The Thelwall Viaduct () is a

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

composite

girder A girder () is a Beam (structure), beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing ''flanges'' separated by a sta ...

viaduct A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide ...

Lymm Lymm ( ) is a village and civil parish in the Borough of Warrington, Cheshire, England. It incorporates the hamlets of Booths Hill, Broomedge, Church Green, Deansgreen, Heatley, Heatley Heath, Little Heatley, Oughtrington, Reddish, Rushgreen and ...

Warrington Warrington () is an industrial town in the Borough of Warrington, borough of the same name in Cheshire, England. The town sits on the banks of the River Mersey and was Historic counties of England, historically part of Lancashire. It is east o ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. It carries the

M6 motorway The M6 motorway is the longest motorway in the United Kingdom. It is located entirely within England, running for just over from the Midlands to the border with Scotland. It begins at Junction 19 of the M1 motorway, M1 and the western end of t ...

across the

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

and the

River Mersey The River Mersey () is a major river 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 h ...

. It is between junctions 20 and 21 of the M6, the former also being junction 9 of the M56.

Structure

It comprises two separate bridges, one of long carrying the northbound carriageway, the longest motorway bridge in England when it was opened in July 1963, and one long carrying the southbound carriageway, opened in 1995. The longest single span is that of crossing the Ship Canal.

History

The scheme was announced on Thursday 9 July 1959 by Minister of Transport Harold Watkinson, with the Gathurst Viaduct and Creswell Viaduct, near Stafford, over the

River Sow The River Sow is a tributary of the River Trent in Staffordshire, England, and is the river that flows through Stafford. Course The river rises to the south of Loggerheads, Staffordshire, Loggerheads, near Broughton Hall, Staffordshire, Brough ...

. The bridge would cost £5,056,678, and was to be built by Leonard Fairclough & Son, and designed by Sir James Drake.

Construction

Work started in September 1959, and was to be finished by March 1962. 10,500 tons of steel superstructure was made by

Dorman Long Dorman Long & Co was a UK steel producer, later diversifying into bridge building. The company was once listed on the London Stock Exchange. History The company was founded by Arthur Dorman and Albert de Lande Long when they acquired '' ...

. Concrete was supplied by Four Square Industries of

Middlewich Middlewich is a town and civil parish in Cheshire East, Cheshire, England. It is located east of Chester, east of Winsford, south-east of Northwich and north-west of Sandbach. The population of the parish at the United Kingdom 2021 census, ...

. On Thursday 16 May 1963, the last two girders were put into place. The bridge had taken longer to build than expected, and the motorway was due to open on Monday 29 July 1963. The bridge was designed to take up to 79,000 vehicles per day. In August 1990 it was proposed to build a second viaduct, to start in 1992. The £52.5m contract was awarded to Tarmac Construction of Wolverhampton in October 1992, with consulting engineers Pell Frischmann. Junctions 20 and 21a would be remodelled. Concrete came from Pochin Group of Middlewich.

Maintenance

In July 2002 a failed

roller bearing In mechanical engineering, a rolling-element bearing, also known as a rolling bearing,ISO 15 is a bearing which carries a load by placing rolling elements (such as balls, cylinders, or cones) between two concentric, grooved rings called race ...

was discovered and it became necessary to close all but one northbound lane. As the M6 at the time carried an estimated 150,000–160,000 vehicles per day, this led to serious congestion. The viaduct was not completely reopened to daytime traffic until February 2005, and subsequently remained partially closed at night for further remedial work to take place. In all, 148 bearings were replaced, the repair scheme costing around £52 million. The bridge's height and openness to the elements mean that it has frequently been the subject of speed reductions because of strong gusts of wind that badly affect the stability of high-sided vehicles. On several occasions lane closures have resulted as a consequence of articulated vehicles simply being blown over. However, the open sides of the bridge are a deliberate design feature to reduce the likelihood of snow drifts building on the carriageways.

Events

1971 multiple vehicle collision

At approximately 8am on 13 September 1971 thick fog led to a catastrophic multiple vehicle crash on the viaduct. More than 200 cars, trucks and tankers piled up, five vehicles burst into flames, 10 people were killed and 70 injured. It was the worst crash ever recorded on British roads at that time.

2011 rave

In April 2011 a massive

free party A free party is a party "free" from the restrictions of the legal club scene, similar to the Free festival, free festival movement. It typically involves a Sound system (DJ)#Free party, sound system playing electronic dance music from late at ...

took place under the viaduct, with reportedly over 5,000 ravers in attendance.

2024 crash

On 30 September 2024, a lorry fell from the viaduct and landed on the embankment below. The driver survived.

References

External links

{{Portal, Cheshire
The Motorway Archive website
Bridges across the River Mersey Bridges in Cheshire Bridges completed in 1963 Bridges completed in 1995 Motorway bridges in England Viaducts in England M6 motorway