Supermarket giant Tesco has finally submitted new plans to Network Rail for its troubled Gerrards Cross store, more than two years after an earthworks induced collapse halted work.
The project has been in limbo since June 2005, after a major rail accident was narrowly avoided when a 30m section of new tunnel caved-in onto the live railway line.
At the time, contractor Jackson was creating a 320m length of tunnel over the railway using precast concrete arch units. The aim was to build up the ground over the tunnel to form a site for the supermarket.
After the collapse Costain replaced Jackson as contractor and Scott Wilson replaced White Young Green as designer. The firms have been reviewing the construction method and working on a revised design since March 2006.
This week Costain said that work was now poised to recommence, with the new plan to build a new reinforced concrete arch to create the tunnel, using the existing units as permanent formwork.
"The detailed design is now complete and it has gone back to Network Rail and the third party checking engineers Atkins for approval," said a Costain spokesman. “Some preparatory works have already been done, including the removal of all backfill material."
"We hope to start work on the new arch in February 2008 for completion in 2010."
Blame for the original collapse is still to be established, but Tesco has already lost a court battle with its insurers over compensation it paid out to Chiltern Railways, the operator of trains which were using the line at the time of the collapse.
The supermarket giant took its insurance company DA Constable to the High Court after it refused to cover Tesco for the compensation it paid out to the train operator.
Before work on the new store began, Tesco agreed to compensate Chiltern for damages or loss of passenger revenue. When the tunnel collapsed the railway line had to close for 51 days and Chiltern lost money from ticket sales.
Tesco compensated Chiltern for the loss of revenue but then asked its insurers to cover them for the pay-out. DA Constable refused, arguing that Tesco was only covered for damage to Chiltern property.