SWANSEA COUNCIL and Tarmac/Soletanche are preparing to go to arbitration over multi-million pound claims on the Swansea Bay bathing water improvement scheme.
The joint venture was kicked off a £10M sewer tunnelling contract last September after making only 50m progress in 18 months. Its 1.84m diameter CSM Bessac tunnelling machine is still stuck 14m underground near the banks of the River Tawe.
Assessment of the claims - understood to be in excess of £10M - is expected in the next two weeks. But City and County of Swansea head of engineering Andy Cluckie said this week: 'Because of the size and nature of the claims we expect to go to arbitration.'
Tarmac/Soletanche stopped work on the 200m southern sewer tunnel beneath the River Tawe amid fears of a violent compressed air blowout - similar to the more recent accident on the Docklands Light Railway extension (NCE 26 February). As the machine approached the river under compressed air, the joint venture is understood to have noticed bubbling in the river as air escaped through perished wooden piles in the bed.
Sources claim that ground conditions above the tunnel were much worse than was shown in the site investigation, being made up of 'mud and slag' rather than the silt, sands and gravels expected.
However, Cluckie denied that the ground conditions were unforeseen, adding: 'It's all a question of whether they read the site investigation properly at the time. We have received opinions which don't really say a lot for their claim.'
A spokesman for Tarmac would say only: 'We are indeed preparing to go to arbitration - if there's no alternative we are going to go.'
Meanwhile Swansea council has re-awarded the contract to Byzac, which has already completed the 250m northern crossing of the river in seven weeks using a Herrenknecht machine.
Byzac is now building a 17m deep sheet pile cofferdam to recover Tarmac/ Soletanche's CSM Bessac machine, and is due to re-start work on the southern crossing in the next two weeks.