The Barton Swing Aqueduct is a moveable

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 ...

Barton upon Irwell Barton upon Irwell (also known as Barton-on-Irwell or Barton) is a suburb of the City of Salford, Greater Manchester, England, with a population of 12,462 in 2014. History Barton Old Hall, a brick-built house degraded to a farmhouse, was the sea ...

Greater Manchester Greater Manchester is a metropolitan county and combined authority, combined authority area in North West England, with a population of 2.8 million; comprising ten metropolitan boroughs: City of Manchester, Manchester, City of Salford, Salford ...

, England. It carries the

Bridgewater Canal The Bridgewater Canal connects Runcorn, Manchester and Leigh, Greater Manchester, Leigh, in North West England. It was commissioned by Francis Egerton, 3rd Duke of Bridgewater, to transport coal from his mines in Worsley to Manchester. It was ...

across the

Manchester Ship Canal The Manchester Ship Canal is a inland waterway in the North West of England linking Manchester to the Irish Sea. Starting at the Mersey Estuary at Eastham, near Ellesmere Port, Cheshire, it generally follows the original routes of the river ...

. The swinging action allows large vessels using the ship canal to pass through and smaller craft, both

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 broad-beam barges, to cross over the top. The aqueduct, the first and only swing aqueduct in the world, is a Grade II*

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 considered a major feat of Victorian

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 ...

. Designed by Sir

Edward Leader Williams Sir Edward Leader Williams (28 April 1828 – 1 January 1910) was an English civil engineer, chiefly remembered as the designer of the Manchester Ship Canal, but also heavily involved in other canal projects in north Cheshire. Early life ...

and built by

Andrew Handyside and Company Andrew Handyside and Company was an iron founder in Derby, England, in the nineteenth century. Biography Born in Edinburgh, Scotland, in 1805, Handyside worked in his uncle Charles Baird's engineering business in St. Petersburg before takin ...

Derby Derby ( ) is a city and unitary authority area in Derbyshire, England. It lies on the banks of the River Derwent in the south of Derbyshire, which is in the East Midlands Region. It was traditionally the county town of Derbyshire. Derby gai ...

, the

swing bridge A swing bridge (or swing span bridge) is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the swing span (turning span) can then pi ...

opened in 1894 and remains in regular use.

History

The Barton Swing Aqueduct is a direct replacement for the earlier

Barton Aqueduct Barton may refer to: Places Australia * Barton, Australian Capital Territory, a suburb of Canberra * Division of Barton, an electoral district in New South Wales * Barton, Victoria, a locality near Moyston Canada * Barton, Newfoundland and La ...

, a masonry structure crossing the

river Irwell The River Irwell ( ) is a tributary of the River Mersey in north west England. It rises at Irwell Springs on Deerplay Moor, approximately north of Bacup and flows southwards for to meet the Mersey near Irlam. The Irwell marks the boundary be ...

and completed in 1761. The construction of the

in the 1890s necessitated the replacement of this structure, as the height of ships using the new ship canal was too great to pass under the old aqueduct. An alternative scheme involving the use of a double

lock flight A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water lev ...

was rejected, because of the need to conserve water in the

above. The new aqueduct was designed by Sir

, engineer to the Manchester Ship Canal Company, and was built by Andrew Handyside and Company of

. The first barge crossed the new aqueduct on 21 August 1893, and it opened to commercial traffic on 1 January 1894. Williams was also involved with the

Anderton Boat Lift The Anderton Boat Lift is a two caisson lift lock near the village of Anderton, Cheshire, in North West England. It provides a vertical link between two navigable waterways: the River Weaver and the Trent and Mersey Canal. The structure is de ...

, another moving canal structure in the region.

Construction

Construction work began in 1890, with the demolition of a Roman Catholic school on the south bank of the ship canal. The scale of the operation meant that the course of the River Irwell had to be temporarily diverted around the site, so that the central island could be built on dry land.

Operation

The aqueduct is a form of swing bridge. When closed, it allows canal traffic to pass along the Bridgewater Canal. When large vessels need to pass along the ship canal underneath, the and long iron trough is rotated 90 degrees on a pivot mounted on a small purpose-built island.

Gates Gates is the plural of gate, a point of entry to a space which is enclosed by walls. It may also refer to: People * Gates (surname), various people with the last name * Gates Brown (1939-2013), American Major League Baseball player * Gates McFadde ...

at each end of the trough retain around 800 tonnes of water; additional gates on each bank retain water in their adjacent stretches of canal. The aqueduct originally had a suspended towpath along its length, about above the water level of the Bridgewater Canal, which has now been removed. The structure is adjacent to, and upstream of, the Barton Road Swing Bridge. Both bridges are operated from a brick control tower on an island in the centre of the ship canal. When in the open position, the aqueduct and road bridge line up along the length of the island, allowing ships to traverse each side. To avoid the risk of collision, the aqueduct is opened half an hour before traffic on the Manchester Ship Canal is scheduled to pass.

Turning mechanism

The turning mechanism built into the central island consists of a race plate embedded in granite blocks. Sixty-four tapered cast iron rollers sat on top of the race plate, held in position by a spider ring. On top of that an upper race plate supports the aqueduct and its circular gear rack, which was powered by a hydraulic engine manufactured by Sir W. G. Armstrong Mitchell of Newcastle. To reduce the pressure on the turning mechanism, a hydraulic press was installed in the pivot. When water was admitted to the press it took up to half the weight. So successful was this system of hydraulic assistance that Leader Williams retrofitted it to several road swing bridges being built over the Ship Canal including the ones at Stockton Heath and Knutsford Road in Warrington. The weight of the structure meant that the design was pushing the limits of the possible. This became clear when the sixty-four 35.5 cm (14 inches) mean diameter hollow cast-iron rollers started to deform. By 1927 the structure had dropped by 8.89 cm ( inches). In 1928 the iron rollers were replaced with steel and since then the bridge has dropped by only 2.4mm (3/32-inch). Once the iron rollers were replaced the hydraulic press assistance was dispensed with. Hydraulic power was originally supplied by steam from two

Lancashire boiler A shell or flued boiler is an early and relatively simple form of boiler used to make steam, usually for the purpose of driving a steam engine. The design marked a transitional stage in boiler development, between the early haystack boilers and t ...

s housed in a pumping station on the Eccles bank of the ship canal; a service culvert beneath the bed of the canal conveyed the water under pressure to the control tower on the island. In 1939 the original hydraulic engines were replaced by a pair of radial three-cylinder engines manufactured by the Hydraulic Engineering Company of Chester, and the following year a power house was built on the island to house two electrically driven pumps. The old steam pumping station was demolished after the Second World War.

References

Notes Bibliography * * * *

External links

Videos of the aqueduct in motionVideo of narrowboat crossing the aqueduct
{{Salford B&S Buildings and structures in the City of Salford Bridges completed in 1893 Grade II* listed buildings in Greater Manchester Swing bridges in England Bridges in Greater Manchester Navigable aqueducts in England Grade II* listed bridges in England Grade II* listed canals Tourist attractions in Salford