Pontcysyllte aqueduct arp.jpg
   HOME

TheInfoList



OR:

The Pontcysyllte Aqueduct (; cy, Traphont Ddŵr Pontcysyllte) is a navigable aqueduct that carries the Llangollen Canal across the River Dee in the Vale of Llangollen in northeast Wales. The 18-arched stone and cast iron structure is for use by
narrowboat A narrowboat is a particular type of canal boat, built to fit the narrow locks of the United Kingdom. The UK's canal system provided a nationwide transport network during the Industrial Revolution, but with the advent of the railways, commerc ...
s and was completed in 1805 having taken ten years to design and build. It is 12 ft (3.7 metres) wide and is the longest aqueduct in Great Britain and the highest canal aqueduct in the world. A footpath runs alongside the watercourse on one side. The aqueduct was to have been a key part of the central section of the proposed
Ellesmere Canal The Ellesmere Canal was a waterway in England and Wales that was planned to carry boat traffic between the rivers Mersey and Severn. The proposal would create a link between the Port of Liverpool and the mineral industries in north east Wales an ...
, an industrial waterway that would have created a commercial link between the River Severn at
Shrewsbury Shrewsbury ( , also ) is a market town, civil parish, and the county town of Shropshire, England, on the River Severn, north-west of London; at the 2021 census, it had a population of 76,782. The town's name can be pronounced as either 'Sh ...
and the Port of Liverpool on the River Mersey. Although a less expensive construction course was surveyed further to the east, the westerly high-ground route across the Vale of Llangollen was preferred because it would have taken the canal through the mineral-rich coalfields of
North East Wales North East Wales ( cy, Gogledd-Ddwyrain Cymru) refers to an area or region of Wales, commonly defined as a grouping of the principal areas of Denbighshire, Flintshire, and Wrexham County Borough in the north-east of the country. These principal ...
. Only parts of the canal route were completed because the expected revenues required to complete the entire project were never generated. Most major work ceased after the completion of the Pontcysyllte Aqueduct in 1805. The structure is a Grade I listed building and part of a UNESCO World Heritage Site.


Etymology

The name ''Pontcysyllte'' is
Welsh Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peop ...
for "Cysyllte Bridge" or "Bridge of Cysyllte", Cysyllte being the township of the old parish of Llangollen in which the southern end of the bridge lies. The northern end of the bridge was in Trefor Isaf township, also in Llangollen parish. Other translations such as "bridge of the junction" or "the bridge that links" are a modern false etymology, derived from the name's apparent similarity to the word ' (plural of ''cyswllt'') which means connections or links.


History

The aqueduct was designed by civil engineers Thomas Telford and William Jessop for a location near an 18th-century road crossing,
Pont Cysyllte Pont Cysyllte,Cysylltau Bridge; Pont Cysyllte
RCA ...
. After the westerly high-ground route was approved, the original plan was to create a series of locks down both sides of the valley to an embankment that would carry the
Ellesmere Canal The Ellesmere Canal was a waterway in England and Wales that was planned to carry boat traffic between the rivers Mersey and Severn. The proposal would create a link between the Port of Liverpool and the mineral industries in north east Wales an ...
over the River Dee. After Telford was hired the plan was changed to an aqueduct that would create an uninterrupted waterway straight across the valley. Despite considerable public scepticism, Telford was confident his construction method would work because he had previously built a cast-iron trough aqueduct – the Longdon-on-Tern Aqueduct on the Shrewsbury Canal. The aqueduct was one of the first major feats of civil engineering undertaken by Telford, who was becoming one of Britain's leading industrial
civil engineer A civil engineer is a person who practices civil engineering – the application of planning, designing, constructing, maintaining, and operating infrastructure while protecting the public and environmental health, as well as improving existing ...
s; although his work was supervised by Jessop, the more experienced canal engineer. Ironwork was supplied by William Hazledine from his foundries at
Shrewsbury Shrewsbury ( , also ) is a market town, civil parish, and the county town of Shropshire, England, on the River Severn, north-west of London; at the 2021 census, it had a population of 76,782. The town's name can be pronounced as either 'Sh ...
and nearby
Cefn Mawr Cefn Mawr () is a village in the community of Cefn within Wrexham County Borough, Wales. Its name translates as "big ridge".Mills, D. ''A Dictionary of British Place Names'', OUP, p.104 The population in 2001 was 6,669, increasing to 7,051 in ...
. The work, which took around ten years from design to construction, cost around of £47,000. Adjusted for inflation this is equivalent to no more than £ in , but represented a major investment against the contemporary GDP of some £400 million. The Pontcysyllte aqueduct officially opened to traffic on 26 November 1805. A plaque commemorating its inauguration reads:
The nobility and gentry, the adjacent Counties having united their efforts with the great commercial interests of this country. In creating an intercourse and union between England and North Wales by a navigable communication of the three Rivers, Severne Dee and Mersey for the mutual benefit of agriculture and trades, caused the first stone of this aqueduct of Pontcysyllty , to be laid on the 25th day of July MDCCXCV
795 __NOTOC__ Year 795 ( DCCXCV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. The denomination 795 for this year has been used since the early medieval period, when the Anno Domini calendar er ...
When Richard Myddelton of Chirk, Esq, M.P. one of the original patrons of the Ellesmere Canal was Lord of this manor, and in the reign of our Sovereign George the Third. When the equity of the laws, and the security of property, promoted the general welfare of the nation. While the arts and sciences flourished by his patronage and the conduct of civil life was improved by his example.
The bridge is long, wide and deep. It consists of a cast iron trough supported above the river on iron arched ribs carried on eighteen hollow masonry piers (pillars). Each of the 18 spans is wide. With the completion of the aqueduct, the next phase of the canal should have been the continuation of the line to Moss Valley, Wrexham where Telford had constructed a feeder reservoir lake in 1796. This would provide the water for the length of canal between
Trevor Basin Trevor Basin is a canal basin on the Llangollen Canal, situated near Trevor, Wrexham County Borough, Wales, in between Llangollen and Ruabon. The basin was originally built at the northern end of the central section of the Ellesmere Canal, ju ...
and
Chester Chester is a cathedral city and the county town of Cheshire, England. It is located on the River Dee, close to the English–Welsh border. With a population of 79,645 in 2011,"2011 Census results: People and Population Profile: Chester Loca ...
. The plan to build this section was cancelled in 1798, and the isolated feeder and a stretch of navigation between Ffrwd and a basin in
Summerhill Summerhill or Summer Hill may refer to the following places: Australia * Summer Hill, New South Wales, a suburb of Sydney *Summerhill, Tasmania, a suburb of Launceston * Summerhill (Mount Duneed), a prefabricated iron cottage in Victoria Canada * ...
was abandoned. Remnants of the feeder channel are visible in
Gwersyllt Gwersyllt () is an urban village and community in Wrexham County Borough, Wales. The densely populated village is one of Wrexham's largest and is situated in the north western suburbs of the city, bordering the nearby villages of Llay, Cefn-y ...
. A street in the village is still named ''Heol Camlas'' ( cy, Canal Way). The physical construction was undertaken by John Simpson (d.1815) of
Shrewsbury Shrewsbury ( , also ) is a market town, civil parish, and the county town of Shropshire, England, on the River Severn, north-west of London; at the 2021 census, it had a population of 76,782. The town's name can be pronounced as either 'Sh ...
. With the project incomplete,
Trevor Basin Trevor Basin is a canal basin on the Llangollen Canal, situated near Trevor, Wrexham County Borough, Wales, in between Llangollen and Ruabon. The basin was originally built at the northern end of the central section of the Ellesmere Canal, ju ...
just over the Pontcysyllte aqueduct would become the canal's northern terminus. In 1808 a feeder channel to bring water from the River Dee near Llangollen was completed. In order to maintain a continual supply, Telford built an artificial weir known as the Horseshoe Falls near Llantysilio to maintain water height. Subsequently, the Plas Kynaston Canal was built to serve industry in the Cefn Mawr and Rhosymedre areas in the 1820s. There might have been another canal extension ("Ward's") but detailed records do not survive. Goods traffic was brought down to the canal by the
Ruabon Brook Tramway The Ruabon Brook Tramway was a Welsh branch railway line linking the Ruabon coalfield to the Shropshire Union Canal at Froncysyllte, with a private extension into the Monsanto works at Cefn Mawr which reconnected to the main line at Trevor. T ...
which climbed towards Acrefair and Plas Bennion. This railway was eventually upgraded to steam operation and extended towards
Rhosllannerchrugog RhosllanerchrugogDavies, Jenkins and Baines (eds) ''The Welsh Academy Encyclopedia of Wales'', 2008, p.752 (also spelled Rhosllannerchrugog, or simply Rhos) is a village and community in Wrexham County Borough, Wales. It lies within the histor ...
and Wrexham. In 1844, the Ellesmere and Chester Canal Company, which owned the broad canals from Ellesmere Port to
Chester Chester is a cathedral city and the county town of Cheshire, England. It is located on the River Dee, close to the English–Welsh border. With a population of 79,645 in 2011,"2011 Census results: People and Population Profile: Chester Loca ...
and from Chester to Nantwich, with a branch to Middlewich, began discussions with the narrow Birmingham and Liverpool Junction Canal, which ran from Nantwich to Autherley, where it joined the
Staffordshire and Worcestershire Canal The Staffordshire and Worcestershire Canal is a navigable narrow canal in Staffordshire and Worcestershire in the English Midlands. It is long, linking the River Severn at Stourport in Worcestershire with the Trent and Mersey Canal at Haywoo ...
. The two companies had always worked together, in a bid to maintain their profits against competition from the railways, and amalgamation seemed to be a logical step. An agreement was worked out by August, and the two companies then sought a
Private Act of Parliament Proposed bills are often categorized into public bills and private bills. A public bill is a proposed law which would apply to everyone within its jurisdiction. This is unlike a private bill which is a proposal for a law affecting only a single p ...
to authorise the takeover. This was granted on 8 May 1845, when the larger Ellesmere and Chester Canal Company was formed. In 1846, the canal and the aqueduct became part of the Shropshire Union Railways and Canal Company. But the intent of the merger was to build railways at a reduced cost, by using the existing routes of the canals they owned. By 1849, the plan to turn canals into railways had been dropped. As the aqueduct was largely in an area that was served by railways owned by the
Great Western Railway The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835 and ran ...
, the LNWR was more than happy for the canal to remain open as long as it remained profitable. With the start of the First World War in 1914, the Shropshire Union – which the Pontcysyllte aqueduct was a part – served the war effort with its fleet of more than 450 narrow boats. Commercial traffic on the canal greatly declined after a waterway breach near Newtown, Powys (now part of the Montgomery Canal) in 1936. By 1939 boat movements across the aqueduct to Llangollen had ceased. The canal was formally closed to navigation under the London Midland and Scottish Railway Company Act of 1944. On 6 September 1945, due to inadequate maintenance, the canal breached its banks east of Llangollen near
Sun Bank Halt Sun Bank Halt in Wrexham County Borough, Wales, was a minor station on the Ruabon to Barmouth line. It opened as Garth & Sun Bank Halt but was renamed on 1 July 1906. The line was double track and there was never a signal box nor freight facili ...
. The flow of hundreds of tons of water washed away the embankment of the railway further down the hill, tearing a crater deep. This caused the first traffic of the morning, a mail and goods train composed of 16 carriages and two vans, to crash into the breach, killing one and injuring two engine crew. The aqueduct was saved (despite its official closure to waterway traffic) because it was still required as a water feeder for the remainder of the
Shropshire Union Canal The Shropshire Union Canal, nicknamed the "Shroppie", is a navigable canal in England. The Llangollen and Montgomery canals are the modern names of branches of the Shropshire Union (SU) system and lie partially in Wales. The canal lies in ...
. The aqueduct also supplied drinking water to a reservoir at
Hurleston Hurleston is a civil parish in the unitary authority of Cheshire East and the ceremonial county of Cheshire, England, which lies to the north west of Nantwich. The parish is predominantly rural with scattered farms and buildings and no settleme ...
. In 1955 the Mid & South East Cheshire Water Board agreed to maintain the canal securing its future. In the latter half of the 20th century, leisure boating traffic began to rise. In a rebranding exercise by British Waterways in the 1980s, the former industrial waterway was renamed the Llangollen Canal. It has since become one of the most popular canals for holidaymakers in Britain because of its aqueducts and scenery. The Pontcysyllte Aqueduct is now maintained and managed by the Canal & River Trust (branded Glandŵr Cymru in Wales).
Otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...
s have been seen in the area.


Construction and maintenance

The mortar used lime, water and ox blood. Blood and extracts of blood containing haemoglobin have been used in the construction and building industry since antiquity as air entraining colloids to inexpensively strengthen mortar exposed to freeze-thaw temperature cycles.Use of blood to entrain air in mortar
Free Patents Online; accessed 25 November 2018.
The iron castings for the trough were produced at the nearby Plas Kynaston Foundry, Cefn Mawr, which was built by the Shrewsbury ironfounder and millwright William Hazledine in the hope of gaining the contract. The rib castings may have been made at Hazledine's original works at Coleham, near Shrewsbury. The trough was made from flanged plates of cast iron, bolted together, with the joints bedded with Welsh flannel and a mixture of white lead and iron particles from boring waste. After 25 years the white lead was replaced with ordinary tar. As with Telford's Longdon-on-Tern Aqueduct, the plates are not rectangular but shaped as voussoirs, similar to those of a stone arch. There is no structural significance to their shape: it is a decorative feature only, following the lines of the stiffening plates (see below) in the castings beneath. In nearby Cefn Mawr a high quartz content sandstone was discovered at the location where the new Cefn Druids football stadium has since been built. Known locally as 'The Rock', the sandstone was extracted and worked here into the many numerous shapes as required by the architects. Many remnants of the workings are still visible alongside Rock Road which links Rhosymedre to
Plas Madoc Plas Madoc ( cy, Plas Madog) is a housing estate and former electoral ward near Acrefair, in the Cefn community in Wrexham County Borough, Wales. It is located seven miles to the south-west of Wrexham, and contains The Land adventure playgro ...
. The supporting arches, four for each span, are in the form of cast-iron ribs, each cast as three voussoirs with external arches cast with an un-pierced
web Web most often refers to: * Spider web, a silken structure created by the animal * World Wide Web or the Web, an Internet-based hypertext system Web, WEB, or the Web may also refer to: Computing * WEB, a literate programming system created by ...
to give greater strength, at the cost of extra weight. Using cast iron in this way, in the same manner as the stone arch it supersedes, makes use of the material's strength in compression. They also give an impression of greater solidity than would be the case were the webs pierced. This impression is enhanced by the arrangement of strips of thicker stiffening incorporated into the castings, arranged in the manner of joints between voussoirs. Cast plates are laid transversely to form the bed of the canal trough. The trough is not fastened to the arches, but lugs are cast into the plates to fit over the rib arches to prevent movement. The aqueduct was left for six months with water inside to check that it was watertight. A feature of a canal aqueduct, in contrast with a road or railway viaduct, is that the vertical loading stresses are virtually constant. According to Archimedes' principle, the mass (weight) of a boat and its cargo on the bridge pushes an equal mass of water off the bridge. The towpath is mounted above the water, with the inner edge carried on cast-iron pillars in the trough. This arrangement allows the water displaced by the passage of a
narrow boat A narrowboat is a particular type of canal boat, built to fit the narrow locks of the United Kingdom. The UK's canal system provided a nationwide transport network during the Industrial Revolution, but with the advent of the railways, commer ...
to flow easily under the towpath and around the boat, enabling relatively free passage. Pedestrians, and the horses once used for towing, are protected from falling from the aqueduct by railings on the outside edge of the towpath, but the holes in the top flange of the other side of the trough, capable of mounting railings, were never used. The trough sides rise only about above the water level, less than the depth of freeboard of an empty narrow boat, so the helmsman of the boat has no visual protection from the impression of being at the edge of an abyss. The trough of the
Cosgrove aqueduct Cosgrove aqueduct is a navigable cast iron trough navigable aqueduct that carries the Grand Union Canal over the River Great Ouse, on the borders between Buckinghamshire and Northamptonshire at the northwest margin of Milton Keynes in England ...
has a similar structure, although it rests on trestles rather than iron arches. It is also less impressively high. Every five years the ends of the aqueduct are closed and a plug in one of the highest spans is opened to drain the canal water into the River Dee below, to allow inspection and maintenance of the trough.


World Heritage Site

The aqueduct and surrounding lands were submitted to the "tentative list" of properties being considered for UNESCO World Heritage Site status in 1999. The aqueduct was suggested as a contender in 2005—its 200th anniversary year—and it was formally announced in 2006 that a larger proposal, covering a section of the canal from the aqueduct to Horseshoe Falls would be the United Kingdom's 2008 nomination. The length of canal from Rhoswiel, Shropshire, to the Horseshoe Falls, including the main Pontcysyllte Aqueduct structure as well as the older Chirk Aqueduct, were visited by assessors from UNESCO during October 2008, to analyse and confirm the site management and authenticity. The aqueduct was inscribed by UNESCO on the World Heritage List on 27 June 2009.


Gallery

File:WalesC0171.JPG, A view of the Dee Valley from the aqueduct File:Under Pontcysyllte.jpg, From the river and valley File:Draining Pontcysyllte, Aqueduct - geograph.org.uk - 1579222.jpg, The canal being drained for inspection and maintenance (2009) File:Trevor aquaduct BWver.jpg, Pontcysyllte Aqueduct in Winter File:Aqueduct over the Dee called Pont y Cyssyltau.jpeg File:Pontcysyllte Aqueduct and Cefn Mawr viaduct.jpg, alt=Aqueduct viewed with Pont Cysyllte bridge and Cefn Mawr Viaduct, Aqueduct viewed with
Pont Cysyllte Pont Cysyllte,Cysylltau Bridge; Pont Cysyllte
RCA ...
bridge and
Cefn Mawr Viaduct The Cefn (Newbridge) Viaduct (also known as the Cefn Mawr, Cefn-bychan, Dee Railway, Newbridge (Railway) or simply Cefn Viaduct; cy, Traphont Cefn) is Grade II* listed buildings in Wrexham County Borough, Grade II* listed railway viaduct acros ...
File:Pontcysyllte Aqueduct from above 01.jpg, alt=Aerial view, Aerial view File:Pontcysyllte Aqueduct showing basin and football ground.jpg, alt=Aerial view showing football ground and Cefn Mawr, Aerial view showing football ground and Cefn Mawr File:Pontcysyllte Aqueduct aerial view.jpg, alt=Aerial view, Aerial view File:Aqueduct viewed from below - July 2021.jpg, Pontcysyllte Aqueduct viewed from below at its northern end


See also

* Canals of the United Kingdom * List of canal aqueducts in Great Britain * List of bridges in Wales *
List of Scheduled Monuments in Wrexham Wrexham County Borough is in north-east Wales, straddling the ancient border earthwork Offa's Dyke. There are 107 scheduled monuments in the county borough. The 29 Bronze Age and Iron Age sites are mainly found to the west of Offa's dyke, and are ...
* Archaeology of Wales


References


Further reading

* ''Memories of Pontcysyllte'' by Amy Douglas and Fiona Collins (2006) * ''Pontcysyllte Aqueduct and Canal Nomination as a World Heritage Site: Nomination Document'' (Wrexham County Borough Council and the Royal Commission on the Ancient and Historical Monuments of Wales, 2008) * ''The Shropshire Union Canal: from the Mersey to the Midlands and Mid-Wales'' by Peter Brown (2018), published by The Railway and Canal Historical Society


External links


The Pontcysyllte Aqueduct website

360 Degree panoramic view at BBC Shropshire
(Java Applet Required)


Construction visualisation video

Articles on the construction of the Pontcysyllte Aqueduct from the Royal Commission on Ancient and Historical Monuments of Wales

Management plan for the nomination as a World Heritage Site. Includes detailed description on the scope of the World Heritage site which starts at Rhoswiel and goes through to the Horseshoe Falls
{{Authority control Bridges completed in 1805 Canals in Wales Grade I listed bridges in Wales Grade I listed buildings in Wrexham County Borough Bridges in Wrexham County Borough Bridges by Thomas Telford Landmarks in Wales Llangollen Canal World Heritage Sites in Wales Navigable aqueducts in Wales Tourist attractions in Wrexham County Borough Bridges across the River Dee, Wales Grade I listed canals 1805 establishments in Wales Cast iron aqueducts