06:00PM, Monday 08 June 2020
Over the weekend, Highways England completed the widening of the 60-year-old Thames Bray Bridge, using 400 tonnes of steel and diverting the River Thames in the process.
The work is part of an upgrade on the M4, adding the four extra lanes needed to create running lanes on each side of a smart motorway.
This requires replacing 11 bridges across the motorway. The project is at its halfway point, and Bray Bridge has been ‘the most complex work yet’.
Mike Grant, Highways England delivery director, said:
“The Thames Bray Bridge is different. It doesn’t carry a local road or footbridge over the M4, it carries the motorway over the River Thames.
“Of course, we couldn’t just knock this bridge down and rebuild it, this would put the M4 out of action for months.
“The only option was to build the extended bridge elements on a nearby site and then assemble them over a single weekend.”
The installation of the three bridge beams – the bulk of the work – was completed over the weekend May 30- June 1 with the remaining work completed in 24 hours the following weekend.
Steve Foxley, Highways England programme manager, said:
“We had the huge engineering challenge of tying three new beams into the existing structure. The beams weighed nearly 400 tonnes combined.”
It took around 13 hours to lift the three beams into place and apply tension cables. Each cable has a tension capacity of 295 tonnes.
Shaun Pidcock, Highways England’s smart motorway programme director, said:
“The team also had to contend with social distancing, extremely hot weather, and the added challenge of making sure all was kept to plan so that the M4 was ready and open by Monday morning.
“This was an exceptional achievement by everyone involved.”
*This article was amended to reflect further work was carried out on the weekend of June 6-7, and is not due to take place this coming weekend.