# The Physics of Water Ballast

Save this PDF as:

Size: px
Start display at page:

## Transcription

2 As you lower your boat into the water it starts to be supported by the force of buoyancy. The size of this buoyancy force depends on the amount of water displaced by the boat s hull. It acts through the centre of buoyancy (CoB) which is the centre of volume of the bit of the boat below the water surface. The boat will settle in the water until it is floating at a level where the buoyancy force exactly balances the weight of the boat. So your spring balance now shows the apparent weight as zero even though the real weight of the boat has not changed, and of course, the boat still has the same mass. How people think stability works Deep keeled yachts Many racing yachts have a very long fin keel with a big bulb of lead at the bottom. For yachts like that the centre of gravity can be below the centre of buoyancy (figure

3 1). Thus when the yacht heels, the force of gravity and the force of buoyancy act to rotate the boat back towards an upright position. A longer the keel will give a bigger offset between the CoG and the CoB when the yacht heels, and hence a larger the rotational force bringing the yacht upright. Also a heavier keel will increase both the weight of the yacht and the balancing buoyancy force, again resulting in a larger righting moment. This yotties view of the world, is NOT how most boats and ships work! However it is how many people tend to think of stability. When they look at a large cruise ship with many decks above the waterline and wonder how it stays upright, they are unconsciously assuming that the CoG must be below the CoB to create stability. How stability usually works Most Boats and ships Most boats and ships don t have a deep keel and the ballast or cargo is carried within the main part of the hull. In this case, the centre of gravity, CoG, is higher than the centre of buoyancy, CoB. Figure 4a illustrates what happens when the ship or boat heels. Lets assume the view is from astern so the boat heels to starboard. The effect is to move the CoG to starboard and slightly downwards. However the CoB is moved further still in a starboard direction. As a result the weight and the buoyancy form a force couple which tends to rotate the boat back into an upright position. Figure 4b illustrates the effect of adding a full ballast tank. When the boat is upright it is lower in the water and the CoG is closer to the waterline. As a result, when the boat heels the CoG does not move as far to starboard as when the boat is empty whereas the CoB moves slightly further. This increases the stability compared to the unballasted boat. However the main effect of filling the ballast tank is to increase the boat s weight. As discussed above, the boats sinks downwards until the opposing buoyancy force is

4 also increased by the same amount. The two forces tending to rotate the boat upright are therefore, not only spaced further apart, but also much larger. Thus the boat is more stable with a full ballast tank. Note the increased stability does not require the water ballast to be raised above the water surface, as sometimes believed. As long as the CoB moves out more than the CoG the boat will remain stable, and the heavier the full ballast tank, the more the stability. The importance that the ballast tank is completely full is illustrated by Figure 5. With a partially full tank, the water, and hence the CoG, moves towards the downward side of the boat. In an extreme case the CoG moves out further than the CoB and boat would become unstable and capsize. This also emphasises that, if you are filling the water ballast tanks following an increase in wind strength, it is desirable that the filling is completed in the shortest time possible. The gz curve righting lever values To indicate the stability of a boat, yachting magazines publish a gz curve. gz is simply the horizontal separation of the forces of gravity and buoyancy what we have just been discussing. It should really be called the righting arm or lever. Figure 6 illustrates how the term gz seems to have arisen and shows as an example of a curve (the BC20 with full ballast tanks). For this example the gz value remains positive until about 132 of heel which indicates that the boat would self-right from a knock down condition. For most boats there is one, characteristic gz curve. But for a water ballasted boat that can be sailed with or without ballast, the large changes in the overall weight and it s distribution within the boat result in two distinct gz curves. These are shown in figure 7 for four Swallow Boats using data published in Practical Boat Owner (Harding, 2009, 2010, 2011, 2013).

5 Figure 7 Righting Lever or gz curves for various Swallow Boats as published in Practical Boat Owner reviews. Unfortunately, the ballasted and un-ballasted curves for gz shown in Figure 7 don t fully represent the effect of ballast on stability because they neglect the change in boat weight. In his article on water ballast, Nick Newland (2015) states that for a Bay Raider, the water ballast increases gz by about 30% but more than doubles the righting moment. In fact, for the BR20 Figure 7 suggests that the difference is much more than that. However it is possible that the unballasted curve published in PBO is wrong. It implies that the BR20 is less stable than the BRe which, being more or less a BR20 with a cabin, should be the less stable. The actual righting force (the righting moment ) is given by: (righting moment, rm) = (righting lever, gz) x (weight of boat) Actual righting moment values for different boats are difficult to compare because the boat weights are different. Therefore Figure 8 demonstrates the increase in stability caused by the weight of the water ballast by plotting an adjusted righting lever defined by: (adjusted gz) = ((righting lever gz) x (weight of boat +ballast + equipment)) (weight of bare boat) Thus, if the boat has no ballast or equipment, the adjusted gz is the same as the gz value plotted in Figure 7. The equipment weight ( load = weight of outboard, cooking gear, battery, etc.) has been added so as not to exaggerate the fractional effect of the water ballast weight by comparing to an empty hull. The nominal values used for each boat are shown in the figure. One should also add in the weight of crew but, since people move around and may even hike out, the crews effect on stability is hard to define and has not been included.

6 Figure 8 Adjusted righting lever values (see text) showing the relative difference in stability between having empty ballast tanks (red) and full tanks (blue). The grey lines are the unadjusted gz values as shown in Figure 7. For the unballasted case the small increased magnitude of the adjusted value (red line) compared to the original gz value (grey) is due to the nominal load value assumed. When the ballast tanks are filled with water, there is a small increase in stability due to the change in the righting lever length (upper grey line) but the actual change in stability is much larger (blue line) because of the weight of the ballast. Stability near capsize Figures 7 and 8 show that for each of the boats the maximum stability occurs at around 40 of heel. With greater heel the stability decreases with the unballasted curves showing zero or even negative stability when the boat is on its side at 90. If the position of added equipment such as the outboard were taken into account, the curves suggest that, unballasted, each of these boats would tend to turn turtle. However beyond 90 the curves become positive and for the BR20, BRe, and BC20, the PBO reviews suggest that this is because of immersion of the hollow masts. For the BC23, immersion of the coachroof is suggested. Whatever the cause, this positive stability peak might be enough to keep the boat floating on it s side rather than turning to 180. The situation is much better if the boat is sailed with the water ballast tanks full. In that case all the boats show self-righting ability from a 90 knock down, although the Bay Cruisers, with their smaller cockpits have a greater margin of safety.

7 Nick Newland (2015) notes that with water ballast this self-righting ability comes at the cost of sacrificing part of the hull space near the gunwale to provide the correct buoyancy distribution. For example the BC20 has large full depth buoyancy tanks at each quarter and across the stern. The hull space lost to tanks for ballast and for buoyancy would seem to be the main disadvantage of using water as ballast. Dynamic stability So far the discussion of stability factors has not taken into account the effects of motion. An oft quoted stability parameter, the metacentric height is related to the positions of the centre of gravity and centre of buoyancy, as discussed above. It is of relevance to ships and motor boats since it is related to the period of roll the time taken to roll one way and back the other, in other words how fast the boats rocking motion is. It is much less relevant for sailing boats because of the aerodynamic forces of the sails and the inertial effect of the mast. More important are factors such as momentum and moment of inertia. Both the momentum (mass x velocity), and the force needed to accelerate the boat, are proportional to the boat s mass. Adding water ballast increases the boats mass by exactly the same amount as a similar weight of any other type of ballast. If the ballast tank is full, that extra mass is exists whether the boat is on its trailer or in the water. Figure 9 The yellow shading indicates the amount of the aft section of a Bay Cruiser 20 hull occupied by the buoyancy tanks needed for self-righting. Moment of inertia is a measure of how difficult it is to rotate an object around a given axis (Figure 10). Where the water ballast is contained in tanks fore and aft, as in the Bay Cruiser, filling the tanks makes the boat more similar to the dumbbell shaped object. The axes for which moment of inertia is increased are those for yaw and pitch. The roll axis is not significantly affected. Is the boat faster with ballast tanks full or empty? Figure 10 Two objects which have the same mass but different moments of inertia. Obviously there is no one answer; whether you decide to sail with ballast tanks full of empty will depends on circumstances. If you are out for a day s sail in your Bay Raider you might have the tanks empty and enjoy planing past another boat which is

8 carrying the equipment needed for a few days cruising. But the cruising owner the security of having a self righting boat might well be the decisive factor in keeping the tanks full. At least with a water ballasted boat you have the choice and, hopefully the above discussion will help in weighing up the factors. For example, consider beating into a choppy wind sea. Having full tanks will do more than increase stability and allow the boat to sail more upright. The extra momentum (from the increased mass) will mean that the boat is slowed down less by oncoming waves. The increased moment of inertia will make the boat less twitchy so it is less deflected from the desired course. You can use the Tiller Tamer and make a cup of coffee! If you empty the ballast tanks, the boat will be significantly less stable, heeling more and forcing you to spill wind or feather windward. With less mass the boat will be slowed more by slamming into waves. On the other hand, if slowed up by a wave it will then accelerate faster. The lower moment of inertia along the yaw axis will allow the boat to be quicker in responding to the helm. Rather than cut through the waves, you may be able to thread a course between them or (with less inertia to pitching) ride over them. Actively helming the boat dinghy fashion, you might be able to work up higher to windward. However you probably won t have time to make coffee! Water ballast gives you the choice and can vary that choice during the course of a day s sailing. (Peter Taylor, February 2015) References Harding, David (2009) A different sort of dayboat (review of BR20), Practical Boat Owner 506, February 2009, Harding, David (2010) High-tech tradition (review of BC20), Practical Boat Owner 526, September 2010, Harding, David (2011) Technology meets tradition: Baycruiser 23 (review of BC23), Practical Boat Owner 539, September 2011, Harding, David (2013) The super-simple trailer-sailer (review of BRe), Practical Boat Owner 556, January 2013, Newland, Nick (2015) What s the Point of Water Ballast?, Water Craft no. 109, Jan/Feb 2015, 30 33

### STABILITY OF MULTIHULLS Author: Jean Sans

STABILITY OF MULTIHULLS Author: Jean Sans (Translation of a paper dated 10/05/2006 by Simon Forbes) Introduction: The capsize of Multihulls requires a more exhaustive analysis than monohulls, even those

### S0300-A6-MAN-010 CHAPTER 2 STABILITY

CHAPTER 2 STABILITY 2-1 INTRODUCTION This chapter discusses the stability of intact ships and how basic stability calculations are made. Definitions of the state of equilibrium and the quality of stability

### 1. A tendency to roll or heel when turning (a known and typically constant disturbance) 2. Motion induced by surface waves of certain frequencies.

Department of Mechanical Engineering Massachusetts Institute of Technology 2.14 Analysis and Design of Feedback Control Systems Fall 2004 October 21, 2004 Case Study on Ship Roll Control Problem Statement:

### The Physics of Lateral Stability 1

The Physics of Lateral Stability 1 This analysis focuses on the basic physics of lateral stability. We ask Will a boat heeled over return to the vertical? If so, how long will it take? And what is the

### Optimist Tuning Guide

Optimist Tuning Guide Sail Care: To help you re new racing sail stay in top condition as long as possible here is some tips - Try not to crease your sail, some creases can cause MIT tears in your sail

### In the liquid phase, molecules can flow freely from position to position by sliding over one another. A liquid takes the shape of its container.

In the liquid phase, molecules can flow freely from position to position by sliding over one another. A liquid takes the shape of its container. In the liquid phase, molecules can flow freely from position

### Fluid Mechanics HYDRO STATICS

Fluid Mechanics HYDRO STATICS Fluid Mechanics STABILITY OF FLOATING BODIES Any floating body is subjected by two opposing vertical forces. One is the body's weight W which is downward, and the other is

### In the liquid phase, molecules can flow freely from position. another. A liquid takes the shape of its container. 19.

In the liquid phase, molecules can flow freely from position to position by sliding over one another. A liquid takes the shape of its container. In the liquid phase, molecules can flow freely from position

### INCLINOMETER DEVICE FOR SHIP STABILITY EVALUATION

Proceedings of COBEM 2009 Copyright 2009 by ABCM 20th International Congress of Mechanical Engineering November 15-20, 2009, Gramado, RS, Brazil INCLINOMETER DEVICE FOR SHIP STABILITY EVALUATION Helena

### Stability Is The Key Part 2

Dave Gerr, CEng FRINA, Naval Architect www.gerrmarine.com Stability Is The Key Part 2 Understanding Stability and Sailboat Performance and Safety Reserve Stability By Dave Gerr, 2007 Dave Gerr In the previous

### BUOYANCY, FLOATATION AND STABILITY

BUOYANCY, FLOATATION AND STABILITY Archimedes Principle When a stationary body is completely submerged in a fluid, or floating so that it is only partially submerged, the resultant fluid force acting on

### Structure (Down plane)

By Lauren Russell Structure (Down plane) The body (toes, knees, hips, wrists and shoulders) is aligned parallel to the intended target line. The torso is tilted over the ball from the hips whilst maintaining

### Principles of glider flight

Principles of glider flight [ Lecture 2: Control and stability ] Richard Lancaster Email: Richard@RJPLancaster.net Twitter: @RJPLancaster ASK-21 illustrations Copyright 1983 Alexander Schleicher GmbH &

### Tall Ships America Safety Under Sail Forum: Sailing Vessel Stability, Part 1: Basic Concepts

Tall Ships America Safety Under Sail Forum: Sailing Vessel Stability, Part 1: Basic Concepts Moderator: Captain Rick Miller, MMA Panelists: Bruce Johnson, Co-Chair Working Vessel Operations and Safety

### IMO REVISION OF THE INTACT STABILITY CODE. Proposal of methodology of direct assessment for stability under dead ship condition. Submitted by Japan

INTERNATIONAL MARITIME ORGANIZATION E IMO SUB-COMMITTEE ON STABILITY AND LOAD LINES AND ON FISHING VESSELS SAFETY 49th session Agenda item 5 SLF 49/5/5 19 May 2006 Original: ENGLISH REVISION OF THE INTACT

### . In an elevator accelerating upward (A) both the elevator accelerating upward (B) the first is equations are valid

IIT JEE Achiever 2014 Ist Year Physics-2: Worksheet-1 Date: 2014-06-26 Hydrostatics 1. A liquid can easily change its shape but a solid cannot because (A) the density of a liquid is smaller than that of

### An innovative windvane pendulum system for sailing boats with outboard rudders.

An innovative windvane pendulum system for sailing boats with outboard rudders. Jan Alkema 26 sept. 2005 figure 8. The oar blade retracted figure 7. The oar blade in the water Preface On boats with outboard

### Research on Goods and the Ship Interaction Based on ADAMS

Research on Goods and the Ship Interaction Based on ADAMS Fangzhen Song, Yanshi He and Haining Liu School of Mechanical Engineering, University of Jinan, Jinan, 250022, China Abstract. The equivalent method

### Final KG plus twenty reasons for a rise in G

Chapter 3 Final KG plus twenty reasons for a rise in G hen a ship is completed by the builders, certain written stability information must be handed over to the shipowner with the ship. Details of the

### Multihull Preliminary Stability Estimates are Fairly Accurate

Multihull Design (Rev. A) 45 APPENDIX A ADDITIONAL NOTES ON MULTIHULL DESIGN MULTIHULL STABILITY NOTES Multihull stability is calculated using exactly the same method as described in Westlawn book 106,

### OVERALL STABILITY 4.1 External Forces Acting on a Vessel In Chapter 4 we will study five areas:

OVERALL STABILITY 4.1 External Forces Acting on a Vessel In Chapter 4 we will study five areas: 1. The concept of a ship s Righting Moment (RM), the chief measure of stability. 2. KG and TCG changes and

### An Investigation into the Capsizing Accident of a Pusher Tug Boat

An Investigation into the Capsizing Accident of a Pusher Tug Boat Harukuni Taguchi, National Maritime Research Institute (NMRI) taguchi@nmri.go.jp Tomihiro Haraguchi, National Maritime Research Institute

### Chapter 3 Hydrostatics and Floatation

Chapter 3 Hydrostatics and Floatation Naval Architecture Notes 3.1 Archimedes Law of Floatation Archimedes (born 287 B.C) Law states that An object immersed in a liquid experience a lift equivalent to

### ACTIVITY 1: Buoyancy Problems. OBJECTIVE: Practice and Reinforce concepts related to Fluid Pressure, primarily Buoyancy

LESSON PLAN: SNAP, CRACKLE, POP: Submarine Buoyancy, Compression, and Rotational Equilibrium DEVELOPED BY: Bill Sanford, Nansemond Suffolk Academy 2012 NAVAL HISTORICAL FOUNDATION TEACHER FELLOWSHIP ACTIVITY

### Comparative Stability Analysis of a Frigate According to the Different Navy Rules in Waves

Comparative Stability Analysis of a Frigate According to the Different Navy Rules in Waves ABSTRACT Emre Kahramano lu, Technical University, emrek@yildiz.edu.tr Hüseyin Y lmaz,, hyilmaz@yildiz.edu.tr Burak

### Ship Stability September 2013 Myung-Il Roh Department of Naval Architecture and Ocean Engineering Seoul National University

Planning Procedure of Naval Architecture and Ocean Engineering Ship Stability September 2013 Myung-Il Roh Department of Naval Architecture and Ocean Engineering Seoul National University 1 Ship Stability

Navigation with Leeway Leeway, as we shall use the term, means how much a vessel is pushed downwind of its intended course when navigating in the presence of wind. To varying extents, knowledge of this

### Date: 18th December 2001

Coaching Tips - J/24 Tuning Guide & Sail Trimming Written By: Stuart Jardine Date: 18th December 2001 Stuart Jardine, J/24 national champ five times over, tells you how to get the best results from your

### 2 Buoyant Force. TAKE A LOOK 2. Identify What produces buoyant force?

CHAPTER 3 2 Buoyant Force SECTION Forces in Fluids BEFORE YOU READ After you read this section, you should be able to answer these questions: What is buoyant force? What makes objects sink or float? How

### The SDS Skip. Subsea Deployment Systems Ltd.

The SDS Skip SUBSEA SKIP An alternative to enhance the recovery of structures, spool pieces, mattresses etc. during decommissioning work Can be used to transport complex structures or spool pieces to field

### Melges 24 Sailing Guide

RACING GUIDES www.ullmansails.com Upwind Sailing Melges 24 Sailing Guide The Melges is most efficient when sailed as flat as possible. Excessive heel causes leeway which is slow. The skipper must work

### A Guide to the Influence of Ground Reaction on Ship Stability

Journal of Shipping and Ocean Engineering 6 (2017) 262-273 doi 10.17265/2159-5879/2017.06.004 D DAVID PUBLISHING A Guide to the Influence of Ground Reaction on Ship Stability Ahmed Helmy Abouelfadl and

### Cub Scout Pack Rain Gutter Regatta

Cub Scout Pack 350 2014 Rain Gutter Regatta Event Location & Date: Advance Firehouse, Saturday November 22nd 11:00am-1:00pm (racing as soon as everyone registers) 106 E Wall Street Advance, IN 46102-9407

### Stability Guidance Booklet

Stability Guidance issued Booklet on: version date 2002-10-29 FOR MASTERS AND WATCH KEEPERS for Sailing Vessels Contents 1 Information specific to this vessel 1 2 General cautions 4 3 Stability check lists

### 3D CDF MODELING OF SHIP S HEELING MOMENT DUE TO LIQUID SLOSHING IN TANKS A CASE STUDY

Journal of KONES Powertrain and Transport, Vol. 17, No. 4 21 3D CDF ODELING OF SHIP S HEELING OENT DUE TO LIQUID SLOSHING IN TANKS A CASE STUDY Przemysaw Krata, Jacek Jachowski Gdynia aritime University,

### RESOLUTION MSC.141(76) (adopted on 5 December 2002) REVISED MODEL TEST METHOD UNDER RESOLUTION 14 OF THE 1995 SOLAS CONFERENCE

MSC 76/23/Add.1 RESOLUTION MSC.141(76) THE MARITIME SAFETY COMMITTEE, RECALLING Article 38(c) of the Convention on the International Maritime Organization concerning the functions of the Committee, RECALLING

### EXPERIMENT (2) BUOYANCY & FLOTATION (METACENTRIC HEIGHT)

EXPERIMENT (2) BUOYANCY & FLOTATION (METACENTRIC HEIGHT) 1 By: Eng. Motasem M. Abushaban. Eng. Fedaa M. Fayyad. ARCHIMEDES PRINCIPLE Archimedes Principle states that the buoyant force has a magnitude equal

### II.E. Airplane Flight Controls

References: FAA-H-8083-3; FAA-8083-3-25 Objectives Key Elements Elements Schedule Equipment IP s Actions SP s Actions Completion Standards The student should develop knowledge of the elements related to

### Chapter 3 PRESSURE AND FLUID STATICS

Fluid Mechanics: Fundamentals and Applications, 2nd Edition Yunus A. Cengel, John M. Cimbala McGraw-Hill, 2010 Chapter 3 PRESSURE AND FLUID STATICS Lecture slides by Hasan Hacışevki Copyright The McGraw-Hill

### 10.4 Buoyancy is a force

Chapter 10.4 Learning Goals Define buoyancy. Explain the relationship between density and buoyancy. Discuss applications of Archimedes principle. 10.4 Buoyancy is a force Buoyancy is a measure of the upward

### Rock and Roll: The Lateral Stability of Vessels

Rock and Roll: The Lateral Stability of Vessels Peter Fortune 2012 revised: 2015 Contents Topic Page Introduction 1 Fundamentals of Stability 3 Torque and Stability 5 The Roll Period 9 Wave Frequency and

### 1. GENERAL AERODYNAMICS

Chapter 1. GENERAL AERODYNAMICS Unless otherwise indicated, this handbook is based on a helicopter that has the following characteristics: 1 - An unsupercharged (normally aspirated) reciprocating engine.

### MASTER THESIS PRESENTATION. Comparison Of Seakeeping Performance Of The Two Super Yachts Of 53 And 46 m In Length

MASTER THESIS PRESENTATION Comparison Of Seakeeping Performance Of The Two Super Yachts Of 53 And 46 m In Length Muhammad Asim Saleem Supervisor : Prof. Dario Boote, Universita degli studi di Genova, Italy

### Chapter 6. You lift a 10 N physics book up in the air a distance of 1 meter at a constant velocity of 0.5 m/s. The work done by gravity is

I lift a barbell with a mass of 50 kg up a distance of 0.70 m. Then I let the barbell come back down to where I started. How much net work did I do on the barbell? A) - 340 J B) 0 J C) + 35 J D) + 340

### The Definite Guide to Optimist Trim

The Definite Guide to Optimist Trim by Martin Gahmberg & the WB-Sails team The purpose of this tuning guide is to help you trim your WB sail optimally by learning the effects of the controls: How to change

### RULES PUBLICATION NO. 6/P STABILITY GDAŃSK

RULES PUBLICATION NO. 6/P STABILITY 006 Publications P (Additional Rule Requirements) issued by Polski Rejestr Statków complete or extended the Rules and are mandatory where applicable. GDAŃSK Publication

### Movement and Position

Movement and Position Syllabus points: 1.2 plot and interpret distance-time graphs 1.3 know and use the relationship between average speed, distance moved and 1.4 describe experiments to investigate the

### SAMPLE MAT Proceedings of the 10th International Conference on Stability of Ships

and Ocean Vehicles 1 Application of Dynamic V-Lines to Naval Vessels Matthew Heywood, BMT Defence Services Ltd, mheywood@bm tdsl.co.uk David Smith, UK Ministry of Defence, DESSESea-ShipStab1@mod.uk ABSTRACT

### THE USE OF ENERGY BUILD UP TO IDENTIFY THE MOST CRITICAL HEELING AXIS DIRECTION FOR STABILITY CALCULATIONS FOR FLOATING OFFSHORE STRUCTURES

10 th International Conference 65 THE USE OF ENERGY BUILD UP TO IDENTIFY THE MOST CRITICAL HEELING AXIS DIRECTION FOR STABILITY CALCULATIONS FOR FLOATING OFFSHORE STRUCTURES Joost van Santen, GustoMSC,

### Deepwater Floating Production Systems An Overview

Deepwater Floating Production Systems An Overview Introduction In addition to the mono hull, three floating structure designs Tension leg Platform (TLP), Semisubmersible (Semi), and Truss Spar have been

### The salient features of the 27m Ocean Shuttle Catamaran Hull Designs

The salient features of the 27m Ocean Shuttle Catamaran Hull Designs The hull form is a semi-planing type catamaran. It employs a combination of symmetrical and asymmetrical sponson shapes, thereby combining

### SHIP FORM DEFINITION The Shape of a Ship

SHIP FORM DEFINITION The Shape of a Ship The Traditional Way to Represent the Hull Form A ship's hull is a very complicated three dimensional shape. With few exceptions an equation cannot be written that

### Journal of Aeronautics & Aerospace

Journal of Aeronautics & Aerospace Engineering Journal of Aeronautics & Aerospace Engineering Landell-Mills, J Aeronaut Aerospace Eng 2017, 6:2 DOI: 10.4172/2168-9792.1000189 Research Article Open Access

### Maneuverability characteristics of ships with a single-cpp and their control

Maneuverability characteristics of ships with a single-cpp and their control during in-harbor ship-handlinghandling Hideo YABUKI Professor, Ph.D., Master Mariner Tokyo University of Marine Science and

### Principles of Sailing

Principles of Sailing This is a PowerPoint set of charts presented by Demetri Telionis on March 21, 2015 at the Yacht Club of Hilton Head Island. The aim of this presentation was to help the audience understand

### A TRIP ON THE ALBION

A TRIP ON THE ALBION Last Christmas my children gave me a special Christmas present they had chartered the Wherry Albion for a day. We hoped to get as far as Wayford Bridge, but this was a little bit too

### AP Lab 11.3 Archimedes Principle

ame School Date AP Lab 11.3 Archimedes Principle Explore the Apparatus We ll use the Buoyancy Apparatus in this lab activity. Before starting this activity check to see if there is an introductory video

### Make Model Length Price Year Condition. Beneteau First m EUR 14, Used. Boat Name Hull Material Draft Number of Engines Fuel Type

Beneteau First 30 Make Model Length Price Year Condition Beneteau First 30 8.9 m EUR 14,950 1980 Used Boat Name Hull Material Draft Number of Engines Fuel Type KayJay Fibreglass (GRP) 1.67 m 1 Diesel This

### Front Cover Picture Mark Rasmussen - Fotolia.com

Flight Maneuvers And Stick and Rudder Skills A complete learn to fly handbook by one of aviation s most knowledgeable and experienced flight instructors Front Cover Picture Mark Rasmussen - Fotolia.com

### GUIDANCE NOTICE. Unpowered Barges. Definition. General. Risk assessment. Application. Safety Management. Compliance

GUIDANCE NOTICE Unpowered Barges Definition Unpowered Barge - a vessel that is not propelled by mechanical means and is navigated by a powered vessel that moves it by pushing or towing. General This notice

### Stability Guidance Booklet

Stability Guidance issued Booklet on: version date 2002-10-29 FOR MASTERS AND WATCH KEEPERS for Powered Vessels Contents 1 Information specific to this vessel 1 2 General cautions 3 3 Stability check lists

### COURSE OBJECTIVES CHAPTER 4

COURSE OBJECTIVES CHAPTER 4 4. STABILITY 1. Explain the concepts of righting arm and righting moment and show these concepts on a sectional vector diagram of the ship s hull that is being heeled over by

### COMPARATIVE ANALYSIS OF CONVENTIONAL AND SWATH PASSENGER CATAMARAN

COMPARATIVE ANALYSIS OF CONVENTIONAL AND SWATH PASSENGER CATAMARAN Serđo Kos, Ph. D. David Brčić, B. Sc. Vlado Frančić, M. Sc. University of Rijeka Faculty of Maritime Studies Studentska 2, HR 51000 Rijeka,

### National Maritime Center

National Maritime Center Providing Credentials to Mariners (Sample Examination) Page 1 of 8 Choose the best answer to the following Multiple Choice Questions. 1. In illustration D001SL, what is the edge

### THE 21 st CHESAPEAKE SAILING YACHT SYMPOSIUM ANNAPOLIS, MARYLAND, MARCH 2013

THE 21 st CHESAPEAKE SAILING YACHT SYMPOSIUM ANNAPOLIS, MARYLAND, MARCH 2013 A wind tunnel study of the interaction between two sailing yachts P.J. Richards, D.J. Le Pelley, D. Jowett, J. Little, O. Detlefsen

### North Sails Seattle Thunderbird Tuning Guide

Page 1 of 6 North Sails Seattle Thunderbird Tuning Guide Introduction The following tuning guide is meant as a good starting point in setting up your boat. Since not all Thunderbirds are exactly alike

### Four forces on an airplane

Four forces on an airplane By NASA.gov on 10.12.16 Word Count 824 Level MAX TOP: An airplane pictured on June 30, 2016. Courtesy of Pexels. BOTTOM: Four forces on an airplane. Courtesy of NASA. A force

### WATERTIGHT INTEGRITY. Ship is divided into watertight compartments by means of transverse and longitudinal bulkheads bulkheads.

Damage Stability WATERTIGHT INTEGRITY Ship is divided into watertight compartments by means of transverse and longitudinal bulkheads bulkheads. When a watertight compartment (or a group of compartments)

### MSC Guidelines for the Submission of Stability Test (Deadweight Survey or Inclining Experiment) Results

S. E. HEMANN, CDR, Chief, Hull Division References a. 46 CFR 170, Subpart F Determination of Lightweight Displacement and Centers of Gravity b. NVIC 17-91 Guidelines for Conducting Stability Tests c. ASTM

### RULES FOR THE CLASSIFICATION AND CONSTRUCTION OF SMALL SEA-GOING SHIPS

RULES FOR THE CLASSIFICATION AND CONSTRUCTION OF SMALL SEA-GOING SHIPS PART IV STABILITY, SUBDIVISION AND FREEBOARD 2015 January GDAŃSK RULES FOR THE CLASSIFICATION AND CONSTRUCTION OF SMALL SEA-GOING

### QUESTION 1. Sketch graphs (on the axes below) to show: (1) the horizontal speed v x of the ball versus time, for the duration of its flight;

QUESTION 1 A ball is thrown horizontally from a cliff with a speed of 10 ms -1 shown in the diagram at right. Neglecting the effect of air resistance and taking gravitational acceleration to be g +9.8ms

### Parts of the Ship. Terms you should already know

Parts of the Ship Toronto Brigantine Terms you should already know After-peak Fore-peak Bow Stern Fairlead Scupper Freeing port Hull Deck Lifeline Hatch Skylight Cleat Pin-rail Fife-rail Spider-band Block

### 03 Vessel Fitness and Safety

03 Vessel Fitness and Safety Competence (Skills) Knowledge, Understanding and Proficiency Level Required Vessel Terminology and Characteristics Vessel hull types and configurations Members must know the

### Beauty & performance

Beauty & performance There has been a need for a quick, easy-to-sail dayboat with the properties of a keelboat. That s why I designed the Tarac 33 a lively boat with almost unbeatable performance. Håkan

### New Azimut Magellano 66. Preliminary presentation

New Azimut Magellano 66 THIS DOCUMENT IS VALID AS A PRELIMINARY PRESENTATION ONLY This brochure in no way constitutes a contract of sale for the boatyard s vessels to any person or company. All information

### ITTC Recommended Procedures Testing and Extrapolation Methods Manoeuvrability Free-Sailing Model Test Procedure

Testing and Extrapolation Methods Free-Sailing Model Test Procedure Page 1 of 10 22 CONTENTS 1. PURPOSE OF PROCEDURE 2. DESCRIPTION OF PROCEDURE 2.1 Preparation 2.1.1 Ship model characteristics 2.1.2 Model

### Harmonic Motion: Pendulums Student Version

Harmonic Motion: Pendulums Student Version In this lab you will set up a pendulum using rulers, string, and small weights and measure how different variables affect the period of the pendulum. You will

### Docking & Harbor Handling Techniques

TOP 5 THINGS TO REMEMBER 1. Take your time a. There is never a hurry to leave the dock or return to the dock. When departing, you can sit at the dock for as long as you like until everything is in place

### DP Ice Model Test of Arctic Drillship

Author s Name Name of the Paper Session DYNAMIC POSITIONING CONFERENCE October 11-12, 211 ICE TESTING SESSION DP Ice Model Test of Arctic Drillship Torbjørn Hals Kongsberg Maritime, Kongsberg, Norway Fredrik

### Today Mr. Happer told us to use the following physics vocabulary words and relate them to our experiment:

Design Your Own Experiment Lab Report Objective While making our water rocket, our group tried to achieve different criteria listed by Mr. Happer. With our rocket, we were trying to achieve a distance

### CHUCK PAINE'S BERMUDA SERIES 80 LIGHT DISPLACEMENT KETCH "LEONORE"

CHUCK PAINE'S BERMUDA SERIES 80 LIGHT DISPLACEMENT KETCH "LEONORE" THE 80 FOOT LEONORE WAS COMMISSIONED IN JANUARY 2003 IN AUCKLAND. SHE IS A WONDERFUL EXAMPLE OF THE QUALITY OF WORK THAT CAN RESULT FROM

### The OTSS System for Drift and Response Prediction of Damaged Ships

The OTSS System for Drift and Response Prediction of Damaged Ships Shoichi Hara 1, Kunihiro Hoshino 1,Kazuhiro Yukawa 1, Jun Hasegawa 1 Katsuji Tanizawa 1, Michio Ueno 1, Kenji Yamakawa 1 1 National Maritime

### Raider 16/Sport - Spinnaker Rigging. Rigging Spinnaker

Rigging Spinnaker Step 1: Run the spinnaker halyard (minimum 52' in length) through the block then back down the mast. Step the mast as you normally would. Step 2: Temporally tie one end of the spinnaker

### THEYACHT. report. The leading magazine for the design, construction, management, ownership & operation of luxury yachts. Issue 114 June 2010

THEYACHT The leading magazine for the design, construction, management, ownership & operation of luxury yachts report Issue 114 June 2010 Catamaran or Monohull? Two are better than one... Whether that

### 1. The principle of fluid pressure that is used in hydraulic brakes or lifts is that:

University Physics (Prof. David Flory) Chapt_15 Thursday, November 15, 2007 Page 1 Name: Date: 1. The principle of fluid pressure that is used in hydraulic brakes or lifts is that: A) pressure is the same

### 19 Waves and Vibrations

19 Waves and Vibrations Answers and Solutions for Chapter 19 Reading Check Questions 1. A wiggle in time is a vibration; a wiggle in space and time is a wave. 2. The source of all waves is a vibration.

### FOR SALE 2009 DRAGON

FOR SALE 2009 DRAGON 2009 Petticrows Dragon for Sale Originally built for Rob Campbell [past IDA Chairman] in 2009 by Petticrows in their Burnham-on- Crouch factory where unusually, the hull remained in

### EYC Super Hard Rules Quiz

EYC Super Hard Rules Quiz (Use your rule book and the online ISAF Case Book) 1. Whenever there is contact between 2 boats racing, one boat must take a two-turns penalty, retire, or face disqualification.

### EN400 LAB #2 PRELAB. ARCHIMEDES & CENTER of FLOTATION

EN400 LAB #2 PRELAB ARCHIMEDES & CENTER of FLOTATION Instructions: 1. The prelab covers theories that will be examined experimentally in this lab. 2. The prelab is to be completed and handed in to your

### Optimizing the shape and speed performance of the boats

Optimizing the shape and speed performance of the boats A report submitted to Modelling Week and Study Group Meeting on Industrial Problems-2013 by AWL Pubudu Thilan 1, Baikuntha Nath Sahu 2, Darshan Lal

### ALLURES Excellence has a future 2017

ALLURES 45.9 Excellence has a future 2017 For the past 14 years, the Allures Yachting shipyard has become a reference point for blue water sailing yachts thanks to the support and confidence of its owners.

### Instruction Manual. Features. Specification: Length: 730mm Width: 500mm Height: 1000mm Sail Area: 0.15m 2. Weight: 692g (w/o battery & receiver)

AN UNBELIEVABLE SPEED MACHINE Instruction Manual Features Specification: Length: 730mm Width: 500mm Height: 1000mm Sail Area: 0.15m 2 Weight: 692g (w/o battery & receiver) Thank you for purchasing your

### Comfort onboard yachts in anchored conditions

Comfort onboard yachts in anchored conditions G. Gaillarde, R.P. Dallinga, G. Loeff, H. Luisman, MARIN 1 1. Introduction By limiting comfort and on-board activities poor seakeeping affects the sheer enjoyment

### Edit this text for your title

Edit this text for your title MEK 4450 Marine Operations Edit this text for your sub-title Presenter name, location, date etc. Kværner ASA / DNV, Fall 2013 Lesson 2/3 Lift phases Load out Transportation

### Julian's Skiff Tips. From the Santa Barbara Skiff Clinic - May 2001

Julian's Skiff Tips From the Santa Barbara Skiff Clinic - May 2001 As some of you may know, I have just spent the last month traveling around the world and was presently surprised to see 29er sailing just

### ANGEL INSTRUCTIONS ALMOST READY TO SAIL MODEL YACHT

ANGEL INSTRUCTIONS ALMOST READY TO SAIL MODEL YACHT Long: 920mm High:1840mm Toatl sail area: 0.4 m2 1 MODEL YACHT ASSEMBLY INSTRUCTIONS & SAILING HINTS Thank you for purchasing one of our range of model

### Physics 11 Unit III Practice Test Projectile Motion. Instructions: Pick the best answer available in Part A and Show all your work for Part B

Physics 11 Unit III Practice Test Projectile Motion Instructions: Pick the best answer available in Part A and Show all your work for Part B 1. Which of the following is constant for all projectiles? A.

### NAVAL ARCHITECTURE 1. Class Notes

NAVAL ARCHITECTURE 1 Class Notes d G G 1 W tonnes d G 1 G w tonnes d G 1 G w tonnes Omar bin Yaakob Chapter 1 Introduction Naval Architecture Notes Introduction To carry out various activities at sea,