Full Report for Listed Buildings
The list description is not intended to be a complete inventory of what is listed: it is principally intended to aid identification. By law, the definition of a listed building includes the entire building (i) and any structure or object that is fixed to the said building and ancillary to it and (ii) any other structure or object that forms part of the land and has done so since before 1 July 1948, and was within the curtilage of the building, and ancillary to it, on the date on which said building was first included in the list, or on 1 January 1969, whichever was later.
Summary Description
Reference Number
23826
Building Number
Grade
II*
Status
Designated
Date of Designation
27/07/2000
Date of Amendment
27/07/2000
Name of Property
Embankment & Aqueduct of Brecknock & Abergavenny Canal inc. N Revetment Walls and SW Overflow Bridge
Address
Location
Unitary Authority
Monmouthshire
Community
Llanelly
Town
Locality
Gilwern
Easting
324400
Northing
214472
Street Side
Location
Situated to south-west of village in across deep ravine of river Clydach.
Description
Broad Class
Transport
Period
History
Impressive embanked aqueduct built 1797 by Thomas Dadford, engineer for carrying canal across deep Clydach gorge, also providing a tunnel for the earlier Clydach tramroad leading to Glangrwyne Forge. In 1792, the Act for the Monmouthshire Canal was passed: in the same year, the promoters of the Brecknock and Abergavenny Canal were proposing a canal to run separately, from Brecon to Newbridge. By October 1792 it was resolved to link directly to the proposed Monmouthshire Canal rather than the river Usk, and Thomas Dadford, engineer, was asked to survey a suitable route from Pontypool to Brecon. Work began early in 1797 with the aqueduct and embankment at Gilwern, and by November 1797, the eight-and-a-half mile (13.7 kilometre) section from Gilwern to Llangynidr was open. A further twelve mile section to Talybont was open by February 1799, and on Christmas Eve 1800, the final link to Brecon was opened. After 1798, Thomas Dadford was replaced with Thomas Cartwright, who engineered the extension of the canal form Gilwern to Llanfoist 1802-05. By February 1812 the canal had connected to the Monmouthshire Canal at Ponymoile, and the wharves at Brecon and Gilwern had been extended. The engineer for this section was William Crosley. After, when the Newport and Pontypool Railway was promoted, the canals were in decline. The Brecknock and Abergavenny Company made several unsuccessful overtures to various railway companies, but by 1865 had sold out to the Monmouthshire Canal Company. In 1880, the Monmouthshire Canal Company merged with the Great Western Railway. The last toll on the canal was taken in February 1933.
Exterior
Massive wooded earth embankment standing approximately 25 metres high and some 100 metres long, blocking the lower mouth of the Clydach Gorge, the Clydach River taken through a long segmentally-arched tunnel. Tunnel is approximately 90 metres long. Arched buttressed portals with ashlar voussoirs and rubble abutments. Above, to north is former tramroad tunnel, now used as pedestrian route. Round-arched tunnel with stone voussoirs to portals; segmental over-arch to W side. Very long rubble revetment wall to NW containing earth bank, following line of track to Waterfall Cottages. To NE of tramroad tunnel are sloping splayed revetments. To SW is very small segmentally-arched bridge over overflow with stone voussoirs and rubble-capped parapet.
Interior
Reason for designation
Listed at Grade II* as an outstanding feature of the engineering works associated with the Brecknock and Abergavenny Canal.
Scheduled Ancient Monument Mm 251.
Cadw : Full Report for Listed Buildings [ Records 1 of 1 ]
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