Cause of Collapse of Heathrow Rail Tunnel in 1999 - Essay Example

? The Heathrow Collapse Introduction The case filed by the Health and Safety Executive (HSE) against Balfour Beatty and Geoconsultexposed the causes of the collapse of the Central Terminal Area (CTA) at the Heathrow Express Rail Link at The Heathrow Airport found in London. Mr. Justice Creswell presided over the case. The project involved two companies that is Balfour Beatty from Austria and Geoconsult from Austria used the New Austria Tunnelling Method (NATM) to construct the project. Balfour Beatty operated semi-autonomously and checked its own work while Geoconsult managed data within NATM. NATM was implementing one of the firsts in almost everything. The technology of the method involves spraying shotcrete around the surrounding of the tunnel. This process leads to the formation of the supportive crust though temporarily. It was the first time that the project was used in London clay and the method being new most of the people working in the tunnel were not familiar with some of its aspects. In addition, the New Austrian Tunnelling Method (NATM) applied the self-certification method for the first time at the London Heathrow Airport site (Muir, 2000, p. 19). This method requires that contractors be charged with the responsibility of certifying their work. This method offers no opportunities for oversight management. The case resulted in Balfour Beatty receiving a heavy fine of one point two million pounds while the same court slammed Geoconsult with a five hundred thousand pounds fine for its less capable role. The collapse The collapse occurred on the night twentieth and twenty-first of October in nineteen ninety-four. There were no casualties but the cost of recovery amounted to one hundred and fifty million pounds. The project stalled for six more months and disruption of the underground Jubilee Line Extension. However, there were no casualties, the Health and Safety Executive (HSE) successfully filed a petition that resulted heavy fines of one million and two hundred pounds o both Balfour Beatty and Geoconsult with legal costs amounting to two hundred thousand pounds. Causes of the collapse Balfour Beatty and Geo consult implemented the New Austrian Tunnelling Method despite the method having reservations that were grave. This resulted in one of the worst civil engineering disasters in the last century bearing in mind the fact that the Heathrow accident occurred one month after the Munich disaster. The Health and Safety Executive (HSE) took the initiative to warn the two contractors about being cautionary in their approach but contractors failed to heed the advice. Among other general failures, the case proved that there was flawed workmanship, which included serious flaws in the management of construction procedures and contract arrangements that failed to meet the standard requirements. The New Austrian Tunnelling Method (NATM) operated as UK-NATM and had serious failures. To begin with, the method was appropriate for primary lining. This should only apply to temporary works (Feld and Carper, 1997. P. 33). The method does not put into consideration the primary lining while designing the secondary lining. The method takes these steps while it is normal that secondary lining is the second phase and its design should follow the design of the primary lining. The main cause of the problem in the process employed by NATM is that it designs both linings simultaneously. The right process requires that the design should be subsequent. This means that the design of primary lining should come before the design of the secondary lining. The design process should be design as you go. The UK-NATM method allows little room for convergence under the buildings and works concurrently with grouting. The method does not have oversight supervisors and this denies the opportunity for monitoring the appropriateness of the design and gives information regarding compensation grouting. Construction of Heathrow using this method denied the project oversight management hence corrective measures could not be put in place. A report by the Health and Safety Executive (HSE) notes that other failures were in the faces of the project are hazardous. Surprisingly, this was a common feature at the NATM site. The report however, explains that if the two contractors follow the right procedure, NATM tunnels are effective and are as safe as other tunnels. The contractors engaged in flawed contractual arrangements and culture of work. The management lacked adequate knowledge on the risks that the process of using the New Austrian Tunnelling Method. Furthermore, the two contactors ignored the advice given by the Health and Safety Executive (HSE) over the cautionary approach that the management implementing the project wads to take. Balfour Beatty gave the lowest bid for the project and among its reasons for having the lowest bid was allowing for self-certification, which turned out be one of the biggest failures. In this case, both Balfour Beatty and Geoconsult could not supervise each but operate semi autonomously and interdependently (Anderson, 2000, p. 43). When drawing its design, the contractors failed to appreciate the differences that underlie hard rock and soft clay characteristics. The design was therefore not comprehensive as it is supposed to be. It lacked the robustness expected. When Balfour Beatty and Geoconsult decided to design both the primary and secondary linings simultaneously, it resulted in poor joint build ability. The contractors also flattened the invert and this process reduced the tolerance levels of constructed structures. Other failures in the design included lack of lattice girders making it difficult to profile work processes. Monitoring was poor just like in other parts of the construction exercise at the site and this added to the poor ground conditions as laid by the construction company. When the quality of construction was examined, the procedure was found to be poor in producing correct wall profiles. The construction invert was defective as it could rebound. The poor design procedure resulted in defective joint construction. The details of the design were scanty and less comprehensive while the invert was over-flat. The construction process had insufficient employees that were specialized. Employees were overworked yet some of the miners and supervisors as well as shift engineers lacked the necessary skills, knowledge, and experience (HSE, 1999, p. 12). Complains also came from employees over pressures to compensate for delays and over-excavation. Inexperienced engineers ordered for shotcrete blocks with fifty millimetres of width instead of the standard measurement of between two hundred and fifty to three hundred millimetres. This contributed to the poor quality of construction such as the poor sequence of constructing tunnels. These actions forced the construction company to undertake repairs, which also include poor timing of invert repairs. Since the companies were operating semi autonomously, there was poor communication between them hence it was difficult for information to run across. Planning of construction activities lacked integration because the poor communication channels. The team lacked information regarding the imminent collapse due to communication media that were ineffective. Preventive measures Balfour Beatty and Geoconsult can use the New Austrian Tunnelling Method to put up excellent tunnels if it follows the correct procedures. The contractors need to have understood that failures could arise from multiple causes. It was therefore, supposed to have oversight management officers. Allowing Balfour Beatty and Geoconsult to operate independently was wrong as it gave blocked the opportunity for the project to be supervised. Furthermore, monitoring should have been continuous occurring at every stage, level, and part of the construction exercise to enhance quality. Supervision should have been auto-processed with details of the construction exercise availed on a specific web. Proper procedures in construction ought to have been followed by designing the linings in a subsequent manner. The primary lining should come before the secondary lining rather designing them at them jointly (Reason, 1997, p. 27). The management of the construction company should have informed all the employees about the objectives of design and entire project. This would have made employees to align the objectives of every stage in the exercise to the overall project goals. The contractor was supposed to initiate proper communication channels that allow for various ways of circulating information. Balfour Beatty and Geoconsult is supposed to put quality above costs when operates projects. The two companies slashed the budget by ten percent and in the process reduced the number of expert engineers from six to one. This tempered with the quality of supervision as the Geoconsult concentrated on cost cutting at the expense of quality. One qualified engineer cannot handle supervision of the entire project. Inexperienced supervisors who lacked appropriate skills took the positions of qualified engineers. This compromised the quality of work from the onset (Sandstrom, 1963, p. 41). The management of the company is supposed to give priority to projects they undertake because at the time of the collapse the only qualified engineer was at home and not on site. Negligence contributed to dubious processes that included unsatisfactory ribs and poor quality shotcrete. All the parts of the project were faulty thus pointing to the negligence by the management and lack of quality assessment mechanisms. Understanding the risks involved in any project construction exercise is central to its success. Balfour Beatty and Geoconsult were not aware of the risks. The management was supposed to make a risk analysis exercise and put proactive and reactive measures before beginning the project. This was important because the project was at the Airport, which is one of the busiest public places. Conclusion The Heathrow trail exposed the weaknesses in the New Austrian Tunnelling Method and negligence on the part of Balfour Beatty and Geoconsult. It was evident from the case filed by the Health and Safety Executive that the disaster that was one of the worst tragedies in civil engineering could be avoided. Failure to heed advice from the Health and Safety Executive and insufficient quality assessment measures were central to the failure project. The two companies considered running the project at the lowest cost possible and gave little attention to quality. If the management considered all the aspects of construction by observing health and safety procedures then the New Austrian Tunnelling Method could give the best structures. List of References Anderson, M, 2000, The identification and control of risk in underground construction, London: British Library Thesis service. Feld, J, & Carper, L. 1997, Construction Failure, New York: John Wiley & Sons Inc. Health and Safety Executive, (HSE), 1999, Reducing error and influencing behaviours, HSE 48, HSE Books. Muir, W, 2000, Tunnelling-management by design, London: E & FN publishers. Reason, J, 1997, Managing the risk of an organisational accident. Aldershot: Ashgate Publishing. Sandstrom, E, 1963, The history of tunnelling, London: Barrie and Rockliff. . Read More