UNIVERSITY OF SOUTHAMPTON
FACULTY OF ENGINEERING AND APPLIED SCIENCE
DEPARTMENT OF SHIP SCIENCE

"AN INVESTIGATION INTO SOME ASPECTS INVOLVED IN THE
DESIGN OF AN INTERNATIONAL MOTH RACING SAILING DINGHY"

by DOUGLAS J. CULNANE - 1994 / 1995

Contents

Abstract

List of Tables

List of Figures

Introduction

1 Hull Design

1.1 The Effect of Hull Speed on the Design
1.2 Aussie Axeman Hull Form
1.3 WSH Design
1.4 Comparison of the Two Designs

2 Transverse Stability

2.1 Comparison of GZ Data
2.2 Stability Components
2.3 Investigation into the Crafts Stability With a Heeled Mast
2.4 Transverse Stability Conclusions

3 Longitudinal Stability

3.1 Investigation into Longitudinal Stability
3.2 Stabilising Foil Design
3.3 Longitudinal Stability Conclusions

4 Sail Design

4.1 Restrictions on the Sail Design
4.2 Basic Sail Performance Characteristics
4.3 Spanwise Lift Distribution
4.4 Sail Section Design
4.5 Sail Plan and Area Measurement
4.6 Foil Angle of Sweep
4.7 Mast Raking System
4.8 Sail Controls and their Effects

5 Sail Balance

5.1 Background to the Problem
5.2 Factors Affecting Balance
5.3 Rule of Thumb for Balancing Moths
5.4 Sail Balance Conclusions

6 Rudder Design

6.1 Assumptions and equations used in the Analysis of the Rudders
6.2 Analysis of 4 Different Possible Rudder Designs
6.3 Rudder Design Discussion and Conclusions

7 Mast Design

7.1 Loads on the Mast
7.2 Mast Specification
7.3 Mast Design Example

8 Conclusions and Recommendations

9 References

Appendix 1

International Moth Class Rules

Appendix 2

Moth Mast Raking System

Appendix 3 (Not available on site at present)

Figures 1.1 ® 7.1

Appendix 4 A2 sheets (Not available on site at present)

Lines Plans for:
Aussie Axeman
WSH

Discussion