Clydach up to Trebanos and eventually to reach Pontardawe, with an extension to the south to link up with the Neath and Tennant canals.

How did canal locks work?

A boat travelling down the valley would enter the lock from the upper level. With the gates at each end closed, water was drained from the lock until the boat had reached the lower canal level, then the bottom gate was opened for exit. Water would be admitted to the lock to raise boats travelling up the valley.

With thanks to Hywel Lewis of the Swansea Canal Society

Postcode: SA6 5QR    View Location Map