Austrian tunnelling specialist Geoconsult was found guilty in the Heathrow Express Collapse trial at the Old Bailey in London, last month.
The jury found Geoconsult guilty of failing to ensure the safety of its employees and others in October 1994, when three NATM tunnels collapsed during construction of the Heathrow Express rail link. The charges against Geoconsult had been brought by the Health & Safety Executive following a four year investigation into the collapse. Main contractor Balfour Beatty had pleaded guilty to identical charges before the trial began. Following the jury's guilty verdict in the month long trial, high Court judge Mr Justice Cresswell handed out record HSE-related fines of £1.2M to Balfour Beatty and £500,000M to Geoconsult. The cause of the collapse was a key issue in the case and in this special report Ground Engineering summarises some of the key evidence given in court and explanations given by both prosecution and defence as to the collapse mechanism.
THE GUILTY verdict handed down to Geoconsult and the fact the Balfour Beatty pleaded guilty in the Heathrow Express trial should not be taken as proof that NATM is dangerous. Nevertheless there will be temptation to draw such inferences. Will it be remembered that it was not the method, but the companies who were in dock?
It is unlikely that the true mechanism of the collapse came out in the court proceedings at the Heathrow Express trial. If the construction industry had hoped the case would provide guidance as to the safety of NATM, it is left none the wiser.
Under the English adversarial system a court hearing is a contest in which each party fights its case, and the jury's role is to decide who has won the contest. This is in contrast to an inquisitorial system, such as that used in France, in which each party brings evidence before the court which has a duty to investigate and discern the truth.
The trial was to determine whether Geoconsult and Balfour Beatty had put the safety of their employees and the public at risk. While Balfour Beatty accepted its guilt at the start, Geoconsult chose to plead its innocence in front of a jury.
The guilty verdict simply meant the jury felt that the prosecution proved that Geoconsult had failed to ensure the safety of its employees and of the public; and that Geoconsult was unable to show that it was 'probably not reasonably practicable' to do more than was done to ensure the safety of work.
For the jury it must have been a Herculean, if not impossible, task to absorb and make full sense of the two explanations for the cause of the collapse. One fears that in a highly complicated case of this nature the verdict comes down more to the performances and personalities of the barristers and expert witnesses. Had the jury been made up of tunnelling experts, one doubts that they would they have reached the unanimous decision reached by the lay jury.
The guilty verdict of course suggests the jury favoured the prosecution's line of argument, although in reality neither prosecution nor defence offered a complete explanation. One can not infer from the verdict that Sir Alan Muir Wood's report for the prosecution was completely right and likewise that Professor Rokhar's defence was completely wrong.
The likelihood now is that the prosecution's explanation for the collapse becomes the accepted chain of events and that there will never be a full examination of the reasons for the failure.