steadying sail?

[ROAD Soldier]

I think it is time for some redneck scientific testing. I have a swimming pool and a 5 gallon water can and once this hurrican passes and if there isn't a lot to clean up I will have some results this week end.

[Chinook]

Chinook stated about his canoe trips on the west side of Vancouver Island. Canoes in the ocean?

Actually, there are some excellent canoeing/kayaking waters on the west side of Vancouver Island, which are completely protected from open ocean swell. The area I'm familiar with is out of Tofino, namely Clayquot Sound and vicinity. Most of it is like being on a freshwater lake, except for the starfish on the rocks and rise and fall of the tide. Another area which is doable by canoe or kayak is Barkley Sound, also known as the Broken Islands. It's very popular with sailboats as well as kayaks. When I go out on such waters, I use our spray cover, which completely decks the canoe, making us much like a kayak.

[saltyrogue]

Ray, thanks for the link, I think that this is what I may need.

I found some more info on steadying sails, and I quote....

"Some folks did testing with the sail up and down, and all who have steadying sails say they help damp out rolling at all times, even if there is little wind.

These sails are small, small enough that you can almost forget about them in most situations. If it's blowing half a gale, you'll have to get it down to gain control of the boat, but normally you set it and forget it. Some folks reported 5-10 degrees of heel in a cross wind, but the boat was quite stable with no rolling to windward.

I have used large steadying sails on longliners, and the main reason for their use there is to cock the boat up into the wind to haul gear. But they are stunningly effective across the wind, with the boat moving vertically but not rolling."

Dave

[NiceAft]

I will have some results this week end.

and if we don't see any posts from you again, does that mean I was wrong, and we should call the authorities

Alas, poor ROAD Soldier was no man's fool. He was last seen at the bottom of his swimming pool

Good luck.

Ray

[Catigale]

Dont forget to add 2 metric tonnes of rock salt to the pool to make it scientific...

[vizwhiz]

I think I can help - I know I'm a newb to sailing (not to boating or engineering, though), and I understand the questions being asked about the ballast, water vs. lead, etc. I'm sketching something right now that I'll post a little later with an explanation. What's confusing here is that what we're talking about is the relationship between volume and weight, and how this relates to buoyancy and displacement.

[grady]

This is the best explanation that I have found.

http://kobernus.com/hunter260/water_bal ... index.html

[vizwhiz]

That's an excellent explanation and saves me from posting a long article!

I would like to point out a couple things in the article though:
1. If you see the difference between the two (conventional and water ballasted), the water ballasted boats don't produce much "righting moment" until the boat heels over a little further - the conventional hull has the Cg and Cb separated from the start - on the water ballasted boat the Cg and Cb are nearly in the same spot - so you have to heel over more to get them separated further (which brings me to the next point)
2. the wording is a little misleading - the righting moment is the RESULT of the separation of the Cg and Cb - the further apart they are, the more moment there is (moment is torque or leverage - the length of your cheater bar - further apart equals more twist to right the boat). On the conventional ballasted boat, they start out farther apart and so a small heel results in a larger righting moment than in the water ballasted boat.

This addresses the earlier posts about why the boat heels over so far (or so fast) for the waves and wind blasts...it takes more heeling to get enough righting moment to counteract it...where in a conventional boat a smaller heel will result in a large enough righting moment...

The payoff for losing that stability is in the shallow draft and the planing bottom design...and more open area inside the boat.
And the super-fast blue color...

[NiceAft]

You guys couldn't have waited until after ROAD Soldier does his experiment

Ray

[ROAD Soldier]

Don't worry Nice Aft those technical drawings were not the pop-out kind so I didn't understand them. Hence I am not deterred in my mission. Redneck myth busters skunkworks will settle this argument once and for all.

[grady]

good because no one has answered what is going to be heaver the 500lbs of water or the 500lbs of lead.

[Catigale]

Spoiler alert....





This has been thrashed to death, but the water ballast on a Mac is never 'neutralised by virtue of being under the waterline, of course, Mass is mass, and mass x moment arm = righting moment (misusing vectors and scalars here in interests of brevity.)

[saltyrogue]

Grady- excellent article describing water vs. lead ballast, and vizwhiz, thanks for the clarification.
This discussion is proving to be both informational and entertaining. I am sure we are all awaiting the results of Road Soldier's experiment, whether it is via CNN or otherwise.

Rather than messing with the ballast, I am going to experiment with the steady sail when I am in trawler-mode. If a small patch of canvas can hold me at five or ten degrees in a cross sea, I can simply clip it on whenever I am motoring.

When I sailed my kayak, because the narrow beam and minimal ballast was not capable of supporting a full sheet of sail without capsizing, I fabricated a reversible camber wing sail, 10 ft. by 1.5 ft, that provided tremendous 'lift' (even in light winds) with only a slight amount of heeling (even in heavier winds). I think mounting that sail to my Mac will provide just enough heeling to hold the boat steady, thereby working as both a steadying sail but still providing lift in excess of hull speed while motoring.
(I post this idea with some apprehension because I know from experience that 'traditional' sailors often become indignant whenever wing sails are mentioned )

Thanks to all for the good info.

Dave

[DaveB]

Ray, the Vidio shows the leach clew attached to both Starboard and Port, this is rear and is usually attached to the boom. Also the Luff is much higher than mine on my 35 ft. boat ( I had about 6 ft.).
Getting back to the Mac. The shape of the vidio triSail is what you need just have the luff 4 ft. and the foot 3/4 length of the boom and attach clew at end of boom. Sail should be cut flat (no belly).
Reverseing the sail with the Luff attached to the topping lift and leach clew to mast conection for a steading sail while at anchor. Notice the vidio cut of the sail, the luff is above the mainsail while the leach clew is close to the boom so the shape is not a triangle equal to both luff and foot.
This you can use while motering to reduce roll big time,can use it as a sail in winds over 30 knots or use it as a anchor sail to keep nose to wind and reduce swing.I would make the TriSail out of 8-10 oz dacron.
Hope I explained it right.
Dave

Dave,

I saw this video on a trisail. http://vimeo.com/10756689 . Wasn't your original question whether or not this would work while you are motoring

Ray

[NiceAft]

Thanks Dave.

I had a real eye opener when your post mentioned reversing the sail for an anchor sail. I don't sail great distances, so I don't have a need for such a sail, but if I did, this sort of sail would be of interest to me.

I have a Musclehead for a main, and if the wind picks up, Nice Aft heels nicely. With the Musclehead I reef at a much lower wind speed than with the standard Doyle sail. I have not yet reefed to the second reef point.

Ray