TUNNELLING ON the UK's Channel Tunnel Rail Link's North Downs Tunnel was halted after a miner was crushed by a sudden rock fall during excavation last November.
Shane Holliday was freed by colleagues and rushed to hospital where his left leg and right hand were later amputated. He worked for Miller Civil Engineering, part of the Eurolink consortium which is constructing the tunnel using sprayed concrete techniques.
The accident occurred under Blue Bell Hill, near Maidstone in Kent. The large chalk boulder fell from the roof as the tunnelling crew was putting up steel mesh as part of the primary shotcrete tunnel lining. Rock anchors, spiles and a flash coat of shotcrete had been applied to stabilise the ground.
Project manager Rail Link Engineering insisted that the accident had not jeopardised the integrity of the 3.2km long, 13m wide and 10m high tunnel.
'No adverse movements or ground instability have been recorded in the 1.8km of tunnel which has been driven to date,' it said, pointing out that engineers were working with the HSE to discover why the boulder fell.
RLE said that it was the first serious accident on the CTRL since construction started on Section 1 in October 1998. 'So far the project's safety performance has been excellent, with an accident rate at less than half the national average.'