The Pontcysyllte Aqueduct (; cy, Traphont Ddŵr Pontcysyllte) is a
navigable aqueduct
Navigable aqueducts (sometimes called water bridges) are bridge structures that carry navigable waterway canals over other rivers, valleys, railways or roads. They are primarily distinguished by their size, carrying a larger cross-section of wa ...
that carries the
Llangollen Canal
The Llangollen Canal ( cy, Camlas Llangollen) is a navigable canal crossing the border between England and Wales. The waterway links Llangollen in Denbighshire, north Wales, with Hurleston in south Cheshire, via the town of Ellesmere, Shropshi ...
across the
River Dee in the Vale of Llangollen in northeast
Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...
.
The 18-arched stone and
cast iron
Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ...
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
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
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
, name_etymology =
, image = SevernFromCastleCB.JPG
, image_size = 288
, image_caption = The river seen from Shrewsbury Castle
, map = RiverSevernMap.jpg
, map_size = 288
, map_c ...
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
The Port of Liverpool is the enclosed Dock (maritime), dock system that runs from Brunswick Dock in Liverpool to Seaforth Dock, Seaforth, Merseyside, Seaforth, on the east side of the River Mersey and the Great Float, Birkenhead Docks between ...
on the
River Mersey
The River Mersey () is in North West England. Its name derives from Old English and means "boundary river", possibly referring to its having been a border between the ancient kingdoms of Mercia and Northumbria. For centuries it has formed part ...
. 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
In the United Kingdom, a listed building or listed structure is one that has been placed on one of the four statutory lists maintained by Historic England in England, Historic Environment Scotland in Scotland, in Wales, and the Northern Irel ...
and part of a
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
World Heritage Site
A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...
.
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
A township is a kind of human settlement or administrative subdivision, with its meaning varying in different countries.
Although the term is occasionally associated with an urban area, that tends to be an exception to the rule. In Australia, Ca ...
of the old parish of
Llangollen
Llangollen () is a town and community, situated on the River Dee, in Denbighshire, Wales. Its riverside location forms the edge of the Berwyn range, and the Dee Valley section of the Clwydian Range and Dee Valley Area of Outstanding Natural Beau ...
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
A false etymology (fake etymology, popular etymology, etymythology, pseudo-etymology, or par(a)etymology) is a popular but false belief about the origin or derivation of a specific word. It is sometimes called a folk etymology, but this is also a ...
, derived from the name's apparent similarity to the word ' (plural of ''cyswllt'') which means connections or links.
History
![WalesC0047](https://upload.wikimedia.org/wikipedia/commons/0/0d/WalesC0047.jpg)
The aqueduct was designed by civil engineers
Thomas Telford
Thomas Telford FRS, FRSE, (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotla ...
and
William Jessop
William Jessop (23 January 1745 – 18 November 1814) was an English civil engineer, best known for his work on canals, harbours and early railways in the late 18th and early 19th centuries.
Early life
Jessop was born in Devonport, Devon, the ...
for a location near an 18th-century road crossing,
Pont Cysyllte
Pont Cysyllte,[Cysylltau Bridge; Pont Cysyllte](_blank)
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
The Longdon-on-Tern Aqueduct, near Longdon-on-Tern in Shropshire, was one of the first two canal aqueducts to be built from cast iron.
History
The cast iron canal aqueduct was re-engineered by Thomas Telford after the first construction desig ...
on the
Shrewsbury Canal
The Shrewsbury Canal (or Shrewsbury and Newport Canal) was a canal in Shropshire, England. Authorised in 1793, the main line from Trench to Shrewsbury was fully open by 1797, but it remained isolated from the rest of the canal network until 183 ...
.
The aqueduct was one of the first major feats of
civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage ...
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
William Hazledine (1763 – 26 October 1840) was an English ironmaster. Establishing large foundries, he was a pioneer in casting structural ironwork, most notably for canal aqueducts and early suspension bridges. Many of these projects were c ...
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
Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ...
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
The Moss Valley ( cy, Dyffryn Moss, ) is an area and country park in Wrexham County Borough, Wales. The area, informally known as "''The Moss''" and ''The Aggey'' by local people, has an extensive coal mining history.
History Thomas Telford
In ...
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
Llangollen () is a town and community, situated on the River Dee, in Denbighshire, Wales. Its riverside location forms the edge of the Berwyn range, and the Dee Valley section of the Clwydian Range and Dee Valley Area of Outstanding Natural Beau ...
was completed. In order to maintain a continual supply, Telford built an artificial
weir
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...
known as the
Horseshoe Falls
Horseshoe Falls is the largest of the three waterfalls that collectively form Niagara Falls on the Niagara River along the Canada–United States border. Approximately 90% of the Niagara River, after diversions for hydropower generation, flows ...
near
Llantysilio
Llantysilio ( cy, Llandysilio-yn-Iâl) is a community in Denbighshire, Wales, near Llangollen. It has a population of 472, falling to 421 at the 2011 census.
The community includes the site of Valle Crucis Abbey, the Horseshoe Pass, and Llanty ...
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
Wrexham ( ; cy, Wrecsam; ) is a city and the administrative centre of Wrexham County Borough in Wales. It is located between the Welsh mountains and the lower Dee Valley, near the border with Cheshire in England. Historically in the count ...
.
In 1844, the Ellesmere and
Chester Canal
The Chester Canal was an English canal linking the south Cheshire town of Nantwich with the River Dee at Chester. It was intended to link Chester to Middlewich, with a branch to Nantwich, but the Trent and Mersey Canal were unco-operative a ...
Company, which owned the broad canals from
Ellesmere Port
Ellesmere Port ( ) is a port town in the Cheshire West and Chester borough in Cheshire, England. Ellesmere Port is on the south eastern edge of the Wirral Peninsula, north of Chester, south of Birkenhead, southwest of Runcorn and south of ...
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
Nantwich ( ) is a market town and civil parish in the unitary authority of Cheshire East in Cheshire, England. It has among the highest concentrations of listed buildings in England, with notably good examples of Tudor and Georgian architecture. ...
, with a branch to
Middlewich
Middlewich is a town in the unitary authority of Cheshire East and the ceremonial county of Cheshire, England, east of Chester, east of Winsford, southeast of Northwich and northwest of Sandbach. The population at the 2011 Census was 13,595. ...
, began discussions with the narrow
Birmingham and Liverpool Junction Canal
The Birmingham and Liverpool Junction Canal was a canal in England which ran from Nantwich, where it joined the Chester Canal, to Autherley, where it joined the Staffordshire and Worcestershire Canal. Forming part of a major link between Liverpo ...
, 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.
![Pontcysyllte aqueduct plaque](https://upload.wikimedia.org/wikipedia/commons/4/43/Pontcysyllte_aqueduct_plaque.jpg)
In 1846, the canal and the aqueduct became part of the
Shropshire Union Railways and Canal Company
The Shropshire Union Railways and Canal Company was a Company in England, formed in 1846, which managed several canals and railways. It intended to convert a number of canals to railways, but was leased by the London and North Western Railway (LN ...
. 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
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
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
Newtown ( cy, Y Drenewydd) is a town in Powys, Wales. It lies on the River Severn in the community of Newtown and Llanllwchaiarn, within the historic boundaries of Montgomeryshire. It was designated a new town in 1967 and saw population growt ...
(now part of the Montgomery Canal) in 1936. By 1939 boat movements across the aqueduct to Llangollen
Llangollen () is a town and community, situated on the River Dee, in Denbighshire, Wales. Its riverside location forms the edge of the Berwyn range, and the Dee Valley section of the Clwydian Range and Dee Valley Area of Outstanding Natural Beau ...
had ceased. The canal was formally closed to navigation under the London Midland and Scottish Railway
The London, Midland and Scottish Railway (LMSIt has been argued that the initials LMSR should be used to be consistent with LNER, GWR and SR. The London, Midland and Scottish Railway's corporate image used LMS, and this is what is generally ...
Company Act of 1944. On 6 September 1945, due to inadequate maintenance, the canal breached its banks east of Llangollen
Llangollen () is a town and community, situated on the River Dee, in Denbighshire, Wales. Its riverside location forms the edge of the Berwyn range, and the Dee Valley section of the Clwydian Range and Dee Valley Area of Outstanding Natural Beau ...
near Sun Bank Halt. 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
British Waterways, often shortened to BW, was a statutory corporation wholly owned by the government of the United Kingdom. It served as the navigation authority for the majority of canals and a number of rivers and docks in England, Scotland ...
in the 1980s, the former industrial waterway was renamed the Llangollen Canal
The Llangollen Canal ( cy, Camlas Llangollen) is a navigable canal crossing the border between England and Wales. The waterway links Llangollen in Denbighshire, north Wales, with Hurleston in south Cheshire, via the town of Ellesmere, Shropshi ...
. 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
The Canal & River Trust (CRT), branded as in Wales, holds the guardianship of 2,000 miles of canals and rivers, together with reservoirs and a wide range of heritage buildings and structures, in England and Wales. Launched on 12 July 2012, the ...
(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
Lime commonly refers to:
* Lime (fruit), a green citrus fruit
* Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide
* Lime (color), a color between yellow and green
Lime may also refer to:
Botany ...
, 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
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
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
Coleham is a district of the town of Shrewsbury in Shropshire, England. It is located just south, over the River Severn, from Shrewsbury town centre.
History
Coleham grew up as a village outside medieval Shrewsbury, with the nearest crossing ov ...
, near Shrewsbury. The trough was made from flange
A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of an iron beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer of ...
d plates of cast iron, bolted together, with the joints bedded with Welsh flannel
Flannel is a soft woven fabric, of various fineness. Flannel was originally made from carded wool or worsted yarn, but is now often made from either wool, cotton, or synthetic fiber. Flannel is commonly used to make tartan clothing, blankets, b ...
and a mixture of white lead
White lead is the basic lead carbonate 2PbCO3·Pb(OH)2. It is a complex salt, containing both carbonate and hydroxide ions. White lead occurs naturally as a mineral, in which context it is known as hydrocerussite, a hydrate of cerussite. It was ...
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 ]voussoir
A voussoir () is a wedge-shaped element, typically a stone, which is used in building an arch or vault.
Although each unit in an arch or vault is a voussoir, two units are of distinct functional importance: the keystone and the springer. The ...
s, 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
Archimedes' principle (also spelled Archimedes's principle) states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. Archimede ...
, the mass (weight) of a boat and its cargo on the bridge pushes an equal mass of water off the bridge.
The towpath
A towpath is a road or trail on the bank of a river, canal, or other inland waterway. The purpose of a towpath is to allow a land vehicle, beasts of burden, or a team of human pullers to tow a boat, often a barge. This mode of transport ...
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
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
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
Horseshoe Falls is the largest of the three waterfalls that collectively form Niagara Falls on the Niagara River along the Canada–United States border. Approximately 90% of the Niagara River, after diversions for hydropower generation, flows ...
would be the United Kingdom's 2008 nomination.
The length of canal from Rhoswiel, Shropshire
Shropshire (; alternatively Salop; abbreviated in print only as Shrops; demonym Salopian ) is a landlocked historic county in the West Midlands region of England. It is bordered by Wales to the west and the English counties of Cheshire to th ...
, to the Horseshoe Falls, including the main Pontcysyllte Aqueduct structure as well as the older Chirk Aqueduct
Chirk Aqueduct is a high and long navigable aqueduct that carries what is now the Llangollen Canal across the Ceiriog Valley near Chirk, on the England-Wales border, spanning the two countries.
History
The aqueduct was designed by civil engine ...
, 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](_blank)
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
The canals of the United Kingdom are a major part of the network of inland waterways in the United Kingdom. They have a varied history, from use for irrigation and transport, through becoming the focus of the Industrial Revolution, to today's ro ...
* List of canal aqueducts in Great Britain
This list of canal aqueducts in the United Kingdom covers aqueducts that have articles in Wikipedia. The actual number of canal aqueducts is much greater.
See also
* :Aqueducts in the United Kingdom
*Navigable aqueduct
*Canals of the Unite ...
* List of bridges in Wales
This list of bridges in Wales lists bridges of particular historical, scenic, architectural or engineering interest in Wales. Road and railway bridges, viaducts, aqueducts and footbridges are included.
List
Bridges are listed under the names us ...
* 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
The archaeology of Wales (Welsh: ''Archaeoleg Cymru'') is the study of human occupation within the country of Wales which has been occupied by modern humans since 225,000 BCE, with continuous occupation from 9,000 BCE. Analysis of the sites, arte ...
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