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      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  
Lat21

Caribbean 600

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31 minutes ago, Groucho Marx said:

That was my Line 7 jacket and that sheila was not my sheila but was and still is with a Putiki Bay crazy Waiheke Island man - who was ferrying us out to look at the Angel (but she was cold so I handed over my jacket, like a true gentleman of the '80s).

Here's the same boat a couple of years later but with conventional rig, got rid of the angled in floats but changed to angled out foils plus angled out floats, also fitted central dagger in main hull, went to windward like a witch.

MGAngel - Copy.jpg

That's a pretty wicked looking machine!

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10 hours ago, Rasputin22 said:

Lived in it? My buddy on a TransAt had one of those Line 7 smocks and I laughed at him at the start of the trip. I spent two weeks trying to seal the leaky seams of my kit and he just sat there with a smug smile nice and dry and toasty and I hated him after the second week. I seriously considered tossing him overboard only after taking his Line 7 smock before the passage was over. Only thing that saved him was that it smelled like he had lived in it for weeks/months. I spent the last of my cash on a nice Henri Lloyd Offshore Jacket in Plymouth before the TwoStar. Bit that is another story...

Ah, the rubber dress! Still the best foul language jacket I ever had. With a strip of toweling around my neck it kept me dry all the way across the Atlantic. It was a bit gross diving into it head first after awhile.

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It's great to be talking about old school foul weather gear and how good it was. It's a nice change from the armchair second guessing, etc. 

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11 hours ago, Russell Brown said:

It's great to be talking about old school foul weather gear and how good it was. It's a nice change from the armchair second guessing, etc. 

FFS... then why don’t you start a fucking thread titled “Old School Sailing Gear-open discussion. Everyone except Rob Denney May participate”. That should help you feel better. Or maybe a thread titled, “I can’t fucking stand Rob Denney-who’s with me?”

Because, lord knows, it would be terrible to have discussions, theories, ideas, etc, thrown out there about multihull capsizes, the why’s, the what’s, and the what if’s, in a thread about a race where a notorious Catamaran flipped. 

So let’s keep talking about jackets. :blink:

Or maybe it’s a good time to bring out some tits!

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3 hours ago, Solarbri said:

FFS... then why don’t you start a fucking thread titled “Old School Sailing Gear-open discussion. Everyone except Rob Denney May participate”. That should help you feel better. Or maybe a thread titled, “I can’t fucking stand Rob Denney-who’s with me?”

Because, lord knows, it would be terrible to have discussions, theories, ideas, etc, thrown out there about multihull capsizes, the why’s, the what’s, and the what if’s, in a thread about a race where a notorious Catamaran flipped. 

So let’s keep talking about jackets. :blink:

Or maybe it’s a good time to bring out some tits!

sólo el gas caliente chorros fuera de su culo

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3 minutes ago, olsurfer said:

sólo el gas caliente chorros fuera de su culo

:lol::D

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2 minutes ago, olsurfer said:

Como Bugs Bunny solía decir "qué idiota"! Me refiero a usted.

Ummm yeah. I guess I am an idiot. 

Better than being an Asshole. 

Now FUCK OFF with your clever use of google translate, and stuff your nose further up the hot gas, ass master himself. You fucking groupie. 

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Sorry I stirred the shit pot, everyone. 

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On 3/16/2018 at 4:57 PM, Bruce Sutherland said:

  

And Wess -- not enough money to ship out and back or time to sail -- and yes its going to snow again this weekend ... in Devon???  

 

 

Hope you stay warm and well.  Some flurries headed our way this week but maybe then it ends.  Got some re-rigging done on our F-boat and got to play on the Laser so I can't complain.

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22 hours ago, mad said:

Why do these threads always turn to shit when the proa crowd turn up?

I think they're paid by Putin.

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Just to piss off the traditionalists; here is my other double rig on the Cox's Bay Skimmer, not atwartships though, conventional fore and aft. Initially the wing masts were freestanding but the forward rig bent while carrying full rig in fresh conditions, started letting go near the base in the cantilevered area -  so cut off the low sections and changed to lightweight stayed setups. Problem solved.

earlyskimmer.jpg

skimmerlazer.jpg

 

skimatpointC - Copy.jpg

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15 minutes ago, Groucho Marx said:

Just to piss off the traditionalists; here is my other double rig on the Cox's Bay Skimmer, not atwartships though, conventional fore and aft. Initially the wing masts were freestanding but the forward rig bent while carrying full rig in fresh conditions, started letting go near the base in the cantilevered area -  so cut off the low sections and changed to lightweight stayed setups. Problem solved.

earlyskimmer.jpg

skimmerlazer.jpg

 

skimatpointC - Copy.jpg

How did that rig work out on the boat?  Better upwind, downwind?  Really interested in the comparison to a standard rig.

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Theoretically the double cat rig should be inferior to windward  but the Skimmer's rigs are airfoil shaped in cross section and rotating and that perhaps makes a difference, boat is very closewinded. Everyone knows that on reaches and off wind the low but large area schooner is very efficient. There are now T foils on dagger and rudder, off wind boat lifts off.

skimmerfoils.jpg

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2 hours ago, Groucho Marx said:

Theoretically the double cat rig should be inferior to windward  ....

 

I've heard that often, in the context of a sloop. Yet a sloop has two sails in line. 

But I do believe that an Una rig is the most efficient, proven by many decades of airplane design and also many decades of development class competition. 

On the other hand, your tandem rig looks to be so efficient that you had to reef the foresail in nearly flat conditions (3 pic)? :).

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1 hour ago, DDW said:

I've heard that often, in the context of a sloop. Yet a sloop has two sails in line. 

But I do believe that an Una rig is the most efficient, proven by many decades of airplane design and also many decades of development class competition. 

On the other hand, your tandem rig looks to be so efficient that you had to reef the foresail in nearly flat conditions (3 pic)? :).

Or it means that the boat has too much lee helm with the foremost mainsail fully up?

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1 hour ago, Sidecar said:

Or it means that the boat has too much lee helm with the foremost mainsail fully up?

Or maybe they are coming into anchor, or to the beach, and dropping sail?

...and since no one has said anything recently... Good on you Groucho! Way to dream up, build, and SAIL some REALLY cool boats! You are the MAN!!!

 

 

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Look at that above photograph again, you blokes; see that dirty cloud and look out to beyond the flat water; we're in the lee of Point Chevalier on the Waitemata in that photograph but it was blowing hard outside; in fact we were almost flattened by a hard gust out by Meola Reef, had to ease both sheets and hung there for sometime before climbing out from under the power. There were two reefs in the fore main, treating it like a jib. No problems with steering, helm is light on that boat. Here's another shot out by the reef in some breeze.

flashharrybeat.jpg

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On 3/10/2018 at 2:43 PM, mad said:

That’s going fun onboard, not just potentially holding on, getting shot at!! :P

My bad. The person who checked me out on the Sawstop table saw thought the brake cartridge was powered by a shotgun shell. It's actually a highly compressed spring which is held compressed by a wire. When activated, an electric charge melts the wire, and the spring is released. Obviously not practical for a jib clew release. I still sort of like the idea of a very fast way to blow away wind tension though, even if running a releasable bend in the sheet is more practical...

Sawstop hot dog

SawStop Inside Look Slow Motion

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Just to piss off the traditionalists; here is my other double rig on the Cox's Bay Skimmer, not atwartships though, conventional fore and aft. Initially the wing masts were freestanding but the forward rig bent while carrying full rig in fresh conditions, started letting go near the base in the cantilevered area -  so cut off the low sections and changed to lightweight stayed setups. Problem solved.

earlyskimmer.jpg

skimmerlazer.jpg

 

skimatpointC - Copy.jpg

What’s a Coxs Bay Skimmer?? Looks like fun

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Theoretically the double cat rig should be inferior to windward  but the Skimmer's rigs are airfoil shaped in cross section and rotating and that perhaps makes a difference, boat is very closewinded. Everyone knows that on reaches and off wind the low but large area schooner is very efficient. There are now T foils on dagger and rudder, off wind boat lifts off.

skimmerfoils.jpg

Nice test rig, how much does the hull weigh? Apologies if this has been answered before. 

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...For those interested, I have changed the wand operated sheet dump.  Instead of cleating the mainsheet on the rod attached to the wand, there is an upright stick on the wand with a pulley hooked over it.  The mainsheet runs through this, then to the winch.  Once the wand comes out of the water,  the rod rotates, the pulley falls off and the mainsheet is released.  This way, the device is always ready to operate, with no crew input and it does not matter if the handle is in the winch, the sheet is in the self tailer or the crew is standing on the sheet, half asleep  The only requirement is that the eased sheet length is enough for the boom to weathercock and there is nothing for the released pulley to hit.  Neither is hard to arrange on a rig that does not need a traveller.    Comments/flaws/etc appreciated.            dcn, it could even be made to work on a jib.  

Or even build it in to the boat design, and make it a triple system: Main sheet, main halyard, and jib sheet. Fast depowering, and easy enough to winch back into place. And you could put a shock-absorbing snubber on the pulley to keep it from banging up your boat when triggered / released! I knew I'd get my snubber in there!

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PS - It sure would be nice if all the folks posting here about coulda, woulda, shoulda, would at least post a disclaimer about if they have ever owned and the offshore distance they have sailed on a large performance cruising multihull (trimaran or catamaran) that they owned - in others words crewing, skippering or owning a Hobie don't count - so folks could differentiate informed opinion from speculation.

Have never owned a boat. Didn't really 'sail' a 60ft cat as much as power upwind for a 3000 mile delivery. However, have read a few heavy weather sailing manuals which a good number of 'experienced' racers don't seem to have, and their opinions sometimes don't seem all that informed to me.

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And you can put biplane rigs on trimarans too.....even proas.

Damm, I'd forgotten about that trifoiler. The speed of the tacks had to be measured in G forces. I had a long chat with Doug Kettering on the sand at Chrissy Field while he was testing a prototype (right before he sold it to Hobie). The trouble was the wands breaking, and it's not my memory that they had any mechanical linkage to the foils, or that the foils had flaps. The forward wands were just floating shock absorbers, essentially. The other downside is that you had to sit in the trifoiler like an ice boat, and it just didn't seem like sailing as you were too captive a passenger.

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    I got my antique no-longer-available Quick Release Clamcleat in the mail yesterday and it is a beauty. Not as big as I remembers (no puns please) or maybe there was a larger version but it is perfect for my Jim Brown 28' trimaran on the mainsheet. It really is a nice piece of well thought out concept and nicely fabricated. I still think liability concerns by the company lawyers axed the production of the larger sizes that could be used as such. The only thing that remains (thankfully!) is a small unit that is to keep dinghy (Laser) rudders down and yet kick up before damaging when hitting the bottom or anything. I share photos of the cleat after I get it mounted on the tri.

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......There were two reefs in the fore main, treating it like a jib. No problems with steering, helm is light on that boat. Here's another shot out by the reef in some breeze.

Groucho, I love your boats and have a go attitude........ but if fore main had been a genoa/jib, you could have saved the weight, windage, pitching and cost of the second mast and boom? 

Sloop rigs are the default for performance, not necessarily because they are the  most inherently efficient, but because the name of the game is to carry as much sail  area, with as much luff length as possible off the shortest possible mast whilst minimising mast/luff interference. That brute efficiency trumps everything else.

Have a look at Merloe below.... Bearing in mind it could also carry a staysail (or even 2 as per the VOR boats).... how much more mast would you need to carry that amount of sail area on a una rig, and when you do shorten sail, where is all the redundant weight, and extra drag?

F872EB36-0323-4D15-8E4A-1AC23DBA5E44.jpeg

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My bad. The person who checked me out on the Sawstop table saw thought the brake cartridge was powered by a shotgun shell. It's actually a highly compressed spring which is held compressed by a wire. When activated, an electric charge melts the wire, and the spring is released. Obviously not practical for a jib clew release. I still sort of like the idea of a very fast way to blow away wind tension though, even if running a releasable bend in the sheet is more practical...

Sawstop hot dog

SawStop Inside Look Slow Motion

Need for fast and powerful release:

Sawstop brake cartridge slo mo

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Agreed, Sidecar, a conventional sloop would be simpler ... but the idea of Cox's Skimmer was to have a low rig, so masts are only 6 metres tall (on a 5.5 m platform). It was designed and built for an old friend who wanted some performance without danger, ha. Initially there was water ballast which tamed the boat for old blokes but the tank has since been removed - and Skimmer is much more flighty and tip truck, even with the low rig - which is of some area, see photograph.

skimmersail1.jpg

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Sloop rigs are the default for performance, not necessarily because they are the  most inherently efficient, but because the name of the game is to carry as much sail  area, with as much luff length as possible off the shortest possible mast whilst minimising mast/luff interference. That brute efficiency trumps everything else.

I believe it is less those things, and more the habit and convenience of hanging sails. We know that in a strict contest of efficiency where sail area is the only controlled measurement, (like C class cats) Una rigs won long ago.  For offshore, a sloop is easier to vary the area, and at a much higher state of development than any Una or unstayed rig. In almost any racing, sloop rigs are baked into the rules either explicitly or tacitly. There are very few offshore true development classes than I am aware of, that's where we might see some innovation. 

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I believe it is less those things, and more the habit and convenience of hanging sails. We know that in a strict contest of efficiency where sail area is the only controlled measurement, (like C class cats) Una rigs won long ago.  For offshore, a sloop is easier to vary the area, and at a much higher state of development than any Una or unstayed rig. In almost any racing, sloop rigs are baked into the rules either explicitly or tacitly. There are very few offshore true development classes than I am aware of, that's where we might see some innovation. 

To be fair, the boats  where sail area is the only controlled measurement, (like C class cats)  that have Una rigs, they are also designed for a very small wind range around a race track. If they were allowed to carry downwind sails then in light air they would. If you want to whack a mast up in the cat heads then you gonna have to whack some bouancy up there with it. Any one for a FAT cods head these days?

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. There are very few offshore true development classes than I am aware of, that's where we might see some innovation. 

i might be wrong, but i don't think that the WSSRC places any restriction on the rig-type for the trans-ocean passage records

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A sloop and other split rigs (including the Skimmer above) makes adjusting sail area more convenient. This is a drawback for the pure una rig. There is nothing preventing you from carrying downwind sails on one however if allowed by rules. I carry a 1050 sq ft asym on my unstayed mainmast with a 960 sq ft mainsail. It is interesting how few situations this gains much speed though. The una rig is much more efficient downwind than a sloop, making much of the sloop's downwind sail inventory superfluous. 

Stepping the mast in the bow of a narrow hulled cat would be problematic for sure. If I was doing a cat (and at one time I was about to) I'd step the masts only a little forward, there'd be plenty of length left for enough sail area in a light cat. I'd do 100% of the working area in the mainsails, but also carry one or two light air asyms. 

7070, I believe you are right about passage records, however it is very rare that someone is willing to risk an expensive experiment in a single purpose boat, knowing that rules will keep it from being competitive anywhere else. Sailing is a very conservative and tradition bound business. 

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I believe you are right about passage records, however it is very rare that someone is willing to risk an expensive experiment in a single purpose boat, knowing that rules will keep it from being competitive anywhere else. Sailing is a very conservative and tradition bound business. 

.... Which is why the Super Foiler, the AC cats and the proposed AC75 foiling monohull, having thrown out convention and the rule book, no expense spared, all went for una rigs? Not to mention generations of non rule French RTW record breakers.

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Those boats all have a large list of constraints including expense. The AC72 and 45 cats were una rigs, with jibs added for soft pressure. I'm sure if you ask any of the designers, they'd tell you they would much rather have a selection of the right size wings, than a vestigial jib. There is not a serious aeronautical engineer in the world who believes a tandem or slotted airfoil is superior in efficiency. Adapting a single airfoil to sailboats has practical problems, for which there are likely solutions given 100 years of development that the sloop has enjoyed. Already where these practical problems can be ignored, the una rig rules. My boat is essentially a una rig, and in context seems to be equal or superior to the performance of a sloop, and it's my first try at it. 

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I am not saying that a sloop rig is more efficient theoretically, just that it is more practical in most circumstances as outline previously, and including longitudinal sail spread for ease of balance with increased sail shortening options, facilitates tacking, lowering CE and RM with reduced pitching. All desirable traits, racing or cruising.

Happy to be proved wrong in the future.

PS and the flatwater AC cats with vestigial jibs have solid wings, which produce over double the power for a given sail area. Try doubling the height with a soft mainsail and see how they go?

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Jibs on the AC boats look like a pathetic genuflection to old guard and conformists - a dark ages throwback compared to the full wings?

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Jibs on the AC boats look like a pathetic genuflection to old guard and conformists - a dark ages throwback compared to the full wings?

The vestigial jibs have practical purposes if you can see past your revolutionary dogma....

And the irony is that the most efficient solid una wings in themselves are in effect sloop rigs.....

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I am not saying that a sloop rig is more efficient theoretically, just that it is more practical in most circumstances as outline previously, and including longitudinal sail spread for ease of balance with increased sail shortening options, facilitates tacking, lowering CE and RM with reduced pitching. All desirable traits, racing or cruising.

Happy to be proved wrong in the future.

PS and the flatwater AC cats with vestigial jibs have solid wings, which produce over double the power for a given sail area. Try doubling the height with a soft mainsail and see how they go?

I'm not seeing much of that personally. Longitudinal spread isn't needed on today's light boats, and ease of balance isn't a problem, nor does it (necessarily) lower CE etc. Any time you multiply sails, you do increase the sail shortening options, that's a good argument as well for a 3 masted schooner. An una rig can be shortened easily to just the mast. Solid wings do not produce anywhere near double the power for a given area - where did you get that idea?

 

The vestigial jibs have practical purposes if you can see past your revolutionary dogma....

And the irony is that the most efficient solid una wings in themselves are in effect sloop rigs.....

The most efficient solid una rigs are on C and A class cats, where jibs have been obsolete for half a century. The vestigial jibs do have practical purposes, but efficiency and speed isn't among them. 

It is easy to forget how long (now) obvious improvements have taken to be adopted. Fin keels and spade rudders were known to be superior before the turn of the last century but where only widely adopted in the 60's. Catamarans were proven faster in 1876 but not adopted for racing until a century later. The single handed RTW record was held by monohulls until 2004. Part of this is materials science, but a great deal of it is simply the conservative and deliberate (slow...) adoption of anything in sailing. That is not to say that slow adoption = good, just that slow adoption ≠ bad.

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Comparing conventional headsail/main (and probably a fixed fore and aft mast at that?) to a slotted full wing and saying the latter is similar to the former is beyond incorrect; the headsail/main slot nonsense is simply nonsense, an old wives tale - but still clung to by frightened traditionalists. Also and going further,  do you see any slots (even with the flap) in the inclined split wing of world's fastest sailing boat Vestas Sail Rocket ... or the vertical wing of Macquarie Innovations, or in the rigs of record setting sail boards?

 

 

Macquarie innovations .jpg

vestassailrocket .jpg

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Area for area unarig is better - but when on a M32 - you are sailing in really light upwind - then adding a headsail will sail faster bec more area.

And there will always be situations like that - if you dont care about ratings - ref R2AK they did that on the M32.

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Comparing conventional headsail/main (and probably a fixed fore and aft mast at that?) to a slotted full wing and saying the latter is similar to the former is beyond incorrect; the headsail/main slot nonsense is simply nonsense, an old wives tale - but still clung to by frightened traditionalists. Also and going further,  do you see any slots (even with the flap) in the inclined split wing of world's fastest sailing boat Vestas Sail Rocket ... or the vertical wing of Macquarie Innovations, or in the rigs of record setting sail boards?

Good Luck sailing any of those in the Caribbean 600.

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Comparing conventional headsail/main (and probably a fixed fore and aft mast at that?) to a slotted full wing and saying the latter is similar to the former is beyond incorrect; the headsail/main slot nonsense is simply nonsense, an old wives tale - but still clung to by frightened traditionalists. Also and going further,  do you see any slots (even with the flap) in the inclined split wing of world's fastest sailing boat Vestas Sail Rocket ... or the vertical wing of Macquarie Innovations, or in the rigs of record setting sail boards?

 

 

Macquarie innovations .jpg

vestassailrocket .jpg

Wish I could agree. Slots in wings are required for developing power, i.e high amounts of lift. Double slotted flaps with slats are capable of producing CL's greater than 3.2 and are what allow modern airliners with high wind loadings to take off and land in reasonable distances. The record setters shown here are operating at low CL's, well below the ~1.5 max (1.9 maybe for a high lift foil which is basically pre-flapped) for a clean airfoil, down closer to CL = 0.2, maybe max of 0.5. They are looking for low drag, not lots of lift i.e power. Other boats don't sail in trenches with 20 kts+ worth of clean breeze, and hence the flapped wing systems are needed to operate across a wide range of conditions with the same rig.

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Wish I could agree. Slots in wings are required for developing power, i.e high amounts of lift. Double slotted flaps with slats are capable of producing CL's greater than 3.2 and are what allow modern airliners with high wind loadings to take off and land in reasonable distances. The record setters shown here are operating at low CL's, well below the ~1.5 max (1.9 maybe for a high lift foil which is basically pre-flapped) for a clean airfoil, down closer to CL = 0.2, maybe max of 0.5. They are looking for low drag, not lots of lift i.e power. Other boats don't sail in trenches with 20 kts+ worth of clean breeze, and hence the flapped wing systems are needed to operate across a wide range of conditions with the same rig.

 

aren't the slots on those high CL wings there mostly just to permit the flow to remain attached on the wings when they are adjusted to have a very high camber ratio?

the slots on sloop rigs don't really function that way - the fore and aft sails aren't adjusted so that the overall camber is increased like on a wing

they could still be useful on a high camber wing sail...

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us7070 I was discussing slots and flaps on a solid wing sail. They aren't necessarily to keep the flow attached at high camber ratios, more like to keep the flow attached to the top surface of the wing at high angles of attack which induce flow separation. Similar effects can be had with boundary layer suction devices but those have reliability concerns.

I think slots on sloop rigs serve two purposes, first they tend to clean the flow up some and get it to stay attached to the mainsail longer, second they do accelerate the flow through the slot similar to what I was describing above with wing sails but that doesn't necessarily apply to all rig/sail configurations. If you look closely at the airplane wing example you will see that many high lift devices have their own airfoil/camber, similar to jib/mainsail combinations and getting these to work correctly in unison in both cases is a bit of an art as well as a science.

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All correct Samc99us - but speed record designs are not sailing in light airs or off wind and always have apparent wind well forward, high speed beating, the old world full and bye? Sure, if sailing slightly apparent offwind (because they never broad reach or run anymore) modern high speed designs require slots and flaps to keep flow attachment - but my point is that for a modern or future boat, the rigs will be aerodynamically clean ... because future (and a small number of today's designs) are always going to be sailing to windward. Envisage slots and flaps that open for lift when course and wind conditions apply ...  and close flush for highest speed; same as an aircraft wing?

Sorry, this stuff is very obvious, shouldn't be writing this.

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I will argue that a jib/main combination is a slotted airfoil, and behaves somewhat the same way as one upwind. It has been theoretically and empirically proven that the flow does not accelerate through the slot, it's actually going slower there, but is does keep flow attached at higher angles of attack. I agree that a slotted airfoil (even a sloop) can achieve slightly higher lift coefficients (again this has been proven in wind tunnels). Where area is controlled and the wind is in just the right range, this provides more lift. Slotted airfoils ALWAYS come at the cost of increased drag though. With the exception of limited area in just the right range where power is more important than lift/drag, this results in lower lift/drag and slower speed upwind.

Off the wind, say starting at around 40 deg apparent, a sloop starts looking less like a slotted airfoil and more like a biplane, it's pretty much pure biplane on an apparent beam reach, and as you go deeper it just turns into a mess. A sloop gets less and less efficient as you bear away. In contrast the una rig performs the same close hauled all the way beyond a broad reach*. From 40 deg apparent to DDW, the una is superior area for area. When colored sails come out then it's just a case of whose is bigger, easy enough to fly from either one. Tighter than 40 deg, the una rig is superior when powered up and maybe always - it depends on a lot of other factors as to whether the extra lift is worth the extra drag of the jib. Sloppy seaway and light wind might be an example. 

*On my boat, the Windex is mounted on the rotating mainmast, and the main is trimmed to the Windex as though it was close hauled, on any point of sail except DDW. 

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 - but my point is that for a modern or future boat, the rigs will be aerodynamically clean ... because future (and a small number of today's designs) are always going to be sailing to windward. Envisage slots and flaps that open for lift when course and wind conditions apply ...  and close flush for highest speed; same as an aircraft wing?

Tom Speer: http://www.tspeer.com/

“A single, symmetrical airfoil does not produce high lift and as a result the acceleration of a yacht so equipped is very poor. So rigid wing rigs typically have two or more symmetrical airfoils hinged so that they form a slotted flap when deflected. This produces more lift than the wingmast/sail combination.”

Argue with Mr Speer.

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Mr. Elkaim is badly mistaken. It's hard to know even where to begin in his paper, but we might as well start with his bibliography: I have several of those books and they say nothing like he is attributing to them. Some of his assertions do not pass even a rudimentary reality check and are at serious odds with all other researchers in the field, including the results of full size wind tunnel tests. The results of their experimental prototype also do not bear out anything like their predictions. I suggest he stay in school and study more. I'd suggest picking up a copy of Marchaj "Sail Performance" if you want facts rather than fiction. The main advantage of a wing over a soft sail is not an increase in lift, it is a reduction in drag, and a lot of that is due to planform rather than section. A properly shaped membrane airfoil section is actually pretty good, especially at low speeds. 

Mr. Speer is correct (as is Groucho - the two quotes are not incompatible). A rigid wing sailed boat is likely to have at least one flap, to vary the power, and this might be set at larger angles in light winds and flat, or even negative in heavy winds. On sailplanes we have full span flaps, these are set to a positive angle for slow thermaling flight and to negative angles for high speed cruise between thermals. A sailplane only has to operate efficiently over about a 3:1 air speed range (50 - 150 knots), in a sailboat more like 6:1 or even larger (5 - 30 knots) - that is the challenge for a hard wing. With a soft sail, you vary the area rather than the section for the most part. 

 

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On 3/22/2018 at 3:50 PM, DDW said:

Adapting a single airfoil to sailboats has practical problems, for which there are likely solutions given 100 years of development that the sloop has enjoyed. Already where these practical problems can be ignored, the una rig rules. My boat is essentially a una rig, and in context seems to be equal or superior to the performance of a sloop, and it's my first try at it. 

The practical problems can't be ignored at sea when trying to make the best possible time in weather extremes.

C600 starts ~eight minutes in, Fujin appears briefly at 11:53 - https://youtu.be/Ww2Z4f-n5og?t=11m53s

 

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Sloop rigs are the default for performance, not necessarily because they are the  most inherently efficient, but because the name of the game is to carry as much sail  area, with as much luff length as possible off the shortest possible mast whilst minimising mast/luff interference. That brute efficiency trumps everything else.

Have a look at Merloe below.... Bearing in mind it could also carry a staysail (or even 2 as per the VOR boats).... how much more mast would you need to carry that amount of sail area on a una rig, and when you do shorten sail, where is all the redundant weight, and extra drag?

 

Given the amount of time, effort and money that has gone into perfecting stayed rigs, it is remarkable that unstayed ones are anywhere near them in performance.  Unstayed rigs will be way ahead when we think outside the box and use their potential instead of playing by stayed rig solutions and rules.    

A place to start is telescoping masts.  In the light, the sail area is up high where there is far more wind.    Reefing lowers the windage and the weight so is not the negative it is on conventional rigs.  The top mast can be very light as it is only used in light air, then lowered inside the next section.   Reefing/unreefing on any point of sail without having to drag the sail down against the stays enables area changes to be done quickly.    The sail shape is fixed and cut to suit the mast.    Instead of controlling the shape with highly loaded controls (cunningham, sheet, outhaul and rig tension) the fixed shape sail is simply extended or reduced.   Sail cloth is lighter and does not need to be high tech, battens are pre bent and rotate.  Sail trim becomes: Are we flying a hull? No; extend the rig.  Yes; think about reducing it.

Another area where unstayed has advantages is the ability to eliminate tracks and cars by tieing the sail to the mast.  This saves the weight and cost of tracks and cars in an area where weight is important, eliminates the lee side bubble and requires less sail shaping.    A  short flap on the opposite side to the sail to fair the windward side as well, allows a bigger diameter, lighter and stiffer mast while using far less sail cloth and battens than double sided sails. The result is similar to camber inducers and sock sails on moths and windsurfers, but without the hassle and limitations (hoisting/lowering).

A telescoping rig with a faired leading edge provides more sail, upwind and down, at lower overall weight and windage than a sloop rig.  And when the breeze increases, that area, weight and windage is easily reduced, along with the mast height.  

Merloe has a 30m high mast, carries 300 sq m upwind, 450 down and weighs 6.5 tons.  If the mast was 30% back from the bows and 70% of the mast was extended the sail area would be 51m (luff) x 15m (boom length plus bowsprit length, but at the stern)  x .8 (roach) = 611 sq m, more than twice as much upwind.  The boat would be lighter overall, and could be sailed by 3 instead of 6 people with less deck gear and loads.  If the mast was in 4 sections, the rig height and weight of the fully reefed mast would be about 12m.  Less than half as high, with much less windage than the reefed stayed rig.   The weight in the bow and a 15m boom might be a challenge on a boat designed for a stayed rig, in which case, two masts would be more managable.

If "the name of the game is to carry as much sail  area, with as much luff length as possible", there are better, cheaper, more reliable and easier ways to achieve it than stayed sloop rigs.    

 

Or even build it in to the boat design, and make it a triple system: Main sheet, main halyard, and jib sheet. Fast depowering, and easy enough to winch back into place. And you could put a shock-absorbing snubber on the pulley to keep it from banging up your boat when triggered / released! I knew I'd get my snubber in there!

The latest version has the sheave on the rotating arm.  When it rotates, the sheet falls off and straightens out under the bridgedeck,  so no snubber required.  Sorry. .-)

DDW,

Thanks for the history lesson.  Good to know harryproas have another 80 years or so to get popular.  ;-)

Solarbri,

Thanks.

 

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Quote

...

A place to start is telescoping masts.  In the light, the sail area is up high where there is far more wind.    Reefing lowers the windage and the weight so is not the negative it is on conventional rigs.  The top mast can be very light as it is only used in light air, then lowered inside the next section.   Reefing/unreefing on any point of sail without having to drag the sail down against the stays enables area changes to be done quickly.    The sail shape is fixed and cut to suit the mast.    Instead of controlling the shape with highly loaded controls (cunningham, sheet, outhaul and rig tension) the fixed shape sail is simply extended or reduced.   Sail cloth is lighter and does not need to be high tech, battens are pre bent and rotate.  Sail trim becomes: Are we flying a hull? No; extend the rig.  Yes; think about reducing it.

Another area where unstayed has advantages is the ability to eliminate tracks and cars by tieing the sail to the mast.  This saves the weight and cost of tracks and cars in an area where weight is important, eliminates the lee side bubble and requires less sail shaping.    A  short flap on the opposite side to the sail to fair the windward side as well, allows a bigger diameter, lighter and stiffer mast while using far less sail cloth and battens than double sided sails. The result is similar to camber inducers and sock sails on moths and windsurfers, but without the hassle and limitations (hoisting/lowering).

...

Very interesting discussion. Would you mind clarifying some points ? If the battens are pre-bent they need also to rotate on their axis when switching sides on the mast ? How do you prevent the interference of telescoping with the mast ties ? The short flap is thus not fixed to the main sail and is its own slender battened sail ?  If so it could be fully reefed when going downwind or pushed out wing-to-wing ?   

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13 hours ago, ProaSailor said:

The practical problems can't be ignored at sea when trying to make the best possible time in weather extremes.

 

They can't be ignored - but they probably can be solved so that they are no longer problems.

11 hours ago, harryproa said:

A telescoping rig with a faired leading edge provides more sail, upwind and down, at lower overall weight and windage than a sloop rig.  And when the breeze increases, that area, weight and windage is easily reduced, along with the mast height.  

Sailplanes, as I mentioned above, have somewhat the same problem of operating over a large speed range. As a result, in light weather Open Class sailplanes are unbeatable (wing spans up to 27+ meters) but in strong conditions which favor fast cruising, a 15 meter span will often beat the Open Class. There is only so much you can do with flaps to reduce the drag of the long span. Many years ago in Germany, a sailplane was constructed with telescoping wings in an attempt to overcome this problem. It achieved some of its goals, but ultimately the complexity outweighed the advantages. 

On a sailboat, there are many differences, but the complexity is still there in a telescoping rig. It would be interesting to have an unlimited budget to explore these avenues, but without that we have only the Gedanken experiment. A una rig has to be big enough to carry the entire working sail area for say 10 knots. Above that one might use flying sails if in a hurry. If the available area to rig for a sloop is mast height x length, the una rig is more like mast height x 2/3 length, and perhaps less. So the mast height must be 1.5 x the sloop. Except that, a square head full battened sail una rig approximates an elliptical planform, and a half ellipse with the same height, and 2/3 the base, has more area than the triangular bermudan sloop rig, not less. You can get a very small mount of that area on a sloop with battens, but because of the backstay not very much. 

Also, a stayed rig mast has to be stiffest in the middle of each panel, the practical result being that the mast can be tapered only towards the very tip. A cantilever mast is normally tapered in both section and wall thickness such that the CG is very low by comparison. My mast stands 64 feet above the water, but the CG is only 21' above the water. If an extra 5' were added to the top, it would be a light, small section that would add very little to weight (about 1%) or CG height (a couple of inches).

The windage of an unstayed rig is already much lower than a Marconi, and if it is a shaped section, much lower still. 

All of which argues that there may be no need for a telescoping rig, just make it how high it needs to be. A soft una sail can be reefed to zero area. You are left with the mast, already low windage. One of the practical issues is there is still lift from a shaped section, and this might be unwanted (at anchor for example) so on a cruising boat a round section might be more desirable. The increase in drag and reduction of lift is actually quite small (this has been both wind tunnel and practically tested). There are certain conditions (very light wind, <4 knots) when the reduction of lift is more problematic. 

From my own experience, a pure una rig has some undesirable seakeeping characteristics: you cannot heave to, and cannot control the boat without steerageway. That is why I added the small mizzen on my rig to make a cat yawl. It has been quite effective at solving those problems, as well as a couple more. For a 20,000 lbs + cruising boat, the single driving sail gets pretty big, which becomes a problem. Modern gear lets you handle it with little effort, until something goes wrong - then sails less than 500 sq ft start looking real attractive. 

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I am willing to bet that another undesirable characteristic is additional pitching and pounding due to the mast being so far forward. And maybe mast pump/whip.

And now you confirm that you need a vestigial sail aft for practical purposes. As with Grouch’s Skimmer, I would suggest that if you could start again, you should move the main mast further aft, ditch the mizzen mast and boom and put on a (even vestigial) jib, which would be of greater performance benefit all round...

Have a look at the Radford 12 sometime, which is available as either cat rigged or sloop rigged. You could saw off the extra 6 ft of mast and make the mainsail square headed for a fat ellipse plan shape and equalise the working sail area, but if you put runners or ditched the backstay and put a fathead on the sloop main, as so many other performance sloops have done, you would be miles ahead, and that is before you hoist a gennaker or code zero or spinnaker. Plus staysail(s) of course.

You have suggested that for a una rig 1 1/2 mast height is what you need for sloop equivalency. Using Seagul’s suggestion of the M32 cat (which coincidentally is pretty much the same area, plan shape and mast height as Bucket List) to cover for some of the area in the gennaker, the mast height would have to go from 17 metres to 25 metres. On a 10 metre long boat. Good luck with that.

A long time ago, I did a calculation on Bucket List for harryproa, it is on SA somewhere, shortening the mast and adding foresail(s) and the extra raw sail area added due to the reduced CE height put another 3 knots to its Base Speed. Plenty in hand for any theoretical inefficiencies?

Ask any structural engineer and he will tell you that the most inefficient way to support a span is to do a cantilever. Propped cantilevers will beat it every time, especially if the props are well apart, as is the case with all Multihulls. And you can vary the props and spans to suit any particular application, especially to minimise mast pumping and whipping. For any given length of mast above deck, a stayed rig will always be lighter and smaller in section than a cantilever mast. Moths must be doing it wrong?

From my limited understanding of aeronautics, I thought that one of the main purposes of slots was to increase/maximise leading edge lift area relative to trailing edge drag area. So a sloop inherently doubles luff/leading edge area, streamlines the forestay with no mast shadow in front of it. 

You use A class cats as a good una rig example. They are stunningly efficient and beautiful. But I would say that they are they are the exception which proves the rule, a perfect balance of scale, practicality and sail area for a single handler on flat water in limited  wind speeds. And even then, you have to be pretty skilled to sail one well..... Take away the sail area restriction and it would be interesting to see what you would get?

When Melvin & Morelli, VPLP and others, whose work mostly isn’t genuflecting to tradition, a rule or a rating start using (cantilevered) una rigs, I will be finally converted.
 

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Nothing more to say. I am happy for everyone to draw their own conclusions and go their own way...... I have.

4CAD70DA-7EE2-4401-9F7E-2DAC299B7ACE.jpeg

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That sure is beautiful.  Could you explain some of the bits, such as the object below the aka?  Any video?

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1 hour ago, Sidecar said:

I am willing to bet that another undesirable characteristic is additional pitching and pounding due to the mast being so far forward. And maybe mast pump/whip.

And now you confirm that you need a vestigial sail aft for practical purposes. As with Grouch’s Skimmer, I would suggest that if you could start again, you should move the main mast further aft, ditch the mizzen mast and boom and put on a (even vestigial) jib, which would be of greater performance benefit all round...

Have a look at the Radford 12 sometime, which is available as either cat rigged or sloop rigged. You could saw off the extra 6 ft of mast and make the mainsail square headed for a fat ellipse plan shape and equalise the working sail area, but if you put runners or ditched the backstay and put a fathead on the sloop main, as so many other performance sloops have done, you would be miles ahead, and that is before you hoist a gennaker or code zero or spinnaker. Plus staysail(s) of course.

You have suggested that for a una rig 1 1/2 mast height is what you need for sloop equivalency. Using Seagul’s suggestion of the M32 cat (which coincidentally is pretty much the same area, plan shape and mast height as Bucket List) to cover for some of the area in the gennaker, the mast height would have to go from 17 metres to 25 metres. On a 10 metre long boat. Good luck with that.

A long time ago, I did a calculation on Bucket List for harryproa, it is on SA somewhere, shortening the mast and adding foresail(s) and the extra raw sail area added due to the reduced CE height put another 3 knots to its Base Speed. Plenty in hand for any theoretical inefficiencies?

Ask any structural engineer and he will tell you that the most inefficient way to support a span is to do a cantilever. Propped cantilevers will beat it every time, especially if the props are well apart, as is the case with all Multihulls. And you can vary the props and spans to suit any particular application, especially to minimise mast pumping and whipping. For any given length of mast above deck, a stayed rig will always be lighter and smaller in section than a cantilever mast. Moths must be doing it wrong?

From my limited understanding of aeronautics, I thought that one of the main purposes of slots was to increase/maximise leading edge lift area relative to trailing edge drag area. So a sloop inherently doubles luff/leading edge area, streamlines the forestay with no mast shadow in front of it. 

You use A class cats as a good una rig example. They are stunningly efficient and beautiful. But I would say that they are they are the exception which proves the rule, a perfect balance of scale, practicality and sail area for a single handler on flat water in limited  wind speeds. And even then, you have to be pretty skilled to sail one well..... Take away the sail area restriction and it would be interesting to see what you would get?

When Melvin & Morelli, VPLP and others, whose work mostly isn’t genuflecting to tradition, a rule or a rating start using (cantilevered) una rigs, I will be finally converted.

Wow, I couldn't have said it better. I know that's not saying much, but the examples are good and I couldn't agree more. I like unstayed masts, but they just don't make sense on multihulls unless one just wanted to be different. I don't believe that bucket list ever sailed, so it's not a good comparison to anything except in theory.

I wish I could teleport to Tazzie and go for a ride on Sidecar. That rig looks like it has a low center of effort and gravity.

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2 hours ago, mundt said:

That sure is beautiful.  Could you explain some of the bits, such as the object below the aka?  Any video?

Work in progress...Lots still to sort out/modify and no video yet.

The bit below the aka is a laterally pivoting two way asymmetric centreboard. Canted 45 degrees outboard, it lifts the ama. Pop the board and the ama drops. Canted inboard it provides additional righting moment. Still working on the controls which theoretically can also be connected to a mainsheet. Ie auto dump/trim.

@ Russell: You are welcome any time, but I would rather sort the boat first, which will take some time given my other commitments, finances and health. FWIW Sidecar carries roughly the same sail area as Jester 2 on a 6ft shorter mast. The bare tapered HM carbon tube weighed 14 kg.

 

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Cool looking boat sidecar, a couple of questions. It looks like the jib is tacked on the ama but sheeted on the main hull, is this correct or am I viewing the photo wrong (and does this work)? Also in stronger winds does that thin carbon tube mast handle the loads as I thought carbon didn’t handle compression? I really like the idea of the pivoting centreboard. Keep up the good work, would be great to see a video.

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13 hours ago, Sidecar said:

From my limited understanding of aeronautics, I thought that one of the main purposes of slots was to increase/maximise leading edge lift area relative to trailing edge drag area. 

Just one minor point - the one main goal of slats/flaps is to increase the wing's lift coefficient at slower speeds (no one wants to land at high speeds if avoidable).  The same amount of lift is created and while you need to design it properly there shouldn't be any fore/aft considerations.  

That's a pretty little boat btw.

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So much misinformation, so little time......

I have owned and sailed both una rigs and sloops - a lot - and speak from experience, not speculation.

14 hours ago, Sidecar said:

I am willing to bet that another undesirable characteristic is additional pitching and pounding due to the mast being so far forward. And maybe mast pump/whip.

If the mast is stepped well forward, there is an increase in polar moment (though the main contribution of any mast to polar moment is it's height, not its placement). With carbon masts there is no pump/whip.

And now you confirm that you need a vestigial sail aft for practical purposes. As with Grouch’s Skimmer, I would suggest that if you could start again, you should move the main mast further aft, ditch the mizzen mast and boom and put on a (even vestigial) jib, which would be of greater performance benefit all round...

The mizzen does many things a vestigial jib does not - but I think one or the other is a good idea for seakeeping. Neither adds to  performance. 


Have a look at the Radford 12 sometime, which is available as either cat rigged or sloop rigged. You could saw off the extra 6 ft of mast and make the mainsail square headed for a fat ellipse plan shape and equalise the working sail area, but if you put runners or ditched the backstay and put a fathead on the sloop main, as so many other performance sloops have done, you would be miles ahead, and that is before you hoist a gennaker or code zero or spinnaker. Plus staysail(s) of course.

Experience suggests that you would not be miles ahead, or ahead at all. And you have to deal with runners, a rig that does not work well downwind, etc. Spinnakers can be flown from a una rig for those conditions where it helps, which are rare. This has been covered up thread. Sloops require these sails in many conditions because it is such a poor rig downwind. In the US we have the Wylie sloops and the Wyliecat una rigs. There isn't much difference in rating, and rated non-spinnaker (the Wyliecats do not carry them) they are usually rated faster. 

You have suggested that for a una rig 1 1/2 mast height is what you need for sloop equivalency. Using Seagul’s suggestion of the M32 cat (which coincidentally is pretty much the same area, plan shape and mast height as Bucket List) to cover for some of the area in the gennaker, the mast height would have to go from 17 metres to 25 metres. On a 10 metre long boat. Good luck with that.

Even from your own example, you prove what I said in my post, had you read it. For triangular sails, you may need a higher mast, but with square head full battens you don't. On the Radfords, the mast is the same height and yet the sail area of the una rig is 100 sq ft MORE.


A long time ago, I did a calculation on Bucket List for harryproa, it is on SA somewhere, shortening the mast and adding foresail(s) and the extra raw sail area added due to the reduced CE height put another 3 knots to its Base Speed. Plenty in hand for any theoretical inefficiencies?

Calculations on an unbuilt boat of an unconventional type, using not well studied aerodynamic formula, by a non-believer, are suspect. Come sail with me on my boat. 

Ask any structural engineer and he will tell you that the most inefficient way to support a span is to do a cantilever. Propped cantilevers will beat it every time, especially if the props are well apart, as is the case with all Multihulls. And you can vary the props and spans to suit any particular application, especially to minimise mast pumping and whipping. For any given length of mast above deck, a stayed rig will always be lighter and smaller in section than a cantilever mast. Moths must be doing it wrong?

You must not be a structural engineer. It depends on many factors you are not considering. "always be lighter" is simply not correct. Mast whipping and pumping are not a problem on an unstayed rig, this is an artifact mainly of Euler compression induced in a stayed rig. There is a reason that nearly all aircraft (and all performance aircraft) are built with cantilever spars, even though weight in an aircraft is of far greater consequence than a sailboat. 

From my limited understanding of aeronautics, I thought that one of the main purposes of slots was to increase/maximise leading edge lift area relative to trailing edge drag area. So a sloop inherently doubles luff/leading edge area, streamlines the forestay with no mast shadow in front of it. 

Your understanding of aerodynamics is indeed limited. The purpose of a slot is to delay separation, allowing operation at higher angles of attack. This enables higher lift, but also higher drag. The L/D ratio of a slotted airfoil is NEVER better than an unslotted airfoil. Airplanes only use them when high lift/high drag is appropriate, typically take off and landing. The "mast shadow" is of little consequence in a modern Una rig, and actually beneficial if the mast is shaped. This has been proven in wind tunnels and on the water. The sharp leading edge of a jib isn't bad in low speed aerodynamics, but not ideal as it requires a different shape for every wind change. Look at Marchaj' wind tunnel tests of sloops vs. single sails. The sloops typically have a slighter higher Cl at stall, but higher drag everywhere. Off of close hauled, the inferiority of a sloop is dramatic, this has been proven both in the wind tunnel and in two boat testing on multiple occasions. 

You use A class cats as a good una rig example. They are stunningly efficient and beautiful. But I would say that they are they are the exception which proves the rule, a perfect balance of scale, practicality and sail area for a single handler on flat water in limited  wind speeds. And even then, you have to be pretty skilled to sail one well..... Take away the sail area restriction and it would be interesting to see what you would get?

Not sure why you think it would change - at the same sail area a una rig has been proven more efficient, add more to both and what will be different? This isn't news, in C class cats jibs became obsolete in the mid 1960's are aren't making a comeback. 


When Melvin & Morelli, VPLP and others, whose work mostly isn’t genuflecting to tradition, a rule or a rating start using (cantilevered) una rigs, I will be finally converted.

You are conflating cantilever rigs and una rigs, they are orthogonal issues. When M&M were asked to design a boat to defend the 1988 Americas Cup with no constraints, they designed a una rig catamaran with a vestigial jib. The jib was used mainly (as on Acup cats now) for maneuvering. That was the dark ages of materials science, even now I would not expect an all out racing cat to use a cantilever mast - as discussed well up thread on a cat it is inconvenient structurally, though possible. As materials science advances, this is likely to change. A boat like the Radford was impractical in wood and works much better in carbon than aluminum. Materials now in the lab have many times the strength and stiffness of carbon. These improvements will benefit cantilevers, more than compression members. 
 

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2 hours ago, us7070 said:

VPLP have an idea for an unstayed wing mast...

apparently it furls

885-8.jpg

Amazing how well it works in a rendering

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Hell, VPLP couldn't keep a conventional CF rig in one of their big cats MOUSETRAP for more than a couple years at a time. Two dismastings, the first killed a crewmember.

http://riggingnews.com/2013/04/dismasting-fatality-confirmed.html

Apr 2013

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Crew fatality on board superyacht ‘Mousetrap’ Lulu Trask iconcommentsgrey.png

 

The Cayman Islands Shipping Registry has confirmed the fatality of a crewmember on board JFA’s 33.5m catamaran sailing yachtMousetrap.

Media reports from St Maarten, which is where the vessel was reportedly located prior to the incident, claim the crewmember was hit by a mast cable, though The Crew Report cannot confirm this information. A source close to the yacht confirmed to The Crew Reportthat the crewmember in question was not the yacht's captain.

Mousetrap is a 33.5m catamaran sailing yacht built by JFA Chantier Naval last year and launched in July 2012. The vessel’s flag is that of the Cayman Islands, who will be conducting an investigation into the reported incident. 

The Cayman Islands Shipping registry told The Crew Report: “We have been made aware [of] the fatality of a crewmember on board the vessel Mousetrap and will be conducting our own investigation. No further details are available at this time and our thoughts are with the family of the deceased.”

The Crew Report got in contact with the general manager Etienne Taquin of Marina Fort Louis in St Martin, who confirmed Mousetrap is located at the marina and the sailing yacht is without a mast. Taquin also confirmed: "[The] accident and death of a crewmember has been acknowledged by police, gendarmerie [and] firemen of St Martin."

NM-332285.jpg

Second rig

nDXqjFs.jpg

 

    They kept the second dismasting out of the press for the most part.

 

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We saw Mousetrap pull into Moorea when we were there last year. It really is an awesome sight to see and it will probably be the first catamaran superyacht to visit Oz where it plans to visit some time this year (also NZ) Hopefully they have the rig problems sorted by now.

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2 hours ago, Rasputin22 said:

Hell, VPLP couldn't keep a conventional CF rig in one of their big cats MOUSETRAP for more than a couple years at a time. Two dismastings, the first killed a crewmember.

http://riggingnews.com/2013/04/dismasting-fatality-confirmed.html

http://www.jfa-yachts.com/en/Yachts/mousetrap-catamaran-110-2/

Quote
  • Water Line Length: 33 m
  • Beam: 14,05 m
  • Displacement: 120 tons

Mousetrap-carbon-catamaran-jfa-yachts-vp

Drastically overweight!!!

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5 hours ago, Rasputin22 said:

claim the crewmember was hit by a mast cable, though The Crew Report cannot confirm this information.

Well that's one problem you won't have with an unstayed rig. 

In all seriousness, on a stayed rig there are 50 or even 100 items each of which is critical to the integrity of the rig. On an unstayed rig there is about 1. 

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On 3/26/2018 at 10:03 PM, harryproa said:

Given the amount of time, effort and money that has gone into perfecting stayed rigs, it is remarkable that unstayed ones are anywhere near them in performance.  Unstayed rigs will be way ahead when we think outside the box and use their potential instead of playing by stayed rig solutions and rules.   

The physics just doesn't convince me. When some technology comes along that replaces stays on construction cranes, then maybe. Until then, the leverage of wires looks unbeatable to me. (Although the argument about aircraft spars is a good one. I'm guessing that aircraft speeds / drag over time cost too much fuel to keep wires as part of the design if you don't have to. Not such a big deal under sail).

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On 3/30/2018 at 3:29 PM, ProaSailor said:

Drastically overweight!!!

Drastically high boom / CE / CM too! What's that ratio called in naval architecture?

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1 hour ago, dcnblues said:

The physics just doesn't convince me. When some technology comes along that replaces stays on construction cranes, then maybe. Until then, the leverage of wires looks unbeatable to me. (Although the argument about aircraft spars is a good one. I'm guessing that aircraft speeds / drag over time cost too much fuel to keep wires as part of the design if you don't have to. Not such a big deal under sail).

Nearly all onsite construction cranes are cantilever trusses. It is extremely rare to see one with stays keeping it upright. Not that they share much in common with boat masts.

The lift to drag ratio of the rig directly and proportionately affects your pointing angle. If you add one degree to your drag angle, you add one degree to your pointing angle. Downwind, not such a big deal. 

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5 hours ago, DDW said:

Nearly all onsite construction cranes are cantilever trusses. It is extremely rare to see one with stays keeping it upright. Not that they share much in common with boat masts.

 

Right, but what they do have in common is actually one of the major points of the unstayed rig, which is, the stays would be in the way!

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15 hours ago, DDW said:

Nearly all onsite construction cranes are cantilever trusses. It is extremely rare to see one with stays keeping it upright. Not that they share much in common with boat masts.

The lift to drag ratio of the rig directly and proportionately affects your pointing angle. If you add one degree to your drag angle, you add one degree to your pointing angle. Downwind, not such a big deal. 

s-l1600.jpg

 

Enough with the cranes.

I may have missed it , but after watching the recently completed MOTH (possibly the fastest and most efficient boat around a course in the world with pretty much zero design constraints on the mast) WORLDS there was not a single  "apparently" superior unstayed rig in sight.

Time to school these clowns DDW.

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DDW - a question;

can you let your rig luff on any point of sail?

if you are sailing DDW, can you just let the main luff so that the boom flags out over the foredeck?

or, is there some limit to how far forward the boom can go?

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7 hours ago, overlay said:
I may have missed it , but after watching the recently completed MOTH (possibly the fastest and most efficient boat around a course in the world with pretty much zero design constraints on the mast) WORLDS there was not a single  "apparently" superior unstayed rig in sight.

Time to school these clowns DDW.

The Moth class, while a development class, still has quite a few constraints - among them a severe limit on mast section (must fit through a 90 mm ring). Until material science advances a bit more that pretty much mandates stays. In development classes that are unrestricted there is more innovation in the rig. 

You see this more in racing rules with respect to jibs. While the rule might not say "thou shalt have a jib", the measurements etc. force you to. 

It also appears that Moths are using the rig for significant tuning on the mast to suit conditions. Certainly it is true that the more strings you have to pull, the more things you can change. For sails restricted to a single size, shaping may be the only thing you can do to optimize it. 

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7 hours ago, us7070 said:

DDW - a question;

can you let your rig luff on any point of sail?

if you are sailing DDW, can you just let the main luff so that the boom flags out over the foredeck?

or, is there some limit to how far forward the boom can go?

The rig will go around all the way, though there are some limits. The wiring service loop only allows about 200 deg. The halyards and reefing lines wrap and will eventually limit rotation. I kept the sheet short enough that it will stop the boom just short of 180 degrees, with still enough leverage to get it back again (once it's all the way forward or further, the sheet has no lever to pull on).

For reefing downwind, it is sufficient to let the boom out around 150 degrees or so, head up slightly so the waves are on the quarter and the sail is luffing, then reef like normal. I can strike the sail that way too, raising it is much more difficult because the batten ends catch on the lazyjacks going up and there is less control over all the angles in that situation. 

One of the issues that needed to be solved in the build was that all lines are led aft, and they wrap with mast rotation. I could find no one that had addressed that problem, most rotating mast rigs have reefing and halyard terminations on the mast. I built a full size model and with careful leads and tulip sheaves, got acceptable function at all normal mast angles.

This is at the dock, but you get the idea. The boom is 24' long with the sheet blocks about 20' back on it, so with 4 parts, the mainsheet is 280' or cordage:

Boom_Articulation1.jpg

 

The tulip sheaves allow for unfair angles to some extent. The turning blocks were custom made to split the angles to work on both tacks/gybes:

Mast_Blocks.jpg

Executed later in stainless steel:

Mast_Blocks2.jpg

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2 hours ago, DDW said:

The Moth class, while a development class, still has quite a few constraints - among them a severe limit on mast section (must fit through a 90 mm ring).

NO. You are just making stuff up now.

A moth mast is around 40mm or possibly less in diameter. Mothy's were are you?

If you reckon 90mm  aren't going to be big enough for an unstayed section then you are just bullshiting us.

Who would want to lug around all that material in a 90mm diameter section is beyond me.

 

The 90 mm bit  in the rule just refers to the bit sticking out the bottom of the sail. ie below the lower mast band . This is possibly so some clown doesn't exploit it as UNMEASURED sail area.

See rule..

8.6 Any boom spar section, or mast spar below the lower measurement band shall be capable of passing through a ring of 90mm internal diameter, excluding fittings. The area of these items shall not be included in the total measured area.

 

If you want a massive mast diameter then just make sure the lower measurement band is level with the deck.

And as it happens deck sweepers aren't slow.

If you want a solid wing sail then go your hardest. I'm pretty sure this has been tried. Hopefully a Mothy will chime in.

DDW your argument is looking hollow.

 

 

 

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