970 yards long, the Berwick Tunnel is the only tunnel on the Shrewsbury and Newport Canal, opened January 1797. The overlying burden is shallow, and had the canal been built a little nearer the Severn a cutting would have sufficed, but Humphry Repton's landscaping at nearby Longner Hall prevented this.
The engineer of the Shrewsbury Canal, Josiah Clowes, designed the tunnel to have an internal width of ten feet. At the suggestion of the iron founder William Reynolds a wooden towpath was cantilevered three feet off one wall. Berwick Tunnel was the first of any real length to have a towpath, but this was removed in 1819, after which boats had to be legged through.
The tub boats used on the canal were six feet four inches wide. There was thus not room enough to pass within the tunnel, which is curved such that there is no line of sight through its length. In 1838 a rule was adopted to the effect that laden trains of boats had priority over unladen. Where two laden boats met in the tunnel, that which had first reached the centre point had priority, which required the other to be legged back out.
The tunnel is brick-lined, with ashlar-faced portals. Beside that at the north-west end (top) are the remains of a lengthman's hut (second photo). Both the north-west and south-east (third photo) portals are bricked-up and gated. The canal closed in 1939. The seven ventilation shafts were plugged after 12-year-old Betty Smith was murdered and disposed of down one of them in 1953 - Desmond Hooper was hanged at HMP Shrewsbury.