Information Sheet - Features of the 49er
Centreboard
Purpose - stops the 49er from being washed sideways when it is sailing.
Must be - strong and very rigid.
Made of - plastic foam strengthened with carbon fibre, then fibreglassed.
Carbon fibre - is made from woven carbon stands or filaments (like threads).
Fibreglass - is made from filaments of glass woven to form a cloth.
If the 49er capsizes the crew stand on the centreboard to get it back upright.
DID YOU KNOW?
Carbon and glass fibres alone are very flexible and weak. When set solid in position with a resin they form materials that are strong and rigid.
Keels
Purpose - keep the yachts upright in strong winds.
Made of - usually cast iron, steel or lead.
Must be - a high density material to keep the yacht upright.
DID YOU KNOW?
Some larger keelboats in long distance ocean races have even used extremely heavy depleted uranium as ballast. Depleted uranium is the low radioactive uranium remaining after use in a nuclear reactor.
Rudder
Purpose - steers the yacht.
Must be - strong and rigid to withstand the high stresses when the boat is sailing.
Made of - plastic foam strengthened with carbon fibre, then fibreglassed.
DID YOU KNOW?
Carbon fibre is usually set in position with epoxy resins or glues that are applied as a liquid, and then allowed to harden. To get maximum strength, the hardening process is controlled by changing the temperature.
Hull
Purpose - holds the mast, sails and crew. It reduces the friction of moving through the water and keeps the water out.
Must be - able to withstand the stresses of bending and twisting while sailing.
Made of - fibreglass that is strengthened and stiffened with carbon fibre.
DID YOU KNOW?
The hull is built in a special mold where glass fibre cloth is thoroughly saturated with liquid epoxy resin. This later solidifies. The same mold is used for all 49ers. The colour of the hull is achieved by using a special coloured thick polyester resin, called gel-coat. This opaque resin contains lead and titanium dioxide.
Mast and Boom
Purpose - hold the sails and allow them to change shape for different conditions.
Must be - light, very strong and flexible and able to resist corrosion in seawater.
Made from - a special alloy, called duralumin. This is a mixture of aluminium and small amounts of copper, silicon and magnesium.
DID YOU KNOW?
Duralumin produces a strong metal that has the right flexing properties for masts, booms and spinnaker poles.
Rigging and Fittings
Purpose - wires hold up the mast and support the crew when they are hanging out on the trapeze to balance the yacht. The fittings allow the ropes to be fed through and held fast.Made from - stainless steel which is an alloy of iron with small amounts of carbon, nickel, chromium, manganese and tungsten.
Must be - strong and able to resist corrosion.
DID YOU KNOW?
More and more titanium is being used for yacht fittings because it is very light, extremely strong and will not corrode in seawater.
Sails
Purpose - fill the sails with wind and move the yacht.
Made from - special high strength and non-stretch plastic fibre.
Must be - able to hold their special shape and hold their strength in all directions (unlike normal woven cloth that has different strengths in different directions).
DID YOU KNOW?
These artificial plastic fibres are known by brand names such as 'Mylar' (which is transparent), Kevlar and 'Spectra'. Hockey sticks can also be strengthened using 'Spectra'. These high strength materials are made from petroleum and coal products.
|
The brightly coloured spinnakers are made from nylon. They have to be very light and strong. Nylon, which is made from petroleum, serves this purpose well. |
Ropes
The majority of ropes used on the 49er (and all the other yacht classes as well) are either made from polyester (a plastic) or the more modern "Spectra". Both these products are derived from coal and petroleum.
Crew Clothing
Purpose - keeps crew members warm and dry.
Made of - polyester fibre such as 'Terylene' and 'Gortex.'
Must be - waterproof.
DID YOU KNOW?
Lifejackets are made from polyurethane or polystyrene foam covered with brightly coloured polyester fabric. Polyester, polyurethane and polystyrene (beads in beanbags), are all plastics made from petroleum and coal products.
Trailers
Purpose - move yachts around on land.
Made from - aluminium or galvanized (zinc coated) steel frames.
Must be - strong and durable.
DID YOU KNOW?
Rubber tyres made longer wearing by the addition of zinc to the rubber compound.