National Highways has highlighted its range of complex, often unseen, works on the M5 Avonmouth Bridge as it marks its 50th anniversary.
The government-owned company is currently undertaking a programme of welding on the underside of the bridge over the River Avon near Bristol, which carries an average 125,000 vehicles per day.
It said large water crossings such as Avonmouth, the M4 Prince of Wales Bridge and M48 Severn Bridge require specific maintenance and inspection regimes, and all three are now looked after by is Specialist Bridges Inspection and Maintenance (SBIM) team.
Abseiling engineers and cradle platforms have been employed as part of inspection and maintenance work, while at road level the bridge expansion joints are routinely inspected, assessed and repaired.
National Highways teams have been carrying out extensive welding within the structure since October, unseen by the travelling public, underneath the bridge, along the parapets and within the chambers and mezzanine flooring of the structure.
Terry Robinson, National Highways’ South West Engineering Team leader, said: ‘Through a programme of structural inspections, investigations and assessments we ensure that substandard and potentially vulnerable structures are identified, safeguarding measures adopted, and like the Avonmouth Bridge and Wynhol Viaduct, fully maintained for many years to come.’
Paula Hewitt, chair of the South West Infrastructure Partnership, said: ‘Looking after our critical infrastructure to ensure it can meet the future needs of the region is essential and it is great to see National Highways investing in the bridge’s maintenance to ensure it is able to meet our future needs.’
Shane Stephens, senior inspection assurance manager for National Highways’ SBIM team, said: ‘Like all the infrastructure across the Strategic Road Network, the Avonmouth bridge requires plenty of TLC, and one of the main challenges is to ensure safe access for the inspection and maintenance work around this large and significant structure.
‘The Avonmouth Bridge, like the M4 Prince of Wales Bridge and the M48 Severn Bridge, is a real feat of engineering, and as current custodians, we take a lot of pride in our work as we move into the next 50 years of its life.’
Designed by Freeman Fox and Partners, construction of the original six-lane bridge began in 1969.
Completion was delayed by two years following construction issues with similar box girder structures in Melbourne, Koblenz and Milford Haven.
After further strengthening work. it opened for traffic on 24 May 1974, just weeks after Abba won the Eurovision song contest.
