Box Farm canal locks, Pontnewydd


North of Maendy Way the old Monmouthshire Canal towpath climbs past a flight of three locks. This section of the canal hasn’t been navigable for many decades. Box Farm was on the west side of the canal between these locks and next ones to the north, now the site of Pontnewydd Cascades.

The canal, built in the 1790s, passed through 15 locks in the relatively short distance from Forge Hammer to the top of Five Locks. The locks raised boats c.50 metres (165ft), so that they could continue to Pontnewynydd (near Pontypool) initially. In 1812 the canal was joined to the Brecknock & Abergavenny Canal at Pontymoile, enabling boats to transport heavy goods between Newport and Brecon.

Old photo of canal near Box FarmSo many locks in close proximity made water management a constant challenge. Each flight of locks had balancing ponds, so that water released from the upper locks didn’t cause flooding lower down. The ponds also allowed the lower locks to be filled without seriously lowering the water level below the upper locks – which could have temporarily stranded boats!

From the towpath north of Maendy Way, you might see where the canal widened on the west side to form the lower balancing pond. There was a smaller widening between the middle and top locks.

The upper balancing pond was east of the towpath, south of the white cottage in the picture. The photo was taken looking north from near the top lock, with the Old Bridge End Inn in the distance.

The weather also kept lock keepers on their toes. Water had to be conserved in dry summers. Prolonged rain brought extra water to the canal, and sluices were opened to divert excess water into local watercourses. Letting the excess flow down the canal “would flood Pontnewydd village and lower down”, according to a canal company document.

When the canal froze in winter, boatmen would take a special boat (which had metal bars along its bow and underside) to break the ice. Where the ice was thick, a pair of horses pulled the boat to charge at the ice.

Postcode: NP44 3LH    View Location Map

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