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I have a cunningham plan
FURTHER READINGIllustrated Sail & Rig Tuning
by Ivar Dedekam, Fenhurst
books. An easy-to-understand
guide to trimming sails and
rig tuning.Yachting Monthly Sail Power
by Peter Nielsen, Adlard Coles
Nautical. A more advanced
guide to getting the best
from your sails.North U TRIM by Bill
Gladstone, North U. This book
is part of an excellent series
on sail trim for those who
really want to get the best
from their sails.I
do not claim to be any kind
of wizard at sail trim but, like
many sailors, I do enjoy at
least trying to get a well-set sail.
When my new mainsail arrived
it came with a cunningham
cringle, so it was natural that I
would read up on how to use it.
Put simply, the cunningham line
adjusts the tension in the lower
third of the luff and is used to move
the draught of the sail forward or aft
to suit changing wind conditions.
Tension on the line flattens the sail
and moves the draught forwards.
While you can also do this by
increasing the halyard tension, the
halyard will act on the upper third
more than the lower third due
to friction in the sail sliders. A
cunningham can be rigged quite
quickly using a short line, cleated
at the mast and leading up and
through the cunningham grommet.
The tension is applied to the
cunningham using a simple block
and tackle fastened between the
line and a suitable point such as
the vang fitting. If you want to get
really serious, lead the line back
to the cockpit and a suitable
winch and jammer. If you have the
grommet in the sail already then
set-up costs are minimal as most
of us have odd lengths of line and
blocks which are suitable.
In light airs, you want a fuller
sail with the draught of the sail
aft, so take all the tension off the
cunningham and ease the halyard
a little. As the wind rises, the
mainsail needs to be flatter and the
draught needs to come forwards.
This is where the cunningham
comes into its own. Simply
cranking the main halyard on will
only result in changes at the top of
the sail. Applying tension to the
cunningham will flatten and move
the draught forwards in the lower
part of the sail, so combining both
halyard and cunningham tension
gives both a sail better shaped to
the conditions and a boat which
carries less weather helm, sailing
flatter and faster. Oh, and you get
that racing yachtsman look as well.
The red cunningham line is led from the vang fitting up and through
the cunningham cringle, then down to a block at the base of the mast
and back to the cockpitThe cunningham line passes
through the cunningham cringle
just above the tack of the mainsailThis is the effect of applying
tension to the cunningham lineHere’s a simple fix using a short
line cleated on the port side of
the mast and passing through the
cunningham cringle. Tension is
applied using a simple tackle
cleated on the starboard sideYou can have endless hours of fun
tweaking your cunningham and
changing the shape of the mainsail
to suit the wind...You can immeasurably increase your sailing pleasure by
fitting a cunningham to your mainsail, advises Bob Goode