Catboat across the Atlantic? (16')

[RHP]

I must confess I am not a big fan of the catboat style uni-rig however if I had to swing that way, I'd take a close look at the attached. Great pic.

http://www.sail-world.com/australia/...d-Yachts/39991

[Paul Scott]

Although there are some of us out here on the Left Coast that still think, if Ocean Planet had stuck to her original (WylieCat derived) Una Rig NO JIB (but some assymetricals) theory, right down to a routing strategy that used the strengths of that rig instead of going with the sloop/cutter rigged crowd's strategy, history might have been different. (Look at the recent IC Worlds- the Una rig KILLED downwind.) But I am obsessed. Those of us who saw Ocean Planet being put together at Schooner Creek pretty much thought it was obvious. I believe one should ignore Wildcat. Completely.

Paul

[Ulf]

When it comes to crossing oceans in small boat you sould check out this site: http://www.yrvind.com/. Click on "next boat".
Yrvind has been crossing oceans in small boats for many years without any serious problems. His boats are built to handle getting rolled without taking in any water and are in my opinion safer than many bigger boats.

[sharpii2]

Originally Posted by Ulf

When it comes to crossing oceans in small boat you sould check out this site: http://www.yrvind.com/. Click on "next boat".
Yrvind has been crossing oceans in small boats for many years without any serious problems. His boats are built to handle getting rolled without taking in any water and are in my opinion safer than many bigger boats.

I've been following Mr. Yrvind ever since the '70's when he built his first boat BRIS. I have to agree with you.

Here is my take on an ocean crossing cat boat.

The jib shown is to force the boat to sail downwind without an autopilot. On all other points of sail it won't be used.

The boat is a pram like 10 footer that will displace roughly 1700 lbs loaded.

She is intended for the 'around-in-ten' race.

Just a concept though.

[sal's Dad]

Take a look at Hoyt's latest rig:

http://www.garryhoyt.com/id32.html

[Seafarer24]

Originally Posted by sal's Dad

Take a look at Hoyt's latest rig:

http://www.garryhoyt.com/id32.html

Sweetness- the worlds most advanced "junk" rig- I like it

Although, I do believe that the junk was discovered to sail to weather faster on the tack that pressed the sail against the mast and deformed it.

[sharpii2]

Originally Posted by sal's Dad

Take a look at Hoyt's latest rig:

http://www.garryhoyt.com/id32.html

Very cool.

It is classical Hoyt engineering. He has a talent for making somewhat complicated structures that are very patentable. I hope his royalty fee isn't so high that no one will try it.

17.5 years can be a long time.

Bob

[RHP]

Great vid, thoroughly enjoyed it and I think it would be great fun on a 21-30' yacht.

The top gaff is fixed, the fore and aft stays are wider at the boom than the gaff obviously, the luff runs down the forestay when reefing, but how does the square top edge of the sail maintain its horizontal rigidity when reefed and therefore 3, 4, 5 feet lower than the gaff and wouldnt when sailing off the wind when reefed introduce twist into the leech?

When the sail is fully up and the square head directly attached to the gaff it would be tight and parallel, however I dont quite see how it maintains its integrity when reefed, epecially say when double reefed.

Ideas?

Richard

[Paul Scott]

Originally Posted by Seafarer24

Sweetness- the worlds most advanced "junk" rig- I like it

Although, I do believe that the junk was discovered to sail to weather faster on the tack that pressed the sail against the mast and deformed it.

Any aeroexplanations for THAT?

[Seafarer24]

RHP- there are two halyards, one at the front and one at the aft end of the sail. I assume the aft halyard is used to keep the head from twisting off when reefed.

Paul- there was a lot of scientific discussion about it. It may have even been on this forum. I'm sure a Google search would turn up something.

[RHP]

Ok another thought overnight:

The mast is on the centreline, the boom is offset maybe 12 inches. Wouldnt that induce a pendulum-like roll when no sail is set, also bearing in mind the gaff remains set at the top of the mast? It would be pretty uncomfortable on a mooring/at anchor? Even more so if the yacht was a centreboarder with the board up due shallow water.

If on a centreboarder that dries out on the moorings, wouldnt it be unstable if there was a rough sea and high wind across the moorings?

The test boat used in the video is a fixed keel dayboat with weight in the bulb from memory, or lets say a heavy keel with a low COG. How would a centreboarder fair with an offset boom, particularly when the boom was to leeward? Would it not fall off to leeward?

I wonder how the sail area compares with a traditional set up?

I like the look of this rig but as with anything new, there are questions to ask!

Good day to all,
Richard

[Seafarer24]

Um, I have no idea what you're talking about with regards to the offset boom/gaff causing rolling problems at anchor, etc.

I would imagine that this carbon-fiber rig would weigh considerably less than the typical stayed aluminum rig, and induce less roll at anchor.

Also, the "falling off to leeward" comment... what? I take it you mean while under sail. I really can't see how that would make any difference. There are a lot of craft that have the mast off the centerline. I liked his analogy of the catamaran flying a hull (because I mainly sail small beach-cats). They don't really handle any differently when the mast is suddenly 4' to windward of the center of bouyancy (or 4' to leeward when doing the "wild thing" downwind).

The sail area compared to a traditional rig is sort of irrelevant. You could convert a boat with a sail like this that has equal sail area to a traditional rig and the mast would be shorter and the CoE lower. Or, you could keep the mast height the same and crowd on much more sail.

I wonder if a headsail can still be flown with this rig? I know there are some junk rigs out there with jibs and spinnakers.

If I update my cat-ketch designs with these rigs, I could offset the main and mizzen to opposite sides. Spreading the same sail area, I'd get a lower CoE (than the flat-top, battened sails I'd planned) and a more stable boat!

[RHP]

My thought was that a boom running down the centreline of the hull remains neutral vis-a-vis role when at anchor. An offset boom would natural disturb the balance, more so on a boat with a centreboard up when swinging on a drying mooring. Carbon would minimise it, but would it be affordable (I dont know the comparison in costs).

I take your point about the catamaran, so disregard this concern!

My point about sail area is simply whether to get 6 knots boatspeed from this rig would require more, or less sail area than a conventional rig, ie a comparison of perfoamnce and/or efficiency. (Modesty or is it pride, would also mean not siling round with a stumpy lil´mast and a swaure sail!).

I wouldnt fly a foresail on this rig it would bastardise the concept, tho a asymmetric from a pole might be fun.

Thanks your hehlpful responses.

Richard

[sharpii2]

Originally Posted by RHP

Ok another thought overnight:

The mast is on the centreline, the boom is offset maybe 12 inches. Wouldnt that induce a pendulum-like roll when no sail is set, also bearing in mind the gaff remains set at the top of the mast? It would be pretty uncomfortable on a mooring/at anchor? Even more so if the yacht was a centreboarder with the board up due shallow water.

The 'gaff', really a yard, is made of carbon fiber an should be quite light for its strength. Also the boom could be sheeted down quite tightly to minimize movement. The yard may swing a little bit, but remember, it extends past the mast by about 25%. The portion in front of the mast will probably provide some inertia, so it may not swing as much as one may expect.


If on a centreboarder that dries out on the moorings, wouldnt it be unstable if there was a rough sea and high wind across the moorings?

The test boat used in the video is a fixed keel dayboat with weight in the bulb from memory, or lets say a heavy keel with a low COG. How would a centreboarder fair with an offset boom, particularly when the boom was to leeward? Would it not fall off to leeward?

Probably not. A cenerboarder makes up for its lack of ballast keel in three possible ways:

1.) it can be beamier,
2.) it can have firmer bilges, and
3.) it can have more ballast

Centerboarders tend to be stiffer boats. It would probably perform on par with a centerboarder compared to a keel boat with both having a more conventional rig.

I wonder how the sail area compares with a traditional set up?

It looks to me to be a generous amount of sail. Maybe about 300sft. But keep in mind, it would be difficult to add sail area. The argument could be made that the extra efficiency makes up for this inability.

I like the look of this rig but as with anything new, there are questions to ask!

Good day to all,
Richard

My only criticism of this rig is the expensive materials and craftsmanship that is needed to make it work. I have no idea how much the carbon spars would cost, but I have the impression that I wouldn't like the number. In all fairness, it seams that these spars are all simple tubes with no taper to them which would probably facilitate easier mass production. Just build continuously and cut off to order. I would be more impressed, however, if he made this out of extruded aluminum. I can't see myself making this rig in my back yard like I could the wooden sparred gaff rig I posted earlier on this thread. If you make it yourself, you can repair it yourself.

If, however, this rig were to gain wide popularity like, say, the mast head rig did, much of it could become standardized in various sizes, bringing the cost down.

[sharpii2]

Originally Posted by RHP

Great vid, thoroughly enjoyed it and I think it would be great fun on a 21-30' yacht.

The top gaff is fixed, the fore and aft stays are wider at the boom than the gaff obviously, the luff runs down the forestay when reefing, but how does the square top edge of the sail maintain its horizontal rigidity when reefed and therefore 3, 4, 5 feet lower than the gaff and wouldnt when sailing off the wind when reefed introduce twist into the leech?

When the sail is fully up and the square head directly attached to the gaff it would be tight and parallel, however I dont quite see how it maintains its integrity when reefed, epecially say when double reefed.

Ideas?

Richard

This problem could be fixed with a stiffer batten at the top of the actual sail. Once this batten starts starts bending, as I think you correctly surmised it will, the trouble will start. The top of the sail will bag, creating lots of drag and little lift. The problem is that the aft halyard will be pulling up far more effectively than aft as the top of the sail gets further away from the gaff. I am sure Mr. Hoyt will discover this problem himself once he reefs for the first time in actual reefing wind conditions.

The solution is probably to replace the top batten with another spar. Even then, the top of the sail may either come against the mast or sag off to leeward somewhat. This, to some degree, can be tolerated.