Sails and the way they work | LIBROS NÁUTICOS | Navegación a Vela | Librería Náutica cartamar. Libros Náuticos. Cartas Náuticas | Libreria nautica Cartamar. Libros nauticos. Cartas nauticas.

Contenido:

In this gem of a book, Derek Harvey describes the origins of the different shapes of sail, the way they work, and the practical differences between the various rigs in their handling and performance out on the water. Next he explains the principles of sail design, advises on choice of sailcloth, and shows how a basic home computer can be used to plot the panel shapes so that DIY salmakers can save as much as three-quarters of the cost of small boat sails by making them or recutting old ones. Guidance on lofting, sewing and hand-finishing follow, and finally advice on sail care.

This book contains all the information a boatowner needs to fully understand how sails work, and how to design, make, repair and modify them.



Índice:

Acknowledgements

Introduction

CHAPTER 1. THE FOUR STAGES OF SAIL
Prehistory
- Papyrus rafts
- Skin boats
- Bark boats and dugouts
- The first sails
- Centreboards
- Outrigger canoes
- Axial rudders
Development: trading ships and fishing vessels
- Planked hulls
- Tilting yards
- Chinese junks
- Crab claw and lateen sails
- Square-riggers
- Gaff-rigs and galleons
- Improvements in hull design
- Clippers and windjammers
Progress
- Spritsails
- Dutch sloops
- The dawn of yachting
- Rig design revolution
- Racing measurement rules
- American schooners and sandbaggers
- Cotton sails
Yachting develops as a sport
- The ketch rig
- Lugsails
- The fishing fleets
- The Bermudan rig
- Cross-cut sails
- Mitred headsails
- Spinnakers
- Genoas

CHAPTER 2. HOW SAIL WORK
Speed vs pressure
Airflow and lift
Boundary layer
Starting vortex
Circulation
Camber
Wind angle
Twist
The slot
Sail forces
Form drag
Frictional drag
Induced drag
Aspect ratio
Draft control & sailtrim
Bendy spars
Helm balance

CHAPTER 3. RIG CONFIGURATIONS AND FEATURES
Dipping lug
Standing lug
Balance lug
Lateen
Sprit rig
Crab claw
Sailboard
Catboats
Fractionally rigged Bermudan sloop
Swing rig
Gaff cutter
High performance rig for multihulls
Masthead cutter
Bermudan cat ketch
Gunter yawl
Gaff ketch
Schooner
Junk rigged schooner

CHAPTER 4. SAILMAKING
Sailcloth
Polyester
Nylon
Polyester laminates
Kevlar
- Spectra
- Carbon
- Vectran
Choosing the cloth
Estimating the yardage
Cloth weight
Weight measurements
Sail design
Seam tapers
Edge curves
Computer aided design (CAD)
Vertical distribution curves
Designing the jib
Designing the mainsail
Shaping spinnakers
Turning designs into sails
The tools
Lofting, laying out and cutting
Joining up and rubbing down
Hand-sewing and the stitches
Patches and pockets
Eyelets, rings and thimbles
Headboards, slides and ropework
Faults and remedies
Care and repair

Glossary

Index