//SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 1 ± [1±24/24] 26.7.2001 4:11PM Basic Ship Theory //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 2 ± [1±24/24] 26.7.2001 4:11PM //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 3 ± [1±24/24] 26.7.2001 4:11PM Basic Ship Theory K.J. Rawson MSc, DEng, FEng, RCNC, FRINA, WhSch E.C. Tupper BSc, CEng, RCNC, FRINA, WhSch Fifth edition Volume 1 Chapters 1 to 9 Hydrostatics and Strength OXFOR D AUCKLAND BOST ON JOHANNESBURG MELBOURNE NEW DELHI //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 4 ± [1±24/24] 26.7.2001 4:11PM Butterworth-Heinemann Linacre House, Jordan Hill, Oxford OX2 8DP 225 Wildwood Avenue, Woburn, MA 01801-2041 A division of Reed Educational and Professional Publishing Ltd A member of the Reed Elsevier plc group First published by Longman Group Limited 1968 Second edition 1976 (in two volumes) Third edition 1983 Fourth edition 1994 Fifth edition 2001 # K.J. Rawson and E.C. Tupper 2001 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 Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1P 0LP. 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 Rawson, K.J. (Kenneth John), 1926± Basic ship theory. ± 5th ed. Vol. 1, ch. 1±9: Hydrostatics and strength K.J. Rawson, E.C. Tupper 1. Naval architecture 2. Shipbuilding I. Title II. Tupper, E.C. (Eric Charles), 1928± 623.8 H 1 Library of Congress Cataloguing in Publication Data Rawson, K.J. Basic ship theory/K.J. Rawson, E.C. Tupper. ± 5th ed. p. cm. Contents: v.1. Hydrostatics and strength ± v.2. Ship dynamics and design. Includes bibliographical references and index. ISBN 0-7506-5396-5 (v.1: alk. paper) ± ISBN 0-7506-5397-3 (v.2: alk. paper) 1. Naval architecture I. Tupper, E.C. II. Title. VM156 .R37 2001 623.8 H 1±dc21 2001037513 ISBN 0 7506 5396 5 For information on all Butterworth-Heinemann publications visit our website at www.bh.com Typeset in India at Integra Software Services Pvt Ltd, Pondicherry, India 605005; www.integra-india.com Introduction Symbols and nomenclature 1 Art or science? 1.1 Authorities 2 Some tools 2.1 Basic geometric concepts 2.2 Properties of irregular shapes 2.3 Approximate integration 2.4 Computers 2.5 Appriximate formulae and rules 2.6 Statistics 2.7 Worked examples 2.8 Problems 3 Flotation and trim 3.1 Flotation 3.2 Hydrostatic data 3.3 Worked examples 3.4 Problems 4 Stability 4.1 Initial stability 4.2 Complete stability 4.3 Dynamical stability 4.4 Stability assessment 4.5 Problems 5 Hazards and protection 5.1 Flooding and collision 5.2 Safety of life at sea 5.3 Other hazards 5.4 Abnormal waves 5.5 Environmental pollution 5.6 Problems 6 The ship girder 6.1 The standard calculation 6.2 Material considerations 6.3 Conclusions 6.4 Problems 7 Structural design and analysis 7.1 Stiffened plating 7.2 Panels of plating 7.3 Frameworks 7.4 Finite element techniques 7.5 Realistic assessment of structral elements 7.6 Fittings 7.7 Problems 8 Launching and docking 8.1 Launching 8.2 Docking 8.3 Problems 9 The ship environment and human factors 9.1 The external environment. The sea 9.2 Waves 9.3 Climate 9.4 Physical limitations 9.5 The internal environment 9.6 Motions 9.7 The air 9.8 Lighting 9.9 Vibration and noise 9.10 Human factors 9.11 Problems Bibliography Answers to problems Index //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 11 ± [1±24/24] 26.7.2001 4:11PM Foreword to the ®fth edition Over the last quarter of the last century there were many changes in the maritime scene. Ships may now be much larger; their speeds are generally higher; the crews have become drastically reduced; there are many dierent types (including hovercraft, multi-hull designs and so on); much quicker and more accurate assessments of stability, strength, manoeuvring, motions and powering are possible using complex computer programs; on-board computer systems help the operators; ferries carry many more vehicles and passengers; and so the list goes on. However, the fundamental concepts of naval architec- ture, which the authors set out when Basic Ship Theory was ®rst published, remain as valid as ever. As with many other branches of engineering, quite rapid advances have been made in ship design, production and operation. Many advances relate to the eectiveness (in terms of money, manpower and time) with which older proced- ures or methods can be accomplished. This is largely due to the greater eciency and lower cost of modern computers and proliferation of information available. Other advances are related to our fundamental understanding of naval architecture and the environment in which ships operate. These tend to be associated with the more advanced aspects of the subject: more complex programs for analysing structures, for example, which are not appropriate to a basic text book. The naval architect is aected not only by changes in technology but also by changes in society itself. Fashions change as do the concerns of the public, often stimulated by the press. Some tragic losses in the last few years of the twentieth century brought increased public concern for the safety of ships and those sailing in them, both passengers and crew. It must be recognized, of course, that increased safety usually means more cost so that a con¯ict between money and safety is to be expected. In spite of steps taken as a result of these experiences, there are, sadly, still many losses of ships, some quite large and some involving signi®cant loss of life. It remains important, therefore, to strive to improve still further the safety of ships and protection of the environment. Steady, if somewhat slow, progress is being made by the national and interna- tional bodies concerned. Public concern for the environment impacts upon ship design and operation. Thus, tankers must be designed to reduce the risk of oil spillage and more dangerous cargoes must receive special attention to protect the public and nature. Respect for the environment including discharges into the sea is an important aspect of de®ning risk through accident or irresponsible usage. A lot of information is now available on the Internet, including results of much research. Taking the Royal Institution of Naval Architects as an example xi //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 12 ± [1±24/24] 26.7.2001 4:11PM of a learned society, its website makes available summaries of technical papers and enables members to join in the discussions of its technical groups. Other data is available in a compact form on CD-rom. Clearly anything that improves the amount and/or quality of information available to the naval architect is to be welcomed. However, it is considered that, for the present at any rate, there remains a need for basic text books. The two are complementary. A basic understanding of the subject is needed before information from the Internet can be used intelligently. In this edition we have maintained the objective of conveying principles and understanding to help student and practitioner in their work. The authors have again been in a slight dilemma in deciding just how far to go in the subjects of each chapter. It is tempting to load the books with theories which have become more and more advanced. What has been done is to provide a glimpse into developments and advanced work with which students and practitioners must become familiar. Towards the end of each chapter a section giving an outline of how matters are developing has been included which will help to lead students, with the aid of the Internet, to all relevant references. Some web site addresses have also been given. It must be appreciated that standards change continually, as do the titles of organizations. Every attempt has been made to include the latest at the time of writing but the reader should always check source documents to see whether they still apply in detail at the time they are to be used. What the reader can rely on is that the principles underlying such standards will still be relevant. 2001 KJR ECT xii Foreword to the fifth edition //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTA01.3D ± 13 ± [1±24/24] 26.7.2001 4:11PM Acknowledgements The authors have deliberately refrained from quoting a large number of refer- ences. However, we wish to acknowledge the contributions of many practi- tioners and research workers to our understanding of naval architecture, upon whose work we have drawn. Many will be well known to any student of engineering. Those early engineers in the ®eld who set the fundamentals of the subject, such as Bernoulli, Reynolds, the Froudes, Taylor, Timoshenko, Southwell and Simpson, are mentioned in the text because their names are synonymous with sections of naval architecture. Others have developed our understanding, with more precise and compre- hensive methods and theories as technology has advanced and the ability to carry out complex computations improved. Some notable workers are not quoted as their work has been too advanced for a book of this nature. We are indebted to a number of organizations which have allowed us to draw upon their publications, transactions, journals and conference proceedings. This has enabled us to illustrate and quantify some of the phenomena dis- cussed. These include the learned societies, such as the Royal Institution of Naval Architects and the Society of Naval Architects and Marine Engineers; research establishments, such as the Defence Evaluation and Research Agency, the Taylor Model Basin, British Maritime Technology and MARIN; the classi®cation societies; and Government departments such as the Ministry of Defence and the Department of the Environment, Transport and the Regions; publications such as those of the International Maritime Organisation and the International Towing Tank Conferences. xiii [...]... choice Naval architecture is art and science Basically, naval architecture is concerned with ship safety, ship performance and ship geometry, although these are not exclusive divisions With ship safety, the naval architect is concerned that the ship does not capsize in a seaway, or when damaged or even when maltreated It is necessary to ensure that the ship is suciently strong so that it does not... carriers, the natural-gas carriers, the trawlers and many other interesting ships Indeed, the trend is towards more and more specialization in merchant ship design (see Chapter 16) Specialization applies equally to warships Basically, the warship is designed to meet a country's defence policy Because the design and building of warships takes several years, it is an advantage if a particular defence policy... 4:12PM 4 Basic ship theory a nation which expects to make short harrying excursions from its home ports It is important, therefore, to regard the ship as a complete weapon system and weapon and ship designers must work in the closest possible contact Nowhere, probably, was this more important than in the aircraft carrier The type of aircraft carried so vitally a€ects an aircraft carrier that the ship is... [1±6/6] 26.7.2001 4:12PM 6 Basic ship theory The main elements of the class rules are common for naval and civilian craft This ensures compliance with international regulations such as those of SOLAS and MARPOL The warship is issued with the same range of technical and operational certi®cates as would be the case for a merchant ship One advantage is that the navy, through its chosen shipbuilder, has access... that they would like Authorities CLASSIFICATION SOCIETIES The authorities with the most profound in¯uence on shipbuilding, merchant ship design and ship safety are the classi®cation societies Among the most dominant are Lloyd's Register of Shipping, det Norske Veritas, the American Bureau of Shipping, Bureau Veritas, Registro Italiano, Germanische Lloyd and Nippon Kaiji Kyokai These meet to discuss... Fig 3.30 to calculate the geometric particulars of the form A reference plane is needed about mid-length of the ship and, not unnaturally, the transverse plane midway between the perpendiculars is chosen It is called amidships or midships and the section of the ship by this plane is the midship section It may not be the largest section and it should have no signi®cance other than its position halfway... plane from the top of the ¯at keel to the design waterline If unspeci®ed, it refers to amidships The draught amidships is the mean draught unless the mean draught is referred directly to draught mark readings //SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTC02.3D ± 10 ± [7±51/45] 26.7.2001 4:13PM 10 Basic ship theory Fig 2.4 Moulded and displacement lines Fig 2.5 The moulded depth is the perpendicular... economic aims or military demands Manipulation of the elements of a ship is greatly strengthened by such a `feel' and experience provided by personal involvement Virtually every ship' s characteristic and system a€ects every other ship so that some form of holistic approach is essential A crude representation of the process of creating a ship is outlined in the ®gure Safety Economics of trade or Military... Register of Shipping is concerned with the maintenance of proper technical standards in ship construction and the classi®cation of ships, i.e the record of all relevant technical details and the assurance that these meet the required standards Vessels so registered with Lloyd's Register are said to be classed with the Society and may be awarded the classi®cation 100 A1 The cross denotes that the ship has... classi®cation of the ships are considered The standards to which the ships must be built and maintained are laid down in the ®rst of the two major publications of Lloyd's Register, Rules and Regulations for the Classi®cation of Ships This is issued annually and kept up to date to meet new demands The other major publication is the Register Book in several volumes, which lists every known ship, whether classed . (Kenneth John), 1926± Basic ship theory. ± 5th ed. Vol. 1, ch. 1±9: Hydrostatics and strength K.J. Rawson, E.C. Tupper 1. Naval architecture 2. Shipbuilding I Publication Data Rawson, K.J. Basic ship theory/ K.J. Rawson, E.C. Tupper. ± 5th ed. p. cm. Contents: v.1. Hydrostatics and strength ± v.2. Ship dynamics and design. Includes