INMAST FURLING MAINSAILS
The highest quality dacron sailcloth is required for a durable inmast sail.
To much fabric stretch will soon render a poor quality sail difficult to furl as the extra fullness generated refuses to roll neatly into the mast, larger yachts can benefit from a triradial cut sail with taffeta mylar fabrics this allows weight reductions and lower stretch under high loads.
where improved performance is required, vertical battens can be fitted to the leach so that the roach can be extended.
we do not recommend full height battens that go from the foot up to the leach edge as issues with batten removal and pocket damage are common and can render the sail unusable/unfurlable.
shorter battens that can stay permanently fitted in the pockets even during transport in a car seem to be the best compromise
and as the photos above show can have an efficient roached leach.
the mast section has to have enough room to easily furl the sail away when battens are used, we can advise on this ,
the battens and pockets are designed for minimum interference when furling .
Again the best premium dacron to control sail shape and extend life is used, most cruising rigs work best with flat sail shapes that stay flat when furled. For extra performance or for IRC racing (furling rating allowance) genoas, mylar film based sail fabrics are recommended these sails can be fitted with roller battens if required.
The last 10 years has seen a steady decrease in genoa overlap at the mast, this has the benefits of much easier tacking and winching in together with better forward visibility, you also have a better sail shape in heavier winds as you furl down, the large long footed sails are quicker reaching and in light airs.
For yachts over 30 feet, 1.5oz nylon is recommended, narrow head angle for stability and reaching ,triradial cut for strength, high clew for easy gybing. Area is custom designed depending on use, ie UK waters ,the med, or transatlantic, but most are about 85-90 % of the full size spinnaker area.
Snuffers can be supplied and are recommended for short handed sailing, the type we supply has a flexible mouth for easy stowing and all lines are internally sleeved so they don't tangle up.
purpose built running spinnakers are very useful for long distance sailing .set with a pole ,when the cruising chute is at its least effective, the sail is cut to be stable with curved shoulders for minimum trimming and high clews for visibility. area 10 to 20 % larger than cruising chute works well.
THE CUTTER AND KETCH RIG
Both very good seaworthy rigs, excellent for heavy wind use, sail plans can be customized to suit design of yacht and use.
The cutter rigs twin forstays allow a staysail, furled or hanked for use when the large outer furling genoa is rolled up. Bringing the centre of area nearer the mast produces a relaxed motion in high wind and waves, ketches can drop main and use full mizzen at this point,
Points to note are :
High clew on large genoa so it can be tacked around inner forstay, setting both headsails together is only efficient on a reach, upwind they are very tricky to setup without stalling one or other.
Staysail size is limited by rigging positions forward of the mast, the largest size that doesn't hit the rig is often best. Sail will sheet well inside genoa track fairleads.
Mizzens are usually made as large and as flat as possible to contribute to light winds speed, with the mizzen boom often overhanging the stern a single deep reef is fitted for ease of use.
FULLY BATTENED MAINSAILS
a popular consideration for mainsail shape control in heavy weather and ease of packing away for yachts with high or out of reach booms.
fully battened mainsails have 5 battens running luff to leach parallel to the boom, bolted on sockets for the battens spread the load onto the sail at the leach and to the car at the mast, there are 4 quality systems for the mast cars that will fit a standard mast without additional track, rollerball (Frederiksen), wheeled (Selden and Rutgarson) and low friction plastic (Bainbridge Sailman). all these systems transfer the batten compression loads to the outside of the mast track (normal slides only work under tension) without one of these car systems the sail will tend to jam hoisting or lowering.
sail design for fully battened systems makes use of the fact that the battens control the sail shape rather than the shape put into the sails panels, to this end a very flat sail shape that matches the working mast bend is used, the batten type (round or flat section) is selected to produce the best shape at each batten height, stiffest battens in the lower third of the sail, softest at the top. if the battens are incorrect so will be the sail shape.
because there are fewer cars (sliders) on a fully battened system (typically half the number) there is only one intermediate slider between each batten pocket. correct setup is important. at the sail loft the cars offset from the sail is set by screwing in or out the threaded connector to the socket, the correct set up is with the offset on all slides to be equal to prevent the sail rattling between the slides,
batten tension is adjusted by either altering the batten length or adjusting the screw on the socket that pushes the batten away from the luff in its socket , the amount of batten tension depends on the sail fabric and yacht size, a soft dacron main would be fine with just all the slack taken out, a large laminate sail would need probably as much as the adjusting screw will allow you to turn ,as the sail stretches with use the battens will need to be re tensioned.
swept back spreader rigs (aft sweep greater than 6 degrees) are often fitted to modern yachts, care should be taken in this case to stabilise the rig with a fair mast bend by rig adjustment, a fully battened main will be intolerant of large amounts of sideways or fore and aft bend, sail creases can appear as batten shape conflicts with mast bend, swept spreaders can also have a tendency to weaken or brake battens where shroud and batten collide when running.
reef heights on fully battened mainsails are constrained by the batten spacing , for strength the best position for a reef is a few feet below a batten but no more than one reef should be fitted between the battens as problems can arise tensioning the reef in.
the advantages of a fully battened main are: sail control and handling in a breeze without flogging ,ease of packing sail away with stacker type sail coat and lazy jacks.
the disadvantages are extra weight aloft (around 20% of sail weight), complexity and initial cost (plus 30% on normal sail).
storm jibs and trisails
the best area for a sloop rig is .05 times the mast height squared, this is the RORC offshore maximum size and has shown to be usable in all winds yet with sufficient power to pull you to windward if required.
various methods of attachment are used depending on genoa handling system , to work with a furling gear , eyelets are fitted as well as luff tape and or a dynema (high strength) rope so the sail can be set flying with a tight halliard or laced to the furled genoa with sail ties, if an inner forestay can be fitted (the best setup to have )hanks are fitted.
the best sizes for a trisail are 66% of the mainsail foot by 50% of mainsail hoist ,the sail is cut with a high tack so it can be attached and hoisted above a lowered mainsail and sheeted on the toe rail aft of the cockpit.
most inmast furling masts have a separate track for a trisail as part of the mast extrusion in this case trisail has luff tape to fit.
all storm sails come with triple seams as standard and can be bright orange or white or a white /orange combination.
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