FORMER INSTITUTION of Civil Engineers President Sir Alan Muir Wood has claimed the tunnelling contract for the Heathrow Express project was badly set up, and that the New Austrian Tunnelling Method subcontractor Geoconsult is being made a scapegoat for the collapse.
Giving expert evidence for the Health & Safety Executive at the Heathrow Express tunnelling collapse trial this week, Muir Wood claimed he had warned in an article published in1994 that 'the project management of the work being proposed ... was quite inappropriate'.
Under cross-examination from defence barrister Arthur Marriott QC, Muir Wood told the court that he thought liability for the collapse 'should extend to those who were putting these sorts of contracts together.'
He added: 'I think Geoconsult is very unfortunate to find itself where it is ... Morally it is very hard luck for them.' The HSE is prosecuting main contractor Balfour Beatty and Geoconsult for allegedly endangering their employees and others during the1994 tunnel collapse. Balfour Beatty has pleaded guilty (NCE 21 January) but Geoconsult is fighting the charges.
Muir Wood explained that it is absolutely essential that design and construction are integrated when using the NATM technique.
'The way in which the whole management of this contract was proceeding meant there was this great break between engineering and construction,' he said. 'This, to my mind, is the fundamental ill effect which led to all these things happening.'
However, Muir Wood said that Geoconsult did not have enough resources to carry out its monitoring role properly. 'If I had been Geoconsult I would have insisted on having about six engineers to see the job was being done as it should.'
Starting its defence, Geoconsult presented an alternative theory for the collapse developed by NATM expert Professor Rokahr of Hannover University (see box).
Rokahr claimed the collapse was caused by a softening of the clay which led to a landslide above the tunnels. This caused the large concrete shaft built on the previous contract to fail, starting the progressive collapse of the three tunnels. He said this sequence of events could not have been predicted.
But under cross-examination Rokahr admitted that these sort of collapses would always be possible with NATM because you could never be sure what was in front of the tunnel face.
The trial continues.