Catalina 34

General Activities => Main Message Board => Topic started by: jbstack28 on September 13, 2002, 12:27:55 PM

Title: Asymetric Spinnaker
Post by: jbstack28 on September 13, 2002, 12:27:55 PM
I am considering adding a Spinnaker to my inventory.  Short of going to a sailmaker in the area, can anyone tell me the correct size (Dimensions)

Thanks

Charlie Stackpole
'DESPIDO'
1990  #1029
Title: Asy spinn.
Post by: c34member on September 13, 2002, 01:25:11 PM
Luff: 43.00'
Leech: 38.70'
Foot: 24.00'
1.5 oz. Nylon

These are dimensions for a cruising spinnaker (asymetrical) for the standard rig.  I'm not sure if the tall rig warrants a larger size.
Title: asy Spinnaker
Post by: jbstack28 on September 13, 2002, 01:46:13 PM
And as luck would have it I do have the tall rig.
Also looking at size specs for the whisker pole as well.  And how about discussion the better way to go Eylet on the front of the mast, or Car and track setup?

Thanks
Title: Assy Spinnaker
Post by: jbstack28 on September 16, 2002, 11:52:59 AM
Well two reasons really.  One I consider most sailmakers as salesman.  If I do not have to deal with one I do not.  Second, I had been presented the opportunity to pick up a like new spinn.  I simply did not have the size recommendations so I may buy that or the associated Pole and track. Just trying to gather information from the board, that is what it is here for right.  Why do you ask?

Charlie Stackpole
'DESPIDO'
1990  #1029
Title: Asymetric Spinnaker
Post by: Bill Sedgwick on September 16, 2002, 09:02:01 PM
Charlie,

I had to reply since you boat's almost a the same age as mine. SchatzSea is #1031. You can find the standard calculations for spinakers on the PHRF site: http://www.phrfsocal.org/7.htm (http://www.phrfsocal.org/7.htm). For the asymetrical, these are:

Asymmetrical Spinnaker SLU shall not exceed 1.15 times the square root of (Ic² + Jc²)

Asymmetrical Spinnaker SF shall not exceed 1.8 x Jc

Asymmetrical Spinnaker ASMW shall not exceed 1.8 x Jc

Asymmetrical Spinnaker ASMW/SF ratio shall be equal to or greater than 0.75

I have both a asymmetrical and a symmetrical spinnaker. In my experience, the best performance of a asymmetrical is limited basically to a beam reach. I find that from 70 to 110 (indicated) it is great and better than a spinnaker. However, the spinnaker can sail much deeper. In good wind, the best VMG can be as deep as 170 degrees.

You mention the whisker pole. That is a way to make the asymmetrical sail deeper but I haven't used one with my asymmetrical. If I expect the wind to go below 110, I rig the spinnaker with a rigid pole. One of the best arguments for an asymmeterical is that, without the pole, you don't risk anyone being hit and injured by it. Here the PHRF calculations for poles:

Spinnaker pole shall not exceed 100% of J

Whisker pole maximum length shall not exceed 1.4 x J

I have 6' of track with an adjustable car on the front of my mask. Seems about right for the spinnaker.

If you add the asymmetrical, I believe an adjustable tack is essential. I have a 3:1 advantage led to a cleat in the cockpit. The forward single block has a becket and a single line leading to a block forward of the forstay. It gives about 6' of adjustment to the tack. The aft block is attached to the stantion near the port shrouds. This seems to be a great cruising setup.

Good luck,

Bill Sedgwick
SchatzSea #1031