When Chepstow Bridge opened on 24 July 1816 it was the third largest iron arch bridge in the world (and the largest had only been completed 2 months earlier) so it was a pioneering bridge in its day.
The bridge was also unique for having to face higher tides than any other bridge in the world and this remained the case until the Severn Bridge was built 150 years later. The only higher tides in the world, in NE Canada, are not crossed by bridges. Chepstow Bridge piers had to be very strong to resist strong currents and a direction of flow that changes 4 times a day and a change in water level which can rise up to 13.5 metres (44 feet) in just 4 hours and fall by the same amount in 8 hours twice every day. A single span bridge across such a river would have been ideal but in 1810 this was not technically feasible and piers had to be built in the river. Ironically, within just 5 years of Chepstow Bridge being built, a single span over such a distance was possible (Union Bridge - Brown’s iron chain suspension bridge near Berwick on Tweed in 1820) such was the dramatic speed of technological progress in the decade in which Chepstow Bridge was built.
The magistrates of Monmouthshire and Gloucestershire needed a sturdy bridge with iron arches on stone piers and invited Watkin George who had been the iron master of what was then the world’s largest iron works, Cyfarthfa at Merthyr, to prepare a design for a new iron bridge. They invited also John Rennie, one of the greatest bridge engineers of the time who designed three of Londons’ new bridges of the 19th century (Waterloo, Southwark, and London) to report on the repairs required to the bridge. In 1811 Rennie drew up a ‘repair’ design of 7 iron arches to replace the wooden arches of the old bridge, similar to Watkin George’s design, which would cost £15,191. Both designs included retaining the central stone pier of the wooden bridge which was not helpful for river navigation. Rennie recommended, however, that rather than ‘repair’ Chepstow’s wooden bridge it should be replaced altogether with an entirely new bridge with a cast iron arch that would have been the world largest span at the time, had it been built, but it would cost of £41,890. The estimated cost of Rennie’s new bridge was considered to be too high and no action was taken until after an accident resulting in further damage to the bridge and the tragic loss of six lives.
In December 1813 an advert for a contractor to build Rennie’s ‘repair’ design appeared, and the contract was won in February 1814 by the Bridgnorth Foundry of Hazeldine, Rastrick and Brodie of which John Urpeth Rastrick was the Managing Partner.
John Urpeth Rastrick did not follow Rennie’s ‘repair’ plan but completely redesigned Chepstow Bridge in March 1814 to a design of his own in a ‘Telford style’ rather than a ‘Rennie style’. Magistrates agreed the new design, presumably delighted to have a bridge which did not require an obtrusive central pier and instead had a large central arch for ease of river navigation, and for a price similar to the cheaper of the Rennie designs - so neither of the Rennie designs was ever used.
The contract for the current bridge was let to Rastrick on 4th June 1814 at an estimated cost of £17,150 – a figure that eventually rose to nearly £20,000. The bridge was made of cast iron, the total length being 113 metres (372 feet) with the span of the centre arch being 34 metres (112 feet).
The bridge, that is still in use today, was opened on 24th July 1816 with an elaborate Form of Ceremony: “Company to assemble in the Square at One O’clock. The procession. A pair of Clours. Band of Music. Solicitor. Magistrates walking abreast Seniors in the centre. Gentlemen, Farmers, Tradesmen, and others who may choose to join the Procession walking two by two.”
John Urpeth Rastrick did not build any more iron bridges after Chepstow but went back to building steam engines rather than bridges and he became one of the key players in the genesis of the world’s railways. Among many achievements he chaired the judging panel for the Rainhill Trials in 1829 (which was won by Stephenson’s ‘Rocket’) which was critical in the development of railways and he built the first steam engine to run on rails in the USA - the ‘Stourbridge Lion’. Rastrick built the London to Brighton Railway including the 37 arch Ouse Valley Viaduct at Balcombe, Sussex which is a Grade II Listed Structure and impressive - but not as significant world-wide as his Grade I Listed Chepstow Bridge.
Chepstow Bridge with its 5 arches rising to the centre of the river is the most graceful of all the Georgian-Regency iron arch road bridges, and the largest remaining from that time anywhere in the world. The larger iron arch road bridges of that time have all been demolished in the last 200 years making Chepstow Bridge a piece of world heritage.
The bridge has been repaired and refurbished at various times, most recently in the 1980s, and essential works and repainting in 2015.
For further details and sources see the Town Council's information leaflet "Chepstow Bridge - a piece of world heritage" by John Burrows(2015) and "Chepstow Bridge - Notes, Sources and information" (2015) which accompanies it.
Chepstow Railway Bridge by Brunel
The age of the railway made a second bridge across the Wye necessary and the tubular suspension bridge that took the Cardiff to Gloucester railway line across the river was designed by one of Britain’s most famous engineers – Isambard Kingdom Brunel. The line from the present station, (then called Chepstow West), to Swansea was opened on 18th June 1850 and the line linking Chepstow East station at Tidenham and Gloucester came into use on 19th September 1851. Passengers were taken between the stations by coach until the bridge was opened in July 1852.
Brunel’s tubular suspension bridge was and unusual design and the forerunner of his famous bridge between Plymouth (Devon) and Saltash (Cornwall). Brunel used pioneering techniques in bridge construction and in sinking caissons for the bridge piers.
The iron columns of the bridge piers, which is an important part of the bridge’s heritage, are still in place and still carry the railway.
The elaborate superstructure of the rail deck and above, however, was dismantled and replaced by the present span in 1962.
A48 Bridge at Chepstow
The latest bridge to cross the Wye was the Road Bridge opened in 1988 to take the inner relief road, the A48, across the river. Prior to this all the road traffic from Gloucestershire had to pass through Chepstow and over the cast iron bridge. For 175 years the cast iron bridge carried the main road, the A48, from Gloucester to Newport as well as all ferry traffic from England via Beachley across the Wye and into South Wales until the Severn Bridge was built. Today the A48 bridge shows what concrete (albeit with iron and steel inside it) can do with a single span across the River Wye.
Bridging the River Severn
The idea of a bridge across the River Severn had been a dream for 1,900 years but it took modern techniques to overcome the problems. Until the bridge was opened by the Queen on 8th September 1966, the only way to travel from the West of England to South Wales by road involved a 50 mile detour around Gloucester or face a lengthy wait to board a ferry. By the 1960’s the Beachley – Aust ferry was being swamped. The largest of the three ferries carried just 17 vehicles! Railway passengers were able to avoid the long detour via Gloucestershire since the Great Western Railway opened their Severn Tunnel in 1886 and for a time the Severn Tunnel was used to transport cars, which were loaded onto flat wagons, between Severn Tunnel Junction and Pilning.
The Severn Bridge