27 October 2009

Thousands of discarded tyres, acres of power station waste...and butterflies. All problems that Costain's team on the Church Village Bypass in South Wales had to overcome to relieve local residents from challenging traffic conditions.

The 7.5km bypass will take 70 per cent of traffic off the A473 where it runs through the village. It's the latest in a series of such schemes Costain has tackled for Rhondda Cynon Taf Council in recent years to alleviate congested valley roads.

The £90million contract includes four roundabouts, three foot bridges, two road bridges and one equestrian underpass. However, a major value engineering exercise has hugely reduced the complexity of the scheme, says Project Manager Barry Woodman.

"In value engineering terms I think we've done a job that would be hard to beat," he says. Originally there were to be nine bridges. A 500m retaining wall has also been deleted and structures generally reduced to a minimum.

The two road bridges and culverts are being pre-cast in sections off-site, which brings both quality and safety advantages.

Work began in spring 2008 and progress has been so good that virtually all the structures are already in place, a year ahead of the scheme's completion date of autumn 2010.

Environmental considerations have been high on the agenda: dormice, otters, bats and a rare type of fritillary butterfly have had to be protected or relocated.

The team has also made several positives out of negatives along the route. One landfill site concealed 300,000 old tyres, while others contained huge quantities of pulverised fly ash from a disused power station. "That made ground conditions particularly interesting," says Woodman.

However, the tyres have been bound together to help create a retaining wall and the ash reshaped into bunds and landscaping features to screen the site from homes.

With much of the heavy work complete and around 20 per cent of the roadway laid, the team is keeping its foot on the accelerator to finish on schedule next year.

Ends