Pontcysyllte Aqueduct

button-theme-canalLink to French translationLink to Japanese translationPontcysyllte Aqueduct

This structure is Britain’s longest and highest aqueduct. It was built from 1796 to 1805 as part of a project – eventually aborted – to create a canal from Ruabon and Shropshire to the Mersey.

The aqueduct’s name comes from the Welsh verb cysylltu (meaning “to connect”) and pont (“bridge”). To hear how to pronounce Pontcysyllte, press play: Or, download mp3 (21KB)

The structure consists of a trough of cast iron sitting on tall stone piers. The aqueduct is 307m (1,007ft) long and stands almost 39m above the river Dee. When walking across, notice how the canal water – abstracted from the river Dee above Llangollen – flows southwards, high above the river’s eastward flow. The footpath was installed for the horses which towed the original canal boats. On the opposite side, only the wall of the iron trough separates the water from the drop. Looking down is a thrill you can experience by taking a narrow boat across.

The aqueduct is commonly credited to Thomas Telford, who was overseer of works on the Ellesmere Canal project and claimed the credit decades later. Initially the aqueduct was ascribed to William Jessop, the canal’s engineer. He had earlier helped to found an ironworks in Derbyshire. The concept was probably developed by both men, aided by earlier aqueducts and an American engineer. For more on this, see the Footnotes.

The ironwork was cast by William Hazledine at the nearby Plas Kynaston estate, whose owner was one of the originators of the canal scheme. The canal was intended to continue northwards from Trevor basin but the hills which stood in the way, and the rapid growth of railways, put paid to the idea. The canal’s water supply was originally planned to flow along a trench from beyond Llangollen, but in the event this section was built almost entirely as a navigable canal.

During the Second World War, the London, Midland & Scottish Railway decided to close many of the canals it had inherited, but the Ellesmere Canal had become an important distributor of water. Today Pontcysyllte remains part of the system which takes drinking water to Hurleston reservoir, near Nantwich, Cheshire.

In the 1950s this part of the Ellesmere Canal was renamed the Llangollen Canal, reflecting its growing leisure use. In 2009 the Llangollen Canal was designated a United Nations World Heritage Site. Today it’s managed by the Canal and River Trust.

With thanks to Stephen Hughes, of the Royal Commission on the Ancient and Historic Monuments of Wales, and to Prof Hywel Wyn Owen of the Welsh Place-Name Society for information on the aqueduct’s name

View Location Map

FOOTNOTES: Pontcysyllte’s origins

Llangollen Canal on CRT website


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