Infinity 36 DSS flying!

ZeroTheHero

Super Anarchist
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

Super Anarchist
11,483
21
Cocoa Beach, FL
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.
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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.dynamicstabilitysystems.com/

 
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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

Member
334
68
uk
]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.

 

Mitre cut

Member
329
55
NZ
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
rolleyes.gif


 
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duncan (the other one)

Super Anarchist
5,401
426
Siderney
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.

 
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zzrider

Super Anarchist
2,782
3
New England
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. B)

 

narecet

Super Anarchist
1,055
0
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?

 
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BalticBandit

Super Anarchist
11,114
2
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. B)
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

Super Anarchist
11,483
21
Cocoa Beach, FL
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.dynamicstabilitysystems.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: http://www.youtube.com/watch?feature=player_embedded&v=DwDGKghV8fU

 
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Doug Lord

Super Anarchist
11,483
21
Cocoa Beach, FL
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

Super Anarchist
2,782
3
New England
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?

 

Monkey

Super Anarchist
10,693
2,322
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! :lol:

 

narecet

Super Anarchist
1,055
0
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.

 
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eliboat

Super Anarchist
2,204
596
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

Super Anarchist
5,459
638
Boston, MA
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.

 
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.

 
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