SUPERMARKET GIANT Tesco faces a tough battle convincing Network Rail and Chiltern Railways that work can restart at the site of the Gerrards Cross tunnel collapse.
Full train services resumed on 22 August, almost a month after a 30m section of tunnel being built by Tesco's contractor Jackson collapsed on 30 June (GE August 05). The tunnel was being built over a rail line to create a site for a supermarket and car park.
Despite the Health and Safety Executive (HSE) declaring that what is left of the is tunnel safe, Network Rail and Chiltern Railways said they were far from convinced work should continue.
'Much more evaluation is needed before any potential future work will be allowed on the remaining tunnel, ' said Network Rail contracts director Roger Dickinson.
'Tesco needs to continue to investigate to demonstrate to Network Rail and others that what is left is good enough to be built on.
'This is no easy job for Tesco.
The process will be no less diligent than it was to allow the tunnel to reopen. It is working on providing this information and this will lead to future discussions on the site, ' he said.
Chiltern Railways said it would be 'some months' before a decision on the future of the tunnel was made.
'All safety assessments so far have been based around opening the railway through the existing sections of the tunnel and as such, no decision has been made on the future of the tunnel, or will be made for some months, ' it said in a statement.
The ongoing HSE investigation into the collapse is now focusing on a change in the backfilling method made two days before the collapse. Network Rail has already con' med that the collapse was caused by overloading the tunnel crown (GE September 05).
'It was not a case of the rules being broken all the time, ' Dickinson said. 'There was a very clear point when the change was made and that is what the investigation is focused on now.' To convince Network Rail and the HSE the tunnel is safe, Jackson has removed 12,000t of 'll from above the undamaged tunnel in addition to 15,000t from the collapsed area.
It has also removed 34m of undamaged tunnel segments next to the collapse.
'Tesco and its consultants have produced detailed analysis and substantial evidence and evaluation, independently checked by Atkins, that the remaining structure is safe, ' Dickinson said.
'But Network Rail, the HSE and its advisers will have to give approval for any future work to take place.' Tesco said its priority had been to open the tunnel as quickly as possible, consistent with being con'dent of its safety.
'During this period we have not continued with work on the store itself, ' said a spokesman. 'We are taking this one step at a time and are taking stock of the situation. Everyone is working together to find the right long-term solution.' Mark Hansford