INSTITUTION OF CIVIL ENGINEERS Forensic engineering a professional approach to investigation Proceedings of the international conference organized by the Institution of Civil Engineers and held in London, UK, on 28-29 September 1998 Edited by B. S. Neale V ThomasTelford Conference organized by Thomas Telford Conferences on behalf of the Structural and Building Board of the Institution of Civil Engineers. Technical Committee: B.S. Neale, Health and Safety Executive, Chairman G. Butera, Nabarro Nathanson P. Gardner, Institution of Structural Engineers B. Gloyn, Aon Risk Services Ltd B. Madge, Forensic Engineering Group, University of Cardiff J. Maguire, Lloyds Register E. O'Leary, Veryards Ltd MJ. Pepper, Standing Committee on Structural Safety Supported by Forensic Engineering Group, University of Cardiff Health and Safety Executive Institution of Mechanical Engineers Institution of Structural Engineers Standing Committee on Structural Safety Published by Thomas Telford Publishing, Thomas Telford Ltd 1, Heron Quay, London E14 4JD. URL: http://www.t-telford.co.uk First published 1999 Distributors for Thomas Telford books are USA: ASCE Press, 1801 Alexander Bell Drive, Reston, VA 20191-4400, USA Japan: Maruzen Co. Ltd, Book Department, 3-10 Nihonbashi 2-chome, Chuo-ku, Tokyo 103 Australia: DA Books and Journals, 648 Whitehorse Road, Mitcham 3132, Victoria A catalogue record for this book is available from the British Library Availability: Unrestricted Content: Collected papers Status: Refereed User: Civil and structural engineers ISBN 978-0-7277-2787-9 © The Institution of Civil Engineers unless otherwise stated, 1999 All rights, including translation, reserved. Except as permitted by the Copyright, Designs and Patents Act 1988 ,no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior written permission of the Publishing Director, Thomas Telford Publishing, Thomas Telford Ltd, 1 Heron Quay, London E14 4JD. This book is published on the understanding that the author is/authors are solely responsible for the statements made and opinions expressed in it and that its publication does not necessarily imply that such statements and/or opinions are or reflect the views or opinions of the publishers or of the Institution of Civil Engineers or the organizers. While every effort has been made to ensure that the statements made and the opinions expressed in this publication provide a safe and accurate guide, no liability or responsibility can be accepted in this respect by the authors or publishers. Editor's preface Welcome to this unique book, which draws together thoughts, advice, and opinions from professionals with a wealth of experience in disciplines related to forensic engineering. It is based on the first Institution of Civil Engineers two-day conference held in London, UK in September 1998. These proceedings are an important collection of papers and opinions for those concerned with learning from failures, usually of completed in-service facilities, which are not necessarily catastrophic ones. Value is added by the inclusion of extensive references as well as summaries of the discussions from each session at the conference. The latter enhances its usefulness by allowing the reader to be aware of peer group comments, together with an indication of the authors' responses. Further, this volume will appeal to interests wider than the UK as a number of international contributions are included. Delegates and authors attended from worldwide locations as far apart as South-East Asia, Australasia and the Pacific coast of America. The purpose of the conference was to present an opportunity to bring together appropriate professionals to discuss topics of mutual interest. Thus the focus of the papers is wide ranging and includes many case histories to illustrate particular points. Papers and contributions are included from professionals such as civil and structural engineers, mechanical engineers and materials specialists, barristers, solicitors, health and safety regulators, and the insurance industry. The approach of loss adjusters was also discussed. Benefits can be realised by the whole industry, from building and structure owners (by better design, construction and maintenance), through to, where applicable, the investigation of the performance of constructed facilities that, for whatever reason, did not meet the expectation of the clients. Professionals will be able to benefit from the outcomes of the imparted knowledge by better understanding in the spirit of continuing professional development and perhaps, in some cases, in basic learning. Information can also be fed into drafting of codes and standards. Where safety is concerned, the public, including those at work, will benefit. In a brief overview of the papers, the conference rapporteur considers there are three main categories, and his synopsis is recommended as a concise introduction (see page 164). A number of people have asked what 'forensic engineering' is - sometimes just to be sure! In the context of this book it is taken to mean 'the investigation of failures - ranging from serviceability to catastrophic - which may lead to legal activity, including both civil and criminal'. The inference is that technical investigation may arguably need to be more rigorous to withstand focused and penetrating scrutiny. This relates to the collection of evidence, the processing of the evidence and the presentation of evidence, including expert opinions - or "a professional approach to investigation". In the combined discipline of forensic engineering, the communication channels will be to different people - with different understandings and for different purposes. These may include: the public, engineers, materials scientists, lawyers, loss adjusters, insurance professionals, facility owners and facility managers. The organizing committee was chosen to provide a special multidisciplinary blend, with representation from the Institution of Civil Engineers and most of the organizations below, together with, of course, the legal and insurance industries. We were pleased that formal support was given to the conference by the Institution of Structural Engineers, Standing Committee on Structural Safety (SCOSS), Health and Safety Executive (HSE), Cardiff University Forensic Engineering Group and Institution of Mechanical Engineers. As part of the international interest in the conference, the World Service of the BBC decided to broadcast a substantial item in its programme The Works, which included interviews with four contributors to the conference. Additional media coverage included a lead article in New Civil Engineer on the paper bringing attention to the risk of biological attack on concrete. Links worldwide have been strengthened and the Institution of Civil Engineers looks forward to building on the wishes of delegates that a further conference should be held. Professional colleagues in the American Society of Civil Engineers are also organizing occasional conferences on this topic within the spirit of transatlantic co-operation. As chairman of the conference organizing committee, I should like to thank all the speakers, chairpersons, delegates, the formal supporters, the Organizing Committee, Thomas Telford Conferences and, in particular, Eamon O'Leary, who volunteered for the arduous task of conference rapporteur and prepared the discussion summaries. Brian S. Neale Health and Safety Executive Chairman of Conference Organizing Committee Contents Keynote: setting the scene 1 Engineering W. Marshall 1 2 The unrecognised importance of insurance B. Gloyn 11 3 What are lawyers looking for? J. Ward 19 Examining a high profile case 4 Lessons from the collapse of the Ramsgate walkway J.C. Chapman 27 5 Ramsgate walkway collapse: legal ramifications J. Barber 39 Approach to technical investigation 6 Investigation of non-catastophic failures P. Lindsell and S.H. Buchner 61 7 Averting catastrophic failure using forensic engineering techniques B.L. Karihaloo 69 8 Field investigations following natural catastrophe damage R. Shepherd 77 Keynote: supporting the legal process 9 Supporting the legal process: legal aspects V. Ramsey 85 Picking up the pieces 10 Technical evidence to support enforcement A. Maitra 92 11 Microbiological attack on concrete: a threat to concrete infrastructure N.K. Emami, A. Nicholson, J. Wren, P.D. Moncarz 101 Incident reconstruction 12 Technical investigation of failure: a view from the marine industry J. Carlton, J. Maguire 109 13 Incident reconstruction: Piper Alpha case study R. Sylvester-Evans 127 14 Bucketwheel reclaimer collapse, New South Wales, Australia P. Ho, R. Lewis 138 Lessons to be learned 15 Applying lessons from failures to management and design J.G.M. Wood 148 16 Application of computer technology P. Gardner 157 Conference overview 164 Discussion 165 Engineering W. J. MARSHALL, William J Marshall & Partners, London, UK. INTRODUCTION The three keynote papers which set the scene for this Conference outline the scope and context of engineering in a forensic context and highlight principles which practitioners in this fascinating but extremely demanding field need to recognise. This paper is written from the standpoint of a civil engineer who has witnessed the impact of litigation and forensic inquiry upon our profession and the construction industry generally for more than twenty years. It seeks to introduce the subject and cover as broad a prospectus as possible. The term "forensic" simply refers to disputed claims which are debated or decided in a public arena: it effectively describes all things pertaining to the administration of justice. Initially, such open hearings were held in the forum - the commercial centre and main market of a city. The close links between public interest, commerce, disputants and the legal profession that were first forged in the marketplace have long been integral parts of our society. When disputes cannot be decided without an understanding of some specialist activity, tribunals find it necessary to hear the views of appropriately qualified individuals who have studied the relevant areas of contention and formed an opinion for the guidance of the Court. Forensic science is consequently no more than the application of scientific knowledge to matters in dispute, whether in public or private tribunals. Since such differences may arise in any area of professional or commercial activity, the scope of Forensic Engineering can extend to every element of engineering, its practice calls for, at root, no more than sound knowledge of the subject under consideration. The application of that knowledge is, however, conditioned by the particular discipline of the law. In adversarial systems of justice such as the United Kingdom, each party in a complex dispute will have the technical elements of their case scrutinised and reviewed by separate specialists throughout the action. Such so-called "Expert" witnesses, unlike witness of fact, may express opinions developed from their study of the circumstances of the case in the light of independent investigation and inquiry. The need for independent analysis and judgement is constantly being stressed. In English jurisdictions, Expert inquiry and evidence must always be given from a wholly independent standpoint and be free from partisan bias. It is therefore a serious error to embark on forensic work solely to support some pre-existing case or to imagine that one is "acting for" the client. In certain other jurisdictions, Experts are expected to strain towards their client's case (the hired-gun approach). To my mind, an Expert is most effective in either jurisdiction giving advice to their client and the Court which they believe, from their knowledge of the case, to Forensic engineering: a professional approach to investigation. Thomas Telford, 1999, 1-10 2 SETTING THE SCENE be as penetrating and accurate as possible. Extensive published guidance on this vital part of forensic work, based on a succession of well-known judgements, will be considered in more detail by other speakers. Disputes in the construction industry often involve large sums of money. The outcome is likely critically to affect the future of many professional and corporate firms as well as individuals. It is the duty of the forensic engineer to probe into problems which have defeated normal commercial negotiation and, where required, form carefully considered views on technical matters which will guide the lawyers' actions throughout the dispute. Forensic work is unpredictable and extremely demanding on senior time. As with civil engineering, the consequences of misconceptions or oversights can be severe and very public. Sound reputations are hard won and vulnerable. Despite this, association with legal processes yields many valuable insights into our own profession, while the rigour necessary to meet forensic scrutiny can add numerous practical skills to our intellectual armoury. In essence, the task of the forensic engineer is simply to apply and present a certain standard of technical knowledge within a legal context in the interests of justice. The knowledge required is no more and no less than that called for by the technical issues in that specific case. Additional skills, such as literacy and clear presentation are generally appreciated, but they ultimately should have little effect on the outcome. Perspective, foresight and the proper application of knowledge founded on solid experience will generate the most highly valued advice. The organisers of this Conference have set the subject nicely into context. In addition to engineers practising across the field, there are contributions from other disciplines with whom the forensic engineer will work: representatives of the insurance industry who are responsible, in one capacity or another, for absorbing and spreading the financial risks implicit in construction generally; a Solicitor who for many years has acted for leading professional and commercial clients and a senior member of the Bar from Chambers specialising in construction law. GROWTH OF FORENSIC ENGINEERING The turnover of all facets of the construction industry in the United Kingdom over the years is typically of the order of 7% of the gross national product. Some twelve years ago, at the height of the litigation resulting from the Denning era, I estimated that the cost of all construction disputes which led to civil litigation, including all the costs of the actions, remedial works, and other associated costs, probably totalled not more than one half of one percent of that turnover. I argued that this cost imposed a useful and necessary discipline on practices within the industry which was by no means disproportionate. In the intervening period, professional and commercial relationships that earlier had been constrained within a few well recognised procurement methods have been radically disturbed in attempts to reallocate responsibilities, duties and risk between financiers, clients, designers, contractors and operators. There has, perhaps unsurprisingly, been an increase in the publicity given in the technical press to failures and other shortcomings in the performance of the industry. PAPER 1 : MARSHALL 3 The costs arising from these shortcomings, and in particular that of resolving disputes by litigation, has been much criticised, prompting wide interest in alternative methods of dispute resolution and attempts to streamline legal processes. At the same time Health & Safety legislation has been enhanced, applying further causes of action and the threat of criminal proceedings. Despite the lack of comprehensive statistics, there is a widely-held perception that disputes in the construction industry have generally increased in scale. Yet I note that over the last fifteen years the number of Official Referees, who hear most large construction cases, has scarcely kept pace with construction activity; professional indemnity and contractors' insurance rates have, despite occasional trembles, seemingly changed little. Where is the extra activity and costs that would result from growth? Although there may have been marginal changes in the way in which construction disputes are handled, these broad but telling indicators suggest that the relative incidence and cost in real terms of construction claims and litigation is governed more by commercial pressures such as cash flow and the perception of success, rather than any legal structures. It may also be that our perception of growth in forensic engineering is no more than a heightened perception of matters that were earlier less open to public discussion, or perhaps changes in the amount of detail being digested ahead of the hearing. What is certain is that there have been construction problems which have required informed and disciplined investigation throughout the history of engineering. The capacity for inquiry, the imagination and tenacity needed to trace the causes of unexpected events, should lie within the abilities of every engineer. Most failures in recent centuries have led to forensic inquiry. For example, any review of papers on early dam and bridge failures, train accidents or boiler explosions will reveal the same pattern and techniques of inquiry and analysis that are used today to trace the source of aircraft accidents, design defects or even complex delay claims. The knowledge gained thereby has frequently advanced the state of the art. One important reason, to my mind, for any real development and growth in litigation and forensic investigations might be the reluctance within today's managerial systems to accept responsibility for hard commercial decisions. The decisive facts, issues and arguments in major disputes are frequently hidden in masses of peripheral evidence; it takes an exceptionally independent employee to present fully detailed counter-arguments to an aggrieved senior. Plainly, no informed principal embarks on expensive litigation unless they can perceive some prospect of advantage. As a result, many disputes are resolved in the earlier stages of litigation, as the true pattern of events is uncovered through intense investigation and discovery by the forensic teams. This analysis suggests that forensic engineers are an integral part of the mechanism by which society maintains standards within the construction industry. By proper investigation, explanation and good practice, forensic engineers assist this process, strengthen the industry and bring credit to their profession. 4 SETTING THE SCENE RANGE OF ACTIVITIES Initiation Since disputes can be triggered at any stage in the design, construction, operation, decommissioning, or even the ultimate disposal of engineering works, there are few aspects of engineering which might not come under forensic scrutiny. The engineer must, first and foremost, be competent to inquire into the matters upon which his advice is being sought. A career spent in some extreme specialisation may be ideal in some cases, but a handicap when judgements are to be based on a broader understanding of design or construction procedures. An otherwise thoroughly well-qualified candidate may have unfortunate personal qualities or find it difficult to interpret technical detail for non- technical laymen. The ability to speak and write with authority on complex subjects does not come easily to many engineers, but it is a singularly helpful talent, provided it is combined with the capacity to organise and analyse detail and sound engineering judgement. All engineers are required to have a measure of training in law and the administration of contracts. As their career develops, they gain further practical and theoretical knowledge of their profession and match their skills with those of fellow engineers. With increasing experience comes a broader understanding of engineering principles and the standards that other engineers bring to their work. It is that knowledge which the law needs to tap, whether it is in deciding state of the art questions (such as arise in professional negligence cases) or in interpreting contractual terms in the light of common usage. All that I have said so far has indicated that forensic work calls for no knowledge of engineering beyond that which is expected of the practitioners in the field in question. However, there are without question certain qualities and techniques which, as an engineer, I have come to appreciate as being valuable attributes in forensic work. It is these attributes which are to be highlighted by the various speakers at this conference. This action is restricted to outlining my perception of the work that an engineer will be called upon to perform in the course of a formal hearing of fair size in the English High Court. I leave other speakers to expound on the role of the other participants and the qualities lawyers (whether Solicitors, Barristers or Judges) seek in their engineer witnesses. The basic pattern of events are likely to be less detailed but broadly similar in principle in smaller cases or before different tribunals. Many engineers first come into contact with forensic work when they become embroiled in a dispute. It is also not uncommon for an engineer, first called in to rectify a problem, then to devise remedial works and later be drawn into subsequent litigation as an Expert, rather than a witness of fact. Many engineers are introduced to forensic work by this route. Although the independence of evidence given by such engineers is frequently questioned, the Law sets no different standard: engineers are expected to act equally responsibly when fulfilling their professional duties. Every participant in a case, whether commercial or professional, witness of fact or Expert, has a duty to eliminate extraneous matters from the dispute, and, in common with other witnesses, swear an oath to tell the whole truth. As, in effect, independent technical advisers to the Court, Expert witnesses can be held publically to account if these obligations are breached.