Upwind Tuning with the North American 505 rig

This was originally written and sent to the 505 e-mail distribution list in response to Simon's question.
I use a Proctor D with North Sails Gulf Coast (Ethan Bixby) sails. In North America, I have good all round speed, particularly good in the just-starting-to-plane upwind region. I thought we had very good speed in Mount's Bay any time the breeze was on (which was precious little during the Worlds!). The boat has a forward tack position (jib tacked to bow), with the spinnaker launched out of bags. The mast is stepped about 10" or 10' 1/2" from the transom, and the CB pin is about 8' 7" from the transom (i think that is about 2" further forward than spinnaker launcher boats with the aft jib tack position).

My spreader bracket is 10' 4" above the deck band (higher than european i" think, but standard for North America). My spreaders are about 17" long, and" position the shrouds about 4.5 inches behind the aft part of the mast section (I measure between the mast and a piece of whipping twine stretched from shroud to shroud at the spreaders.)

In drifters, I may use lots of rig tension to help pre-bend the mast; as soon as there is any power available I go to a loose setting that I gradually increase as the breeze comes on. At fully powered up but not overpowered, I judge rig tension by jib luff sag; I want to be able to point (which requires minimal luff sag - at least with the jibs I use). I think that would be in the 200-300 pounds range on the shroud. As the breeze gets harder, I keep tightening the shrouds. When the boat feels "stuck" upwind, I rake to depower. Standard setting for me is 25' 8" in drifter to starting to" be overpowered. I rake enough so the boat feels fast and no longer "stuck".

The first time I rake, I pull the ram down a little so I do not bend the mast any more. After that, I just ease forestay and tighten shrouds, pulling down on the ram just a little, so that I rake and bend. The extreme limit to the rake is maybe 25' 2" (in 32 knots in santa cruz!). i rarely sail in that much breeze" (Chesapeake Bay is more light and medium), but would probably rake more if I could get under the boom. I may have close to 1,000 pounds on the shrouds at that point.

Vang starts out very little, and increases to keep the upper leach powered up. By the time it is windy, I am pulling very hard on an 18:1 cascade. If I ever have the mainsheet loose, and the top of the main is still pulling me over, it is time to rake more.

I also pull on the cunningham to depower, and even sometimes in light and medium to make the sail look better (though I never pull it hard till we are overpowered).

I think the basic idea of this rig - which is fairly typical on the East Coast of North America - is that the mast stays straight sideways until it is quite windy and the load on the sail and the vang force the tip to leeward, which in turn pushes the middle to windward a little. The longer spreaders limit how much it goes to windward.

It would appear that I sail with the mast less raked than the Europeans, though I notice that Simon does not rake as much as the Pinnell tuning sheet suggests.

I believe that I sail with a straighter mast fore-and-aft than most Europeans (my spreaders are more forward, and I use the ram to control lower bend), but probably have less luff curve on the main to compensate.

For years, NA boats used fore and aft (or up and down) jib leads, without an in-out adjustment. This is quickly changing. We added a primitive barber hauler for Mounts Bay, which we used in one of the two windy pre-worlds races (I broke the tiller on a gybe in Race of the Year and we DNF'd). Our speed upwind in the other windy pre-worlds race was excellent, with the jib leads pulled outboard (once the breeze came up). Since I am not used to the outboard adjustment, I am currently trying to set up the boat as I used to, but add a little outboard sheeting when I am easing the main a lot. I would guess that I would not have to rake as much if I sheet more outboard, but do not know for certain yet.

After having written all the above and maybe sounding like I know what I am talking about, I must confess that I have asked many questions of people like Ethan Bixby and Larry Tuttle and other top 505 sailors, and simply try to do what they suggest. I think I have developed a "feel" for making this rig work for me, without necessarily understanding it.

I should do a matrix as everyone else seems to do, but so far do it by feel (when it feels good, I am very fast while still pointing high..... :-) I wish it felt good all the time!


Ali