timeline item
Results
Here is the information we have
on the item you selected
This entry was funded by
More like this
NEW SEARCH
| |
sign up for our newsletter
© 2017 Engineering Timelines
engineering-timelines@severalworld.co.uk
engineering timelines
explore ... how   explore ... why   explore ... where   explore ... who  
home  •  NEWS  •  search  •  FAQs  •  references  •  about  •  sponsors + links
George Street Bridge
River Usk, Newport, Wales, UK
George Street Bridge
associated engineer
Mott Hay & Anderson
date  2nd July 1962 - 9th April 1964
era  Modern  |  category  Bridge  |  reference  ST318877
ICE reference number  HEW 346
photo  © Jaggery and licensed for reuse under this Creative Commons Licence
George Street Bridge — a steel cable-stayed road bridge spanning between reinforced concrete towers — was the first of its type constructed in the UK. It crosses the River Usk in Newport, Wales, and remains in use. It is now Grade II* listed, reflecting its importance to Britain's engineering heritage.
Mott, Hay & Anderson designed the bridge for the Borough of Newport. It was Britain’s first example of cable-stayed cantilever bridge construction and carried the A48 trunk road. It is located almost 1km downstream of Newport's town bridge (ST312884), opened in 1927, to the east of Newport Castle.
George Street Bridge has maximum headroom of 13.1m above high water level — the River Usk’s tidal range is more than 9m. By the time it was built, there was no longer any need to provide clearance for tall-masted sailing ships, as there had been in 1906 when the nearby Newport Transporter Bridge (ST317862) was constructed.
The bridge is 539.5m long between abutments with a centre span of 152.4m over the river. The deck is 20.1m wide, which includes a 14.6m carriageway with two lanes in each direction and two 2.7m footways for pedestrians and cyclists. However, the footways over the river are wider and here the overall width is 25.6m.
The approach viaducts are of flat slab construction in prestressed and reinforced concrete, 189m long at the east end and 198m long at the west. Either side of the river they are supported on three trestles, at 16.9m centres, carried on pairs of tapering square section columns, wider at the top. Thereafter, the trestles up to the abutments consist of rows of four cylindrical columns.
The main span is a steel box girder deck structure, which forms part of the cable-stayed cantilever. The principal tension members are the steel wire ropes through the concrete support towers. Their inner ends are attached to the suspended cantilever span and their outer ends to the anchorage spans, which are the first three spans from the river bank on each side. The arrangement is self-anchoring, deriving its stability from the weight of the bridge approaches.
The hollow bridge towers are constructed on cylindrical 9.1m diameter reinforced concrete caissons, founded in red marl rock at 13.7m below sea level. The towers rise 51.8m above the top of the caissons (4.6m above sea level). They are rectangular in section, tapering from 4.1m x 3m at the base to 3m x 2.1m at the top, with wall thickness varying from 457mm to 305mm.
Each of the four towers has three openings, at 11.7m centres vertically, through which passes a pair of 76mm diameter locked coil steel cables. Each cable has a breaking load of 508 tonnes.
Additional pedestrian access is provided via concrete steps (ST317876) on each side of the bridge, near the west towers.
Construction commenced on 2nd July 1962 and the bridge opened to traffic on 9th April 1964. The cost was £980,000. Standardisation and prefabrication of parts wherever possible was used to minimise expenditure and also reduced construction time to 21 months.
Originally, George Street Bridge was going to have had six lanes, but with plans for the M4 motorway to have a new bridge over the River Usk further upstream, the design was amended to four lanes. Work on the M4 bridge (Junctions 25 to 25a) began in summer 1962 and the Newport bypass section of the motorway — Junctions 24 to 28 — opened in 1967.
In October 2001, George Street Bridge received Grade II* listed status. In 2004, the new City Bridge (ST325868), 1km downstream, opened as part of the Newport Southern Distributor Road. The new road became the A48 and George Street Bridge was renumbered as part of the B4237. It is maintained by Newport City Council.
Resident engineer: R. Hodges
Contractor: Cleveland Bridge & Engineering Co Ltd
Steelwork: Fairfield Shipbuilding & Engineering of Chepstow
RCAHMW_NPRN 611
Research: ECPK
bibliography
"Design and Construction of the George Street Bridge over the River Usk, at Newport, Monmouthshire" by Charles Dargle Brown, ICE Proceedings, Volume 32, Issue 1, pp.31-52, London, September 1965
"Discussion. Design and Construction of the George Street Bridge over the River Usk, at Newport, Monmouthshire" by Charles Dargle Brown et al, ICE Proceedings, Volume 34, Issue 4, pp.552-561, London, August 1966
http://cadw.wales.gov.uk
http://newportbridges.weebly.com
www.coflein.gov.uk
www.ice.org.uk
www.newportpast.com
www.sabre-roads.org.uk
reference sources   CEH Wales
Location

George Street Bridge