Introduction to Naval Architecture This page intentionally left blank Introduction to Naval Architecture Third Edition E. C. Tupper, BSc, CEng, RCNC, FRINA, WhSch OXFORD AMSTERDAM BOSTON LONDON NEW YORK PARIS SAN DIEGO SAN FRANSISCO SINGAPORE SYNDEY TOKYO Butterworth-Heinemann An imprint of Elsevier Science Linacre House, Jordan Hill, Oxford OX2 8DP First published as Naval Architecture for Marine Engineers, 1975 Reprinted 1978, 1981 Second edition published as Muckle's Naval Architecture, 1987 Third edition 1996 Reprinted 1997, 1999, 2000, 2002, 2002 Copyright 1996, Elsevier Science Ltd. All rights reserved. No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licencing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder's written permission to reproduce any part of this publication should be addressed to the publishers. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0 7506 2529 5 Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress For information on all Butterworth-Heinemann publications visit our website at www.bh.com Composition by Genesis Typesetting, Rochester, Kent Printed arid bound in Great Britain Contents Preface to the third edition vii Acknowledgements ix 1 Introduction 1 2 Definition and regulation 5 3 Ship form calculations 19 4 Flotation and stability 30 5 The environment 81 6 Seakeeping 100 7 Strength 121 8 Resistance 173 9 Propulsion 209 10 Manoeuvring 252 11 Vibration, noise and shock 276 12 Ship design 304 Appendix: Units, notation and sources 347 Index 353 V This page intentionally left blank Preface to the third edition One definition of wisdom is the thoughtful application of learning; insight; good sense; judgement. It can be said that this book aims to contribute to the reader's wisdom. It sets out to provide knowledge of the fundamentals of naval architecture so that the reader can define a ship form, calculate its draughts and displacement and check its stability. It seeks to give an understanding of other aspects of the ship such as the possible modes of structural failure and its manoeuvring and seakeeping performance. It presents information on the environ- ment in which the ship has to operate, and describes the signs that might indicate pending trouble. As with all branches of engineering, naval architecture is changing dramatically as a result of modern technology. Computers have made a big impact on the design, construction and operation of ships. New materials and changing world economics are bringing new ship types into commercial use or resulting in changes in more established types. Greater emphasis on protection of the environment has led to new regulations on waste disposal and the design of ships to minimize the harmful results of oil spillages and other accidents. There is now greater attention to safety of life at sea, not least as a result of the tragic loss of life in passenger ferries such as the Estonia and the Herald of Free Enterprise. Because of the rate of change in the subject, new texts are required not only by those beginning a career in the profession but also by those already involved who wish to keep their knowledge up-dated. This book is intended only as an introduction to naval architecture. It sets out to educate those who need some knowledge of the subject in their work, such as sea-going engineers and those who work in design offices and production organizations associated with the maritime sector. It will help those who aspire to acquire a qualification in naval architecture up to about the incorporated engineer level. Most major design calcula- tions are, today, carried out by computer. However, it is vital that the underlying principles are understood if computer programs are to be applied intelligently. It is this understanding which this book sets out to provide for the technician. vii viii PREFACE Apart from ships, many are involved in the exploitation of offshore energy resources, harvesting the riches of the sea or in leisure activities. Leisure is an increasingly important sector in the market, ranging from small boats to large yachts and ferries and even underwater passenger craft to show people the marvels of marine life. All marine structures must obey the same basic laws and remain effective in the harsh marine environment. Many of those working in these fields will have had their basic training in a more general engineering setting. This volume presents the essential knowledge of naval architecture they need in a form which they should find easy to assimilate as part of a course of learning. Those who are already practitioners will find it useful as a reference text. Acknowledgements Many of the figures and most of the worked examples in this book are from Muckle's Naval Architecture which is the work this volume is intended to replace. A number of figures are taken from the publications of the Royal Institution of Naval Architects. They are reproduced by kind permission of the Institution and those concerned are indicated in the captions. I am very grateful to my son, Simon, for his assistance in producing the new illustrations. ix This page intentionally left blank 1 Introduction SHIPS Ships are a vital element in the modern world. They still carry some 95 per cent of trade. In 1994 there were more than 80 000 ships each with a gross tonnage of 100 or more, representing a gross tonnage of over 450 million in total. Although aircraft have displaced the transatlantic liners, ships still carry large numbers of people on pleasure cruises and on the multiplicity of ferries operating in all areas of the globe. Ships, and other marine structures, are needed to exploit the riches of the deep. Although one of the oldest forms of transport, ships, their equipment and their function, are subject to constant evolution. Changes are driven by changing patterns of world trade, by social pressures, by technological improvements in materials, construction techniques and control systems, and by pressure of economics. As an example, technology now provides the ability to build much larger, faster, ships and these are adopted to gain the economic advantages those features can confer. NAVAL ARCHITECTURE Naval architecture is a fascinating and demanding discipline. It is fascinating because of the variety of floating structures and the many compromises necessary to achieve the most effective product. It is demanding because a ship is a very large capital investment and because of the need to protect the people on board and the marine environment. One has only to visit a busy port to appreciate the variety of forms a ship may take. This variation is due to the different demands placed on them and the conditions under which they operate. Thus there are fishing vessels ranging from the small local boat operating by day, to the ocean going ships with facilities to deep freeze their catches. There are vessels to harvest the other riches of the deep - for exploitation of l 2 INTRODUCTION energy sources, gas and oil, and extraction of minerals. There are oil tankers, ranging from small coastal vessels to giant supertankers. Other huge ships carry bulk cargoes such as grain, coal or ore. There are ferries for carrying passengers between ports which may be only a few kilometres or a hundred apart. There are the tugs for shepherding ships in port or for trans-ocean towing. Then there are the dredgers, lighters and pilot boats without which the port could not function. In a naval port, there will be warships from huge aircraft carriers through cruisers and destroyers to frigates, patrol boats, mine countermeasure vessels and submarines. Besides the variety of function there is variety in hull form. The vast majority of ships are single hull and rely upon their displacement to support their weight. In some applications multiple hulls are preferred because they provide large deck areas without excessive length. In other cases higher speeds may be achieved by using dynamic forces to support part of the weight when under way. Planing craft, surface effect ships and hydrofoil craft are examples. Air cushion craft enable shallow water to be negotiated and provide an amphibious capability. Some craft will be combinations of these specialist forms. The variety is not limited to appearance and function. Different materials are used - steel, wood, aluminium and reinforced plastics of various types. The propulsion system used to drive the craft through the water may be the wind, but for most large craft is some form of mechanical propulsion. The driving power may be generated by diesels, steam turbine, gas turbine, some form of fuel cell or a combination of these. The power will be transmitted to the propulsion device through mechanical or hydraulic gearing or by using electric generators and motors as intermediaries. The propulsor itself will usually be some form of propeller, perhaps ducted, but may be water or air jet. There will be many other systems on board - means of manoeuvring the ship, electric power generation, hydraulic power for winches and other cargo handling systems. A ship can be a veritable floating township with several thousand people on board and remaining at sea for several weeks. It needs electrics, air conditioning, sewage treatment plant, galleys, bakeries, shops, restaurants, cinemas, dance halls, concert halls and swimming pools.