Windward sheeting??

[DanBerger]

OK, this one is for Bill..

I just picked up a SC 17 with the wire traveler and I want to change it over to a Harken traveler on the beam. I have a track and traveler from a Sol cat that has windward sheeting capabilities.

What's your take on windward sheeting--does it make any difference on a boomless rig??

[Matt Haberman]

Dan,

Typically a windward sheeting traveler car is not of any benefit on a catamaran. Sheeting the car to windward produces a poor angle of attack on the sail and will typically act like a speed brake versus a performance enhancer.

(I'll let Bill get into the technical details)

[Bill Roberts]

Windward sheeting of the mainsail is a correction for a boat that has a basic design flaw in it. I first saw windward sheeting on an J24 many years ago, like 20+ years ago. I sailed this J24 to windward with the traveller centered and the helm was was dead neutral with the boat heeled slightly to a slight lee helm with the boat straight up. One would never pick up a slight lift in the breeze on a boat with this feel to it. The boat just had a dead tiller feeling to it to a slight lee helm. The problem is/was that the keel on this boat is located too far aft. Windward sheeting the mainsail, which hooks the mainsail leech to windward in the bottom part of the sail, loads up the rudder from the windward side and this gives the boat a slight weather helm. This eliminates the rudder side force that was pushing the boat to leeward, the lee helm, and gives the boat a normal feel to the tiller. With a slight windward helm the boat will be sailed to windward better; the skipper is much more likely to pick up the minor variations in wind direction, the wind shifts.
Sheeting a mainsail to windward actually forces that part of the mainsail that is "hooked to windward" to produce sail thrust to the rear. Evidently on the J24 this is a smaller penality to pay in overall boat performance than saliling to windward with extra rudder drag and a rudder side force to windward and no "hooked to windward mainsail leech".
Hooking the leech of the mainsail to windward on a boat that does not need it is like putting the brakes on. It is like driving your car around with the emergency brake on slightly. Windward sheeting is not a go fast thing; it is a correction for a boat that was designed with a basic flaw/error in it.
Bill

[SC15Dave]

Hello - I've been putting back together a SC15 and it also has the wire traveler. I also thought about changing it, but now after reading your explanation I'm not so sure. Is there a benefit of going with a Harken style traveler over the wire? Thanks.

[Matt Haberman]

Dave,
A well maintained Wire Traveler car works just fine, but the Harken system is much nicer and will probably roll from side to side better.
The cable traveler was originally used on the SC20 to allow for the telescopic feature. As a result all of the SuperCat products utilized the cable traveler for the first few years of production until switching over to Harken in the early 80's. Maybe 1982? The SC20 continued using the cable until the mid 80's when the fixed beam version of the boat was introduced in 1985 and the cable was replaced with the Harken car.

Not sure that really answers your question, but it might give you some insight on the history of the cable traveler.