96 replies to this topic

[Doug Lord]

Check this out: From "Foilers!" http://foils.wordpress.com/

[zerothehero]

I think it looks very cool but what happens when it looses grip? Being so close to the surface I would thin cavitation would lead to a downward spiral of performance. True, untrue? Not trying to blow holes in it. I thinks it's cool, just seriously curious.

[Doug Lord]

I think it looks very cool but what happens when it looses grip? Being so close to the surface I would thin cavitation would lead to a downward spiral of performance. True, untrue? Not trying to blow holes in it. I thinks it's cool, just seriously curious.

==================
Hugh Welbourn can add more but basically if the foil comes to the surface thats because it is unloaded. To work well when loaded it needs to be one chord below the surface-if the load goes away and the thing surfaces-minimum drag when unloaded.

New DSS website: http://www.dynamicst...itysystems.com/

[DRIFTW00D]

Thanks for the post. I had NO IDEA!

Fish use a lot of fins for stability in 3 axes. How many more fins do lead needs to loose the lead completely?

What are they doing about break away when the fin hits something solid to a stop the can opener affect to hull side? Next is the cavity it rides in a water filled trunk below the water line in the cabin with all the leek problems of old centerboard trunks?

[hughw]

]What are they doing about break away when the fin hits something solid to a stop the can opener affect to hull side? Next is the cavity it rides in a water filled trunk below the water line in the cabin with all the leek problems of old centerboard trunks?


Same as the open 60's and multis do for their daggerboards - the hull exit is well reinforced so the board will break first - and it is designed to do this - in the event of a serious impact.

Yes we do have a casing through the boat with a sump in effect for the drive system - but unlike the canters this does not pressurise so its not an issue for sealing off. Also, there are multiple containment levels to deal with problems if they should occur.
Structurally it is not that hard a problem - we're operating in a reinforced keel area anyway.

[overbend]

But it is till dragging a big lump of lead through the water with all the inherent displacement and drag issues that creates, it will always be slow compared to a non-ballasted boat.
Get rid of the lead and it will go much faster - but to do that the foil thing will need to up out of the water and attached to another vertical lifting or buoyancy component thing to create speed and stability, oh yeah, thats called a multihull

[duncan (the other one)]

flying my ass.. that video is sped up when under kite at about 1min.

If the thing goes in and out at the touch of a button, how about some solid comparative numbers.

[zzrider]

flying my ass.. that video is sped up when under kite at about 1min.

If the thing goes in and out at the touch of a button, how about some solid comparative numbers.

I'm struggling with this too... I can see where the stability imparted by the wing could reduce the amount of ballast needed to achieve the same effect, the question is, how much ballast does it replace? Obviously there is a tradeoff - drag. I'd be curious to see what that horizontal plane does in a lumpy sea state as well.

It's not for me; I like simplicity and I don't know if I'd ever be comfortable with a motorized thing piercing the hull below the waterline on both sides though (hell just keelbolts give me anxiety). Mad props to the DSS folks for trying something new though.

[narecet]

The website claims that the resulting boats will be cheaper to build, faster, safer, more comfortable, and easier to sail. Cruising yachts will have the advantage of better being able to avoid bad weather thanks to the higher speed. No tradeoffs in any way, just pure and significant advantage in every regard.

I'm all for any boats that actually combine all these things at the same time. We will see.

It appears that the claims of 10 knots more speed and 40% more speed aren't presently being put out anymore, though on the other hand has there been a specific retraction?

[BalticBandit]

flying my ass.. that video is sped up when under kite at about 1min.

If the thing goes in and out at the touch of a button, how about some solid comparative numbers.

I'm struggling with this too... I can see where the stability imparted by the wing could reduce the amount of ballast needed to achieve the same effect, the question is, how much ballast does it replace? Obviously there is a tradeoff - drag. I'd be curious to see what that horizontal plane does in a lumpy sea state as well.

It's not for me; I like simplicity and I don't know if I'd ever be comfortable with a motorized thing piercing the hull below the waterline on both sides though (hell just keelbolts give me anxiety). Mad props to the DSS folks for trying something new though.

Yeah the claim dougie put forth that it only loses lift when unloaded is a bit of bunkum as well. foils like that are very close to the surface, so a chaotic and aerated sea state that you would experience in heavy weather would also cause unloading.

There's no question its a cool approach - essentially like "Veel Heel" on the foiler moths, but as they point out - it works better with larger yachts where you can immerse it more deeply and which already has a reduced pitching moment.

Now we know it works pretty well for Cruise Liner sized ships where they use actual articulating and non-retractible stabilizing fins - so its not that far out there.

[Doug Lord]

Yeah the claim dougie put forth that it only loses lift when unloaded is a bit of bunkum as well. foils like that are very close to the surface, so a chaotic and aerated sea state that you would experience in heavy weather would also cause unloading.

There's no question its a cool approach - essentially like "Veel Heel" on the foiler moths, but as they point out - it works better with larger yachts where you can immerse it more deeply and which already has a reduced pitching moment.

Now we know it works pretty well for Cruise Liner sized ships where they use actual articulating and non-retractible stabilizing fins - so its not that far out there.

==================
Hugh Welbourn can add more but basically if the foil comes to the surface thats because it is unloaded. To work well when loaded it needs to be one chord below the surface-if the load goes away and the thing surfaces-minimum drag when unloaded.

New DSS website: http://www.dynamicst...itysystems.com/

=================
No such claim was made: what was said that if the foil rises to breach the surface it is not loaded-nothing was said about losing lift. Further,DSS boats have been sailed in all kinds of conditions with no untoward behavior of the foil. The Quant 28DSS was raced all summer and won the Bol D'OR in class and won class or overall in two or three other regattas.


http://forums.sailinganarchy.com/index.php?showtopic=136009


http://www.boatdesign.net/forums/sailboats/quant-28-foil-assist-keelboat-dss-38421-7.html


Quant 28 moving fast:

[Doug Lord]

The website claims that the resulting boats will be cheaper to build, faster, safer, more comfortable, and easier to sail. Cruising yachts will have the advantage of better being able to avoid bad weather thanks to the higher speed. No tradeoffs in any way, just pure and significant advantage in every regard.

I'm all for any boats that actually combine all these things at the same time. We will see.

It appears that the claims of 10 knots more speed and 40% more speed aren't presently being put out anymore, though on the other hand has there been a specific retraction?

=======================
A guy using the name "Trenace" on the sport boat forum was told specifically(by the owner builder of the Quant 28) that the claim of 40% more speed was never made on behalf of DSS.
"10 knots more speed" is just silly-what size boat? what windspeed? Not made by anyone connected with DSS.

[zzrider]

The website claims that the resulting boats will be cheaper to build, faster, safer, more comfortable, and easier to sail. Cruising yachts will have the advantage of better being able to avoid bad weather thanks to the higher speed. No tradeoffs in any way, just pure and significant advantage in every regard.

I'm all for any boats that actually combine all these things at the same time. We will see.

The "cheaper to build" claim is puzzling to me.... unless I'm missing something, this boat is essentially a regular fixed-keel monohull, with the added complexity of the moving horizontal foil. Where is the cost savings in building? Less lead in the keel?

[Glitter In The Eye]

i dont see how it would be faster. stable yes faster no.

[Bow Monkey]

First I'll just say that this thing is pretty damned cool. I'm curious to see how well it'll work in a real world racing scenario though. Mostly, I'm wondering about tacking in big seas and heavy air. If you catch a wave wrong while tacking in big breeze, your speed will fall waaaaaaaaaaaaay off. I would think you'd find yourself in a bit of a Catch-22 situation. The foil needs speed to create lift and generate righting moment. However, the boat needs righting moment in order to stay upright and generate speed. Would you just find yourself flogging along, or does this thing still carry enough lead underneath to get going?

I won't even go into how many new owners are going to find themselves hooking the anchor line of the weather mark when they're still getting used to the boat!

[narecet]

The website claims that the resulting boats will be cheaper to build, faster, safer, more comfortable, and easier to sail. Cruising yachts will have the advantage of better being able to avoid bad weather thanks to the higher speed. No tradeoffs in any way, just pure and significant advantage in every regard.

I'm all for any boats that actually combine all these things at the same time. We will see.

The "cheaper to build" claim is puzzling to me.... unless I'm missing something, this boat is essentially a regular fixed-keel monohull, with the added complexity of the moving horizontal foil. Where is the cost savings in building? Less lead in the keel?

OK, to be clear, as personal opinion I think it's unlikely that any technology, short of perhaps some remarkable advance in composite construction, is going to accomplish to substantial extent as many positive things as this simultaneously with no tradeoffs. Tradeoffs almost always exist, and substantial new benefits almost always cost money. When I read claims like the above I become suspicious and want to see evidence, just as happened before with the very large, numerically-specific claimed speed increases that apparently never have been substantiated.

However, that said, I suspect that "compared to what?" justifications can be made.

Cheaper than a canting keel, I'd think.

Faster than a Hunter.

And so forth.

Also, let's say we disallow such cheap escapes and still want to find something. Arguably -- assuming that the previously-stated licensing cost comparable to the price of a new mainsail has been reduced to something making more business sense -- then for example conceivably a boat with the same speed might require sufficiently less ballast (assuming ballast in the first place was enough in excess of that needed for specified capsize stability) to allow a sufficiently smaller rig to yield an overall cost savings. Perhaps. We will see when Infiniti announces pricing.

But for example, really making enough speed difference to significantly improve safety for cruising yachts with regard to weather routing, while also being cheaper to build, overall-safer, etc, as well? Sure, Banque Populaire takes control of the weather (so to speak) with her speed, but... I will have to see it before thinking much of the claim that enough speed increase really to change weather routing is going to be seen in cruising yachts from this. For example.

[eliboat]

Yeah...still a lead bulb there, so I doubt that there is an advantage over a canting keel boat or even a lifting keel boat. Same old problem. Less weight (lose the keel), less drag (narrow as possible), Lots of righting moment... At the end of the day, the best solution always ends up being a multihull, assuming you're not foiling, which raises the theoretical bar quite a bit.

[Ryley]

i dont see how it would be faster. stable yes faster no.

I think the process is that since you are gaining lift on the leeward side, more of the effect in the sails go to speed rather than heeling moment, the boat is easier to balance, and can remain powered up longer than a rig that is constantly getting knocked on its ear.

But maybe I'm wrong.

[Par Avion]

i dont see how it would be faster. stable yes faster no.

This.

I love seeing new tricks, especially when they can change the game entirely. Props for getting this this far.

While it does seem like it will be incredibly more stable, I don't see how dragging an additional foil through the water will make the boat faster. I guess this warrents the question, by what degree of heel do we need this to increase performance. Certainly, in light air, with little heel, this thing is worthless.

[duncan (the other one)]

i dont see how it would be faster. stable yes faster no.

This.

I love seeing new tricks, especially when they can change the game entirely. Props for getting this this far.

While it does seem like it will be incredibly more stable, I don't see how dragging an additional foil through the water will make the boat faster. I guess this warrents the question, by what degree of heel do we need this to increase performance. Certainly, in light air, with little heel, this thing is worthless.

I don't think it has to heel..

The light air problems are taken care of by retracting.. so we're ok there.

Presumably, you get a better lift/drag ratio from the foil than you do the hull at speed.. so it helps there. Plus you have the RM at anything above 0 angle of heel. Severe angles of heel it hinders you, as you're getting pulled to leeward.

[BalticBandit]

i dont see how it would be faster. stable yes faster no.

This.

I love seeing new tricks, especially when they can change the game entirely. Props for getting this this far.

While it does seem like it will be incredibly more stable, I don't see how dragging an additional foil through the water will make the boat faster. I guess this warrents the question, by what degree of heel do we need this to increase performance. Certainly, in light air, with little heel, this thing is worthless.

I don't think it has to heel..

The light air problems are taken care of by retracting.. so we're ok there.

Presumably, you get a better lift/drag ratio from the foil than you do the hull at speed.. so it helps there. Plus you have the RM at anything above 0 angle of heel. Severe angles of heel it hinders you, as you're getting pulled to leeward.

You'd also get away with a lighter structure to hold the keel since you are carrying slightly less loads here (BTW Ryley physics of sails doesn't quite work that way). Tacking in a big sea way? or wind? Do what skiffs do - nose down with eased sails to get speed and THEN come up.

[bruno]

Fan of this, good way to take weight out andvreduce wetted surface. Justvwould be nervous in Maine orvkelpbeds. Monomarans usually cheaper than multis. Watching that JS9000 vid noticed what looked like 8' draft on 5' beam, this would make it more feasible, shallower.

[mezaire]

Am a bit dumbfounded by people comments on how or why it would make the boat faster. Do you understand sailing and basic physics?
Did you guys say the same thing about the first foiling moth?

As far as I see it the DSS system basically gives you three major advantages;
1. When sailing upwind the foil creates lift on the leeward side giving more RM
2. when sailing down wind the foil gives the boat lift and makes it far more stable. eg. less digging the bow in
3. Less weight needed in the bulb

If any or all of these things make the boat faster than the added wetted surface area makes it slower then you are onto a winner.

I think it could eventually take oner from canters. Unlike canters where if the canting system fails you are basically jumping in a raft, with DSS the boat still has a decent bulb and would sail fine with reduced sail area.

I honestly think this is the biggest game changer since canters and probably the biggest thing stopping it is the fact it is licensed and you can't just go and build your own 40 footer with DSS like you can a canting system.

[duncan (the other one)]

Am a bit dumbfounded by people comments on how or why it would make the boat faster. Do you understand sailing and basic physics?
Did you guys say the same thing about the first foiling moth?

.. how much of the range from zero to liftoff is a foiling moth faster than a non-foiler?

Does the DSS easily get to the point where the extra lift from the foil is beneficial (other than for RM)?

These are easy to test.. run downwind with the thing, press those magic buttons and watch the speed.

[mezaire]

Am a bit dumbfounded by people comments on how or why it would make the boat faster. Do you understand sailing and basic physics?
Did you guys say the same thing about the first foiling moth?

.. how much of the range from zero to liftoff is a foiling moth faster than a non-foiler?

Does the DSS easily get to the point where the extra lift from the foil is beneficial (other than for RM)?

These are easy to test.. run downwind with the thing, press those magic buttons and watch the speed.

I guess the biggest difference with the DSS over a moth is the ability to pretty much retract the foil inside the hull, reducing wetted surface but still keeping the weight down.

I'm sure the guys running this program have done tests like this. Sail uphill in 5 knots and try the foil at different lengths. Repeat for 10, 15, 20 knots etc.
My guess is as soon as you move the crew to the top side then the foil is worth using to leeward.

As for the foiling Moths, I think it's a fairly mute point as a Moth with or without foils is pretty hard to sail in sub 5 knots and the foilers are up and flying in 10 knots so there isn't much of a window for the non-foilers to capatilize. As I said above the advantage for DSS is it is mostly retractable.

[By the lee]

Bah. Wings on sailboats. Next you'll be tellin' me they gonna' put blub keels on aeroplanes.........

[duncan (the other one)]

Am a bit dumbfounded by people comments on how or why it would make the boat faster. Do you understand sailing and basic physics?
Did you guys say the same thing about the first foiling moth?

.. how much of the range from zero to liftoff is a foiling moth faster than a non-foiler?

Does the DSS easily get to the point where the extra lift from the foil is beneficial (other than for RM)?

These are easy to test.. run downwind with the thing, press those magic buttons and watch the speed.

I guess the biggest difference with the DSS over a moth is the ability to pretty much retract the foil inside the hull, reducing wetted surface but still keeping the weight down.

I'm sure the guys running this program have done tests like this. Sail uphill in 5 knots and try the foil at different lengths. Repeat for 10, 15, 20 knots etc.
My guess is as soon as you move the crew to the top side then the foil is worth using to leeward.

As for the foiling Moths, I think it's a fairly mute point as a Moth with or without foils is pretty hard to sail in sub 5 knots and the foilers are up and flying in 10 knots so there isn't much of a window for the non-foilers to capatilize. As I said above the advantage for DSS is it is mostly retractable.

Agreedt... so why aren't they showing us the numbers?

[Tanton Y_M]

Side Boards.
www.tantonyachtdesign.blogspot.com
 316pic2-JL9-12.jpg   191.5K   13 downloads

[narecet]

It turns out that they are putting out numbers again, for the not-yet-built 100 footer. In six knots breeze, 11.12 knots at 75 degrees TWA, etc: http://www.yacht-zoo...resentation.pdf

Also speaking qualitatively, they say:

Infiniti Yachts are faster, smoother and lighter than any other superyacht, delivering a quantum increase in raw speed - for the yachtsman not prepared to compromise.

Infiniti Yachts blend extraordinary performance with an unsurpassed motion and perfect balance ensuring they comfortably reach cruising speeds far in excess of any other comparable superyacht - guaranteed.

So this basically seems the same, or highly similar to me, to the previous 10-knots / 40 percent faster claims which of course were computer-program-only with methods that could be questioned and a distinct lack of real-world results demonstrating such extreme increases.

It wouldn't surprise me that if you let a VPP calculate lift and drag the same way that it generally does for a foil that you'd get numbers far more favorable than actual, as the DSS foil is instead operating near-parallel to and close to the surface, as well as being adversely effected by waves and having less or nearly no end plate effect. Was custom code written for the VPP to account for this? If so how was it validated? Against boats actually sailing? My bet is not and certainly I've seen no fact saying that it was.

Which might explain the previous claims that reality never backed up and perhaps the current ones? I'm skeptical that it is going to be faster than any other superyacht, or have cruising speeds "far in excess" of comparable superyachts. Even if the computer says so for whatever reason. Need to see it. 

[Doug Lord]

You don't have to see numbers-go to the record of the Quant 28 in her first major races all thru the summer-see previous page for links. She won lst in class and in one she was 7th out of something like 270 other boats(while being 1st in class). In another, she was 1st out of 66 boats. Beating larger boats boat for boat. Unmatched performance in all conditions for a 28 footer..

[blunted]

Some of you cynics have missed some other good points that the system offers.

For starters as the boat speeds up, the wave drag and wetted surface drag is rising quite quickly. On a simple lift to drag ratio the horizontal foil is better at carrying displacement at speed than a hull, no matter how pretty you designed the hull. So as speeds rise, chock one up for the foils.

Next, the foil is lifting the boat, a little, or a lot, doesn't matter, it's reducing wetted surface area and disp applied to the hull so you reduce hull form drag, same point as above, just the other end of the situation.

Next, where do you guys calculate your center of buoancy from? Why do I ask? Well that's where your leverage begins for righting moment. Let's say the foil is taking 25% of the displacement of the boat at speed and it's a few feet to leeward of the hulls center of buoancy, well you just made your righting moment arm that much more effective. So the fulcrum has moved to leeward, everything to windward of that point is now helping to keep the boat flat and powered up. If this was a multihull, you just added two feet to the length of the beams and I can assure you that you would use that additional leverage to sheet harder and go faster.

Pitch and heave stability. Well an immersed foil helps your craft move smoothly through chop and sea for sure. It's down there in the fluid. Your hulls is sometimes in, sometimes out, and when ever it's going between those two states the breeze is not steady on the rig and you are pissing away power potential in the rig. Who wins, the guy with his foot on the pedal the whole time, or the stuttering car with a messed up distributor? No question, steady power wins every time. Not to mention that if the hull is getting just a little less immersed on every wave you have reduced wave and skin friction drag.

Granted you take a hit on the added friction of an immersed foil but it's extremely low.

As for complexity, sure, it's some extra holes in the hull etc, but I think sailors, designers and builders have been working with that problem for more than a few months now, perhaps a few decades if not hundreds of years. I suspect it can be sorted out.

Does it work at low speed? Sure, why not, if you're a low speed coming out of a tack in hairy conditions, ease the sails and just get the boat moving a bit, like every other wet foil on your boat works, unload it a bit, put some flow over it and she'll start working right away. Go faster, get more fun. Seems pretty simple to me. (If you're the type who just sheets the shit out of everything following a tack in any conditions, I know you will miss the point of this argument).

I say Bravo HB, been following your work for a while and I like it. Look forward to seeing SD on the water soon.

If I was in the market for a new boat any time soon that was limited to one hull, I would not hesitate to look for a DSS system in it, cruiser or racer it's all good.

Cheers

B

[narecet]

Some of you cynics have missed some other good points that the system offers.

For starters as the boat speeds up, the wave drag and wetted surface drag is rising quite quickly. On a simple lift to drag ratio the horizontal foil is better at carrying displacement at speed than a hull, no matter how pretty you designed the hull. So as speeds rise, chock one up for the foils.

It's rare to see someone combine the strawman and ad hominem approaches at the same time (labelling those you disagree with "cynics," and then purporting that they are doing things they are not and arguing against that.) But no matter: onto more substantive things, where possible.


Do you have a fact that a foil generates better L/D than the bouyancy-to-drag of the hull even when the foil is near-parallel to and close to the surface, particularly in the ocean?
Or is this a supposition?

I don't think anyone is saying that there are no good points. But, if you want to call others cynics, then perhaps you should be called gullible if you find little to no question as to whether it really is all good points with no tradeoffs and cheaper to build as well; and whether the claims of being faster than all other superyachts, etc are sufficiently backed up or are even warranted at all.

[blunted]

Some of you cynics have missed some other good points that the system offers.

For starters as the boat speeds up, the wave drag and wetted surface drag is rising quite quickly. On a simple lift to drag ratio the horizontal foil is better at carrying displacement at speed than a hull, no matter how pretty you designed the hull. So as speeds rise, chock one up for the foils.

It's rare to see someone combine the strawman and ad hominem approaches at the same time (labelling those you disagree with "cynics," and then purporting that they are doing things they are not.) But no matter: onto more substantive things, where possible.


Do you have a fact that this is so even when the foil is near-parallel to and close to the surface, even in flat water? How about with waves?

Or is this a supposition?

I don't think anyone is saying that there are no good points. But a question is to whether it really is all good points with no tradeoffs of any kind, and being cheaper to build at the same time to boot; and whether the claims of being faster than all other superyachts, etc, are sufficiently backed up.

Well as luck would have it I do have facts, but sadly I am not going to share my data here as in one case it is protected by legally binding non disclosure agreements and in another case(s), well I am simply not going to share my data.

As for the foil operating flat, sure it still generates lift. Here is a small hint, it's an assy foil. Try reading some simple texts like Theory of Wing Sections by Abbot and Von Doenhoff, it might be a revelation for you. If it's something like a NACA 64-412, it generates lift all the way down to a negative 2 degrees angle of attack and it's still inside the drag bucket all the way up to 3 degrees AOA.

I concede that if the foil is within a chord length of the surface it's not going to be optimum by any means, the drag rise will be substantial and you will potentially piss away any advantage you might have gained. To that I see two easy solutions, sheet harder, or deploy less foil and let the boat roll to leeward a few degrees to get it immersed properly again. This is you solution in waves too. A few degrees of heel can be your friend if you think the foil is ventilating or ratcheting up too much drag due to be too close to the surface.

Shame on me for assuming you could work your way through the simple mechanics like that on your own.

I don't seem to recall suggesting it had no compromises. It does, such is the nature of boat design. It's more complexity, it has more holes in the boat, it's more mechanical systems to design, build, operate, maintain and manage. It may have some unforeseen side effects. But I could see how you could easily trade off some bulb for foil and net out with less displacement over all.

nor do I recall making claims about how great a maxi boat will be etc. I think perhaps you are inserting words into my argument to build your own straw horse.

I don't think calling someone a cynic is an ad homenim argument. I sensed a genuine level of cynicsm on the part of a number of posters and I offered some counter points to consider.

Over to you.

To be clear, my non disclosure agreements are not with any team or person that has anything to do with DSS. so before you get all excited about potential conflict of interest, stow that shit.

B

Edit, I should clarify, above a certain boat speed, a foil is more efficient at carrying displacement that a well designed hull form. from a purely lift to drag perspective. This changes for each hull shape and is effected by size, reynolds numbers sea state etc. But in general, most hulls you see today, particularly anything sporty, can get to a speed where a foil will be more efficient than a displacement hull. Sorry I failed to make this distinction previously.

[narecet]

Ah, I see some apparent hostility.

And gullibility.

As well as a really condescending attitude, and thinking you know far more than you do. No airfoil data [edit: I'm referring to aeronautical sources, as cited in the above post] is going to treat the issue of a foil [edit: immersed foil] operating near-parallel to and close to the surface of the ocean. Your attempt to cite data regarding lift at zero or slightly negative AOA shows near zero grasp of what is being talked about and, in your case, a little knowledge is a dangerous thing. You have totally confused what was being talked about. I had said nothing about angle of attack. You've completely mixed up the issues.

I don't know what to make of your nonsense about me supposedly saying you made claims about how great a maxi boat will be. You seem to be making things up.

The party saying that this boat will be faster than all other superyachts is Infiniti.

I don't know why you're taking your above approaches, except that I suspect there is no rational way to answer the statements I posted that in any way legitimately refutes them. Either that or you are just very confused.

Personal opinion.

[blunted]

Ah, I see some apparent hostility.

And gullibility.

As well as a really condescending attitude, and thinking you know far more than you do. No airfoil data is going to treat the issue of a foil operating near-parallel to and close to the surface of the ocean. Your attempt to cite data regarding lift at zero or slightly negative AOA shows near zero grasp of what is being talked about and, in your case, a little knowledge is a dangerous thing. You have totally confused what was being talked about. I had said nothing about angle of attack. You've completely mixed up the issues.

I don't know what to make of your nonsense about me supposedly saying you made claims about how great a maxi boat will be. You seem to making things up.

The party saying that this boat will be faster than all other superyachts is Infiniti.

I don't know why you're taking your above approaches, except that there I suspect there is no rational way to answer the statements that I posted that in any way legitimately refutes them. So instead you posted the above stuff. Either that or you are just very confused.

Personal opinion.

OK, if you say so.

[Amati]

Some of you cynics have missed some other good points that the system offers.

For starters as the boat speeds up, the wave drag and wetted surface drag is rising quite quickly. On a simple lift to drag ratio the horizontal foil is better at carrying displacement at speed than a hull, no matter how pretty you designed the hull. So as speeds rise, chock one up for the foils.

Next, the foil is lifting the boat, a little, or a lot, doesn't matter, it's reducing wetted surface area and disp applied to the hull so you reduce hull form drag, same point as above, just the other end of the situation.

Next, where do you guys calculate your center of buoancy from? Why do I ask? Well that's where your leverage begins for righting moment. Let's say the foil is taking 25% of the displacement of the boat at speed and it's a few feet to leeward of the hulls center of buoancy, well you just made your righting moment arm that much more effective. So the fulcrum has moved to leeward, everything to windward of that point is now helping to keep the boat flat and powered up. If this was a multihull, you just added two feet to the length of the beams and I can assure you that you would use that additional leverage to sheet harder and go faster.

Pitch and heave stability. Well an immersed foil helps your craft move smoothly through chop and sea for sure. It's down there in the fluid. Your hulls is sometimes in, sometimes out, and when ever it's going between those two states the breeze is not steady on the rig and you are pissing away power potential in the rig. Who wins, the guy with his foot on the pedal the whole time, or the stuttering car with a messed up distributor? No question, steady power wins every time. Not to mention that if the hull is getting just a little less immersed on every wave you have reduced wave and skin friction drag.

Granted you take a hit on the added friction of an immersed foil but it's extremely low.

As for complexity, sure, it's some extra holes in the hull etc, but I think sailors, designers and builders have been working with that problem for more than a few months now, perhaps a few decades if not hundreds of years. I suspect it can be sorted out.

Does it work at low speed? Sure, why not, if you're a low speed coming out of a tack in hairy conditions, ease the sails and just get the boat moving a bit, like every other wet foil on your boat works, unload it a bit, put some flow over it and she'll start working right away. Go faster, get more fun. Seems pretty simple to me. (If you're the type who just sheets the shit out of everything following a tack in any conditions, I know you will miss the point of this argument).

I say Bravo HB, been following your work for a while and I like it. Look forward to seeing SD on the water soon.

If I was in the market for a new boat any time soon that was limited to one hull, I would not hesitate to look for a DSS system in it, cruiser or racer it's all good.

Cheers

B

What he said.

[duncan (the other one)]

blah blah blah....

numbers for a boat that hasn't hit the water are dubious - I don't trust modelling that much.

There's this 28 footer sailing.. Show me the measured polars with the foils extended and retracted.

It .. is .. that .. easy.

[Doug Lord]

blah blah blah....

numbers for a boat that hasn't hit the water are dubious - I don't trust modelling that much.

There's this 28 footer sailing.. Show me the measured polars with the foils extended and retracted.

It .. is .. that .. easy.

===================
Polars? When you can see concrete results? Thats really something........see the previous page and links.

[Christian]

It turns out that they are putting out numbers again, for the not-yet-built 100 footer. In six knots breeze, 11.12 knots at 75 degrees TWA, etc: http://www.yacht-zoo...resentation.pdf

Also speaking qualitatively, they say:

Infiniti Yachts are faster, smoother and lighter than any other superyacht, delivering a quantum increase in raw speed - for the yachtsman not prepared to compromise.

Infiniti Yachts blend extraordinary performance with an unsurpassed motion and perfect balance ensuring they comfortably reach cruising speeds far in excess of any other comparable superyacht - guaranteed.

So this basically seems the same, or highly similar to me, to the previous 10-knots / 40 percent faster claims which of course were computer-program-only with methods that could be questioned and a distinct lack of real-world results demonstrating such extreme increases.

It wouldn't surprise me that if you let a VPP calculate lift and drag the same way that it generally does for a foil that you'd get numbers far more favorable than actual, as the DSS foil is instead operating near-parallel to and close to the surface, as well as being adversely effected by waves and having less or nearly no end plate effect. Was custom code written for the VPP to account for this? If so how was it validated? Against boats actually sailing? My bet is not and certainly I've seen no fact saying that it was.

Which might explain the previous claims that reality never backed up and perhaps the current ones? I'm skeptical that it is going to be faster than any other superyacht, or have cruising speeds "far in excess" of comparable superyachts. Even if the computer says so for whatever reason. Need to see it.

It is pretty funny to see some of these claims. Every naval architect (even most amateur ones) know that testing usually is good for boats within +/- 50% in size, can give a hint of something within +100/-75% in size and outside this is pretty meaningless. When the "test boat numbers" is not even well defined the whole premise is a joke.



It will be interesting to see what the real numbers are - in time

[Doug Lord]

Real race results for the Quant 28 DSS right here: http://www.boatdesig...ss-38421-7.html

Picture from Quant 28 site-light air. Foil can be retracted so it sticks out to weather to reduce drag in these conditions:

Attached Files

•  Quant 28-daily sail boldor 2012.jpg   368.94K   46 downloads
•  Quant 28-Welbourn DSS.jpg   94.35K   42 downloads

[narecet]

Well, not that easy when the 100 foot boat has not been built.

On the 36 foot boat, they should be able to do that. Personally my interest would be in the actual performance when operating in best mode for each condition, versus other boats that seem logical matchups.

The same boat against itself with foil extended and not may not always be as meaningful as it might seem, because I suppose it would be a poor job of design for the boat without foil extended to be optimized for that condition. In other words, designing a proper DSS boat is presumably not identical to taking a given design, optimized for no DSS, and then adding the foil.

But if it were -- if in other words ballast would be the same, beam and hull shape would be the same, etc, then indeed that simple test would tell the whole story.

If however say ballast is reduced, or perhaps the boat is given a higher length to beam ratio for reduced drag as it is not so dependent on form stability, or other optimizations for when the foil is deployed, then the boat would be non-optimized with the foil retracted. Speed increase on extension of the foil might differ than from speed increase compared to a no-DSS optimized boat.

While it's generally desirable for all else to be held constant when making a comparison, sometimes the nature of a thing makes that not really possible. Here, for example, part of the benefit is supposed to be from reduced ballast. So for example if the optimized DSS boat would be sailing on its ear (I exaggerate) with the foil retracted when it absolutely SHOULD be deployed, then a large speed increase on deployment wouldn't necessarily be so meaningful. But yes, at a minimum, it should occur! And I suppose most likely does to at least some extent. The question is how much and what is the evidence, which given how many years DSS has been around I think is a fair question after all this time?

[Par Avion]

The fact that there are no hard numbers, speeds with vs those without should be enough to question it. I don't anyone is doubting that it could be better. Why are there no numbers though? This should be one of the easiest tests for new tech ever.

[duncan (the other one)]

Real race results for the Quant 28 DSS right here: http://www.boatdesig...ss-38421-7.html

Picture from Quant 28 site-light air. Foil can be retracted so it sticks out to weather to reduce drag in these conditions:

Doug... go away. I say that not because of this thread in particular, but every other thread in the world that you pollute.

Those results are meaningless. How would a Thirty year old Elliot have gone?

[Glitter In The Eye]

too lift something you have to press against something. so if you are lifting from the lee you are pressing to windward. does the better righting moment overcome the drag?

[Somebody Else]

I like the idea and look forward to more development.

In essence, it is a further development--a more efficient implementation--of the curved daggerboards being deployed on multis. Those are boats racing like-against-like and they seem convinced that the increased lift adds more than the increased drag detracts.

too lift something you have to press against something. so if you are lifting from the lee you are pressing to windward. does the better righting moment overcome the drag?

We get it. That subject was breached and laid to rest a few days ago. It's called lift-to-drag ratio and it's been understood for a century now.

I think you can answer your own question:
If you assume the designers and engineers have even the bare minimum engineering degree from any school on the planet, they are aware of lift-to-drag ratios and can calculate it. I think it would be safe to also assume that if the numbers didn't support their idea they would not have gone ahead and spent hundreds of thousands of money-units on the project. What do you think?

[narecet]

I like the idea and look forward to more development.

In essence, it is a further development--a more efficient implementation--of the curved daggerboards being deployed on multis.

More efficient?

How is much narrower righting arm and operating closer to the surface of the water more efficient? Unless you don't mean sailing efficiency but space efficiency. It is admirably space efficient.

[Somebody Else]

More efficient?

Yes.

You're a smart guy; you figure it out.

[narecet]

No, it would seem not as I don't get what you are saying.

I don't see where much shorter righting arm and operating closer to the surface of the water are efficiency-boosting features compared to the multihull foils.

And if you consider a foil providing both needed lift to windward and vertical lift at the same time, due to angle, to be less efficient than two foils at 90 degrees to each other, I'd disagree. For example, say that about 700 lb of lift is needed for both windward and vertical lift. (I'd agree that the numbers won't necessarily be identical, but this is an example.) One foil at 45 degrees can accomplish this while generating 1000 lb of hydrodynamic lift (as both the sin and cosin of 45 degrees are .707.) If using two foils at 90 degrees to each other, each needs to generate the 700 lb, for a total of 1400 lb needing to be generated. So what is more efficient about using two foils at 90 degrees instead of one angled foil? Not that I am saying that that is your meaning. I expect it's not.

So rather than ask me to figure out what you mean, which I can't or am missing, why not share with us? Not everyone has got what you are talking about, obviously, as I'm not assuming that you are relying on an angle argument like the above.

[Somebody Else]

A curved board provides vertical lift for a small percentage of its length; the rest of the length that is not being used as a normal daggerboard is parasitic.

The closeness to the surface of the water doesn't matter; at small angles of heel where it is closest to the surface, it is needed less (or not at all). The designer mentions efficiency is found around one chord beneath the surface. You think one chord isn't enough?

I don't think either of those two approaches to dynamic stability (one curved board or two straight boards at 90°) are the one final optimal solution. I think that the lift-to-drag ratios are within similar scopes. I "look forward to more development."

[narecet]

I believe that multihull boards are providing more or less the amount of vertical lift that the designers wish, as a proportion to the windward lift generated rather than being short of what they would want.

I am guessing the reason they are not angled more strongly is because they are already generating the vertical lift aimed for with the current angles and curvatures.

The more vertical portions of the foil aren't wasted, but instead are generating needed windward lift. The DSS boat also has this type of foil area but separated out into the keel, at 90 degrees to the DSS foil. I don't think this is more efficient than the multihull arrangement.

Perhaps I have seen too many DSS pics where the foil looked closer to the surface than one chord. It's possible I have a misimpression there. But I also question whether operating in the ocean, instead of in flat water, the foil is going to reliably be at least that deep. Despite all the time that DSS has been out, there seems no evidence of it being a super performer in the ocean, and at least some accounts of it giving apparently no advantage. For example, one of the boats has been racing against Shaw 650s etc and on elapsed time has finished DFL in nearly every race -- yes, I know, Doug has excuses -- and on the Sport Boat forum Steve has given what seems some insightful observations of seeing it actually racing in the ocean. Not all is completely rosy.

I think it needs to show itself rather than that there should be any assumption that it's nearly as fantastic as Doug says, or meets Infiniti's claims which at least in combination sound excessive and unlikely as personal opinion. It's certainly unproven in the ocean, and not really proved to be faster inshore or even on lakes either, though Quant28 has done well, but so have many non-DSS boats in many other races, obviously. Props to the Quant28 owner, the builder, and Hugh Welbourn for those results. I hope to see more good results.

[Catalina30]

Very cool, new ideas for sailing is always good. This is going to need plenty of mark room while racing =)

[narecet]

The closeness to the surface of the water doesn't matter; at small angles of heel where it is closest to the surface, it is needed less (or not at all).

I hadn't thought about it before but perhaps this introduces a bit of a paradox.

There's been a tendency thus far to put DSS on as skiff-like boats as possible, e.g. Brace Brace Brace. Quant 28 is very light also and while not racked, has big wings. For that matter even the hypothetical Infiniti 100, while obviously not a skiff, is slated to have a DLR of only about 33, which actually is lighter than skiffs' sailing displacement when counting crew weight.

Brace Brace Brace certainly should be sailed nearly flat I would think; the videos I've seen of Quant 28 are pretty flat. Certainly the crew is working to keep the boat fairly flat.

So if the foil is needed less or not at all when at low angles of heel.... ?


Perhaps with the bigger keelboats, more heel will be optimal while sailing and then the closeness to the surface factor won't matter or not as much.

On the other hand, as stability from ballast increases according to the 4th power of increase in size (at least where draft is allowed to increase proportionally: to the cube if not) maybe the 100 foot boats don't "need" it as much either. And on the benefit of reducing ballast: do people really want cruising superyachts of DLR 33? Don't know. Perhaps there is such a thing as too light for comfort -- seems that way -- yet Infiniti touts the comfort of the boat. Somewhat of a puzzler. But anyway if keeping the vertical accelerations tolerable to the customer requires a given amount of ballast, then the benefit of potentially reducing it disappears, as may the speed benefit. The antiroll and antiheel benefits would remain. I just question whether you get everything claimed simultaneously in the same boat as Infiniti says.

[hughw]

As ever, its fun reading the assorted comments and thoughts!

However I would like to thank Blunted for being both perceptive and totally accurate in his comments, and some of the others would be well advised to think over what he said.

However Trenace/Narecet has also hit a rather large nail on the head when commenting on the difficulty of testing and numbers....

If we go back quite a long way in time, then one of our first ideas was to pick up a 1720 and modify that, see what happens. plenty of other boats around to test against...or are there? As has been pointed out, and its the same with a canter but more so with DSS, that designing a boat that utilises DSS results in a very different animal to one without - so what are you comparing to what?? And how?

Its very easy to go sailing, pull the foil in or out and see what happens, but if you take the conditions say that you see on the Q28 videos, then I'm sailing the thing with couple of other light guys, 8-9 knots TWS, boatspeed pretty steady between 15 and 16 knots. So pull the board in, then what?? We couldn't sail that angle with the kite...so back to a headsail and then be sailing maybe 10 or 11 knots only, or keep the kite and we'd have to bear off probably 30 degrees and again we'd be sailing back in the low teens. So how do you relate that? We are then about 50% quicker...or are we? Answers on a postcard please. But the Q28 has been doing a horizon job on a wide variety of boats for quite a while now so can't be all bad.

So figures are rather meaningless except in a very careful context - we know what the boats do, and upcoming soon is a head to head test with some journalists against some comparably sized boats which will tell more of the story in a reasonably controlled environment.

Relative testing even against very similar boats is fraught with pratfalls - done enough hours in the AC and other fields to know damn well how difficult it is to resolve the data...

Early on too I logged a huge amount of data from the 40 in Oz, none of it was bad, some of it extremely good, but of great importance in determining the routes that I needed to explore in the design parameters. The Brace was a major step along from the 27, Q28 was again a step along from the Brace, and the 36 takes further steps but also incorporates some of the features that are required as you move up the scale. Scale effect on the whole is working in our favour, but there are subtle differences so its not a question of pressing the scale button!

Something else of note - every time we take people out that are new to the boat - doesn't matter which one - they all want to pull the board in and then out a few times so see what happens. After 10 minutes of that, then they don't bother...its either in 'cos you don't need it, or out 'cos you do.

Foils near the surface....well thats a very interesting scenario where the wing is moving from being submerged and acting as an airfoil, to something that is actually quite an efficient low aspect ratio planing surface. Anyone that doesn't get that needs to go back into the archives and read up some very basic textbooks and get a handle on the numbers.

Also of course, we're learning from every boat we do - design refinements are still making major improvements in how it works in practice.

Goodbye.

[narecet]

I'm kind of surprised to see you've followed my posts closely enough to keep track of my necessitated change in username! You are quite correct of course. But back to things of substance:

Can you point us to a "very basic textbook" that deals with a submerged wing (not a planing hull, which has no water flowing over a top surface and has half the wetted area, roughly speaking) operating very close to and near parallel to the surface of water with some amount of waves, and which has figures on the resulting lift to drag? What are the numbers of which you speak in that situation? If they're in basic texts then that would seem not proprietary. I understand there would be no reason to give out confidential company data, but generally speaking?

Or are you out of here already? (I refer to the "goodbye," which suggests that you pre-decided to not answer any questions.)

Thank you for contributing your posts and thank you for your work!

[_DB]

Somewhat related, but I'm not sure if any of you have seen an old CALTECH concept for a "winged" 12m back in the 80's. I think it was an alternate concept for (B)Eagle ... and it had two long but narrow wings extendng down in an inverted V shape under the hull. The wings produced all the righting moment through hydrodynamic lift and so it didn't have any ballast. I think the same article also showed that, in flat water, the 12meters had less drag in reverse.

The DSS concept looks more practical. I wonder this could fit in under the rules for a mini 6.5?

[Doug Lord]

Somewhat related, but I'm not sure if any of you have seen an old CALTECH concept for a "winged" 12m back in the 80's. I think it was an alternate concept for (B)Eagle ... and it had two long but narrow wings extendng down in an inverted V shape under the hull. The wings produced all the righting moment through hydrodynamic lift and so it didn't have any ballast. I think the same article also showed that, in flat water, the 12meters had less drag in reverse.

The DSS concept looks more practical. I wonder this could fit in under the rules for a mini 6.5?

------------------------
Definitely. One being developed now-built by Isotop: (pix from SA)

Attached Files

•  DSS isotop sa mystery.jpg   87.44K   38 downloads

[duncan (the other one)]

As ever, its fun reading the assorted comments and thoughts!

However I would like to thank Blunted for being both perceptive and totally accurate in his comments, and some of the others would be well advised to think over what he said.

However Trenace/Narecet has also hit a rather large nail on the head when commenting on the difficulty of testing and numbers....

If we go back quite a long way in time, then one of our first ideas was to pick up a 1720 and modify that, see what happens. plenty of other boats around to test against...or are there? As has been pointed out, and its the same with a canter but more so with DSS, that designing a boat that utilises DSS results in a very different animal to one without - so what are you comparing to what?? And how?

Its very easy to go sailing, pull the foil in or out and see what happens, but if you take the conditions say that you see on the Q28 videos, then I'm sailing the thing with couple of other light guys, 8-9 knots TWS, boatspeed pretty steady between 15 and 16 knots. So pull the board in, then what?? We couldn't sail that angle with the kite...so back to a headsail and then be sailing maybe 10 or 11 knots only, or keep the kite and we'd have to bear off probably 30 degrees and again we'd be sailing back in the low teens. So how do you relate that? We are then about 50% quicker...or are we? Answers on a postcard please. But the Q28 has been doing a horizon job on a wide variety of boats for quite a while now so can't be all bad.

So figures are rather meaningless except in a very careful context - we know what the boats do, and upcoming soon is a head to head test with some journalists against some comparably sized boats which will tell more of the story in a reasonably controlled environment.

Relative testing even against very similar boats is fraught with pratfalls - done enough hours in the AC and other fields to know damn well how difficult it is to resolve the data...

Early on too I logged a huge amount of data from the 40 in Oz, none of it was bad, some of it extremely good, but of great importance in determining the routes that I needed to explore in the design parameters. The Brace was a major step along from the 27, Q28 was again a step along from the Brace, and the 36 takes further steps but also incorporates some of the features that are required as you move up the scale. Scale effect on the whole is working in our favour, but there are subtle differences so its not a question of pressing the scale button!

Something else of note - every time we take people out that are new to the boat - doesn't matter which one - they all want to pull the board in and then out a few times so see what happens. After 10 minutes of that, then they don't bother...its either in 'cos you don't need it, or out 'cos you do.

Foils near the surface....well thats a very interesting scenario where the wing is moving from being submerged and acting as an airfoil, to something that is actually quite an efficient low aspect ratio planing surface. Anyone that doesn't get that needs to go back into the archives and read up some very basic textbooks and get a handle on the numbers.

Also of course, we're learning from every boat we do - design refinements are still making major improvements in how it works in practice.

Goodbye.

Hugh.

thanks for the response.. and I understand where the problems are in just pulling foils in and out and comparing direct speeds - don't polars deal with that?

Obviously, there are a bunch of other issues related to the fact that the Quant etc. are specifically designed around the benefits of the foils, and so maybe don't work so well in non-foil mode, which biases the polar comparison somewhat.

Nevertheless, it would be instructive to see direct comparisons of the boat against similar (but non-foiling) sportboat designs.

[narecet]

Will the Infiniti 36 be entering ocean and/or inshore races? That also would give some rough idea of how the design, at this scale, compares with other boats.

[Doug Lord]

Hugh.

thanks for the response.. and I understand where the problems are in just pulling foils in and out and comparing direct speeds - don't polars deal with that?

Obviously, there are a bunch of other issues related to the fact that the Quant etc. are specifically designed around the benefits of the foils, and so maybe don't work so well in non-foil mode, which biases the polar comparison somewhat.

Nevertheless, it would be instructive to see direct comparisons of the boat against similar (but non-foiling) sportboat designs.

=========================
Not accurate. One of the beauties of DSS is that the system benefits the boat in light and moderate/heavy air. The size of the rig reflects the RM from the foil which allows a larger than "normal" rig. So in light air, when the foil is not effective, it is simply retracted leaving a very powered up light air rocket. The foil, the design and the system were proved time and again in all conditions this summer where the Quant 28 DSS beat many much larger boats boat for boat.

[Stanuel]

Somewhat related, but I'm not sure if any of you have seen an old CALTECH concept for a "winged" 12m back in the 80's. I think it was an alternate concept for (B)Eagle ... and it had two long but narrow wings extendng down in an inverted V shape under the hull. The wings produced all the righting moment through hydrodynamic lift and so it didn't have any ballast. I think the same article also showed that, in flat water, the 12meters had less drag in reverse.

The DSS concept looks more practical. I wonder this could fit in under the rules for a mini 6.5?

------------------------
Definitely. One being developed now-built by Isotop: (pix from SA)

Been waiting for news of that DSS mini forever, first saw pic in sea horse months and months ago. And what you posted pics of it when Doug? 10-30-2011

[bruno]

Mr. Welbourn,

Thanks for enlightening posts, good luck with this, hope the mini is a giant killa

[hughw]

Will the Infiniti 36 be entering ocean and/or inshore races? That also would give some rough idea of how the design, at this scale, compares with other boats.

36 is just creeping in to the finishing line of the Palermo2Monte Carlo race, will be 4th boat home behind Kuka , almost entirely upwind and very very light, Class 40's behind, very difficult race, so with almost no time on the foil its done well. Off the start went like the robber's dog until wind crapped out!

[narecet]

Thank you for the update, Mr Welbourn! Sounds like a very fine result, looking forward to further good results.

[narecet]

Btw, as contributing an entirely-amateur thought, this seems another example of why measuring the value of the system is not necessarily so simple.

For example let's imagine a worst-case, that I doubt is true, where despite all reason and good efforts, nothing really is to be seen in terms of increased speed under the conditions you'd expect DSS to do well. As an very unlikely worst case.

It could still be true that compared to other boats which would seem fair comparisons overall, the system results in allowing higher SA/D or SA to wetted area, and advantage is seen in light air even with the foil not extended.

So, while it would be nice to have foil-extended-vs-foil-retracted examples, the measure of success really can't be from just that. Both because it could overestimate value (for reasons given in some previous posts) and also could underestimate (for the reason in this post, and perhaps other reasons.)

However what will really tell the story is results on the water, not reasoning about it, so I'm glad that we're getting results from the Infiniti actively racing.

[STYACHT]

Will the Infiniti 36 be entering ocean and/or inshore races? That also would give some rough idea of how the design, at this scale, compares with other boats.

36 is just creeping in to the finishing line of the Palermo2Monte Carlo race, will be 4th boat home behind Kuka , almost entirely upwind and very very light, Class 40's behind, very difficult race, so with almost no time on the foil its done well. Off the start went like the robber's dog until wind crapped out!

Hugh,

any chance you want to share the light weight of the 36? Infinity has nothing on their site. Boat seems to be pretty quick, thumbs up!

[hughw]

Will the Infiniti 36 be entering ocean and/or inshore races? That also would give some rough idea of how the design, at this scale, compares with other boats.

36 is just creeping in to the finishing line of the Palermo2Monte Carlo race, will be 4th boat home behind Kuka , almost entirely upwind and very very light, Class 40's behind, very difficult race, so with almost no time on the foil its done well. Off the start went like the robber's dog until wind crapped out!

Hugh,

any chance you want to share the light weight of the 36? Infinity has nothing on their site. Boat seems to be pretty quick, thumbs up!

Its on the IRC cert Doug - nothing secret apart from the fact its heavier than its supposed to be! But we know where and why and boat #2 will be down to the design weight. Anyway, this one measured in at 2570kgs. Yes we're pleased so far, seems to do all the right things, would have been nice to have had some better weather in the race, but your guys on Kuka would say the same thing I'm sure:) Sailing to the ratings in those sort of conditions are tough for us lighter boats!

[STYACHT]

Will the Infiniti 36 be entering ocean and/or inshore races? That also would give some rough idea of how the design, at this scale, compares with other boats.

36 is just creeping in to the finishing line of the Palermo2Monte Carlo race, will be 4th boat home behind Kuka , almost entirely upwind and very very light, Class 40's behind, very difficult race, so with almost no time on the foil its done well. Off the start went like the robber's dog until wind crapped out!

Hugh,

any chance you want to share the light weight of the 36? Infinity has nothing on their site. Boat seems to be pretty quick, thumbs up!

Its on the IRC cert Doug - nothing secret apart from the fact its heavier than its supposed to be! But we know where and why and boat #2 will be down to the design weight. Anyway, this one measured in at 2570kgs. Yes we're pleased so far, seems to do all the right things, would have been nice to have had some better weather in the race, but your guys on Kuka would say the same thing I'm sure:) Sailing to the ratings in those sort of conditions are tough for us lighter boats!

The rating, ... that's funny! Beyond performing to rating, from my desk, I can't say I learned so much from this race. I am sure they did on board though. As much as I am tempted to winge about the extra extra light airs, I am more inclined to give Lauria the praise for pointing it right at the mark and trimming and steering to make the boat run. They got lucky sure, but luck can also be engineered. Did they go below 4 knots of boatspeed ever?

Extra props to Foiled! for opting not to be scored under IRC after they made the decision to use a sail that was not accounted for on that cert. Fair play to the end.

[Amati]

When the foil is deployed is there any noticeable lee helm?

[hughw]

When the foil is deployed is there any noticeable lee helm?

You can feel a small difference sure, but the overall balance design parameters of the boat mean that by the time you need to deploy the foil then the natural weather helm build ensures that this is a favourable aspect of the overall effects. We worried about that a lot in early days, but as soon as we did our first full scale trial then we realised that it was never going to be a major issue.

So the boat feels good and nicely balanced for the desired rudder angle in the light with no wing out, and also in a breeze with the foil deployed it is equally nicely balanced.

[Christian]

When the foil is deployed is there any noticeable lee helm?

You can feel a small difference sure, but the overall balance design parameters of the boat mean that by the time you need to deploy the foil then the natural weather helm build ensures that this is a favourable aspect of the overall effects. We worried about that a lot in early days, but as soon as we did our first full scale trial then we realised that it was never going to be a major issue.

So the boat feels good and nicely balanced for the desired rudder angle in the light with no wing out, and also in a breeze with the foil deployed it is equally nicely balanced.

So Hugh - have you even tried for an IRC rating yet? I am curious how this boat will get rated under IRC - probably not a low number I would guess.

[Donjoman]

Kudos on the innovation, it's right up there and I cannot wait to see you get some owners throwing down the hard earned for the bigger designs.

I am curious, is it downwind and reaching where the maximum gains are? What sort of numbers do you see upwind sailing VMG.

One thing i noticed on the kite run in the video is that the foil becomes a pivot, when you have a wave under the stern it looks to get a bit nose down - is there any thoughts on how to control the fore and aft trim of something that gives so much lift?

How does IRC rate such an appendage.

[ColinG]

So Hugh - have you even tried for an IRC rating yet? I am curious how this boat will get rated under IRC - probably not a low number I would guess.

1.24 ish I understand

[Presuming Ed]

So Hugh - have you even tried for an IRC rating yet?

Its on the IRC cert Doug...

...Palermo2Monte Carlo race...

http://lmgtfy.com/?q...rmo2Monte Carlo

GBR1361R INFINITI 36GT 1.2290

[hughw]

Kudos on the innovation, it's right up there and I cannot wait to see you get some owners throwing down the hard earned for the bigger designs.

I am curious, is it downwind and reaching where the maximum gains are? What sort of numbers do you see upwind sailing VMG.

One thing i noticed on the kite run in the video is that the foil becomes a pivot, when you have a wave under the stern it looks to get a bit nose down - is there any thoughts on how to control the fore and aft trim of something that gives so much lift?

How does IRC rate such an appendage.

Current IRC rating is 1.229 and so thats a high rating for a little boat....however, the boat is quick for its size and the problem with any single figure rating is that uphill it still is just another 36' boat. Rating under IRC is really stick a finger in the air number, so theres been hefty whack on the HF and thats it.

Also too, this is a light carbon boat in the medium/small size ranget which IRC rather dislikes as a matter of principle - so overall we were well pleased to be able to finish as well as we did.

Under ORC club, then the size of the wing is taken into consideration, ( work was done by the ORC with the IMS VPP to allow for DSS ) so what is probably a much fairer estimation of the boat and its potential has been made.

You can't read much into the race/rating results form the Palermo epic - but what we could see was how effective the boat could be against whatever was around at the time.

This 36' size is actually one of the hardest to get to work - scale effect at work - so overall we're well pleased, and everyone that has sailed it so far really likes how it works and behaves.

[hughw]

I am curious, is it downwind and reaching where the maximum gains are? What sort of numbers do you see upwind sailing VMG.

One thing i noticed on the kite run in the video is that the foil becomes a pivot, when you have a wave under the stern it looks to get a bit nose down - is there any thoughts on how to control the fore and aft trim of something that gives so much lift?
-------

Gains are all the way round really - because we have the foil for stability when needed we can design a lighter boat with higher sail area ratios - hence the way the 36 dealt with the race and light airs against bigger boats even though it has a relatively short rig. Reaching and 2 sail in particular is great! Dead downhill, well its a bit like skiff sailing in sailing angles to generate the maximum power for best VMG, So wing might or might not be in use.
Upwind is interesting - flat water then you'll probably see no difference but in a seaway then we consistently see VMG gains even though you don't appear to be sailing any fast - but thats from overall motion damping giving you better efficiency from the rig and some other things too.

Thing is though that we can design a much nicer and faster boat in general - its an efficiency game rather than brute force.

[Amati]

I've liked the idea of a skini mini for a while.

Kudos Hugh!

Tried 2 DSS foils on one hull?

[Christian]

Kudos on the innovation, it's right up there and I cannot wait to see you get some owners throwing down the hard earned for the bigger designs.

I am curious, is it downwind and reaching where the maximum gains are? What sort of numbers do you see upwind sailing VMG.

One thing i noticed on the kite run in the video is that the foil becomes a pivot, when you have a wave under the stern it looks to get a bit nose down - is there any thoughts on how to control the fore and aft trim of something that gives so much lift?

How does IRC rate such an appendage.

Current IRC rating is 1.229 and so thats a high rating for a little boat....however, the boat is quick for its size and the problem with any single figure rating is that uphill it still is just another 36' boat. Rating under IRC is really stick a finger in the air number, so theres been hefty whack on the HF and thats it.

Also too, this is a light carbon boat in the medium/small size ranget which IRC rather dislikes as a matter of principle - so overall we were well pleased to be able to finish as well as we did.

Under ORC club, then the size of the wing is taken into consideration, ( work was done by the ORC with the IMS VPP to allow for DSS ) so what is probably a much fairer estimation of the boat and its potential has been made.

You can't read much into the race/rating results form the Palermo epic - but what we could see was how effective the boat could be against whatever was around at the time.

This 36' size is actually one of the hardest to get to work - scale effect at work - so overall we're well pleased, and everyone that has sailed it so far really likes how it works and behaves.

But not nearly as bad as Full Pelt that initially came in right under 1.8 - and that is a 30 footer.............
Hope that RORC/UNCL eventually makes a move to make it possible to race fast boats under the 45/50 foot range - but it will take time.

[bruno]

2nd order effects were a pleasant surprise when we upgraded to a T foil rudder, seems like that is true as well with your new design, damping, etc.

[hughw]

I've liked the idea of a skini mini for a while.

Kudos Hugh!

Tried 2 DSS foils on one hull?

Mini will will be out late September/October - taken a while as Dom ( Isotop ) has been doing it in spare time/cash, building the mast and everything else - so that'll involve a quick trip to La Rochelle I reckon:)

Multiple foils - looked at it, discounted apart from possibly Tfoil on the rudder in some circumstances. Flat water you might be able to do it, but in a seaway then it kills the boat. One of the issues is the interaction with the natural hull waves and local angles of attack on the foil and there ore others.

Key to getting it all to work is to have the trim balance from the dynamic effects working for you which has involved some serious head scratching - theres a lot going on as you move up the speed/heel range.

(Q One thing i noticed on the kite run in the video is that the foil becomes a pivot, when you have a wave under the stern it looks to get a bit nose down - is there any thoughts on how to control the fore and aft trim of something that gives so much lift? Q )

Trim is self controlled by the assorted effects from hull/rig/crew/wing and what you're seeing is same as any boat really - except here the boat is overtaking the waves at some pace and for sure its going to head off down - as far as the driver is concerned, its no big deal and having the wing just gives you a lot bigger comfort zone to put the boat where you want it. Ther are no issues about having the foil emerge or re-enter waves - its all a non-event and a bit of vector geometry will explain that!

and btw Duncan (too) - that video is not speeded up - I checked with the guys that made it;)

[triciarob]

Mr W, well done for getting the idea this far !
As a muppet I can see that increasing the RM and lowering the overall weight will make a faster boat and the loading and unloading of the foil as it goes through the waves is just ( ) an engineering problem. But I am curious as to what % of the bulb weight you feel you can lose ? For an inshore racer people will accept low margins of safety in their quest for more speed but when you head offshore racing or cruising without a full crew ... ?

Without giving away any trade secrets can you publish the GZ curve and AVS with the foil both in and fully extended ? ( Is the foil bouyant or neutral ? )
What's the measured RM max in the static case ?
What's the thoretical RM max at say 10 kn and 20 kn ? ( I say theoretical because I imagine it's quite difficult to measure at this speed )

Rob

Ps. Doug using the word "flying" in the thread title about a boat with a foil when you mean "going really fast" is the sort of marketing a used snakeoil salesman would use. Please don't do it again.

[narecet]

Now, now, Doug's snake oil is only very, very little used. He sailed his foiler for something like 3 hours then gave up on it, if I recall correctly. But his new efforts are on schedule for possible completion by the year 2525.

[hughw]

Mr W, well done for getting the idea this far !
As a muppet I can see that increasing the RM and lowering the overall weight will make a faster boat and the loading and unloading of the foil as it goes through the waves is just ( ) an engineering problem. But I am curious as to what % of the bulb weight you feel you can lose ? For an inshore racer people will accept low margins of safety in their quest for more speed but when you head offshore racing or cruising without a full crew ... ?

Without giving away any trade secrets can you publish the GZ curve and AVS with the foil both in and fully extended ? ( Is the foil bouyant or neutral ? )
What's the measured RM max in the static case ?
What's the thoretical RM max at say 10 kn and 20 kn ? ( I say theoretical because I imagine it's quite difficult to measure at this speed )

Rob

Ps. Doug using the word "flying" in the thread title about a boat with a foil when you mean "going really fast" is the sort of marketing a used snakeoil salesman would use. Please don't do it again.

You have to remember that for most keelboats we have to conform to some minimum stability requirements so that puts a hard limit in place. However we don't have to put more in necessarily - and certainly we don't have to add as much over base as others in order to extract the performance potential.

And no, I won't be handing out data:) If you know enough to be requesting that you should be able to go figure it out for yourself!

Oh yes, and flying...well thats exaclty what we don't want to to be doing - nearly flying is fine but full flight and you are into longitudinal trim control issues, and where we want to be is still having the boat sort itself out without any involvement other than natural forces.

[narecet]

Mr Welbourne, some of your replies are surprising to me, and certainly seem less than informative and less than helpful to questions which seem pretty reasonable ones.

There seems no way that from the information provided thus far on the Infiniti that a person could calculate the GZ curve or AVS without having specific information on the hull shape, CG, etc. Nor, as the foil section aren't given so far as I've seen, could a person "figure it out for yourself" what the contributed RM of the foil is for the Infiniti 36.

Previously, you replied that elementary (or perhaps "basic") texts give L/D values for immersed foils operating close to and parallel to the surface of the water, after I'd asked about L/D in a sea state, any sea state of your choice. I asked for what text you meant that gives such information as I know of no basic text that does -- it's not of aeronautical interest, and in naval architecture obviously this is not a widely-preferred mode of operation so it's hardly a basic question but would be specialized -- but you said "goodbye" and did not ever let us know an example basic or elementary text where we could find and learn from the data you say is in such texts.

It seems to me these are rhetorical ways of not answering but working to dismiss by giving the impression that the person asking the question is ignorant and really shouldn't even be asking the question, and that the answer is surely to your favor. Any who have questions are really too dumb to even be asking. This is a style that some adopt, it is your right of course. It's less than informative, but that may be your choice.

Each can have their own preference: personally I'd rather see a flat refusal to answer, or absence of answer, than IMO-untrue implications that others could go look it up in a basic text, or could go calculate these righting moments or AVS themselves.

Now of course I could be wrong... what is the basic text that has L/D values in these conditions, or how could triciarob or any of us figure the GZ curve or AVS without the hull shape or CG, etc, or the contributed RM of the DSS foil at any speed with only the extremely limited information provided?

[hughw]

It seems to me these are rhetorical ways of not answering but working to dismiss by giving the impression that the person asking the question is ignorant and really shouldn't even be asking the question......
---
FFS - Just why the hell should I be handing out costly and hard earned information to I don't know who?? If someone has enough interest to be asking that question and understanding what it means then they should go figure for themselves. If they just want free information then tough. We had to do it the hard way over a long period of time and many experiments to figure things out.

Heres a clue - if the boat was fully supported on the wing then where would the effective Cb be? Right, so you know the displacement then that gives you a maximum figure. So its somewhre less than that.

Texts of interest...if you are sufficiently interested then NA of planing hulls is useful, assorted NACA reports are online with regard to hydrofoils in all modes and so on.
Foil sections and so on - a million sources of information.

AVS - I've already said that we have to meet a minimum AVS depending on ISO Cat or wheover we have to work to these days.

Do some of the work for yourself for a change.

[narecet]

It seems to me these are rhetorical ways of not answering but working to dismiss by giving the impression that the person asking the question is ignorant and really shouldn't even be asking the question......
---
FFS - Just why the hell should I be handing out costly and hard earned information to I don't know who?? If someone has enough interest to be asking that question and understanding what it means then they should go figure for themselves. If they just want free information then tough. We had to do it the hard way over a long period of time and many experiments to figure things out.

Heres a clue - if the boat was fully supported on the wing then where would the effective Cb be? Right, so you know the displacement then that gives you a maximum figure. So its somewhre less than that.

Texts of interest...if you are sufficiently interested then NA of planing hulls is useful, assorted NACA reports are online with regard to hydrofoils in all modes and so on.
Foil sections and so on - a million sources of information.

AVS - I've already said that we have to meet a minimum AVS depending on ISO Cat or wheover we have to work to these days.

Do some of the work for yourself for a change.

Previously I was not sure, perhaps it was not deliberate, but now it is clear that this is very deliberately your approach.

You have clarified where you are coming from exactly. I now understand you as a person and as a yacht designer / promoter better. Clarity is always better and at least for me, I now have it. So, thank you.

EDIT: That said, as a post-script, now I'm finding it pretty darn funny that on the one hand you have it that anyone qualified even to ask about the righting moment, static and contributed by the foil, of the boat in question could go calculate the values themselves, but then on the other you talk about how hard you had to work to find the data over so many experiments. Can't be both, Hugh. The truth is there is no way that triciarob or anyone here could figure the righting moment curve, static or with DSS, of the boat being asked about. Your second claim was the one that was right: that only experimentation can accurately determine the effect of the foil. Whether the results are sufficiently favorable remains an open question. Basic texts and calculations a person can do himself let alone from the extremely limited available information will NOT give the answers to his righting moment questions.

[Ballast Technician]

It seems to me these are rhetorical ways of not answering but working to dismiss by giving the impression that the person asking the question is ignorant and really shouldn't even be asking the question......
---
FFS - Just why the hell should I be handing out costly and hard earned information to I don't know who?? If someone has enough interest to be asking that question and understanding what it means then they should go figure for themselves. If they just want free information then tough. We had to do it the hard way over a long period of time and many experiments to figure things out.

Heres a clue - if the boat was fully supported on the wing then where would the effective Cb be? Right, so you know the displacement then that gives you a maximum figure. So its somewhre less than that.

Texts of interest...if you are sufficiently interested then NA of planing hulls is useful, assorted NACA reports are online with regard to hydrofoils in all modes and so on.
Foil sections and so on - a million sources of information.

AVS - I've already said that we have to meet a minimum AVS depending on ISO Cat or wheover we have to work to these days.

Do some of the work for yourself for a change.

Hugh, don't bother with trenace/naracet. He is either trolling and/or supremely uninformed - there is a reason many of us have him on the ignore list...

[hughw]

Hugh, don't bother with trenace/naracet. He is either trolling and/or supremely uninformed - there is a reason many of us have him on the ignore list...
...........

Yes, I made the dreadful mistake of thinking that there possibly some intelligence there....won't happen again;)

[narecet]

Yes Hugh, all who have technical questions about DSS, such as triciarob's questions on this specific boat's righting moment curve and amount contributed by DSS, or my question on lift/drag in a sea state of your choice, are best dodged and then followed with insults about how the persons lack intelligence and are lazy, and don't know enough to be able to use the answers they asked for.

This is how you've repeatedly chosen to present yourself and to educate (?) about your system.

And that's okay. It's good to know where people are coming from, and reports of the boat sailing are quite valuable, so thank you for your participation. That's not an ironic or sarcastic statement: it's very straightforward.

[blunted]

Mr Welbourne, some of your replies are surprising to me, and certainly seem less than informative and less than helpful to questions which seem pretty reasonable ones.

There seems no way that from the information provided thus far on the Infiniti that a person could calculate the GZ curve or AVS without having specific information on the hull shape, CG, etc. Nor, as the foil section aren't given so far as I've seen, could a person "figure it out for yourself" what the contributed RM of the foil is for the Infiniti 36.

Previously, you replied that elementary (or perhaps "basic") texts give L/D values for immersed foils operating close to and parallel to the surface of the water, after I'd asked about L/D in a sea state, any sea state of your choice. I asked for what text you meant that gives such information as I know of no basic text that does -- it's not of aeronautical interest, and in naval architecture obviously this is not a widely-preferred mode of operation so it's hardly a basic question but would be specialized -- but you said "goodbye" and did not ever let us know an example basic or elementary text where we could find and learn from the data you say is in such texts.

It seems to me these are rhetorical ways of not answering but working to dismiss by giving the impression that the person asking the question is ignorant and really shouldn't even be asking the question, and that the answer is surely to your favor. Any who have questions are really too dumb to even be asking. This is a style that some adopt, it is your right of course. It's less than informative, but that may be your choice.

Each can have their own preference: personally I'd rather see a flat refusal to answer, or absence of answer, than IMO-untrue implications that others could go look it up in a basic text, or could go calculate these righting moments or AVS themselves.

Now of course I could be wrong... what is the basic text that has L/D values in these conditions, or how could triciarob or any of us figure the GZ curve or AVS without the hull shape or CG, etc, or the contributed RM of the DSS foil at any speed with only the extremely limited information provided?

I would wager this paper might offer some insight to your questions:


Papers

The effect of gravity and cavitation on a hydrofoil near the free surface

ODD M. FALTINSEN^a1 and YURIY A. SEMENOV<sup>a1


a1</sup> Centre for Ship and Ocean Structures, NTNU, N-7491 Trondheim, Norway

Abstract

A nonlinear analysis has been made to determine the effects of the free surface and transverse gravity field on the steady cavity flow past a shaped hydrofoil beneath the free surface. A closed cavity wake model has been proposed, and a method for the determination of an analytical function from its modulus and argument on the region boundary has been employed to derive the complex flow potential in a parameter plane. The boundary-value problem is reduced to a system of integral and integro-differential equations in the velocity modulus along the free boundaries and the velocity angle along the hydrofoil surface, both written as a function of parametric variables. The system of equations is solved through a numerical procedure, which is validated in the cases of a cavitating flat plate and non-cavitating shaped hydrofoils by comparison with data available in the literature. The results are presented in a wide range of Froude numbers and depths of submergence in terms of the cavity and free-surface shapes and force coefficients. The influences of the free surface and gravity on the aforementioned quantities are discussed. The limiting cavity size corresponding to zero cavitation number in the presence of gravity is found for various initial flow parameters.
or perhaps this one?



ISSN: 2152-209X Online Online subscription Year 2011, Volume 1 / Issue 3
DOI: 10.1615/VisMechProc.v1.i3
DOI: 10.1615/VisMechProc.v1.i3.120

FLOW BEHAVIOR AROUND A HYDROFOIL CLOSE TO A FREE SURFACE

Ichiro Kumagai
Hokkaido University
Takafumi Kushida
Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Hokkaido, Japan
Koji Oyabu
Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Hokkaido, Japan
Yuji Tasaka
Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Hokkaido, Japan
Yuichi Murai
Hokkaido University, Sapporo 060-8628, Japan
ABSTRACT


Keywords: multiphase flow, hydrofoil, entrainment, vortex shedding, free surface

And I imagine this will help you organize your thinking about the problem you lazy jackass, do your own math you slacker

http://www.saimeche....0_1___18-23.pdf

[narecet]

The rudeness apparently never ends from the corner in question.

Regardless, nowhere does the above deal with effects of a sea state, and it's hardly obvious that that would be negligible. For example, eyewitness account of a DSS boat reports it crashing on going down waves and being "a bit stop/start," which suggests waves can add a lot of drag to the foil. Also slower than a Shaw 650 in the conditions: it's not that all boats were doing this.

Further, from that paper why don't you calculate for us lift and drag of the Infiniti's DSS foil, from the nearly no information provided? After all, anyone but a "lazy slacker" can do it, or so you, Hugh, and Doug have it. A sea state of your choice, but at least moderate chop.

However, though you seem to be neglecting it, Hugh himself acknowledged that it took a lot of experimentation to determine such values for the DSS. You don't just get the true values for the righting moment achieved, or the resulting drag under sailing conditions, from a simple calculation on things like this.

I'll make it easier for you: Why don't you calculate for us just the Infiniti's DSS lift in flat water, as you consider it lazy to not do so. You don't have the Infiniti's foil section, you don't have the angle of attack that the Infiniti would have under the condition you'd be looking at, you don't have the area, you don't have accurate information on how close to the water it will be under the sailing condition being looked at, you don't have much to help you on determining what degree of end plate effect or interference you are going to get from the hull.

But really, even if you can do that which it's pretty obvious you cannot, that wouldn't answer the question of how much this changes in a sea state, and it's hardly obvious or proven that that is irrelevant.

(EDIT: I don't know why the bold print. It's not deliberate, and I can't get rid of it. No attempt to shout.)

[Doug Lord]

Check this thread out-Infinity 36 DSS Quad- http://forums.sailin...howtopic=139251

[MSA]

Yes Hugh, all who have technical questions about DSS, such as triciarob's questions on this specific boat's righting moment curve and amount contributed by DSS, or my question on lift/drag in a sea state of your choice, are best dodged and then followed with insults about how the persons lack intelligence and are lazy, and don't know enough to be able to use the answers they asked for.

This is how you've repeatedly chosen to present yourself and to educate (?) about your system.

And that's okay. It's good to know where people are coming from, and reports of the boat sailing are quite valuable, so thank you for your participation. That's not an ironic or sarcastic statement: it's very straightforward.

Mate if you want anything from Hugh, How about you email him, sign a confidentiality agreement and cough up some cash and start the design process for a new boat or build one of the 36's... Ive spoken to him about a production DSS 36? Interested?

Pretty simple, Bashing someones "credibility" is out, So 2005 on this website...

Hey while your at it, Can you call up Dalts and ask the Lift/drag numbers on the L foils they put on the AC 72, hell how about the twist and flow report from the wing?.. I'm sure he is can hand them out no worries, Douche.

[Jagtek Performance Products]

Hugh, don't bother with trenace/naracet. He is either trolling and/or supremely uninformed - there is a reason many of us have him on the ignore list...
...........

Yes, I made the dreadful mistake of thinking that there possibly some intelligence there....won't happen again;)

Yeah, sorry, homeboy gets on here and raves like a lunatic and picks fights with NAs about design/engineering. I have him on the ignore, but sometimes i peek to have a laugh. He's some joe schmoe who sails rent-a-boats out of a community sailing center, doesn't own a boat, and occasionally gets on here and talks about how he's going to get a classe 40 when he grows up or wins the lottery or something.

[atg]

Yes seems more interested in scoring rhetorical "points" than anything else. This is like the fifth grade, except more tedious.

"Prove it."
"No - YOU prove it"
"I don't have to prove it"
"Yes you do or you're a wanker"
"No I'm not - I design yachts. And you can't make me"
"Prove it or you're being illogical, your mother's a so-and-so and you're a wanker. And your boat's a piece of crap"
"FFS"
"If your boat is so great, why are you so defensive?"
"I'm not defensive."
"Yes you are. And your boat sucks in a seaway."
"No it doesn't"
"Prove it, or all your arguments are straw men, and your attacks ad hominem"
"Jesus - this guy thinks he's Aristotle or something. Why don't you prove that it DOESN'T work?"

S: Ah don' wanna talk to you no more, you empty-headed animal food-trough
wiper! Ah fart in your general direction! Your mother was a hamster, and
your father smelt of elderberries!
Galahad: Is there someone else up there we can talk to?
S: No!! Now go away, or I shall taunt you a second time!

(pause)

A: Now this is your last chance! I've been more than reasonable....
S: (to four other soldiers, standing behind him on the rampart)
Fetchez la vache.
Other Soldier: qua?
S: Fetchez la vache!

(the other soldiers are seen leading a cow... mooing noises)

A: (continued) ...if you do not agree to my commands, than I shall--

(Boing! The cow goes flying through the air over the rampart...
A: Jesus Christ!
(...and lands, amid great mooing, on one of the footmen. Various crying-outs
from Arthur's party.)

A: (determined) Right!
(drawing sword) CHARGE!
Rest of Arthur's Party: CHAAAARGE!

(As they run towards the French Castle, swords drawn, they are met by a huge
onslaught of live animals of all sizes, that come plummeting down from the
ramparts of the castle. Amid screams, they all turn back before even reaching
the castle walls, save Launcelot, who reaches the stone wall in time to give
it one stroke with his sword before retreating.)

French Soldier: (throwing down a goose) Hey, this one is for your mother!
(and a duck) And this one's for your gran!

Arthur's party: (hastily retreating) Run away!
RUN AWAAAAY!

*************

Until they get a bit better about enforcing some sort of anti-troll policy around here, the keyboard hero syndrome will continue to rear its ugly head.

[hughw]

Classic!!

[Jagtek Performance Products]

Where'd he go???!

[blunted]

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