Jib
(genoa) controls and adjustment
For this section, it would
be useful to define light, medium, and heavy air sailing conditions.
It can be different for each skipper/crew/boat combination. It is
set by conditions sailing to windward:
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light: The crew must sit inside
the boat or to leeward to keep the boat flat.
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medium: The crew and skipper can
keep the boat flat while normally sitting or hiked on the side deck.
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heavy: The crew and skipper cannot
keep the boat flat without luffing, easing the sheets or flattening the
sail shape.
1. jib halyard
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Use 1/8” 7 x 19 stainless steel
wire to handle the high tension on the halyard.
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Have an adjustable fitting between
the top of the jib and the halyard to accommodate different sail sizes.
Small galvanized chain links work well and the appropriate number of links
can be left on each sail.
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Connect the wire halyard to a
Highfield lever or magic box to adjust the jib luff tension.
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To set the jib halyard tension,
sail to windward and check if the leeward shroud is slack. Tighten
till it is just tight or, if necessary, loosen until it is just straight.
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Another guide to jib halyard tension
is the sag in the jib luff when sailing to windward. There should
always be some sag (approx. 2-3” at the middle of the luff) as compared
to the vertical line of the forestay.
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It is useful to mark the approx.
settings for light, medium and heavy air so that rough adjustments can
be made quickly when necessary.
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Coil the rope halyard and fasten
with a Velcro loop out of the way (on the side of the mast step).
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Set the jib tack low enough so
that the foot of the genoa will lie along the deck preventing air from
flowing underneath. This escaping air will make the foot vibrate and reduce
the power of the sail.
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In light wind use the jib halyard
to apply rig tension and some pre-bend to the mast. Take up this
tension on the forestay control line. Then loosen the jib halyard
tension until there is approx. 3” of luff sag.
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If the genoa tack is not fastened
to the bottom of the wire luff, it will be necessary to to install a genoa
cunningham. This must be used sparingly trying to leave small horizontal
"speed wrinkles" along the luff of the sail.
2. jib sheets
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Install the fairlead track on
the outside of the inside board on the front seats. Use jam cleats
with stainless steel jaws to positively grip the sheets. The fairlead jam
cleat plate often gets bent down accidentally (stepped on!) making it hard
to cleat when the crew is hiked out. This can be prevented by installing
a plastic or rubber spacer to the underside of the jam cleat and a spacer
strip for it to rest on, along the top of the seat board just under where
the jam cleat travels along its track.
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The basic fore/aft position of
the fairlead is set by running a string from the center of the jib luff,
through the clew and extending in a straight line to the fairlead track.
This is a good guide to the correct position.
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Install tell-tales along the luff
of the genoa. Top one at 3/4 of the way up the luff, center one in the
middle, and lower one about 25% from the foot. These are best made by using
brightly coloured wool. Pull a strand through the sail cloth with a needle,
then put knots on each side of the cloth to hold it in place. Locate
the tell-tales approx. 5” back from the luff wire and cut them to be 4”.
This prevents them from getting stuck around the front of the luff. Periodically
treat them with anti-static spray.
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When sailing to windward, set
the mainsail sheeting. Then sheet in the jib until it slightly backwinds
the main. Then just ease till the back-wind stops. When close to the correct
jib sheet position very small adjustments make a big difference to performance.
A one inch change in sheet position will open or close the slot between
the jib leach and the main by approx. 6 inches. It also changes the
relative tension in the upper and lower sections of the jib. To fine
tune the jib sheet adjustment, luff the boat slightly and check if the
three windward tell-tales react evenly: If the
upper one breaks first, sheet in slightly; if the lower one breaks first,
ease the sheet slightly. The goal is to have all three tell-tales
break evenly. Once set, the skipper should steer the boat by watching the
middle tell-tale. In the optimum position, it should be streaming
backwards and slightly upward at an angle of about 45º.
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It is useful to sew in brightly
coloured threads into the jib sheets about every 2” along about a 12” section
which is normally passing through the fairlead when going to windward.
In this way you can learn which settings work well for different wind conditions,
then use them as a guide each time you tack.
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Do not oversheet the jib
as this reduces the power of the sail and will slow windward speed. "When
in doubt, let it out" is especially true as the wind drops to
light air. Ease the sails, bear off slightly and keep the boat moving.
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In gusty wind conditions, ease
the sheet slightly as the wind drops, then sheet in again as the next gust
hits.
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Install a tell-tale about 2/3
up the leech of the jib. This can be used as a guide to jib sheet tension.
Trim the sheet until the tell-tale no longer flows straight out then ease
it slightly. To use this continuously a window would be required in the
luff of the main.
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When going to windward in heavy
air, the jib can be kept sheeted to a typical position for medium air (perhaps
slightly eased). Then the boat is kept flat by luffing the sails as much
as necessary. Ignore the tell-tales and just pinch up enough to keep the
boat flat. This combined with hiking, flattening the main sail, easing
the traveler, and perhaps slightly raising the centreboard provides good
speed to windward. The real key is to keep the boat flat.
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