Monument Type(s):

• AQUEDUCT (1796-1801, Late 18th century to Early 19th century - 1796 AD to 1801 AD)

Summary

An aqueduct, 1796-1802, which is protected by Grade II* Listing.

Related records

Associated Finds: None recorded

Associated Events

• ESA7810 - 2008 Conservation Management Plan for Pontcysyllte Aqueduct and Canal WHS by Purcell Miller Tritton

Description

Canal aqueduct. 1796-1801 by William Jessop and Thomas Telford for the Ellesmere Canal. Roughly coursed limestone rubble with ashlar dressings and cast-iron railings to parapet on east side. Approximately 20m high with 10 round-headed arches divided by pilaster strips; curving end walls to north and south. Arches have keystones and imposts struck through to soffit. Canal in trough with cast-iron bed and stone side walls. The aqueduct which cost £20,898 and was opened in 1801, spans the valley of the River Ceiriog and is partly in Wales, the border bisecting the structure at an angle of approximately 45 degrees from south-west to north-east. Forms an impressive sight with the Chirk Viaduct (qv) running parallel immediately to west. Buildings of England. P313; Edward Hubbard, The Buildings of Wales: Clwyd (1986) p130; Charles Hadfield, Canals of the West Midlands (3rd edn. 1985) p173 <2>

A conservation management plan was prepared in 2009 for the Pontcysyllte World Heritage site, including a gazetteer of heritage assets (mainly focused on the Welsh side). ->

-> Chirk Aqueduct was designed by Telford and Jessop in 1796 for the Ellesmere Canal Company. Its purpose was to carry the Llangollen Branch Canal over the 700m wide valley of the Afon Ceiriog. Telford and Jessop originally planned for the aqueduct to be a relatively small one spanning a short section of the valley over the River Dee and built with traditional stone and puddle-clay. The canal would then have been carried across the remaining sections of the valley along a huge earthwork embankment. This proposal was however vetoed by Richard Myddleton (the owner of Chirk Castle) on the grounds that his view across the polite landscape and down the Ceiriog Valley would be ruined. The initial response was to move the aqueduct upstream where it would be less intrusive on the landscape. However when structural problems started occurring on other aqueducts in Derbyshire which had been built using the traditional combination of earthworks and puddle-clay based aqueducts, Jessop ordered a complete reassessment of the project. Telford proposed the revolutionary use of iron at Chirk and Jessop and Telford decided to construct an iron trough which would be supported on stone columns and could span the full width of the valley. The Canal Committee passed the plan in mid 1795 and a group of specialist craftsmen were brought on board for construction to begin. These included men who had previously worked with Telford including John Simpson (mason), William Hazeldine (ironmaster at the Plas Kynaston Foundry), William Davies (manager of earthworks) and Matthew Davidson (overall supervisor and mason). However before construction began Telford altered the proposal yet again, replacing the trough with a series of rubble-stone built arches, lightened because they had hollow sprandrels and strengthened by cross walls and bonding timbers. The reasons for this change were probably time and cost. The final design was for a conventional arched masonry structure with cast iron plates only employed to form the base of the trough. Most of the stonework was sourced from a local riverside quarry. ->

-> It is possible to regard Chirk as a halfway stage towards the concept of a full iron trough carried on free-standing masonry piers. The foundation stone was laid by Richard Myddleton of Chirk Castle in June 1797. A watercolour by Sir Richard Colt Hoare c.1799 shows only six arches. The iron for constructing the aqueduct channel was provided by William Hazeldine of Shrewsbury at the Plas Kynaston foundry. The masonry was provided by James Varley of Colne. The total cost was almost £21,000. Chirk Aqueduct was completed and opened in 1801. The canal was extended at the suggestion of William Jessop to obtain headwater from the River Dee at Llantsilio-yn-ial. Then in c.1869-70 additional cast iron side plates 1.25m in length and 23mm thick were inserted at the trough. <6>

Photographed during aerial survey in 2010. <7>

Sources

Search results generated by the HBSMR Gateway from exeGesIS SDM Ltd.