505 a-Sail Test

8/14/2019 505 a-Sail Test

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505 A-Sail test

We tested an Asymmetric spinnaker on a 505 at this year’s midwinters. Larry Tuttle and I havediscussed this occasionally, and after many hours of fiddling with a dual pole system I decidedgive it a try. We sail the boats like skiffs now, with the exception of windspeeds from about 5-10

knots where we sit run. Larry agreed to make up the carbon bowsprit and I would do the sail, so

Larry and I worked with Steve Calder of North Sails’ Performance Resource Group to model upan appropriate sail. Our goal was to make a test platform that could be easily bolted onto any

existing 505, and work with the existing launchers. So this test is with a fixed bowsprit that is 48”past the bow. It attaches with 4 bolts through the gunwale and a Spectra or Vectran bobstay thatsecures just above the waterline. The sail area is sized to be of similar surface area to our

existing spinnaker, and perform in the 80-90 degree apparent wind angles.

The midwinters have traditionally been a testing time – new teams, new sails, etc. Actually Ali

Meller and Larry Tuttle raced one midwinters with the first American 6m luff spinnaker! Wethought that including it in a fleet race would be the best way to evaluate the performance.

We had all the components ready and bolted it on Thursday morning before the regatta and wentfor a sail in 8-13 knots of wind. Then we raced with it in windspeeds from the high of maybe 25 to

a little bit of sit running conditions. Our racing time was limited by breaking a rudder one day andpulling the bobstay fitting out of the bow, but we were able to compete in all the races on Sunday.

Simplicity is a key point here. We could remove the following items if it was a permanent

installation:

? Two topping lift systems

? Two downhaul systems

? Two poles and shock cord systems

? Spiro fitting

? Guy purchase system and guys

To use the kit we needed a longer spinnaker halyard due to the double dousing patch. We alsogot some longer spinnaker sheets but I am not positive that was necessary. We used a tack line

and just lead it to the starboard pole launcher cleat. Also 4 ¼” bolts and nuts, and some scrapspectra for a bobstay. I drilled a hole through the bow to mount an eyestrap as a temporaryfixture. This part did not go well and it was truly temporary in 20+ knots when the sprit wants tolift the bow!

My impression is that it is really easy to use, and it is impossible to run over a spinnaker sheet!Jibing is very easy as the boatspeed seems stays up when the crew comes in off the wire, and

you just turn the boat with no hesitation and the boom comes over with less load. The crew justeases into the jibe, and trims out the other side. Consequently, I felt more able to jibe any timeneeded, without worries of a swim test.

Performance wise, it seemed the harder it blew the faster we were relative to the standardspinnakers. And the interesting thing was that the boat seemed to track better and was more

stabile in the changing windspeeds. It just felt right and rock solid. In moderate conditions theperformance was similar, and maybe just slightly faster. Effective angles were the same. As itgot lighter it changes, but we were impressed at the range of angles you could sail at. In the very

light air on Thursday we just eased the tack line up and soaked down well. You had to steercarefully. We did try wing and wing and that would be a tactical option too. With the niceseparation of the sail plan provided by the long sprit, the sail seemed surprisingly effective in light

air.

8/14/2019 505 a-Sail Test


I think the size of the sail we tested would match well with the courses we currently sail. If wewere to go to 100% windward leeward courses you would certainly look at a larger sail. We

opted to keep the halyard at the same height to avoid further rig issues.

The permanent sprit takes a few minutes to get use to, but you quickly adapt to the change in

length of the boat in crossing situations. Onshore, I would release the bobstay so we could

center the boat on the dolly. The class could look at a retractable pole and I understand that itwould not be hard to make retrofit kits. Ours could have been a little higher to clear more waves,

but we punched it through a few and it didn’t seem an issue. I was chasing one wave downwindto see if I could put the sprit through it, but Erik discouraged me!

The pdf image can be rotated for different views. Just click on it, let Adobe load for 3d, and thenclick and drag it around.

There are some photos below.

Enjoy,

Ethan BixbyNorth Sails Gulf Coast

8/14/2019 505 a-Sail Test


505 a-Sail Test

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