Highways England is to split off a “de-risking” £200M enabling works contract from the main contract to build the A303 Stonehenge tunnel project, New Civil Engineer understands.
The £1.6bn A303 Stonehenge tunnel project is one of the most complex and controversial projects Highways England has undertaken. It involves building a 2.9km long twin-bore tunnel through the World Heritage Site with portals inside its boundaries.
It is understood that this new contract will help mitigate the construction risks and make the project more attractive to potential contractors.
Speaking at the New Civil Engineer Tunnelling summit last year Highways England programme director A303 Stonehenge Derek Parody said that while there had been a strong appetite from some contractors, the issue of risk allocation was one of the sticking points.
Parody said archaeology was a perceived risk, but because the site had been mapped that aspect was really well understood. However, contractors would face challenges such as making it “invisible” during construction, water from a significant aquifer with rapidly changing seasonal levels and disposal of spoil through the World Heritage Site.
A prior information notice (PIN) was put out by Highways England in late December last year searching for contractors which had an interest in the the A303 and Lower Thames Crossing tunnels.
In the PIN it said the A303 Stonehenge project was currently anticipated to be primarily a privately financed design, build, finance & maintain the contract, and “some associated enabling works”. It went on to say it reserved the rights to award contracts in lots or groups of lots.
New Civil Engineer understands the enabling works contract has been priced at £200M, but Highways England was not able to confirm the cost and said it had not yet finalised its procurement approach.
“A PIN has been issued which provides potential bidders with an early indication that a procurement process may be launched in the future for the A303 Stonehenge project,” said a Highways England spokesperson.
“We have not yet finalised our procurement approach. This will be announced in due course.”