[C320-list] Asymmetrical spinnaker sheets

[Denny Browne]

I run my tack line from the tack of the sail, down to a block on the anchor
roller bail along the deck to a small bulls eye fairlead on the side of the
cabin top near the bow, back to a second fairlead about half way down the
cabin and up slightly to a cam cleat on the side of the cabin but at the aft
edge. This arrangement allows for the most direct pull on the line to
control the tack of the sail and, as a result, the curve in the luff. I can
even run it to a jib winch if need be and ccasionally I need the winch.

I use two sheets so I can easily jibe the sail on the outside of the head
stay. I have a titanium snap shackle on each sheet, so it's pretty easy to
detach one if the air is very light. This requires a spinnaker halyard, by
the way. If you use a jib halyard, it wraps around the head stay a half turn
when you jibe, and chafes the halyard and may damage the shackle. You can
use a jib halyard, but then must jibe the sail inside the head stay. If you
use a jib halyard, you probably want the attachment point for the tack line
to be aft of the furling drum rather than on the anchor bail so the tack
line doesn't end up chafing either. Also, in either case, an ATN Tacker,
Parrel Beads from Neil Pryde Sails or that sailcloth strap from North Sails
should be used to keep the tack close to the center line of the boat.  

The problem with this arrangement (in addition to the foredeck trip hazard)
is that the fairleads are the same ones I use for the foreguy on the
symmetrical spinnaker. There's a matching pair on the other side of the boat
and the foreguy is double ended so it can be tightened or released from
either side of the boat. Therefore, I like the idea of running the tack line
outside the stanchions, and plan to do this at some point. I'm
procrastinating the purchase of a hexaratchet block with fiddle and cam
cleat along with a mounting point. I'd attach this hexaratchet block at the
base of the stanchion in front of the boarding gate so it's not another trip
hazard when boarding. I'd have the tack line run to it through two blocks on
the forward stanchions. I like the ones that run the line outside the
stanchions rather than inside, just because it's one less line to trip the
crew. 

The blocks, if attached to the stanchions, need to be as close to the deck
as possible because of the load. I've put considerable thought into the
outside option, but you'd be well advised to check with a rigger to be
confident that the stanchion mounting hardware is stout enough to handle the
shear load applied by the tack line. I suspect it's fine, but I'm not an
engineer and I'd want to be sure. The greater the bend in the line, by the
way, the greater the load on the block and attachment point. The inside
option is probably better and significantly cheaper. It works fine and I've
yet to actually want to use the symmetrical and asymmetrical sails on the
same outing. It seems this is an even better option if you use a jib
halyard, as the turns in the line may put too much load on the stanchion
base. Keep in mind, they're designed to stand up to pressure from the inside
out, not from the outside in, which the tack line would provide.

Sorry to be so wordy...

Denny Browne
A Cappella #935
Redondo Beach

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Martin Raphael
Sent: Sunday, October 12, 2008 11:33 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Asymmetrical spinnaker sheets

I have a couple of additional questions:  Do you use two sheets or just one 
to save weight?  How do you run your tack line back to the cockpit...do you 
run it along the rail, much like the furler line, or did you rig some leads 
over the top of the cabin?
Thanks
Martin Raphael
Rhapsody #108
----- Original Message ----- 
From: "Denny Browne" <dennybrowne at verizon.net>
To: <C320-List at Catalina320.com>
Sent: Saturday, October 11, 2008 6:26 PM
Subject: Re: [C320-list] Asymmetrical spinnaker sheets


> You can use 3/8" Sta-set with little problem, but it can get a little 
> heavy
> in light air, particularly if it gets wet. It's double braid polyester,
> which absorbs water. That pulls the clew down and misshapes the sail.
>
> I use 10mm (about 13/32") Spect-set from New England ropes, but it's
> discontinued. It's a spectra, or Dynema core with polyester cover. Spectra
> (Dynema) does not absorb water. I stripped the cover for about 20 feet so
> there is very little weight pulling down on the clew and way more strength
> than the application requires. The stripped core is also far easier to put
> an eye splice in. The result is that it'll fly in very light air 
> eliminating
> the need for light air sheets, although I have those too. The 8mm 
> Spect-set
> II would have been fine, but the 10mm is a little easier on the hands
> because the larger size is easier to grip, especially when it's a little
> windy and I found a screamin' deal from West Marine on it a couple of 
> years
> ago. I find the 8mm to be a little stiff, too, but that may work itself 
> out
> as a spinnaker sheet.
>
> West Marine has a special on green 8mm Spect-set II for 56 cents a foot. 
> The
> 8mm Endura Braid is great, probably the best, but it's $2.43 a foot today.
> Another spectra core option is Maxibraid Plus. Better Dynema core, but 
> also
> discontinued and very hard to find. I built two 8mm spinnaker halyards out
> of that stuff and it would be a wonderful, high strength very lightweight
> sheet. If you can find it.
>
> By the way, if you're going to use a tack line, I'd encourage a vectran 
> core
> line for that and lead it aft to the cockpit. The tack line takes a far
> greater load than the sheet (as does the halyard) and you really don't 
> want
> it to stretch. Spectra core is fine for that, but it should be a little
> bigger than the sheet. The stretch probably only matters if you're racing,
> but the light weight sheet will enable you to fly the sail and keep the 
> boat
> moving in pretty light air.
>
> More than you wanted to know, I'm sure. Good luck with the search.
>
> Denny Browne
> A Cappella #935
> Redondo Beach
>
> -----Original Message-----
> From: c320-list-bounces at lists.catalina320.com
> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of MARTIN and
> SUSAN RAPHAEL
> Sent: Friday, October 10, 2008 8:23 AM
> To: c320-list at catalina320.com
> Subject: [C320-list] Asymmetrical spinnaker sheets
>
>
>
> I recently purchased an asymmetrical spinnaker and am anxious to try it 
> out.
> I need to purchase sheets for it and wonder what you might recommend for
> type and diameter.  I will be sailing in the Puget Sound area, where the
> winds are typically light.  What works for you?
> Thanks,
> Martin Raphael
> Rhapsody #108=
>
>