Thanks Chuck for making this important point regarding the upper black band.
A well measured racing main will reach the black band with only low
moderate tension on the halyard (for maximum area). No kidding..
foaming at the mouth racers believe even a few centimetres can make
the difference. When more luff tension is required it is taken on
with the cunningham. The old Harken "Magic Box" , at 8:1
purchase, was made for this purpose.
Cheers, Russ
Sweet 35 mk-1
At 07:18 AM 18/08/2013, you wrote:
Nicely written Josh.
I would add the main halyard setup properly, can only be tensioned
to raise the sail to the black band.
As wind increases, the draft of the mainsail will move aft and the
Cunningham is used to add a little more tension along the luff and
bring the draft forward into the proper position, 45 to 50%. The
Cunningham needs to be eased if the wind dies or turning downwind
reduces the pressure on the sail.
On bendy rigs like our three spreader rig, adding backstay tension
shortens the P dimension, reduces the tension on the main halyard,
so we add Cunningham to compensate. We ease the Cunningham before
easing backstay as they are related. Easing backstay increases the
P dimension and doing so without easing Cunningham or halyard can
rip the mainsail. Lesson learned the hard way.
Chuck
Resolute
1990 C&C 34R
Atlantic City, NJ
----------
From: "Josh Muckley" <muckl...@gmail.com>
To: cnc-list@cnc-list.com
Sent: Sunday, August 18, 2013 12:23:16 AM
Subject: Re: Stus-List 1985 C&C - 33 Missing Cunningham
What do you mean missing? Do you mean you have a jammer that is
labelled Cunningham that doesn't have a line running through it?
The cunningham opposes the main halyard by pulling down on the tack
of the mainsail. So, you can tension the main by pulling up on the
head or down on the tack. Usually it is easier and more controlled
to use the cunningham but you risk having odd sail shapes if pulled
too far. Additionally it is usually desired to hoist the main as
high as possible, not down. So, a tight halyard tends to be
preferred and the Cunningham is used when tightening the halyard is
too difficult or unsafe, such as when the wind pipes up and on a close reach.
On your mainsail you should find a metal Cunningham eye about 5-6
inches above the tack ring. Different makers provide different
attachments but what I have found works well for me is to create a
2:1 advantage by running a line through the eye and attaching it to
the reefing hook/horn just outboard of the tack
ring. (Alternatively you could also tie it to the boom.) By
pulling down on the free end of the line you will be pulling down on
the Cunningham ring with 2x the power.
The PO had this free end led to the mast base and back to the cabin
top jammer. I regularly had to use a winch to tighten the
Cunningham. When I replaced the line I added a 4:1 block and
tackle. The 2:1 bitter end stops just below the boom and is
finished with an eye. The 4:1 hooks on the eye and attaches to the
mast base. The free end of the block and tackle is then led back
the the jammer. The 4:1 pulls down on the 2:1 for a total of 8:1.
I also used a hook between the 2:1 and 4:1 so that it is easy to
disconnect the 4:1 and reattach it to the reefing eye when
reefing. Our mainsail has "floppy rings" or "dog bones" that pass
through the reefing eye in the sail. They are made of nylon webbing
running through the reefing eye and finished off on both ends by
stainless rings larger than the eye. Traditionally when reefing you
would let the sail down and hook one of the floppy rings to the
reefing horn. The ring on the other end of the "dog bone" prevents
the nylon webbing from pulling out of the reefing eye and now the
main halyard can be pulled tight. While sailing, if you find that
there is not enough tension on the halyard you can unhook the
Cunningham 4:1 from the 2:1 and re-hook it to the "lazy" ring in the
dog bone. You once again have an 8:1 Cunningham, but now on a reefed sail.
Arguably, a Cunningham could be considered a fix for a poorly
tightened halyard...at least on our "big boats". On some smaller
boats the cunningham is the only thing holding the tack ring. But
those cunninghams are also held forward ensuring proper foot tension.
Josh Muckley
S/V Sea Hawk
1989 C&C 37+
Solomons, MD
--
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On Aug 17, 2013 12:22 PM, "Raymond Macklin"
<<mailto:ray.mack...@gmail.com>ray.mack...@gmail.com> wrote:
I purchased a 1985 C&C - 33 and I am missing the cunningham. Does
anyone have a diagram of where it runs on the boat or could explain it to me.
Thanks,
Ray Macklin
Libertyville, IL
LakeHouse
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