Ancient Monuments

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Remains of Lock and Dry Dock at Pantyffynnon

A Scheduled Monument in Ystalyfera, Neath Port Talbot (Castell-nedd Port Talbot)

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Latitude: 51.7513 / 51°45'4"N

Longitude: -3.8003 / 3°48'0"W

OS Eastings: 275825

OS Northings: 207378

OS Grid: SN758073

Mapcode National: GBR H3.0SZ6

Mapcode Global: VH5G8.27TS

Entry Name: Remains of Lock and Dry Dock at Pantyffynnon

Scheduled Date: 8 November 1978

Source: Cadw

Source ID: 3739

Cadw Legacy ID: GM397

Schedule Class: Transport

Category: Lock

Period: Post Medieval/Modern

County: Neath Port Talbot (Castell-nedd Port Talbot)

Community: Ystalyfera

Built-Up Area: Ystradgynlais

Traditional County: Glamorgan


The monument consists of the substantial remains of Lock 17, Pant-y-ffynnon Lower (or Thick Lock) of the Swansea Canal and of a dry dock which was added to the lock platform after 1875. The lock by-pass was used to drain the dock when required for the maintenance of boats. The rubble sandstone eastern side is stepped and wooden posts with slotted tops remain in the centre of a brick paved floor - these supported cross-pieces to carry boats under repair. The winding stair down the lower face of the lock podium is unique and this is one of only two locks with stop-plank grooves halfway along the lock chamber. The west wall of the dock has small brick pillars which supported a roof and in the south west corner was a pitch boiling hearth.

The monument is of national importance for its potential to enhance our knowledge of 19th century transport and boat repair systems. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. A lock may be part of a larger cluster of industrial monuments and their importance can further enhanced by their group value.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.

Source: Cadw

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