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Tweegs 07-05-2012 10:44 AM

Rigging up an A-sail
 
Weíve discovered that the JAM credit doesnít nearly compensate us for not flying a spinnaker/Asym, and in order to get in the game, weíve got to start flying a kite (our local race series doesnít have a separate JAM class. JAM boats get a 12 sec. credit).

Typical winds on the lake are 15 knots or less and seldom do we have dead downwind legs. This makes the Asymmetrical the most commonly used spinnaker in the fleet.

The issue at hand is that my boat isnít A sail friendly. Masthead rigged, only two sheaves in the truck (main and jib halyards) and no deck hardware for the tack.

Iím getting conflicting advice on whether the A sail should be rigged outside the fore triangle, or inside. Either way, I have to get a block fixed to the mast and run a halyard external to the mast.

Inside the fore triangle would be easiest. An eye pad, perhaps, just below the forestay with a good block and shackle. A block on deck as far forward as I can get, with a backing plate, for the tack.

Outside the triangle, as I see it, would be a bigger challenge. There isnít any real estate above the forestay, so Iíd need something on top of the truck. There Iím going to run in to clearance issues with the VHF and anemometer. The halyard from the block to the cleat (not so much to the head) might have an issue with the forestay if we need to jibe over to the other board. Also, I canít get someone far enough up the mast where they could see while drilling into the truck, the work would have to be done overhead and blind. This is sure to result in a drill bit going through a sheave, pin or halyard, and with my luck, all three. And there is still the tack to deal with.

Maybe there is a better way to get the block above the forestay. Maybe everything will be just fine with the sail rigged inside the fore triangle. I donít have the experience to make that call on my own and could use a little help. Maybe Iím missing something entirely. What do you think?

Tim R. 07-05-2012 10:59 AM

Re: Rigging up an A-sail
 
What model boat do you have? Surely, others who own that same boat have flown an A-sail.

We also have a masthead and fly ours in front of the headstay but we also have a nice sprit with a padeye.

Tweegs 07-05-2012 11:07 AM

Re: Rigging up an A-sail
 
It's an Irwin 39, not many of them out there.

zz4gta 07-05-2012 11:43 AM

Re: Rigging up an A-sail
 
Rig it outside the forestay.
Post a picture of your masthead bits, or draw a sketch and post it.
You'll need a halyard, internal is better in most cases, but external works as well.
The tack line needs to be adjustable and preferably in front of the forestay, but attached somewhere on the stem works well. I would not tack it behind the forestay.
Do you have turning blocks at the aft corners?
How long is the luff on your chute compared to the forestay length?

Now for the news you don't want to hear:
If you're already getting a 12 sec. credit for not flying a chute, and there aren't many DDW legs, then you're not that disadvantaged and need to find improvements elsewhere.

Tim R. 07-05-2012 12:08 PM

Re: Rigging up an A-sail
 
Quote:

Originally Posted by zz4gta (Post 892885)
...Now for the news you don't want to hear:
If you're already getting a 12 sec. credit for not flying a chute, and there aren't many DDW legs, then you're not that disadvantaged and need to find improvements elsewhere.

Not necessarily true. Asyms do much better on broad reaches. If you have a lot of broad reaches, an Asym should overcome a 12sec/mi adjustment. On some boats, the Asym is so much better on a reach that they will do linked reaches to a downwind mark to achieve a better VMG compared to DDW.

Try these sites for specific info regarding your Irwin:

Irwin Owners Group

Irwin Yachts

Stumble 07-05-2012 01:50 PM

Re: Rigging up an A-sail
 
Tweegs,

It really depends on how much you want to spend. The ideal would honestly be to replace your mast head crane with one that has more sheaves to install a halyard, possibly with a spinnaker crane. Run the new halyard internally, and drill a new exit plate in the mast. For the tack, add a retrofit spinnaker pole (I like the one from Selden).

This will also be the most expensive by far.

Instead of the new crane you can likely install a spinnaker bail (see Masthead Spinnaker Bails ) it is still much prefered to run the halyard internally, but if you can't, these will act as a location to add a block.


Either way a spinnaker should always be flown above the forestay, and outside of it. Otherwise you will have major chaffing issues as the halyard tail is forced outside and around the stay attachment points. A-sails in particular need clear runs, because they are pulling to the side, not just forward. If the sail can't fly free of the stay it will defiantly rub there, and you will spend a lot of time either replacing the halyard or the head patch of the spinnaker.

sailingfool 07-05-2012 02:09 PM

Re: Rigging up an A-sail
 
To properly fly a spinnaker you need to add a spinnaker crane.

If you want to use an asym for performance, you need to also add a sprit to get sail area, otherwise you should use a symmetric with a pole. Flying a cruising chute (no sprit, no crane, no pole) would be better than a white sail, but not close to a sym or large asym.

SchockT 07-05-2012 06:53 PM

Re: Rigging up an A-sail
 
You definitely need to fly the chute outside the foretriangle, and you will need a spinnaker halyard. If you really want to do it right a small bowsprit should also be used, although plenty of cruisers fly them from the stem or anchor roller. If you are going to get a chute built new, then you should do it right!

paulk 07-06-2012 12:21 AM

Re: Rigging up an A-sail
 
The simplest setup might be to bolt a nice solid tang flat on top of your mast, sticking out forward, to act as a crane. The tang has to be long enough and strong enough so you can mount a very strong swivel block on it that is completely clear of the forestay. You can then run the halyard through it externally, and not have to worry about exit holes weakening your mast. You will probably need to add some cleats P & S for the new halyard. You will also want to figure out how to work a winch into the equation in case it fills 10' from the top and starts to hoist your crew off the deck. 12 sec/ mile is a LOT.

Tweegs 07-06-2012 03:34 PM

Re: Rigging up an A-sail
 
3 Attachment(s)
Appreciate the feedback.

Treilley- Yea, I spend a fair amount of time on those sites. Lots of good general info there, but not much on racing the boat.

Zz4gta- Weíve got a ton of work to do from a crew perspective. Weíre running a 144 phrf and really canít even sail to that. We know of one other Irwin 39 here in the State that has a 126 and wins. Tomorrow, weather permitting, we are bringing on a pro to help tune the rigging. Once thatís done, itís all about us. New main last year, new 135% genny this year (both are Pentax, Mylar/Kevlar), feathering prop this year, new traveler, new Genoa lead tracks and cars, rigid vangÖno excuses left, got to be us.


Seems I didnít take any pics when the mast was down. I need to send someone up to adjust the windex anyway, Iíll have him snap a few while heís up there.

I assume the crane would have to be a custom fab. Easy enough, plenty of machinists here at work that owe me a favor. The question then becomes how much load would be on it. (40 footer with an appropriate size asym).

I keep looking at the bow and wondering how I would put on a sprit or get a block out there. Have a look:
Attachment 11567

Attachment 11568

Attachment 11569


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