Avoncliff Aqueduct

Avoncliff Aqueduct (grid reference ST803599) carries the Kennet and Avon Canal over the River Avon and the Bath to Westbury railway, at Avoncliff in Wiltshire, England, about 1 ¹⁄₂ miles (2.4 km) west of Bradford-on-Avon. It was built by John Rennie and chief engineer John Thomas, between 1797 and 1801. It is a Grade II* listed structure.[1]

Avoncliff Aqueduct
Coordinates	51.3389°N 2.2825°W / 51.3389; -2.2825
OS grid reference	ST802593
Carries	Kennet and Avon Canal
Crosses	River Avon, Heart of Wessex Line
Locale	Avoncliff
Maintained by	Canal & River Trust
Characteristics
Trough construction	Brick and stone
Pier construction	Brick and stone
Total length	330 feet (100.6 m)
Traversable?	Yes
Towpaths	Both
Longest span	60 feet (18.3 m)
No. of spans	3
History
Designer	John Rennie
Construction start	1797
Opened	1805
Location

During construction, stone from a local quarry was used which split when affected by frost. This caused buttresses to collapse and parts of the structure to need rebuilding. Eventually Bath stone from Bathampton Down was used to ensure greater stability.[2]

The aqueduct has three arches and is 110 yards (100.6 m) long, with a central elliptical arch of 60 ft (18.3 m) span, and two semicircular side arches each 34 ft (10.4 m) across, all with V-jointed arch stones. The spandrel and wing walls are built in alternate courses of ashlar masonry and rock-faced blocks.[3] The central span sagged soon after it was built and has been repaired many times.[4]

As part of the 20th-century restoration of the canal, the aqueduct was lined with a concrete "cradle" and made watertight in 1980.[5]