A £150m road being built for Lincolnshire County Council will be delayed again and see another cost increase, due to a second alleged error in the design of a bridge.
The bridge over the River Witham and the East Coast Main Line is part of the third phase of the Grantham Southern Relief Road being built by Galliford Try.
The highway authority said the project is now expected to be complete in 2026 following a design error related to the installation method of the bridge.
It said the ‘supplier error’ could add an extra £20m to the project, which is currently costed at £148m. This would take it to around double the original cost.
The council said that on learning about the issue, it had demanded a solution and is seeking to recoup the additional costs.
Cllr Richard Davies, executive member for highways, said the error ‘related to the how the bridge was to be installed and us being told it couldn’t be pushed into place as intended due to concerns relating to specific wind conditions’.
He said: ‘The complexities of designing and constructing this relief road, particularly this bridge, are far beyond what we as a council can do directly.
‘That’s why top international engineering companies and experienced contractors were entrusted to handle the project. Although we oversee the scheme as a whole, we rely on our suppliers’ combined expertise.
‘When undertaking a project of the magnitude, all design work also undergoes a mandatory, additional layer of independent checking. Unfortunately, despite all of this, a mistake was made along the way that’s led to this new delay.’
Cllr Davies’ reference to a new delay reflects the fact that the completion of the project had already been put back from an earlier completion date of 2023 after what the council called an ‘unexpected engineering issue’.
In July 2022, it announced that the site team had identified a section of soft, unstable ground where the new bridge was being built, which would require increasing the length of the bridge to avoid the unstable ground.
At that time, Cllr Davies said the council was working with bridge designer WSP ‘to determine the cause of this issue and why it wasn't accounted for when WSP designed the foundations for the bridge’.
He said at that time: ‘The co-ordination of the ground investigation information and the subsequent design of the bridge was and is the responsibility of the bridge designer, WSP.’
In November 2002, Cllr Davies was ‘happy to update that we’re now well underway with installing the first three of six new bridge piers that are part of the structure’s redesign’.
The £3.5km relief road was priced at £81.5m in 2018, with phase 3 estimated to cost around £44m but a year later the projected cost had risen by 25% to £102m.
WSP has been approached for comment.
Image credit: Lincs CC
