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Couple more images. The beam swings fore and aft for legal trailering; that is, if you don't shift hull in early hours on top of car and then the beam later. And this is early image; had to increase the size of the non-floats - as seen in above image.

frogbowbeam.jpg

frog7copy.jpg

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Sid is no more, got smashed into several pieces. All the broken stuff (7 bulging  plastic sacks) has gone to the tip. Main hull is on shore but very broken. Could be repaired, make a proa maybe ... but not by me, interest has strangely waned. Wing mast in two; could be repaired no trouble but no boat to put it on.

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Love your experiments!!! I assume you will be hoisting a mainsail up each side of the ‘D’ mast making it a soft wing(?) this is something I hope to experiment with on my bi plane rigged cat as the existing masts are round and easily turned into a ‘D’. What type of foil(s) are you using using on the main hull ( I can see a case offset on the bottom of the hull so I’m assuming there may be  two of them)? Are the foils on the floats permanently attached at that depth or is there any form of adjustment for depth or angle of attack? Sorry for all the questions but I’m totally intrigued!! Good luck with the launch and can’t wait to see it sailing. PS, I’m in the process of turning my 5mtr biplane catamaran tender into a foiler.

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Intended to sail today but I screwed up on the tiller head shaft connection (original has been lost somehow) so bodgied up a replacement from various other boat parts (of which I have a few) - anyway had to saw away cured epoxy and re-glue slightly higher on shaft.  By the time that semi-cured, tide was on the way out.

Yes, have tested hoisting the two schooner rigged mains from the Skimmer as a double luff main, works fine - but too small because they're from the 18 foot  boat. But they will give an indication of whether the setup will work.

Only a conventional dagger offset to one side of main hull (so to have a wider but still cramped entry down below). Sleeping there will be hellish - but not as bad as on Eric Eason's beyond cramped Buccaneer 24. I could put a small T foil on the dagger but that means it has to be semi-permanent ... unless you go for a swim to remove it from bottom. I'm avoiding this T foil main dagger because it would mean acquiescing to madman Doug Lord's harping on about the subject. But if Frog is slow to lift off (it won't be) will bite the bullet and become his friend again?

The float foils are fixed, main at 3 degrees AoA, upper at 6. Will suck and see. The beam could be set up to alter foil angles, if necessary.

Here's a shot of the rudder during build. Changed my mind and made assembly swing out/in for "ease of use." Formerly was conventional dagger setup. And here's the D mast.

frog4 copy.jpg

D mast copy.jpg

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Sorry to here about Sid :(

Hope you keep building and experimenting I love your work !

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Sailed today with the Skimmer's two mains set up as one to make a very reduced double luff main for Frog. Number of little problems, as expected; the rudder cam re-glued yesterday was still too close to deck so had to brutally sand deck and cam back with rasp, still not quite right but at least I could steer crudely. When gusts arrived Frog surprised by sailing with some speed and panache - slow in the light stuff though. Since the double luff main worked okay, have to get full size version built by Bill Barry; that is, if he still wants to be associated with my contraption. Have to say looking out leeward at the tiny floats is little unnerving but in the gusts the leeward float was flying clear, so foils definitely do their job. By the way, complete boat without sails weighs 127 kgs.

frogsail2.jpg

frogsail.jpg

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Had some correspondence and replied to questions from an Australian small boat expert and enthusiast; might be of interest:

"The upper foils are for when overpowered; didn't see that occur during test, breeze gusted up occasionally and then Frog felt not too bad with float lifted clear, riding on lower foil (plus rudder too of course). There was no breaching, platform is steady. I realize that the tip must be close to surface but the platform heels so it must be down enough. Early days, lot to observe and learn. The main foil area is not large and I may have to increase the span - but in past foils I've found too large an area to be pain in arse, boat starts to lift too far, then rocks to other side. So prefer smaller area. Must say Frog seems a very small and flighty boat compared to my others, whole boat with rig weighs around 130 kgs, including Skimmer's "double" sail. And will be probably overpowered with full sized main. That's okay, I like flying along in light airs, magical.
I think the double luff will work out okay; looking at rig when sailing it sets smoothly with pleasant curves off the D mast to windward and to leeward.
Reefing will lower power but then I will have some turbulence set up behind the upper bare D mast section; have to live with that. The mast has luff of 8.6 metres, which is not excessive proportionately - compared to my other boats.
A Moth has, to my eye, a very fine mast, meaning  width/chord measurement - so drag is not really a problem but larger boat needs a decent stick. Frog's is 200 x 240mm, weighs with rigging 26kgs.
I find it odd that the A's haven't got a decent airfoil mast that works; maybe they're just too small and too light a platform to handle the slightly heavier rig. Could you imagine a C Class today without a full wing? Or even 3/4 decades ago without a wing mast?
The first sail revealed a number of mistakes with Frog but I'll get them sorted and when the new sail arrives will be another steep learning curve. Looking forward to it."

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Nice Groucho.

The reason for the A-Cat not going to a solid wing is the current rig setup works brilliantly across a wide range of conditions and 10 years ago the best rig guy in the world couldn't build a wing sail that was the same weight as the mast+rig. Add to that the hassle of rigging/transport and the inevitable wing breakage in a capsize and it hasn't made inroads.

There are some efforts on the D-tube mast over in A world, so definitely keeping an eye on this. One potential issue is getting the mast to bend correctly. How are you finding hoisting the double luff sail?

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Well, the make do setup using the Skimmer's sails, meaning the double luff sails are shorter compared to envisaged full size main, creates no problems hoisting. They have to be hoisted together  and as the sails go up, (talking about the couple of times I've lifted Frog's make do main) I lash the batten leech ends together. Another way would be to first unclip the angled down boom from its position, hoist the already batten leech attached sails, then when up get in between the two sails and reattach boom to mast.

Because of D wing mast and usual teardrop shaped wing mast stiffness, there is little bend so you have to live without the flattening ability of conventional bendy rigs. Like to hear what cat experts have to say about this. Wing mast mains, I've found, are completely flat and you rely on mast rotation to alter sail shape?

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Well, the make do setup using the Skimmer's sails, meaning the double luff sails are shorter compared to envisaged full size main, creates no problems hoisting. They have to be hoisted together  and as the sails go up, (talking about the couple of times I've lifted Frog's make do main) I lash the batten leech ends together. Another way would be to first unclip the angled down boom from its position, hoist the already batten leech attached sails, then when up get in between the two sails and reattach boom to mast.

Because of D wing mast and usual teardrop shaped wing mast stiffness, there is little bend so you have to live without the flattening ability of conventional bendy rigs. Like to hear what cat experts have to say about this. Wing mast mains, I've found, are completely flat and you rely on mast rotation to alter sail shape?

This is a fantastic project - really amazing work, post more photos!

I designed some WS sails for a rotating D mast in the 90s - I designed in a basic camber flow and twist via seamshape, and was able to get controllable, dynamic leech behaviour similar to a normal slalom sail, largely due to the full batten/square top geometry. It was very fast at the bottom end of the wind range, but never really 'locked in' when maxed out - it had a kind of spongy feel that in turn created board control issues. IMO this was because it had considerably less skin tension than a normal WS slalom sail that typically rigs with over 100 kg of downhaul tension - this probably would not be an issue for you.

Having said that, I imagine the A cat sails are light years ahead of that by now. 

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The main for my cat has subtly little shape, only maybe 10mm luff curve (that's from memory, I designed it 20 years ago). It's a 30' cat and is hoisted on a 500mm *125mm wing mast that, as with your's, does not bend F&A. Shapewise the sail still looks good, mold wise it looks like something out of Waterworld, but that's another story. ^_^

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Here's the late lamented Sid's conventional single skin, flat main and 500mm chord mast. Sid got really smashed into pieces in a recent blow - but could be rebuilt - if I was completely bonkers. Beam, main hull, one float and mast all in many pieces. RIP Sid.

sid'smastsail.jpg

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On 3/22/2018 at 4:46 AM, Groucho Marx said:

No, that's including the mast - which weighs including running and standing rigging 26 kgs.

Height is 8.83 metres, including bearing and the section is 200 x 240mm.

Staggering. 

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Windward and leeward sides of bodgied up ex-Cox's Bay Skimmer's two separate mains to create single double main for Frog. Boat went okay this morning but that will be the last with make-do sail; next will be with full sized new Bill Barry main.

frogmain2.jpg

frogmain.jpg

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  • 2 weeks later...

Bump?

Frog, like the frightened mother hen, survived the recent savage cyclone winds of 110 plus knots at Manukau Heads. Didn't sleep well that night but Frog moored in close to the point survived unscathed. But Auckland and rest of the country has been smashed, trees down everywhere.

frightenedchook copy.jpg

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yeah... good news for all.....  We have been seeing some crazy weather this year.....  Today in Sydney will top out at 35 degrees C when it should be more like 22 degrees C.....

the seasons looked to have shifted by 6 weeks later in the year !  Very warm ocean currents still off NSW.

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18 hours ago, xsailmakerSYD said:

yeah... good news for all.....  We have been seeing some crazy weather this year.....  Today in Sydney will top out at 35 degrees C when it should be more like 22 degrees C.....

the seasons looked to have shifted by 6 weeks later in the year !  Very warm ocean currents still off NSW.

same here in southern brasil. we should be seeing temperatures in the low to mid 20s (in°C). and it's in the low to mid 30s instead.

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  • 1 month later...

Couple of 1990 shots of my old trifoiler Misguided Angel; the only time my better half set her posterior on the thing; Jim Keogh helming. Frog is just a smaller, more developed version of the Angel.

heatherJimMA3.jpg

MAstern24.jpg

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  • 3 weeks later...

Went sailing on Frog today; went okay but there are a number of mistakes in the setup; rectified some of them when I returned to bay. Worst was the runners which kept fouling the double sail leech area when tacking/gybing - have moved them forward from transom. The longer foils worked well; the originals were too short. No sailing shots; Frog is a very small boat so stuff taken on board would be of little use.

IMG_6381 - Copy.JPG

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Congratulations- wonderful stuff. I love the earlier picture of the Melanesian boat with the kids playing with models in the foreground. Seems every picture I see from there has kids sailing model boats- that show I grew up to love sailing.

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Love it! @Groucho Marx what's the logic behind the kink in the main foils?

I would have expected the foil to kink similar to ETNZ's -- from the strut, initially horizontal or even slanted down, then a concave kink halfway so the wingtip is pointing up. This gets you a baseline lift from the section closer to the strut; then the outer section provides (a) diminishing lift if it comes out of the water, and (b) dyhedral stability (airplane wings dyhedral).

I'm not saying it's the only way to reason about foil design. Interested in the thinking behind yours. 

Also - tell us / show us more, lots more about that mainsail...

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Martin, I have tried many types of foil designs and shapes (see photograph of the late Sid) and Frog's is just me trying something different. Also the original float foil was simply angled up, no kink, but it was too short, not enough lift ... so if I increased length, then the tip would break water at rest, hence the new angle down. ETNZ's foils were very subtle in design, very sophisticated and also very long (apparently built of steel because of cavitation eating tip material?) - Frog is an experiment especially the rig where I'm just following my nose but if the foils turn out to be incorrect, then I'll change them, it's not a problem.

sidrepair2.jpg

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  • 5 weeks later...

Nothing very exotic, basic 10 -12% asymmetric  foil profiles. set at 3 degrees AoA, rudder asymmetric lifting foil set at zero. I have tried a thick 15% symmetric foil (on basic daggerboard) but felt it was too draggy, just my opinion; this was Malcolm Tennant influence, he liked the fatties because they allowed a broad range of attack with little stalling at high angles. This referring to his catamarans. Here's an early drawing and photograph of Sid with curved foils

IMG_2069.JPG

 

Sidfoils.jpg

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  • 1 month later...

Extended the transom on Frog, main hull is now 7 metres and now the transom doesn't drag in light airs, also increased buoyancy of the mini floats, and made them near flat underneath with only slight rocker - which has cleaned up the float wake also in lighter conditions. So now Frog is getting closer to being a complete boat have finally turned attention to Groucho and framed up the new floats.  Watched the Coastal Classic start this morning; beautiful Auckland spring weather and a very large fleet; the ORMA 60 was very impressive and she will win easily?

grouchofloats.jpg

 

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  • 1 month later...

Light airs, leeward float foil flying. Missed moment to get fast foiling shot in earlier medium strength breeze, too busy; but will try harder next time. Need someone in another boat. Have added a vertical strut between the two foils - which has stopped flexing of main lower foil tip. Also had to beef up the interior of the beam/clamp positions plus adding an angled strut from main hull to shroud/beam staying position. Have same setup on my other boats but thought I could get away with not having struts on the smaller boat - but was wrong. Slowly getting the Frog sorted. Boat is fast by the way. As it should be for a 7 metre/150kgs boat?

frogleefloat.jpg

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  • 4 weeks later...

Sitting on the edge of my seat waiting for a sailing report.....        (what is this thing called "patience" ?)

Also I note that that old, balena/bullfrog sunblock is now referred to as "frog"

You are going to have to have a word to them for stealing YOUR name.     :rolleyes:

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  • 1 month later...

Realized Frog lifted off during a reach yesterday, went quiet aside from some gurgling noises from aerating main hull dagger case. It has happened before but haven't been paying attention.  Leeward float (with foil) stays just above water surface yet platform doesn't heel much . When beating the float flat bottom just skims surface so the longer foil is working okay. Changed main sheeting system to two spread lines going to the deck outriggers which allows me to crank boom to and above centreline. Was too far to leeward before with old central setup. Apologies for boring and pedantic report.

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Thought my Frog name was original but then later read of a US boat named same. Always liked the Lock Crowther trimaran Bullfrog - but also remember a US big Peterson? 50 monohull named same - but from the 1980s. There is a Sail cover shot of a light displacement Laurie Davidson 50 leading BF in Hawaii. Will try and find it. Here's the Davidson Jumpin Jack Flash taken during same series.

jumpin j flash.jpg

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A bit of history, Bullfrog (the tri) was originally launched as Balena then Ian +Cathy scored some sponsorship from a product called Bullfrog Sunblock. I was lucky enough to get invited to the launching and got a photo of me holding the bow line during the launch. The photo was used in Cathies book ‘Return in the Wake’ which is a great read, which I suppose you have read Bottman? Cheers.

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On 12/12/2018 at 7:57 PM, Groucho Marx said:

Frog with extended stern and altered foils.

frogstern.jpg

Does the extended stern become part of the waterline at higher speeds?  

If so, any change in helm feel?  (Say if held it very lightly?)

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Glad to see this thread back near the top. You should share more @Groucho Marx

There are folks interested to follow your progress and its nice to hear from someone who does more than type at a keyboard!

 

 

 

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6 hours ago, Amati said:

Does the extended stern become part of the waterline at higher speeds?  

If so, any change in helm feel?  (Say if held it very lightly?)

I have a thing about dragging sterns in light airs and when on other boats look at disturbed wake and think there is speed being wasted there. Sailing faster the stern doesn't touch water, just a thin wake left by the rudder. Actually there is more disturbance from the lee float foils - see photograph. I need to polish them and have read that Kiwi/Aussie Glen Ashby uses 2000 grit on his A Class foils ... and no one is ever allowed to touch them.  But then he is an extremist and has only won near a dozen A Class world championships?  One or two others of lesser importance too?

There is no difference in helm feel. However that is another area I need to work on because there are four linkages between rudder head and tiller - and they could be made tighter fits.

frogfoilwake2.jpg

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3 hours ago, Groucho Marx said:

I have a thing about dragging sterns in light airs and when on other boats look at disturbed wake and think there is speed being wasted there. Sailing faster the stern doesn't touch water, just a thin wake left by the rudder. Actually there is more disturbance from the lee float foils - see photograph. I need to polish them and have read that Kiwi/Aussie Glen Ashby uses 2000 grit on his A Class foils ... and no one is ever allowed to touch them.  But then he is an extremist and has only won near a dozen A Class world championships?  One or two others of lesser importance too?

There is no difference in helm feel. However that is another area I need to work on because there are four linkages between rudder head and tiller - and they could be made tighter fits.

frogfoilwake2.jpg

I’ve used 2000 + grit for decades voicing pianos (and some on boats) it’s magical stuff.  Addicting actually.  Dry or wet?

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  • 5 weeks later...

Broke Frog yesterday, leeward beam let go/snapped at exit point of main hull flare and down came the rig.

We've been having south east winds here, a rare wind for Auckland, colder with hard and savage gusts ..  and I was fooling around with the rudder (which kept lifting a couple a mms and then jamming) making a temporary lash up with line and wedges to stop it lifting at speed - and then you had locked steering; beyond annoying? So I was sitting at transom dicking around and the boat gybed, no runner set on the new side and merde and defecation, down came the rig. Then I saw half the beam and float floating away too. Paddled to shallow water and then waded/towed the pile of wreckage back to Cox's Bay mooring. all the time contemplating my sanity.

Anyway that beam had given signs of trouble before and I'd beefed up the two interior hard points with extra layers of ply, glass and carbon ... but obviously not enough. So new and stronger beam required. And this time I'll get rid of the clamps and epoxy new beam into the box instead.. So Frog won't be able to be demount-ed (well not unintentionally - slight joke) which will destroy the concept of trailerable boat geared to sell in hundreds to the masses?

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3 hours ago, Groucho Marx said:

Broke Frog yesterday, leeward beam let go/snapped at exit point of main hull flare and down came the rig.

Sorry to read that Groucho. Glad you are OK and plans are being made to Phoenix the Frog.

What other mods will you undertake? Apart from Wet Sanding @ 2000 

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4 hours ago, Groucho Marx said:

Broke Frog yesterday, leeward beam let go/snapped at exit point of main hull flare and down came the rig.

We've been having south east winds here, a rare wind for Auckland, colder with hard and savage gusts ..  and I was fooling around with the rudder (which kept lifting a couple a mms and then jamming) making a temporary lash up with line and wedges to stop it lifting at speed - and then you had locked steering; beyond annoying? So I was sitting at transom dicking around and the boat gybed, no runner set on the new side and merde and defecation, down came the rig. Then I saw half the beam and float floating away too. Paddled to shallow water and then waded/towed the pile of wreckage back to Cox's Bay mooring. all the time contemplating my sanity.

Anyway that beam had given signs of trouble before and I'd beefed up the two interior hard points with extra layers of ply, glass and carbon ... but obviously not enough. So new and stronger beam required. And this time I'll get rid of the clamps and epoxy new beam into the box instead.. So Frog won't be able to be demount-ed (well not unintentionally - slight joke) which will destroy the concept of trailerable boat geared to sell in hundreds to the masses?

‘Tis a fine madness (to coin a phrase :))!  You’re inspiring me out of my dark funk (you know, the one surrounded by disappointments, deathrolls, leaks, and splinters) and back to doodling on the Vacanti, at least.

Onward!

(And never throw a sail or spar away.....)

 

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Have cleaned up the mess and already decided what changes (slightly radical?) to be made; beam will be straight instead of the angled forward from the straight section of main hull and the point of cantilevered sections will have be solid carbon reinforcement. Since I'm forced to make changes in those area will also build new floats (lighter and better shaped) the originals look somewhat Michael Mouse; although they worked okay, Will salvage the foils and use them again. But these changes will have to wait while I finish the new floats for Groucho, Will be busy with my craziness.

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Changed mind deciding how to repair Frog. Today epoxied and glassed Frog's beam back together. Discounted building a new straight beam but will retain the original angled forward one - but later will cut a long access hole on the top box section at the cantilever point where it broke and will lay in carbon reinforcement. At the moment I've reached in through the small inspection cover and laminated some thick glass - so Frog is one unit again. Which is a plus compared to the sorry mess of a couple of days ago. As said, will still get rid of the clamps and epoxy the beam to main hull.

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Bite the bullet Gary and simply put in some Dyneema stays from about the water line up to the outer beam, you could even go slightly forward of the beam to give some diagonal support. bits of string in appropriate places saves huge amount of weight in the beams.

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Thanks Wayne - but I already have hollow strut diagonals handling tension and compression running from main hull to side stay positions on the beam. Of course it got torn out in the collapse. My problem I think, is that the beam collapsed first, not that the runner wasn't tensioned and let the rig topple forward - which broke beam - but it is hard to say since I was facing aft and fooling around, feet in water, by the rudder. Here's the same diagonal setup on my earlier boat Sid.

sidrepair2.jpg

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Have done basic job of re-attaching Frog's beam and will finish reinforcing job in a couple of days. But have also been busy finishing Groucho's new floats; here's the starboard one with outfacing foil. Port one is half completed in shed.

grouchofloat.jpg

grouchofloatstern.jpg

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Cool beans. It’s nothing compared to your efforts but the wife and I and eyeballs deep in bringing a much abused larger Corsair tri back to life from the dead. Hope we both get to the water soon! Wess

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  • 2 weeks later...
  • 4 weeks later...

the paint job is fine, very in fashion.         You know people spend hours trying to get that patina look.

Initial observations on the new floats & foils ???     (too early ?)

Is the float attached this way (to the beam) too allow AOA adjustments ?

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Only beginning to attach the new floats in uni-glass here, the port side is all carbon and when finished will be all fared in pretty much the same as the old float/beam setup, see photograph.  Btw Groucho is 40 now. Foil is fixed at 3 degrees AoA. That is a Tennant 54 Power of 2 that Groucho is passing in photograph.

misty4.jpg

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On 4/15/2019 at 7:03 PM, Groucho Marx said:

Only beginning to attach the new floats in uni-glass here, the port side is all carbon and when finished will be all fared in pretty much the same as the old float/beam setup, see photograph.  Btw Groucho is 40 now. Foil is fixed at 3 degrees AoA. That is a Tennant 54 Power of 2 that Groucho is passing in photograph.

misty4.jpg

Been following for a while... I love a doer .... too many talkers... hope it succeeds 

BTW.. I all but bought Power of 2 in the back ground but pulled the pin last minute after the survey... Great boat but suspect build quality

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  • 2 weeks later...

Going through old shots; here's a couple of very early 1980s ones of Groucho, had a bi plane rig mounted halfway out on the single main beam, plus angled in, narrow floats plus foils. Went okay but I had trouble sheeting down hard the two mains, nothing to attach the sheets to, hence the complicated boom.sheeting setup. Later went back to conventional single mast.

MA2rigs.jpg

biplanerig_copy.jpg

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  • 2 weeks later...

So many cool boats (tinkerers) all over the world and from way back.  We had Invictus here in Puget sound.  Thanks for the inspirations.  Bladon, cool name, I read it, as in; "Blade on, man".  

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Some more information from Light Brigade:

An early 32 foot trimaran Atria was designed by Jim Young for Dooley Wilson and launched in 1964. This yacht had classical sheer in the main hull and because of this low freeboard amidships, placed the beams too close to the water surface, an early multihull design mistake, for the beams slowed the boat when driving through waves –  a common problem with trimarans at that time. Wilson raced Atria in Tauranga for some years and then sailed it to Wellington where it was sold. Then in the mid 1970’s Young designed Wilson a 40 foot open wing deck trimaran named Blaydon Racer; called a sketch for it was neither ketch nor schooner because both masts and mainsails were the same height and carried the same sail area in two roached, fully battened mainsails. “This was a low sail plan which kept the centre of effort down and reduced the tipping moment,” said Young. Although Young drew water ballast to be carried in the windward float to provide extra power, this was not fitted by Wilson.  In the clever drawing, tanks which were linked to the centre board cases, could fill or empty to produce either buoyancy or lever arm weight.