Building the First Severn Bridge

The first of the two main Severn Bridges was completed in 1966. But proposals nearly 150 years earlier  for a Severn Bridge at the same location had first been advanced by Thomas Telford In 1824, Telford had been invited to bring forward suggestions as to how mail coach services between Wales and London could be improved. Over the following decades however rail travel became the principle  choice for long distance travel and the idea of a Severn Bridge fell by the wayside. In the meantime a Severn Railway Bridge was built at Sharpness in 1879 and the Severn Tunnel was competed in 1886. The idea of a Severn Bridge to carry foot and road traffic had become redundant. By the 1920s however road use was growing significantly and Chepstow Urban District Council called a meeting of neighbouring local authorities to consider ideas for a Severn Bridge river crossing. It was intended to avoid the traffic congestion which was by then affecting Chepstow and was causing tail backs on the A48. In 1935 Monmouth and Gloucestershire County Councils tried to get a Bill placed before Parliament to obtain powers to construct a Severn Bridge further down the estuary with three quarters of the costs being borne by the by the Ministry of Transport. But the influential Great Western Railway Company opposed the bill and it was lost.

The Old Severn Bridgesevern bridge

Following the Second World War, plans were set in motion for a national set of trunk roads of which a Severn Bridge crossing would be part. A contract was agreed with ‘Freeman Fox and Partners’ and ‘Mott Hay and Anderson’. Bristol University hosted a public enquiry into the Severn Bridge proposals in 1946. Unfortunately the Severn Bridge had to take second place in priority to the ‘Forth Road Bridge’ in Scotland which was opened in 1964 and construction on the Severn Bridge did not start until1961. In 1962 the UK government decided that construction costs would be recovered by vehicles paying a toll of two shillings and six pence (12.5p in today’s decimal money). Walking and cycling across the Severn Bridge would be free. ‘Associated British Builders Ltd’, (a joint enterprise involving ‘Dorman Long’, ‘Cleveland Bridge & Engineering Company’ and ‘Sir William Arrol and Co’), were awarded the contract to build the superstructure in 1963 and the Severn Bridge was finally completed in 1966. Starting in England and working towards Wales, the Severn Bridge itself comprises four structures, ‘Aust Viaduct’, ‘The Severn Bridge’, ‘Beachley Viaduct’, and ‘Wyes Bridge’. Both Aust Viaduct and the Severn Bridge were granted Grade 1 Listed Status in 1999. Beachley Viaduct and Wye Bridge had already been given Grade 2 status in 1998. In 1968 the Severn Bridge received a Civic Trust Award.

The Old Severn Bridge (‘Pont Hafren’ in Welsh), is an iconic image which touches the hearts of the population of South Wales. Whenever the Welsh see the Severn Bridge in the distance on their way back from England, on the motorway they know that they are only a short distance from the gateway to home. And whilst they cross over they see Wales stretching forth beyond. The Severn Bridge crossing spans the England and Chepstow in South Wales via the River Wye and the River Severn (‘Hafren’ in Welsh). It does so via Beachley, the peninsula between the two rivers in Gloucestershire.  The old Severn Bridge cost £8 million, to build and was opened by the Queen on September 8th 1966. Soon after it was opened an Anglo Welsh Poet Harri Webb wrote an ‘Ode to the Severn Bridge’

Two lands at last connected

Across the waters wide,

And all the tolls collected

On the English side.

The side on which the Severn Bridge tolls are collected however is not a significant issue for anyone in Wales or anywhere else . The Severn Bridge tolls would be collected and kept by the same management company regardless of where the gates were located. And in point of fact both sides of the old Severn Bridge are actually in England. The Welsh border only starts just after the end of the ‘Welsh side’. Of more concern is the fact that any tolls are collected at all. The old Severn Bridge and the new Severn Crossing are after all integral parts of the public motorway system and it would be virtually impossible to use the stretches of the motorway either side without the Severn Bridges. Another feature of the tolls is that since the early 1990s they are collected in one direction only, from traffic travelling to Wales, on the ‘English side’. So in jest, the toll has been dubbed, a ‘Tax on entering Wales’. But as nearly all Severn Bridge traffic either way goes back again it doesn’t matter which direction the toll charge applies so there’s no point in having two sets of toll gates.

severn bridgeThe Old Severn Bridge Structures     

The Aust Viaduct is a twin box girder construction incorporating a concrete deck. It carries the road from the top of Aust Cliff, to the old Severn Bridge’s first gravity anchorage before the road. The actual Severn Bridge is located near where the old ‘Aust Ferry’ operated. The Severn Bridge itself is a conventional suspension bridge with a deck held up by two main cables running between two towers made of steel. The original cables put up in 1966 were made from 18,000 miles of wire and over 16,500 separate strands of 5mm wire. Unusually for a suspension bridge the Severn Bridge suspension cables carrying the deck are not vertical. Instead they are placed in a zigzag arrangement with closely spaced adjacent mounts. Along with the use of ‘Stockbridge Dampers’ on the cables the zigzag arrangement is an attempt to reduce vibration. The old Severn Bridge is 5,240 feet long, consisting of a central span between the two towers and two 1000 foot side spans. The hollow towers rise to 445 feet above the River Severn’s High Water mark. The Severn Bridge’s deck itself is an orthotropic, aerofoil shaped box girder construction with the footways and cantilevered cycle tracks supported from the box. Designers ‘Freeman Fox and Partners’ arrived at the shape of the Severn Bridge having conducted wind tunnel tests for the ‘Forth Road Bridge’. The original wind tunnel tests for the ‘Forth Road Bridge’ had been destroyed by accident. The Severn Bridge deck sections each weighing 132 tonnes, were built locally by Chepstow firm ‘Fairfield-Mabey and were hoisted into position after having been floated down the River Severn. Six men, Thomas Edward Baines, Harold Eric Croft, Ivor J Halliday, Albert Sydney Nelmes, John Newton, and Henry Virgo lost their lives during construction and a memorial plaque was erected to remember them.

Severn Bridge Memorial Plaque

severn bridge memorial

In 1977 Severn Bridge traffic in each direction had to be restricted to single lanes for several months when it was discovered that weaknesses had appeared in the structure. The bridge was resurfaced and further strengthened in the late 1980s owing to the ever increasing burden of heavy traffic. The Severn Bridge deck and towers were reinforced and at the same time ‘Wye Bridge’ also benefitted from replacement of its original single stays with a new arrangement of two stays and towers which were themselves extended.. The new open design of the new stays is intended for ease of maintenance. Most of the Severn Bridge reinforcement work is concealed in its own towers and deck box, so few of the changes are visible. The new Severn Bridge surfacing is a 1.4 inch thick coating of mastic asphalt laid on an acrylic waterproofing membrane.

Wye Bridge and Beachley Viaduct

The Beachley Viaduct at 2,444 feet long is of the same box girder construction as the Severn Bridge itself. It was built by the ‘Cleveland Bridge & Engineering Company’ but differs from the Severn Bridge itself in that it’s held up by steel trestles as traverses the Beachley Peninsula. The Peninsula is home to an army camp which located under the Viaduct. The Wye Bridge is 1340 feet long and crosses from Wales to England, over the River Wye, two miles South of Chepstow. It’s a ‘cable stayed bridge’ consisting of one big cable stayed section and two single leg pylons supporting the bridge deck from the centre of the roadway. Like the Severn Bridge, the Wye Bridge deck is an orthotropic box girder structure but with a very different appearance. It has two sets of cable stays on each of its two towers. When it was built it only had one set of stays but the addition of a second set was thought necessary when it was strengthened