Specifications
BASIC SPECIFICATIONS AND DIMENSIONS
Specifications for the following allow room for the thoughtful builder to experiment and apply his own theories.
HULL
Overall length- 3657mm
Maximum beam- 1181mm Gunwales each side (optional).
Maximum depth- 375mm
Side deck widths may vary from 216mm to 266mm
Hull to be covered with marine ply not less than 3mm thickness.
Buoyancy bulkheads other than those fore and aft are not permitted.
The weight of the complete hull, in a dry condition, unrigged, which shall include only splashboards, floorboards, chainplates and basic fittings shall not be less than 35 kilograms.
plus, or minus 12 mm tolerance on hull measurements.
RUDDER
Length of blade not to extend more than 610mm below the hull at
the stern.
CENTREBOARD
Maximum length- 1321mm
Maximum width- 355mm
Maximum thickness- 25mm
TILLER
Size optional (suggested Length 508mm). ~ extension (suggested
length 914mm)
MAST
Maximum section 127mm x 63.5mm or equivalent cross sectional
area (suggested size 76mm x 63.5mm maximum).
Height above deck not to exceed 5.6m
Maybe of timber or metal or carbon.
Maybe of hollow construction.
Height of jib halyard optional (suggested 3657mm from deck).
Spinnaker halyard height optional (suggested 4419mm from
deck).
May be fixed or rotating.
Sail track must be straight when not under pressure.
BOOM
Maximum length- 2362mm including gooseneck.
Maximum depth- 152mm.
Width optional (suggested size for central sheeting 57mm
round).
Sail track must be straight when not under pressure.
Maybe timber or metal or carbon.
Maybe of hollow construction.
SPINNAKER POLE
Maximum length including fittings - 3505mm
May be timber or metal or Carbon (suggested size 25mm round). May be of hollow construction.
GENERAL
Trapezes
optional, one each side of the mast.
Venturis and self bailers
Optional.
Sheeting system for mainsail
To individual requirements.
SAILS
General
Only three sails to be set at the one time, i. e., mainsail, 1 jib, 1 spinnaker. (may carry more than one spinnaker on the boat)
Maximum main and jib sail area 10.5sqm
Sailcloth- optional weight woven synthetic material.
Plastic windows in working sails are permitted.
Number and length of battens optional.
Vents and zips are not permitted.
Every National Rainbow to carry the class insignia, i. e., a red " R" in a blue circle. The outside diameter of the circle to be 381 mm, height of the R 203mm.
The registered number to be 290mm high and 50mm wide.
Sails to be dry when measured.
Main
Maximum sail luff 4800mm
Maximum Foot 2180mm
Maximum Leach 5110mm
Maximum Half Girth 1680mm
Maximum Three Quarter 1220mm
Maximum 7/8 Girth 740mm
Maximum Quarter Girth 1990mm
Maximum area 8sqm
Jib
Maximum sail luff 3825mm
Maximum Foot 1330mm
Maximum Leach 3490mm
Maximum Half Girth 650mm
Maximum Head 70mm
Maximum area 2.5sqm
Spinnaker
*Currently Under Trail*
Maximum area 9sqm
RIGGING SUGGESTIONS.
Stays
1x19 3.5mm circumference stainless steel wire.
Trapeze
1x19 2.5mm circumference stainless steel wire.
Spreaders or a preventer are now widely used to counter
spinnaker pole pressure.
Spreaders
2200mm from the deck. (mast base)
Hounds
4000mm from the deck. (mast base)
Gooseneck
540mm from the deck. (mast base)
Snotter
Suggested height above deck, 840mm.
Preventer
Wire from snottier to fitting at bow or mid bow frame.
Spinnaker halyard
10m x 4mm circ. polyester.
Jib Sheet
5.5m x 6mm circ. polyester.
Main Sheet
5.5m x 10mm circ. polyester.
Spinnaker Sheet
10m x 4mm circ. polyester.