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  #46  
Old 03-08-2010, 10:34 AM
ancient kayaker ancient kayaker is offline
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Bob, on a smaller scale I used a similar scheme for my sailing canoe tacking proa experiement, but did not ballast the float. I sized it to offset double my weight when seated on the gunnel. It worked but the float had a lot of drag.
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  #47  
Old 03-08-2010, 04:53 PM
Earl Boebert Earl Boebert is offline
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Proa fans may be interested to know that Nathanael Herreshoff made a sailing model of one, which can be seen in the model room of the Herreshoff museum. It has a brass plate keel and two rudders on the main hull, and a crab claw sail. Based on its condition I estimated it as being built at the same time as the catamaran sailing model that led to Amaryllis (1875). Both were, as far as we know, inspired by a book or manuscript on South Sea sailing craft provided to Herreshoff by a sea captain.

Cheers,

Earl
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  #48  
Old 03-10-2010, 12:10 AM
sharpii2 sharpii2 is offline
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Quote:
Originally Posted by ancient kayaker View Post
Bob, on a smaller scale I used a similar scheme for my sailing canoe tacking proa experiement, but did not ballast the float. I sized it to offset double my weight when seated on the gunnel. It worked but the float had a lot of drag.
It probably had a lot of surface area.

That is why the float is to windward on a Pacific proa. The method of getting the best speed out of it was to have the float just touching the water or just out of it.

Not the best plan for a cruising sized boat.

Float design is also an issue.

I see a pacific proa or a single outrigger as a poor man's catamaran, which for safety reasons is allowed only minimum sail area, if its anything bigger than a daysailer. 'The Harry Proa(r)' is a possible exception to this rule as it acts more as an Atlantic proa. Still, if it were a modern trimaran or catamaran, it would be able to carry more sail and be somewhat faster.
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  #49  
Old 03-10-2010, 01:31 AM
peterAustralia peterAustralia is offline
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single outrigger sailing canoe as poor mans catamaran?

Hmmm,

May I politely respond do that. One advantage of a smaller outrigger is that you can right the craft should it be tipped over. This is not theoretical, Tim Anderson did it on his trip to Cuba. Now just say as a hypothetical instead of a craft with hulls 19ft and 14ft long, he had a conventional 18ft cat. Should he tip over it would be very very difficult for a single person to right the craft, more so when out to sea. This could have potentially fatal consequences. This is probably why you do not see many people sailing multiday trips in 18ft catamarans. It is true that the cat would be harder to tip in the first place, but it is possible.

read his account here
http://web.media.mit.edu/~tim/pix/cuba.html

Next sailing outrigger canoes do not by definition need to be slow. There is a fast looking one here. http://www.tacking-outrigger.com/ninja_pro2.html
Additionally there are some Youtube videos of this craft about. Put in tacking outrigger into Youtube and you should be able to find it.

Sailing outrigger canoes were used by the Hawaiians for many many decades after the arrival of europeans as they were considered superior sea craft to the vessels on offer from the Europeans. The outrigger sailing canoe could go over reefs undamaged, handle very large surf and had high speed. If swamped they would not fall to the bottom of the sea as a ballasted craft could. If winds were low they could be paddled at good pace. Thus a vessel with many many plusses.

Yes if you want pure speed, go for a Tornado cat. If you want to add some shelter and carry some supplies, then something else may work better. Yes they are different, but not by definition bad.

I made a small paddeling outrigger canoe out of a 13ft ama and a small outrigger. I found that the small 4ft outrigger did not work. Next I made an 8ft outrigger (lenght of a piece of plywood) with a deep V section. This worked quite well and had low drag. One problem is for the outrigger to have small drag at both high and low displacements. I used a deep Vee section and a lot of rocker as my solution for this problem.
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  #50  
Old 03-10-2010, 01:56 AM
peterAustralia peterAustralia is offline
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Pacific Proas can be very fast

Jzerro was sailing up in Queensland a few years ago and an article appeared in one of the sailing magazines. It apparently blitzed the other multihulls. One thing it can do is adjust the weight of its outrigger using water ballast. Strong winds more righting moment, go faster, light winds use a light outrigger with less drag.

As to safety Jzerros has stays aligned so that if backwinded teh mast will not fall down. Additionally there is a leeside 'pod'. The theory is that should the wind exceed teh righting moment of the outrigger, the pod comes into play thus avoiding anything serious. Having that feature in the back of your mind, the skipper could afford to be more generous with sail area, knowing that if he gets it a fraction wrong, the consequences will be limited.

The Pacific Proa Equilbre was built without a pod and it turned turtle whilst as anchor in the caribean (this is my understaning going from memory, and I may be mistaken) Also from memory they were thinking of retrofitting this feature. I dont think anyone was injured and the craft was righted.
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  #51  
Old 03-10-2010, 10:38 AM
ancient kayaker ancient kayaker is offline
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Earl: there’s a sort of proa in the Canadian Canoe Museum in Peterborough (Ontario Canada). It inspired me to do something similar, but it was not the real thing, just a regular canoe with a simple 2 pole outrigger and what looked like a heavy float.

Bob: my float was very light, 7' (2.1 m) long, narrow and canoe shaped but with a flat bottom. Probably too short to slice rapidly through the water, but not much surface area compared to the main hull which was double the length and 4x the beam. It was a few years back but I believe the ama drag problem was wave drag. It only showed while sailing, at paddling speeds there was little difference from the plain canoe. Iw was easy enough to lift out of the water but I did not have enough confidence back then to try it deliberately.

Peter: your experiences seem to mirror my own. The deep vee section is one remedy for float drag. Others would be a planing hull and a wave piercing shape. I had planned to try 2 small amas kept out of the water for speed, but it was abandoned when the canoe was destroyed. If the first ama is small, light and cheap there is little incentive for not having a second one. I have a sailing kayak concept now being built which will have Bruce foils under small amas.

Basically for me the main value of ama(s) was the extra stability while I changed from paddle to sail and back. I did not keep records; the canoe with the 7' ama did not have a large or efficient sail, but it easily achieved hull speed when sailed with the ama dry, despite my complete lack of knowledge at the time of things like board and rudder design etc.
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  #52  
Old 03-10-2010, 05:16 PM
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rwatson rwatson is offline
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Originally Posted by ancient kayaker View Post
.... The deep vee section is one remedy for float drag. Others would be a planing hull and a wave piercing shape.......

Hmmm - no, deep V is maximum drag configruation, half round is the least wetted surface for displacement shape.

But - deep V's are wonderfully 'soft' though waves, slicing smoothly instead of pounding.

I wonder if anyone has built an Ama with Hydrofoils ? This would provide the large wave slicing ability while lifting the hull out of the water for increased sailing performance.
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  #53  
Old 03-10-2010, 06:22 PM
ancient kayaker ancient kayaker is offline
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Originally Posted by rwatson View Post
... I wonder if anyone has built an Ama with Hydrofoils ? This would provide the large wave slicing ability while lifting the hull out of the water for increased sailing performance.
The sailing kayak concept with the Bruce foils under small amas mentioned before has some potential for operation as surface piercing foils but I would have to rebuild the foils much stronger than present. maybe ...
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  #54  
Old 03-11-2010, 07:59 AM
pacificproa pacificproa is offline
 
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atvantage

many people don't realize some of the great advantages of proas.
much kinder sea keeping the motion is much better than a cat.
better speed and accommodation for money, Harrys boats are not as cheap as he says, because, he does not in clude the expensive bits like electronics sails and winches.
I have built 10 yachts and it can almost amount to halve the price of the yacht.
On gaiasdream "www.pacificproa.nl" we spend a 100.000 on sails winches electronics engine and other hardware.

I have sailed a 40 foot tacking proa single handed from the Netherlands to Australia.
She sailed at its best with the little hull to windward and survived 3 major storms during that trip.

Cheers Ini
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  #55  
Old 03-12-2010, 01:41 PM
sharpii2 sharpii2 is offline
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Quote:
Originally Posted by peterAustralia View Post
single outrigger sailing canoe as poor mans catamaran?

Hmmm,

May I politely respond do that. One advantage of a smaller outrigger is that you can right the craft should it be tipped over. This is not theoretical, Tim Anderson did it on his trip to Cuba. Now just say as a hypothetical instead of a craft with hulls 19ft and 14ft long, he had a conventional 18ft cat. Should he tip over it would be very very difficult for a single person to right the craft, more so when out to sea. This could have potentially fatal consequences. This is probably why you do not see many people sailing multiday trips in 18ft catamarans. It is true that the cat would be harder to tip in the first place, but it is possible.

read his account here
http://web.media.mit.edu/~tim/pix/cuba.html

Next sailing outrigger canoes do not by definition need to be slow. There is a fast looking one here. http://www.tacking-outrigger.com/ninja_pro2.html
Additionally there are some Youtube videos of this craft about. Put in tacking outrigger into Youtube and you should be able to find it.

Sailing outrigger canoes were used by the Hawaiians for many many decades after the arrival of europeans as they were considered superior sea craft to the vessels on offer from the Europeans. The outrigger sailing canoe could go over reefs undamaged, handle very large surf and had high speed. If swamped they would not fall to the bottom of the sea as a ballasted craft could. If winds were low they could be paddled at good pace. Thus a vessel with many many plusses.

Yes if you want pure speed, go for a Tornado cat. If you want to add some shelter and carry some supplies, then something else may work better. Yes they are different, but not by definition bad.

I made a small paddeling outrigger canoe out of a 13ft ama and a small outrigger. I found that the small 4ft outrigger did not work. Next I made an 8ft outrigger (lenght of a piece of plywood) with a deep V section. This worked quite well and had low drag. One problem is for the outrigger to have small drag at both high and low displacements. I used a deep Vee section and a lot of rocker as my solution for this problem.
Hi, Peter.

When I said "...poor man's catamaran.", I didn't mean that as a put down.

I also see scows, sharpies, and dories as poor man's monohulls. In the days of sail, I have read, the sailing scow was the most numerous sailboat around.
Watching the pdracer racer crowd, I can see why.

You can take a dory and put a ballast keel on it and you end up with quite a nice seagoing boat. You can take a sharpie, round or 'V' its bottom a bit, then add a ballast fin keel and you have a fairly high performance monohull. Indeed, if you look at a lot of recent (post IOR era) sailboats, you will find the resemblance striking.

I see the single outrigger in the same light.

Yes it can be fast, but only with move able ballast. As a high performance sail boat in the dinghy size range, it is hard to beat, cost wise. With the float to windward, it doesn't have the problem of small, narrow monohulls capsizing to windward should the wind suddenly lull.

As a seagoing paddle boat, or, in larger sizes, a sea going motor boat, it will likely out perform anything in its displacement class in speed for power and displacement.

That all being said, I stick to my statement that, in a long distance ocean cruising mode, (as a sailboat) it probably will not be as fast for its length as a more conventional multihull, if safety is to be a major consideration.

But who cares?

If I can build a thirty foot single outrigger for the cost of a, say, twenty foot catamaran, and still sail well past 'displacement speed' such a sacrifice might be worth it.
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  #56  
Old 03-12-2010, 02:04 PM
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Alex.A Alex.A is offline
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Hi - know nothing about proa's/outriggers but have an idea - while shunting is an odd idea and puts most off - and as it'd be a cruising proa, why not have 2 rigs - one on each hull, diagonally across from each other? Sail into turn and simply drop one and raise the other? Wt an issue? Again as cruiser..... but it also seems to me that proa's are sppedmachines and therefore suited to racing and not cruising.... ok i asked for it? I drew it as a cat - sorry - but i guess it'd have to be more equally weighted - like Tepuke? Downwind= more ballanced helm? Could it even be sailed as bi - no sail blanketting either?
One more (stupid) question - why are rigs not central/beam mounted as with cats? Too stressed?
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  #57  
Old 03-12-2010, 05:28 PM
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marshmat marshmat is offline
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One more (stupid) question - why are rigs not central/beam mounted as with cats? Too stressed?
Why would they be? A typical cat's rig is mounted on the crossbeams solely because of port/starboard symmetry- the boat is expected to behave identically on either tack. On a shunting boat, there'd be no reason to expect a loss in performance by stepping the masts on one hull, but- if it's the leeward hull- there are certainly structural advantages to doing so.
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  #58  
Old 03-12-2010, 07:51 PM
peterAustralia peterAustralia is offline
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Hi Sharpril2,

On safety the small outrigger can he righted in event of capsize (as Tim Anderson has done). As the outrigger having to alternate between a float and a righting weight, yes that ideally requires different floats. However water ballast and modern materials allow for construction of watertight, strong, buoyant and light outriggers. So in some ways you can have the best of both worlds. If you are on a long stretch with outrigger to lee, move some of the water-containers from the outrigger to the main hull, for better trim.


In larger craft, the safety ama is a good thing in my opinion. Of the 2 large pacific proas without safety amas that I can think of at this moment, one tipped over at anchor. Whereas the three others with safety amas/pods have never tipped over.

Given that a safety ama can be built rough, with low cost materials, it can be boxy, light, and does not have to be built to withstand thousands of miles of ocean waves, logic suggests it can be a simple light plywood box. It might touch the water once in a blue moon. It seems a very smart thing to have with very little downside.

In the end it comes down to people. If someone wants one they can build it. Me I am saving my money and getting financially more solvent every week, so that some day in the future......... well...... I might just build a nicer boat.

So many words for 5 or 6 craft,,, hmmm
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  #59  
Old 03-12-2010, 10:27 PM
ancient kayaker ancient kayaker is offline
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Kayakers use an inflatable air bag on the end of a paddle to stabilize the boat for a wet re-entry. Perhaps that would be sufficient for a safety ama, if it's only needed at anchor.
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  #60  
Old 03-13-2010, 09:36 PM
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rwatson rwatson is offline
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Once again, thats where the uniquensss of the 'harryproa' design comes in. You dont have the 'small ama' problem when the accomodation is sitting away from the main hull. Capsizing at anchor speaks of a serious design problem.

Re the 'tacking versus shunting' discussion, how many times would I have loved to have been able to sit in the same shelltered spot, and simply steered onto the next tack without having to move my large ass uphill on the the other side of the windswept boat. Also, keeping the 'crew' keen to standby to get wet, cold active to assist in the rigging changes is a real downer.

Sailing on open water is such a miserable task 50% of the time, that you would have to get 40% performance increase to justify a less comfortable ride. On some sailing shots on You Tube, crew actually had to walk up really narrow bows to adjust sails on 'traditional' shaped Proas. Might have been ok back in the days of 'pressganged sailors', but not in this safety concious era.
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