Runnymede Bridge

Description

Runnymede Bridge

Runnymede Bridge carries the northbound lanes of the M25 motorway and A30 Staines Bypass across the River Thames, downstream of Bell Weir Lock, near Staines-upon-Thames in Surrey. It has a total length of 415 ft and the main span across the navigable river channel is 173 ft. The towpaths pass through two smaller arches, one on each side of the river, each with a span of 31 ft. The reinforced concrete deck is 100 ft wide.

The foundations of the bridge reach into the London Clay, which is 21 - below ground level. The deck is supported by 18 arched steel ribs, clad in concrete. The sides of the bridge are clad with hand-made red bricks, with Portland stone and white concrete mouldings. The bridge provides a clearance of 23 ft for river traffic.

New Runnymede Bridge

New Runnymede Bridge, immediately downstream of Runnymede Bridge, carries the southbound lanes of the M25 and A30 across the River Thames. It has a total length of 137.6 m. The piled foundations rest on London Clay and support four concrete arches with a span of 54.66 m. The roadways rest on a reinforced concrete deck, with a total width of 34 m. The bridge provides a clearance of 23 ft for river traffic.

History

Runnymede Bridge was built to carry the A30 Staines Bypass road across the River Thames. The design was modified to accommodate greater traffic volumes by the engineering firm, C. W. Glover and Partners, and the architect, George Stewart, although the external appearance of the bridge remained faithful to Lutyens's original intentions.

Construction work was undertaken by W. & C. French Ltd at a total cost of £476,000 (equivalent to £ million in ), and Runnymede Bridge was formally opened on 17 November 1961 by John Hay, the Parliamentary Secretary to the Ministry of Transport. The road over the bridge was initially configured as a dual carriageway, with two 12 ft lanes provided for traffic in each direction, and a 9 ft footpath adjacent to the parapet on each side. At the time, plans were in development to route the proposed North Orbital Road (constructed as the M25) over the bridge, and a 34 ft central reservation was therefore provided to allow for the addition of further running lanes, giving the completed bridge a total width of 100 ft. The channel of the River Thames was also widened at the crossing to improve navigation conditions and to reduce the potential for bridge scour.

Detailed proposals were published in November 1975 for the extension of the M25 north from Egham over the Thames, which required the construction of a second bridge between Runnymede and Staines. Although widening of the existing bridge was considered, the design of the foundations meant that it would have been technically challenging to add additional arch girders. The new bridge was designed by Ove Arup and Partners with a similar arch profile to complement the 1961 bridge. The construction, undertaken by Fairclough Civil Engineering Ltd, was completed in November 1981 at a cost of £1.7 million (equivalent to £ million in ).

Evidence of human activity, dating from the Mesolithic to the Bronze Age, was discovered during preparatory works for the construction of New Runnymede Bridge. Archaeological investigations in 1978 revealed a late Bronze Age settlement on the south bank of the Thames, beneath which there was evidence of a Neolithic site. Human remains uncovered included two jaw bones and a skull, as well as artefacts including amber and blue glass beads, a pottery ladle and shale bracelets.

References

Bibliography

References

1. River Thames Alliance. [https://web.archive.org/web/20080124114502/http://www.visitthames.co.uk/text.asp?PageId=320 Bridge heights on the River Thames]
2. Cracknell, Donald William. (July 1963). "The Runnymede Bridge". Proceedings of the Institution of Civil Engineers.
3. (24 November 1961). "Staines By-pass".
4. (23 April 1955). "Proposed new bridge over the River Thames". Surrey Advertiser.
5. (17 October 1959). "New bridge on Surrey border". Surrey Advertiser.
6. (25 November 1961). "Sir Winston at Harrow; and other home news in pictures". Illustrated London News.
7. (30 January 1976). "Question on M25 work". Bucks Free Press.
8. (19 November 1981). "M-way completed". Daily Telegraph.
9. (14 August 1986). "Skull found at dig site". Staines Informer.
10. (14 August 1986). "It's Runnymede Man". Staines & Ashford News.