Monday, November 23, 2009

A naval architect from Indonesia

She is a fresh graduate from naval architecture department of Hasanuddin University. She studied ship theory, ship construction and ship design. The most memorable experience was when she had to calculate the longitudinal and vertical centers of gravity of a ship (LCG and VCG). It was a semester assignment and not many naval architecture students passed easily. She was one of the few who could do and pass the subject in first attempt. Although naval architecture is an interesting field of engineering, it seems that now she is more interested in art particularly dancing. Nadia Siregar, an Indonesian girl, began learning Papuan traditional dance in 1993 when she was still at grade 3 of elementary school. She likes dancing because she sees that Papua island has many tribes and every tribe has its own unique cultural characteristics. "They are very interesting but I only want to focus on the traditional dance," she said.
master-dancer-nadia-siregar.jpg
National and International Performance - Nadia is now a member of IRIANTOS Dance Group. Its chairman is George Wellem Yomaki. Their dance group has 30 members. Together with this group, Nadia has traveled across the country and even abroad to perform various Papuan dances. Some of the festivals where she and her friends performed were: Papuan Art Festival in Biak island in 2002; Multicultural Festival in Australia from 14-18 February 2004; Dance performance in Korror city of Palau islands in 2004; T heater Performance on the Exiled and Virtual Body in Makassar city from 10 to 11 August 2007; Monolog Performance of Makkunrai Project at the Societet de Harmoni building of Makassar city celebrating Kartini Day on 1 May 2008; Nusantara Cultural Carnival in Jembrana Bali in September 2008; President and Vice President of Indonesia's Campaign Declaration at the Monument of Proclamation in February 2009; Festival of Folk Theater Media on national level in Malang city of East Java, 30-31 May 2009; Nusantara Cultural Festival at the State Palace of Jakarta on 18 August 2009.

Wednesday, November 18, 2009

Ship Design and Performance for Masters and Mates

If you are now working in Ship design office or are now doing your ship design semester assignment in the university, then this book is suitable for you. Students and practicing Naval Architects will find that this book is very useful in helping them carrying out preliminary design calculations to obtain the principal dimensions of ships ranging from container ship to bulk carrier and passenger ship.
If you are a yacht designer then this book is not recommended for you. There is another book entitled Principles of Yacht Design written by Lars Larsson and Rolf E Eliasson that is more suitable for you. Most of the ships that are discussed in this book are displacement ships with hull material made of steel.
This ship design and Performance for Masters and Mates is divided into two main parts. Part 1 deals with Ship Design and Part 2 dicusses the Ship Performance.The followings are the detailed information about the book.
When I was still studying Naval Architecture in Pattimura University in 1996, I used Merchant Ship Design book which was written R Munro Smith and Caldwell's Screw Tug Design as a major reference for the design assignments. Although Merchant Ship Design is an old book, it is still widely read by most of students of naval architects in Indonesia due to the availability of explanations on how to develop hull form or lines plan manually without using ship's hull fairing software such as Maxsurf, Autoship, Rhino Marine, or Delftship. But now with the development of computer technology, the tedious hull fairing task has been omitted by these software.
Title: Ship Design and Performance for Masters and Mates
Author: Dr. C.B. Barrass
Publisher: Elsevier
Thickness: 265 pages, First published in 2004
Table of Contents
Acknowledgements ix
Introduction xi
Part 1 Ship Design
1 Preliminary estimates for new ships: Main Dimensions 3
2 Preliminary estimates for group weights for a new ship 17
3 Preliminary capacities for a new ship 34
4 Approximate hydrostatic particulars 40
5 Types of ship resistance 54
6 Types of ship speed 63
7 Types of power in ships 68
8 Power coefficients on ships 74
9 Preliminary design methods for a ship's propeller and rudder 82
Nomenclature for ship design and performance 91
Part 2 Ship Performance
10 Modern Merchant Ships 103
11 Ships of this Millennium 109
12 Ship Trials: a typical 'Diary of Events' 116
13 Ship Trials: speed performance on the measured mile 120
14 Ship Trials: endurance and fuel consumption 132
15 Ship Trials: manoeuvring trials and stopping characteristics 137
16 Ship Trials: residual trials 144
17 Ship squat in open water and in confined channels 148
18 Reduced ship speed and decreased propeller revolutions in shallow waters 164
19 The phenomena of Interaction of ships in confined waters 180
20 Ship vibration 191
21 Performance enhancement in ship-handling mechanisms 202
22 Improvements in propeller performance 218
Useful design and performance formulae 228
Revision one-liners for student's examination preparation 235
How to pass examinations in Maritime Studies 239
References 241
Answers to questions 243
Index 247

Tuesday, November 17, 2009

Ship Stability for Masters and Mates

Hydrostatics and Stability of ships are important subjects that are studied not only by naval architects but also by deck and engineering officers who are working aboard ships. The topics in this book are similar to the volume 1 of Basic Ship Theory and another ship theory book written by Russian naval scientists entitled Statics and Dynamics of the Ships.
I like this book very much because it provides a lot of worked examples ranging from simple up to complicated ones. The concept of mathematical integration using Simpsons' rules is introduced in page 68. These rules are used in most of the hydrostatics and volume calculations of ship forms.
Hydrostatic components such as form coefficients, ship displacement, center of buoyancy, center of gravity, metacenter height are discussed in the first few chapters of the book while more complicated subjects related to transverse stability, and effect of free surface of liquids on stability of ships are presented in later chapters of the book.


Although most of the ship form calculations are now executed using naval architecture and ship design software such as Maxsurf, Delftship and Fasthip, the author of the book deliberately provides samples of manual calculations to help students and practicing naval architects understand the philosophy and the theoretical foundation involved in ship theory and design.
The followings are the table of contents of the book
Preface vii
Introduction ix
Ship types and general characteristics xi
1 Forces and moments 1
2 Centroids and the centre of gravity 9
3 Density and speci®c gravity 19
4 Laws of ¯otation 22
5 Effect of density on draft and displacement 33
6 Transverse statical stability 43
7 Effect of free surface of liquids on stability 50
8 TPC and displacement curves 55
9 Form coef®cients 61
10 Simpson's Rules for areas and centroids 68
11 Final KG 94
12 Calculating KB, BM and metacentric diagrams 99
13 List 114
14 Moments of statical stability 124
15 Trim 133
16 Stability and hydrostatic curves 162
17 Increase in draft due to list 179
18 Water pressure 184
19 Combined list and trim 188
20 Calculating the effect of free surface of liquids (FSE) 192
21 Bilging and permeability 204
22 Dynamical stability 218
23 Effect of beam and freeboard on stability 224
24 Angle of loll 227
25 True mean draft 233
26 The inclining experiment 238
27 Effect of trim on tank soundings 243
28 Drydocking and grounding 246
29 Second moments of areas 256
30 Liquid pressure and thrust. Centres of pressure 266
31 Ship squat 278
32 Heel due to turning 287
33 Unresisted rolling in still water 290
34 List due to bilging side compartments 296
35 The Deadweight Scale 302
36 Interaction 305
37 Effect of change of density on draft and trim 315
38 List with zero metacentric height 319
39 The Trim and Stability book 322
40 Bending of beams 325
41 Bending of ships 340
42 Strength curves for ships 346
43 Bending and shear stresses 356
44 Simpli®ed stability information 372
Appendix I Standard abbreviations and symbols 378
Appendix II Summary of stability formulae 380
Appendix III Conversion tables 387
Appendix IV Extracts from the M.S. (Load Lines) Rules, 1968 388
Appendix V Department of Transport Syllabuses (Revised April 1995) 395
Appendix VI Specimen examination papers 401
Appendix VII Revision one-liners 429
Appendix VIII How to pass exams in Maritime Studies 432
Appendix IX Draft Surveys 434
Answers to exercises 437
Index 443

Basic Ship Theory

Basic Ship Theory were published in two volumes. The first deals with Hydrostatics and Strength of Ship whereas the second deals with Ship Dynamics and Design.
I have been reading the books since 1993 or 1994. They are easy to understand reference both for students and practicing naval architects.

Contents of volume 1:
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
Contents of Volume 2
Powering of Ships: General Principles; Powering of Ships: application; Seekeeping; Maneuverability; Major ship design features; Ship design; Particular ship types
The thickness of volume 1 is 400 pages. For volume 2, it has 373 pages. The books are now published in a combined volume by the publisher to lower the price so that it can be sold or bought easily.
I like these books very much because they have many worked examples which can be solved through manual calculation or using computer spreadsheet software.
For volume 1 which deals with Ship Hydrostatics the use of computer spreadsheet software such as Microsoft Excel is highly recommended. To further your investigation on this subject, I should recommend another important book entitled Statics and Dynamics of the Ship published by Mir, now Pacific Publisher, whose authors are V Semyonov, Tyan, Shansky.
I remembered seeing, the first time, the two volumes of these Basic Ship Theory books in 1993 or 1994 in the library of Pattimura University of Maluku islands Indonesia. They were red labeled meaning that they could only be read in the room and were not available for renting.
I had to approach a staff of the library to request permission from him for photocopying them. During that years, internet was not available in my campus and the students did not know how or where to order the Basic Ship Theory books.
After long conversation and some arguments, I was then allowed to take the books out of campus to photocopy them in the downtown of Ambon city. That's what most university students in Indonesia did to be able to read the books. Why we photocopy them? The price of these two books equals to one month salary of middle level government employee in this country. So, a father must stop feeding the whole members of the family to set aside the money for his son or daughter to buy them.
I hope now that it is more affordable to students all around the world. Perhaps Longman as the publisher of Basic Ship Theory has provided the e-book or international edition versions to make the price cheaper.

Monday, November 16, 2009

Introduction to Naval Architecture

I read it for the first time in 1993 when I was still a student studying Naval Architecture in Pattimura University in Ambon city of Maluku islands Indonesia. Previously it was entitled Muckle's Naval Architecture for Marine Engineers. This book has been revised several times by its author E.C. Tupper. The latest edition of this book has Appendix B that explains how to use spreadsheet computer software for calculating hydrostatic properties of ships. This Appendix B is closely related to Chapter 4 and 5 which are the main topics that beginning students of naval architecture must understand before continuing their studies to more complicated theories.
In my opinion, the book is suitable for anybody who wants to study Naval Architecture for the first time besides similar other naval architecture books i.e. Basic Ship Theory Volume 1 and Volume 2, also written by the same author with his colleague K.J. Rawson.
The followings are the table of contents of the book Introduction to Naval Architecture
Preface to the fourth edition ix
Acknowledgements xiii
1 Introduction 1
Ships 1
Naval architecture and the naval architect 1
The impact of computers 6
2 Ship design 8
The requirements 8
Design 10
Developing the design 11
The design process 12
Some general design attributes 20
Safety 23
Summary 29
3 Definition and regulation 30
Definition 30
Displacement and tonnage 38
Regulation 40
Summary 48
4 Ship form calculations 49
Approximate integration 49
Spreadsheets 59
Summary 61
5 Flotation and initial stability 62
Equilibrium 62
Stability at small angles 66
Hydrostatic curves 74
Problems in trim and stability 76
Free surfaces 81
The inclining experiment 84
Summary 86
6 The external environment 87
Water and air 87
Wind 88
Waves 89
Wave statistics 99
Freak waves 100
Other extreme environments 101
Marine pollution 101
Summary 103
7 Stability at large angles 104
Stability curves 105
Weight movements 111
Dynamical stability 113
Stability standards 116
Flooding and damaged stability 118
Summary 127
8 Launching, docking and grounding 128
Launching 129
Docking 133
Grounding 139
Summary 142
9 Resistance 143
Fluid flow 143
Types of resistance 146
Calculation of resistance 157
Methodical series 162
Roughness 164
Form parameters and resistance 165
Model experiments 169
Full scale trials 169
Effective power 172
Summary 172
10 Propulsion 174
General principles 174
Propulsors 176
The screw propeller 178
Propeller thrust and torque 186
Presentation of propeller data 189
Hull efficiency elements 195
Cavitation 199
Other propulsor types 205
Ship trials 209
Main machinery power 214
Summary 216
11 Ship dynamics 218
The basic responses 218
Ship vibrations 224
Calculations 226
Vibration levels 230
Summary 232
12 Seakeeping 233
Seakeeping qualities 233
Ship motions 234
Presentation of motion data 236
Motions in irregular seas 237
Limiting factors 240
Overall seakeeping performance 243
Acquiring seakeeping data 244
Effect of ship form 247
Stabilization 248
Summary 252
13 Manoeuvring 253
Directional stability and control 254
Manoeuvring 255
Manoeuvring devices 261
Ship handling 269
Dynamic stability and control of submarines 272
Modifying the manoeuvring performance 273
Underwater vehicles 274
Summary 275
14 Main hull strength 276
Modes of failure 277
Nature of the ship's structure 279
Forces on a ship 280
Section modulus 289
Superstructures 294
Standard calculation results 297
Transverse strength 301
Summary 303
15 Structural elements 304
Strength of individual structural elements 304
Dynamics of longitudinal strength 311
Horizontal flexure and torsion 317
Load-shortening curves 318
Finite element analysis 321
Structural safety 322
Corrosion 324
Summary 327
16 The internal environment 328
Important factors 328
Summary 334
17 Ship types 335
Merchant ships 336
High speed craft 359
Warships 363
Summary 373
References and Further reading 375
Appendix A: Units, notation and sources 385
Appendix B: The displacement sheet and hydrostatics 391
Appendix C: Glossary of terms 414
Appendix D: The Froude notation 423
Appendix E: Questions 428
Index 437

Saturday, November 14, 2009

Ship Design


I have written several articles related to ship design calculation. If you are interested in reading them, please, check the label Ship and Boat Design of this blog. During the design process, naval architects will be required to determine such parameters as main dimensions, hull form, displacement, freeboard, depth, capacities, trim and stability, economic considerations, longitudinal and transverse strength, structural scantlings, resistance and powering, machinery, endurance, wood and outfit, lightweight and deadweight, and the material costs.
After calculating the above parameters, the next step will be the design or drawing of the ship. The first drawings will be the linesplan and the general arrangement. The detailed construction drawing will be made based on the rules and guidande provided by such classification societies as NK, ABS, LR, DNV, and etc.

Propeller and Ship Propulsion

I have written a number of articles related to resistance and propulsion of ship especially in relation to the design of marine screw propellers. You can see them at labels Marine Propeler and Resistance of Ship that you can see on the left column of this blog. Please, click the following links to read each of them. In the design of marine screw propeller, the first thing that naval architects must perform is carrying out resistance calculation. After obtaining the effective power and speed curve the next step is doing the forward calculation to obtain delivered power, shaft power and finally the brake power. The calculation will then be continued backward using the real break power (in kilowatt or horse power) obtained from the engine's brochure to obtain the shaft power and delivered horse power by considering the losses in gear box, shaft bearings, stern tube and bossing. When these have been done, the next step is executing the propeller design calculation.

Saturday, November 7, 2009

Adding Knuckle Line or Hard Chine to a Boat’s Hull in Delftship

Delftship is a ship design software which enables naval architects to create, or modify the hull of a boat or a ship effortlessly. The ship can be modeled accurately in Delftship environment. In my previous article, I discussed about the drawing modes which delfship has and how to draw deck for yacht design in Delftship.
delftship-knuckle-hull-1.jpg
When designing high speed boat, a naval architect will design the form of the hull that is not fully displacement one. In high speed displacement form boat will face problems related to stability. So, to solve the problems, naval architects will use plane hull or semi displacement hull which has V form. In other words, the hull will not round but will have knuckle lines.
To create such hull with chines, with the Delfship program on your computer screen opens, first click the longitudinal line of a half bread hull in perspective view while you are pressing Ctrl key. Look at the above picture.
After that when the line has got yellow color, click Edit in the menu bar and select Edge. Then click the Crease option. Now, the yellow line of the hull line which we want to knuckle will be stronger.
delftship-knuckle-hull-2.jpg
To visualize the hard chine which we have just created for the boat's hull, in perspective view, press Ctrl - G. The computer screen will present a 3D view of the designed boat like the following.
delftship-knuckle-hull-3.jpg
If we want to see the underwater form of the boat, we just turn it by moving the scroll bar at the right and at the bottom of the computer screen. The boat's or ship's hull with hard chine should look like the one below:
delftship-knuckle-hull-4.jpg
If you do not have the program, just go to delftship.net and register your name in the website. They will give you access to the content of the Delftship website including the download link for getting the free edition of Delftship. Delftship is similar to Maxsurf, Rhino Marine, and Autoship. It can be used to create 3D forms of ship models including the hulls, superstructure, masts, rudder and other appendages. It can also calculate the hydrostatic properties and resistance of the boat or ship. by Charles Roring

Sunday, November 1, 2009

The Environmental Impact of Marine Tourism

Sunbathing, snorkeling, scuba diving, wave surfing and water skiing are some of the activities that tourists typically enjoy when they go to the beach. These activities can bring positive and negative impacts to marine environment. To reduce negative impacts of tourism activities on the environments, people who work in this industry need adequate knowledge about conservation and coastal management.
Marine tourism is a business that generates big revenues during holidays and special occasions. Being a part of the tourism industry is a great way to make money because life seems like one endless holiday. Yes, it does have its downs like any other business, but for the most part, the going is good especially if you are well-established and your customers come back to give you repeat business. Marine tourism has come into its own with the advances that have been made in the field of technology. Locations that were earlier inaccessible or unsafe are now well-known tourist spots in marine environments. The seas and the coastlines of the world are much sought after destinations for tourists all over the world, and this makes marine tourism a booming industry.
But all this interest in water sports, cruises, underwater explorations and other activities that involve the marine environment are definitely having an adverse effect on marine ecosystems and animal species that live on or near the coast.

• Natural habitats are destroyed when hotels, restaurants and other entertainment and hospitality facilities are built along the coastline.
• Surrounding areas are also destroyed in order to provide access to these facilities. With the advent of roads, airports and sea ports, people begin to populate the area and drive out the natural wildlife whose habitat the area was originally.
• The level of pollution increases with the increase in population
• Essential resources like water become critical and are sometimes in shortage.
• The coastline is destroyed due to erosion and the sea also becomes polluted with effluents from hotels and other establishments in the area.
• Cruise ships produce and dump waste in mid ocean, leading to pollution in the high seas too.
• Sewage causes algae to form over coral reefs and damages and destroys them.
With all these detrimental effects, we must adopt techniques to manage the pollution and the destruction of ecosystems, not just because we need to save the environment, but because we need to save the tourism industry itself. The environment and its quality are very important if tourism is to survive and thrive; with polluted beaches and diminishing wildlife, the tourists are going to be few and far between. And when this happens, it is the end of marine tourism as we know it.
For man and nature to coexist in peace and thrive, it is up to us to ensure that we do not wreak havoc on the environment; for if we do, it will come back to haunt us in the form of global warming and climate change.
By-line:
This guest article was written by Adrienne Carlson, who regularly writes on the topic of construction management degrees . Adrienne welcomes your comments and questions at her email address: adrienne.carlson83@yahoo.com