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AC trickle down... multihull designers can you do it?


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#1 Wess

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Posted 09 September 2013 - 01:06 PM

OK, if you asked me a year ago I would have said Ian's F22 was one of the more sexy things (eventually) available to Joe Blow sailors. Not quite right for me, I was likely headed away from racing my multi and towards more of a crusing multi again.

The along came foiling AC45s and now AC72s and all I can say is Holy Sh*t! Suddenly my dreams of a Chris White Atlantic 42 seem very pedestrian and the F22 looks far less sexy!

So my question for multihull designers is... is there any realistic potential for trickle down from this foiling AC class?

* Is it within the range of doable to design/build a cat (or tri) that is just large enough to have minimial accommodations below, be fully foiling, and still forgiving enough and affordable enough for the average Joe Blow multihull sailor?

Am kinda thinking of an R33 with bigger bows, L boards, elevators on the rudders, etc...

Can it be done without blowing up the kid's college fund?

Wess

#2 Doug Lord

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Posted 09 September 2013 - 01:37 PM

There already trickle down under 20' with Sail Innovation and the Flying Phantom-and others- and there are more manufacturers getting into it. The M32 may change their foils to a full flying, 3 foil configuration and then there is the Morrelli and Melvin California 45-designed to foil and inspired by the AC boats.
Many people have had concern about whether this type of boat could be raced effectively-up until yesterday with the greatest AC race in history.

#3 Wess

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Posted 09 September 2013 - 02:00 PM

No, thats not it. Not looking for an RC boat; hoping to hear from folks that design and build these things.

Its not a souped-up beach cat either. Needs at least minimal accommodations below ala the R33 or its excluded from too much racing of interest.

#4 Doug Lord

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Posted 09 September 2013 - 02:08 PM

 

No, thats not it. Not looking for an RC boat; hoping to hear from folks that design and build these things.

Its not a souped-up beach cat either. Needs at least minimal accommodations below ala the R33 or its excluded from too much racing of interest.

----------------------
I didn't mention an RC boat! I mentioned the rumor about the M32 adding new foils that allow full flying and the California 45' foiler-hardly rc boats.......And there are more coming all the time.

#5 darth reapius

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Posted 09 September 2013 - 02:36 PM

Actually good point raised by Doug, i do believe that 45 footer has a hard-deck, and acomodation in each hull, and there has been a few orders already from the only minor plans released!



#6 Wess

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Posted 09 September 2013 - 02:40 PM

Not trickle down if it does not trickle down to the masses.  RC = Russell Coutts boat.  Expensive boats for rich folks racing.  Need to knock a zero off the price for the California 45 before it has mass appeal.

 

What Ian did with the Corsair F27.

 

Can it be done with foilng?



#7 Tornado_ALIVE

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Posted 09 September 2013 - 02:43 PM

There already trickle down under 20' with Sail Innovation and the Flying Phantom-and others- and there are more manufacturers getting into it.

 

Who would have thought foiling wing sail cats would trickle down from the AC.......

 

c180cclass2.jpg

 

VealCrazyAngle.jpg



#8 Wess

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Posted 09 September 2013 - 02:59 PM

OK, well trickle down from ICCCC then.  Not picking sides.  Love em both but can't afford either, LOL.

 

Point is you know what the Corsair F27 did in the mid-80s.  Game changer that reached the masses.  Between 400-500 built of that one model alone and likely over 1000 of all Corsair models.  You can cruise them, you can race them, you can overnight on them, and you don't need to be a multi-millionare to do so.

 

*  Question remains; can it be done for foiling multis?

 

Wess



#9 Catnewbie

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Posted 09 September 2013 - 03:10 PM

To foil weight is the enemy,

So the performance-effective accomodations could be some carbon rod to fit a tent above the trampoline.

Beyond that accomodaion must account for such a small % of displct that it imposes you to have a big one, so probably a very expensive one.

Cheers

W

#10 catsailordude

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Posted 09 September 2013 - 03:48 PM

I think you should look to semi foiling like on the heavier MOD 70s as something that may "trickle down".  The full foiling is great for lightweight development classes sailing inshore in relatively flat water, but I don't think there is much application to cruising multis.  Cruising multis need to be designed such that they are unlikely to capsize, which basically means they have a shorter mast.  To get enough lift to foil, they would either need very large foils (which would create a lot of drag when not foiling) or they would need to lose a lot of weight and would no longer be cruisers.

 

The F22 is a great design and a fast boat, considering everything it can do (be launched off a trailer and rigged by one person in minutes) and be sailed safely in a variety of conditions.  We shouldn't let the "coolness" of these boats stop us from enjoying more practical boats.  

 

What these guys are doing in the America's cup is amazing, but I don't see much trickle down happening in anything other than very expensive light weight development classes.  



#11 unShirley

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Posted 09 September 2013 - 03:56 PM

I know I have referred to this in a previous thread. 

 

Wouldn't it be great if somebody could build a modern version of this for a reasonable price:

 

http://proafile.com/...ine/article/342



#12 Chris O

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Posted 09 September 2013 - 04:53 PM

... The full foiling is great for lightweight development classes sailing inshore in relatively flat water, but I don't think there is much application to cruising multis.  Cruising multis need to be designed such that they are unlikely to capsize, which basically means they have a shorter mast.  To get enough lift to foil, they would either need very large foils (which would create a lot of drag when not foiling) or they would need to lose a lot of weight and would no longer be cruisers.

 

... We shouldn't let the "coolness" of these boats stop us from enjoying more practical boats.  

 

What these guys are doing in the America's cup is amazing, but I don't see much trickle down happening in anything other than very expensive light weight development classes.  

 

 

+100

 

Wonderfully enunciated and to the point.



#13 SL33_SF

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Posted 09 September 2013 - 05:08 PM

If I ordered a cruising cat today, I would insist on some horizontal surfaces on the rudder. Not for performance reasons, but seeing what the new T-elevators (rudders) do to the SL33 it's a no brainer; the boat feels 30% longer and sails much smoother. Plus the bear-away wind limit has increased by ~30%.

 

My personal guess is that there will be no serious new multi designs with vertical foils only...

Trickle down? More of a waterfall IMHO.



#14 SL33_SF

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Posted 09 September 2013 - 05:22 PM

New gussets between the transom plate and hull, new rudder gudgeons to take the vertical loads.

Rudder bracket and vertical part of rudder was strong enough and remains unchanged.

When the WW rudder T is hitting the waves the forces are temendeous and it looks scary, but it has been working very well for a few months now, with the AYSF boys giving it a good workout...

May need to mention that my SL33's rudders are *very* long and both T are usually fully submerged, similar to the AC72.

T is not particularly high aspect ractio, to keep it sane.



#15 Doug Lord

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Posted 09 September 2013 - 06:13 PM

I think you should look to semi foiling like on the heavier MOD 70s as something that may "trickle down".  The full foiling is great for lightweight development classes sailing inshore in relatively flat water, but I don't think there is much application to cruising multis.  Cruising multis need to be designed such that they are unlikely to capsize, which basically means they have a shorter mast.  To get enough lift to foil, they would either need very large foils (which would create a lot of drag when not foiling) or they would need to lose a lot of weight and would no longer be cruisers.
 
The F22 is a great design and a fast boat, considering everything it can do (be launched off a trailer and rigged by one person in minutes) and be sailed safely in a variety of conditions.  We shouldn't let the "coolness" of these boats stop us from enjoying more practical boats.  
 
What these guys are doing in the America's cup is amazing, but I don't see much trickle down happening in anything other than very expensive light weight development classes.

===================
Not true. Trickle down technology would improve the foils and allow a much improved version of David Keipers 50 year old cruising foiler trimaran "Williwaw"  to be practical today. He did it a long time ago and the AC has shown us a lot about foil technology that he didn't know. Not to mention materials etc. It is highly likely that cruiser version of full flying foilers could be built but they will be expensive as well as fast. The Catri 27 foil assist cruiser is an example of one approach. 

It just takes people with a vision and a pocket book to back up the vision. You'll see examples as time goes by....



#16 BalticBandit

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Posted 09 September 2013 - 07:07 PM

Well considering how much you have dissed Williiwaw its funny that you bring it up now.

 

Wes it really depends on what you mean by "trickle down"  Remember that Nathan Outeridge who is one of the best foiling drivers in the world, had a tough time flying the Artemis Racing boat on a consistent basis.  And notice how a momentary timing misstep by Jimmy Spithill in race 4 caused a splashdown that just about cost him the race. 

 

Now consider who the average driver and crew of an F27 is.  I've sailed an F27 in mid teens wind,  and I've sailed an F40 Tri in similar breeze.  Neither of them foiling,  and I can tell you that the reaction times, and making the right decision AHEAD of time (rather than in reaction to the change) is already difficult for the average driver on an F40 compared to an F27

 

Adding foils more than doubles the skill required to drive the boat.   Furthermore, if you hit a plastic bag, or a bit of kelp or a log (in the PNW) at speed, you are going to auger in at speeds that most folks do not have the skills to recover from.

 

So it is highly unlikely that you will see a "cruiser version"  of full flying foilers.    Doug basically is full-of it.  He wants to see it built but he cannot see the barriers in place. 

 

 

Remember Wes that the foils used on the AC boats are NOT optimal.  Moth Foils  with sensor wands make a lot more sense,  but those have been available for coming onto 2 decades and yet no cruiser.  Think about how unusual "Cheeky Monkey" has been, and yet few takers to expand on that.

 

Meanwhile you already are seeing foil assist for improved heavy weather/higher speed handling, but I just don't see it going any further.  Its not about "vision", its about safety.



#17 Wess

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Posted 09 September 2013 - 07:47 PM

Ah geeze, I hoped if I avoided saying foiling in the title and posted in Multihull anarchy I might avoid both side of the typical DL fight.  Such is the nature of SA I guess.

 

Few thoughts.  An F27 in mid teens breeze is pretty darn tame.  Thinking most multihull folks can handle a bit more than that.  Heck many dinghy sailors can handle more than that.

 

Curious about the SL33.  It all started there for ETNZ (full foiling with rules constraints dictating sub-optimal systems) and while not exactly affordable its not a California 45 either.  Add a very modest shelter and its close to what I am wondering about.

 

With the right foils and systems, and enough volume forward for the eventual crash, I wonder if it can be brought down to the level of your typical weekend warrior racing dingy sailor.

 

Not convinced either way.

 

Wess



#18 Doug Lord

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Posted 09 September 2013 - 08:33 PM

Well considering how much you have dissed Williiwaw its funny that you bring it up now.

 

Another blatant fabrication-I have never dissed Williwaw or Dave Kiepers accomplishments.

--------

The concept can be improved upon and it did prove ,beyond a shadow of doubt, that the boat Wess is going on about is possible. And the new technology would only make it more possible.



#19 SL33_SF

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Posted 09 September 2013 - 09:27 PM

Meanwhile you already are seeing foil assist for improved heavy weather/higher speed handling, but I just don't see it going any further.  Its not about "vision", its about safety.

 

Agree, fully foiling is great for toys but still quite far away from being universally useful.
Remember that Hydroptere has canceled their record attempt because there is more than saltwater between LA and Hawaii...



#20 Doug Lord

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Posted 09 September 2013 - 09:39 PM

 

Meanwhile you already are seeing foil assist for improved heavy weather/higher speed handling, but I just don't see it going any further.  Its not about "vision", its about safety.

 
Agree, fully foiling is great for toys but still quite far away from being universally useful.
Remember that Hydroptere has canceled their record attempt because there is more than saltwater between LA and Hawaii...
 -------------------------
Try not to forget what Dave Keiper did. Crap in the water is a danger to every boat-not just Hydroptere. Don't forget her other records. Foils can be a tremendous benefit and the technology has been around for decades for full flying cruisers. Daysailer/weekender designs that fully foil are probably a lot closer to reality than a Keiper type boat. And the new technology just makes it more likely we'll see them sooner rather than later.
In the meantime, "toys" will be flying all over the place.....

#21 Chris O

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Posted 09 September 2013 - 09:44 PM

The things about which you ask, Wess, are not the realm of the cruising mentality. Others have already pointed out that to establish a boat as a comfortable cruiser, you'd need to add a lot of weight to the typical racer for the creature comforts in order to satisfy the usual cruiser functions that are the hallmark of that style of production boat. This puts a huge negative premium on the foiling function.

 

So, weight is a big issue that simply must be dealt with either through bigger, more expensive foils and adjustment systems, or by getting onboard with the design spiral that comes with a bigger boat... and then that, too, will push the pricing strategy of the builder well into another category, quite a bit out of reach of the guys who are looking to purchase your suggested F27 style of machine.

 

As a simple few word answer, I'll give you the yeah, sure, it can be done, response, but I'll load it up with such a list of caveats that it immediately takes it out of the realm of the buyer you have suggested.

 

Now, if you really can absorb the absolutely Spartan accommodations that would be required to get in the game, AND you can also absorb the hefty bottom line price tag increase, well, you may be able to do that. But that, my friend, is not what I would call a cruiser in the accepted definition of the term in sailing as we know it. You will also have a really difficult time selling the beast once you tire of the buzz... and as you get older, you will most certainly tire of that and want something more sedate. So, if you approach this the way one might approach the purchase of say, something like a retired ORMA60, or a no longer speedy MOD70, be willing to spend lots of cash on it to keep it in the zone, as it were AND then eat it when you have to sell it, then it would seem that this is your animal.

 

Other than that buzzkill, it is a fun mental exercise, is it not?



#22 Keith

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Posted 09 September 2013 - 10:44 PM

Meanwhile you already are seeing foil assist for improved heavy weather/higher speed handling, but I just don't see it going any further.  Its not about "vision", its about safety.

 

Agree, fully foiling is great for toys but still quite far away from being universally useful.
Remember that Hydroptere has canceled their record attempt because there is more than saltwater between LA and Hawaii...

Yes, and didn't the big 72 foot trimaran, while racing to Hawaii,  get her dagger-board hit, 2 or 3 times by debris ?

 

I think ocean crossing, in the north pacific, from the equator up, is sketchy at best, due to way too much tsunami debris in the water, It will take years for this too change.



#23 SL33_SF

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Posted 09 September 2013 - 11:46 PM

think ocean crossing, in the north pacific, from the equator up, is sketchy at best, due to way too much tsunami debris in the water, It will take years for this too change.

 

There is an easy solution for this:

Sharks with frikin laser beams attached to their heads:

 

Pretty sure we will see the day where any fast boat will have forward looking short range radar on the mast, scanning the wave tops for debris.

If I get 100 orders @ $15k I will develop it. -> Kickstarter project?!



#24 Basiliscus

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Posted 10 September 2013 - 12:09 AM

I think the key to designing a cruising foiler is to aim for high average speeds, not high top speeds.  Instead of being The 40 kt Sailboat, a cruiser should aim to make 20 kt as boring as possible.  Instead of using foils to make a boat fast, they should be used to make a fast boat more seaworthy.

 

I think the Keiper diamond configuration (bow foil, two lateral foils, stern foil) helps to minimize the drama by being self-tacking (windward foil out of the water via heel angle) and having separate foils providing heave stability (bow foil), roll stability (lateral foil) and pitch stability (stern foil).  Ladder foils are structurally robust, but have drag issues that Keiper didn't understand.  The 34th AC has shed a lot of light on the coupling between leeway and vertical lift.  I think that a cleaner, simpler foil design can provide better performance than Williwaw.  

 

This is what it might look like:

foilset2.jpg



#25 eric e

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Posted 10 September 2013 - 12:18 AM

imagine berthing that monster

 

or even getting it up to a buoy 



#26 Scarecrow

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Posted 10 September 2013 - 01:02 AM

It is never going to work.......

 

The lateral foils aren't even connected to the boat.



#27 AVID

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Posted 10 September 2013 - 02:55 AM

If you look at commercial vessels, foiling ferry's were the rage long before foiling sail boats. However current thinking would apear to have moved away from foils to simply wave piercing. Depth? Ease of use? or fuel efficiency?

Foiling is fantastic, but simple is fun

#28 SL33_SF

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Posted 10 September 2013 - 04:28 AM

I think the key to designing a cruising foiler is to aim for high average speeds, not high top speeds.  Instead of being The 40 kt Sailboat, a cruiser should aim to make 20 kt as boring as possible.  Instead of using foils to make a boat fast, they should be used to make a fast boat more seaworthy.

 

I think the Keiper diamond configuration (bow foil, two lateral foils, stern foil) helps to minimize the drama by being self-tacking (windward foil out of the water via heel angle) and having separate foils providing heave stability (bow foil), roll stability (lateral foil) and pitch stability (stern foil).  Ladder foils are structurally robust, but have drag issues that Keiper didn't understand.  The 34th AC has shed a lot of light on the coupling between leeway and vertical lift.  I think that a cleaner, simpler foil design can provide better performance than Williwaw. 

 

Ah, the Flintstones approach... ;-)

The California 45 will have powered winches (GM:"I want to go race with my friends, not a bunch of 20 year old")

If you take that one step further why not electric foil control?

And while your at it, why not control all the foils with a high speed Inertial Measurement Unit and sensors to measure height above the water in each hull?

Difficult? Your smartphone has enough IMU sensors and computing power to adjust the foils 100 times per second.... That's about 50 times more often than Jimmy, Dean, Nathan and Chris can do it. Less latency in the system, too...



#29 BalticBandit

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Posted 10 September 2013 - 08:51 AM

SL you are absolutely right that you can put a fair amount of "logic" into the foil controls.  But that's Dinghy world bubbling up not AC trickling down.  Until Doug chased the foilers out of the DA threads, there was an interesting project being discussed that used a PLC (industrial control computer known as a Programmable Logic Controller)  to take as inputs: ride height, wave height, and boat speed to control the boat.

 

Now for a day sailing protected coastal waters, this might work.  And you would not necessarily need to go to a Keiper diamond config. because if you have electronic foil controls you can get a much more stable ride,  And the default of course is that in case of a fault, you flop back into surface hugger mode and drag yourself into port.

 

Now as to Dougie's comment about stuff in the water being a problem for other vessels as well - once again we have Dougie's lack of real world boating experience coming out.  In the PNW we used to have a hydrofoil passenger ferry between seattle and Victoria BC (it ran the old Boeing production prototype).  It went bust after 3-4 seasons.  Meanwhile now we have an ever-expanding fleet of Jet Catamarans running the same route with ever expanding profitability.

 

Why?  What's the diff?

 

Well the Boeing foiler was very unpredictable.  if it managed to make the whole run on foils it was about 70-90 minutes.  about twice as fast as the Clipper Jet Cats do it.  but the problem was that they would spend much of their time coming off their foils because either they hit something or were about to hit something.    Futhermore their payload capacity was dramatically less than the Jet Cats can go.

 

The reason an immersed hull isn't as susceptible to being disabled by in-water debris is twofold: 

  1. It pushes a pressure wave ahead of it that has the effect of deflecting even large objects out of the way
  2. the bow sections of a hull can be, and ARE built to handle some collisions in ways that foils cannot be.

I've hit logs in the PNW doing 12 knots in my cruising ketch (full keel) and it barely scuffed the bottom paint.  I've hit logs doing 14+ knots on J-120 under kite,  and again, scuffs on the bottom paint.  Hit those while on foils and even if the foil doesn't get damaged, the loss of lift will cause a hull splashdown that is quite frightening.

 

 

 

And the reason that even with a PLC you are limited to coastal waters is that electronics fail.  A friend of mine just qualified for the Mini Tranasat.  One of his qualifying races had him staying awake for 60 hours straight because his fully sealed, made for wet boats, autopilot control failed.  and he had no way to even steer the boat automatically much less control its ride height.

 

Murphy is always present offshore.



#30 Wess

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Posted 10 September 2013 - 02:41 PM

I still hope somebody finds a way to build and market this.  We are already not that far away from it with an SL33 with a modest shelter beter foils and controls.

 

To those that say it can't be done I point to a note a friend just sent me:

 

"yeah, who would have thought we would be watching boats match race at 40 knots through San Francisco Bay.  Ten years ago only boats on sheltered single-tack drag race courses hit 40 knots."

 

The future knocked on our door with the Moth.  Its knocking again only its a bit bigger this time and has two hulls.



#31 Doug Lord

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Posted 10 September 2013 - 02:46 PM

 

I still hope somebody finds a way to build and market this.  We are already not that far away from it with an SL33 with a modest shelter beter foils and controls.
 
To those that say it can't be done I point to a note a friend just sent me:
 
"yeah, who would have thought we would be watching boats match race at 40 knots through San Francisco Bay.  Ten years ago only boats on sheltered single-tack drag race courses hit 40 knots."
 
The future knocked on our door with the Moth.  Its knocking again only its a bit bigger this time and has two hulls.

==============
Well said. It most certainly can be done-now.

#32 Evil Gnome

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Posted 10 September 2013 - 03:09 PM

I like the jibs on these boats, this is an affordable trickle down benefit to most multis without going crazy, the concept is so simple to allow the jib to twist off in the gust and not choke the slot and to stand up when  the gust drops and to allow more sail area but low to keep down the lifting affect  it's definitely going on the Evil Gnome.

Evil

ps  thankfully it didn't cost me tens of millions of dollars to find this out,



#33 BalticBandit

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Posted 10 September 2013 - 03:15 PM

I still hope somebody finds a way to build and market this.  We are already not that far away from it with an SL33 with a modest shelter beter foils and controls.

 

To those that say it can't be done I point to a note a friend just sent me:

 

"yeah, who would have thought we would be watching boats match race at 40 knots through San Francisco Bay.  Ten years ago only boats on sheltered single-tack drag race courses hit 40 knots."

 

The future knocked on our door with the Moth.  Its knocking again only its a bit bigger this time and has two hulls.

That you can carry such speeds in racing at top levels is very different. 

 

The issue is control and there isn't much being done to address that.  Top boats have always been at the hairy edge of control.  But explain to me what great features have come to cruising multi's from say the ORMA 60 class?

 

For cruisiing multis- the most innovative work has come from folks like Ian Farrier who are purpose building for the cruising market    Remmember how much structure is necessary to drive one of these beasts with only 11 bodies worth of payload.  Now how many cruisers are willing to foregoe a head, a galley, a berth?

 

How many cruisers are willing to constantly be strapped in down below for safety and to sleep in tight hammocks, feet forward in case of a decelerating smash into the waves?

 

 

And if you just want a day racer,  get an F18.  you don't need foils to get to the edge of what you can control

 

 

Ignore Doug he has no real world experience

 

 

 

As to the jibs, the way you can get this benefit is only through very expensive sail cloth.  So you aren't likely to see this show up soon on your average cruising multi either



#34 Steve Clark

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Posted 10 September 2013 - 03:18 PM

Foils can be used effectively to manage sea keeping and therefore significantly improve speed and safety of catamarans, particularly fore and aft stability.

Orma 60s have been using curved asymmetrical ama foils to reduce bow burying for some time with significant increases in speed.  This is mostly due to being able to drive the boat harder. Nigel Irens pointed out that being able to push harder doesn't necessarily mean the boat is safer. It just means they have more drastic accidents when the exceed the limits.

 

Nevertheless for Joe sailor, reducing the possibility of a pitchpole is a great improvement in multihull sailing.

 

As to whether a Farrier like small cruiser could be built that flies around in winds that most cruisers find acceptable is pretty hard to envision. Dave Keiper certainly achieved this with Williwaw, but there is really no way to determine how effective this vessel was relative to other more conventional multihulls.  A modern F-28 may have made those voyages faster and safer with better accommodation. If it isn't getting you there faster or more safely and comfortably at the same speed, what is the point?

 

A final point, read the recent Seahorse article on foil construction for AC72s.  Sure this is the very high end, but it demonstrates that hydrofoils are a whole lot more demanding structures than straight centerboards. The Curved daggerboards in the A Class have about twice as much carbon in them as the former straight boards.  L shaped boards are harder still to construct. Ask anyone with a Hobie Trifoiler .   So expect the foiler price to be higher than you might expect.

 

SHC



#35 Lohring Miller

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Posted 10 September 2013 - 03:59 PM

This is a good explanation of the state of the art in the C class.  It gives a lot of hints on how to do it.  It should work in other small cats if designers really understand the hydrodynamics involved.  It will take some testing even so.  We'll see how well it works really soon in racing conditions. 

 

 

Lohring Miller



#36 Basiliscus

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Posted 10 September 2013 - 05:38 PM

imagine berthing that monster

 

or even getting it up to a buoy 

All the foils retract.  In light air, the boat can be sailed as a pure displacement craft with no extra wetted area in the water.  The design also had a centerboard for good performance in non-foiling conditions, but I'd like to get rid of the weight and drag of the CB and trunk if I could.  Still, I believe a cruising hydrofoil needs to be a competent boat in its own right, exclusive of the foils.  

 

The bow foil would pivot forward to sit up in front of the bow, Williwaw style.  The strut is swept so it provides support against drag loads, and when the foil is retracted the base of the strut comes up to the head of a stanchion to secure the foil in the up position.  

 

The junctions of the lateral foils are all hinged joints.  The loads on the inboard portion of the lateral foil tend to make it rotate downward, so it doesn't take a lot of force on the top strut to hold it in place.  When the hold-down latch is released, the lateral foil can be raised up until the lifting element is vertical and lying along the side of the ama.  I would have liked it to form a vertical leeboard in this position for displacement sailing, but I wasn't able to have enough foil sticking down into the water without it extending too far inboard and reducing the righting moment when the foil was deployed.  The vertical position is sufficient for most purposes, like docking, but by pulling the pin on the inboard end of the top strut the foil can be rotated forward and inboard to lie flat on top of the ama and be totally out of the way.

 

The stern foil pivots fore and aft like Williwaw's stern foil, with the upper legs forming twin rudders when the foil is retracted.  When the foil is retracted, it can also serve as a davit to swing the dinghy off the aft deck and into the water.  I was playing with the design of a nesting dinghy that would have had a similar shape as the aft cabin top, so it would make the whole cabin top a mushroom vent when the dinghy was stowed, and minimize the windage of the dinghy.

 

All the latches for the foils would be accessible from deck without having to climb out on the foils to insert bolts as Dave Keiper had to do with Williwaw.  The foil mounts would also be designed to shear and allow the foil to break clear in the event of a collision.  When foiling, the anchor rodes would re-purposed as tethers attached to each foil so the boat has room to decelerate from the obstruction and the foil can be retrieved after being sheared from the boat.  None of the foils penetrate the hull, so there's no risk of breaching the water-tight integrity.  In the event of a foiling collision with the proverbial semi-submerged container, the boat would pass over the container and land on the far side.  A foil might be toast, but the boat would still be intact and capable of completing the voyage.

 

The foils would be designed structurally so the boat can rest on the hard on the tips of the foils, with some boards placed under them for protection and to lower the footprint.  This makes it possible for the boat to dry out on her foils so bottom work can be done on the beach without needing a boatyard to haul the boat.



#37 Basiliscus

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Posted 10 September 2013 - 05:42 PM

It is never going to work.......

 

The lateral foils aren't even connected to the boat.

The CAD model at that stage was for preliminary design and generating models for CFD analysis.  Not all of the details were captured in it.  I was still playing with the exact location of the inboard end of the top strut to allow for the proper folding geometry and loads when deployed.  The vertical strut would have ended at the indicated location, with a pinned joint and blister-shaped trunions.



#38 Basiliscus

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Posted 10 September 2013 - 05:48 PM

...The California 45 will have powered winches (GM:"I want to go race with my friends, not a bunch of 20 year old")

If you take that one step further why not electric foil control?

And while your at it, why not control all the foils with a high speed Inertial Measurement Unit and sensors to measure height above the water in each hull?

Difficult? Your smartphone has enough IMU sensors and computing power to adjust the foils 100 times per second.... That's about 50 times more often than Jimmy, Dean, Nathan and Chris can do it. Less latency in the system, too...

For a cruiser, I would prefer to avoid electrical systems like the plague.  I come from a fly-by-wire flight controls background, and I've seen what it takes to have a system with high availability - which you'd need to have if you're going to depend on active control.  But probably the biggest obstacle is the power required for the actuators.  There's a reason why 10 out of 11 guys on the AC72 are grinding.  The power for active control just isn't available on a cruising sailboat - that's why it's propelled by sail to begin with.



#39 Basiliscus

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Posted 10 September 2013 - 05:57 PM

...The reason an immersed hull isn't as susceptible to being disabled by in-water debris is twofold: 

  1. It pushes a pressure wave ahead of it that has the effect of deflecting even large objects out of the way
  2. the bow sections of a hull can be, and ARE built to handle some collisions in ways that foils cannot be.

...

I would add that with a hull the lines are such that a collision is most likely going to be a glancing blow, but with a hydrofoil, it is nearly always head-on.  You only have to look at a front view like that above to see the hydrofoils as very efficient strainers sweeping out anything that's in a large volume of water.  This is why I don't think hydrofoils are very well suited for coastal sailing.  Too much stuff in the water.  But they should be good for long distance passage-making where the boat is out and away from most of the man-made and shore-based debris. 



#40 Chris O

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Posted 10 September 2013 - 05:59 PM

Tom,

 

Have you ever run any numbers for ballpark cost to build all the foil elements for the concept boat?



#41 SL33_SF

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Posted 10 September 2013 - 06:02 PM

For a cruiser, I would prefer to avoid electrical systems like the plague.  I come from a fly-by-wire flight controls background, and I've seen what it takes to have a system with high availability - which you'd need to have if you're going to depend on active control.  But probably the biggest obstacle is the power required for the actuators.  There's a reason why 10 out of 11 guys on the AC72 are grinding.  The power for active control just isn't available on a cruising sailboat - that's why it's propelled by sail to begin with.

 

The reason the guys are grinding on the AC72 is that the class rules prevent an efficient solution: No flaps and no adjustable rudder elevator.

This is similar to steering a jumbo jet by rotating the main wings, instead of the elevator; very silly.

 

I agree that the mechanical actuators are currently a weak link in such a system, but the electronics can easily be protected (pot them in epoxy...).



#42 Basiliscus

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Posted 10 September 2013 - 06:17 PM

Tom,

 

Have you ever run any numbers for ballpark cost to build all the foil elements for the concept boat?

I was shooting for $250K for the whole boat, over a decade ago.  It would be more today, of course, and that figure may have been more hopeful than realistic.  At the time I thought that the boat had to be designed for foiling from the outset.  Now I'm not so sure, and I think a performance racer/cruiser might be converted to foils.  Buying an existing boat is probably the single biggest way to reduce the costs.  (Alas, I don't think a Chris White Hammerhead 34 is quite in that class.)

 

The foils had some features intended to reduce their cost.  All of the foil elements were constant chord and of two sections - a cambered section for lifting elements and a symmetrical section for struts. etc.  That way one could go into production of the foil stock using techniques like resin transfer moulding with, say, a pair of 8 - 10 ft molds.



#43 unShirley

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Posted 10 September 2013 - 06:50 PM

 This is why I don't think hydrofoils are very well suited for coastal sailing.  Too much stuff in the water.  But they should be good for long distance passage-making where the boat is out and away from most of the man-made and shore-based debris. 

 

You mean like the Transpac this year? ;)



#44 BalticBandit

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Posted 10 September 2013 - 09:57 PM

Thanks Steve for the sanity check.  I agree about the seakeeping issue - which was what I was trying to allude to about how this is not anything new trickling down from the AC 72s

 

SL just because you put electronics in an epoxy pot does not mean they are "high Availability" I've done some HA work as well and frankly even with all the monitoring working in a chemical plant or a refinery is highly dangerous work because those systems fail.  and essentially you are talking about bringing the same issues to an offshore boat. 

 

Bas  -- unfortunately I think the Ocean is getting enough debris in it that you are going to start running into problems.  In the last Mini Transpac, a friend of mine hit a whale.  When you are travelling at foiling speeds but with the silence of a sailboat, you start to have these sorts of risks as well.  Imagine what happens if you hit a 500# tarpon or similarly large sea creature (it need not be a whale or a submerged container)  heck, what happens if you hit a garbage bag with one of your outer foils?  Lift goes to zero very quickly



#45 madboutcats

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Posted 11 September 2013 - 12:36 AM

If we were talking about a cruising boat would it be possible to have foils that lift the boat a small distance above the waves with built in breakaways so that if you hit something at whatever force the foil would shear before the case got damaged and it would be like landing off a wave.



#46 Doug Lord

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Posted 11 September 2013 - 12:42 AM

The Cartri tri uses foil assist as do some Farriers and many other tri's and some cats now.



#47 Scarecrow

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Posted 11 September 2013 - 12:47 AM

The funny thing about this conversation is that 95%+ of cruising cats built don't even have daggerboards because the market is willing to sacrifice upwind performance for the sake of simplicity.

#48 Keith

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Posted 11 September 2013 - 03:22 AM

The funny thing about this conversation is that 95%+ of cruising cats built don't even have daggerboards because the market is willing to sacrifice upwind performance for the sake of simplicity.

Most cruising cats are designed to be marketed to, the family decision maker, and sorry, but that's usually your wife.  If your wife agrees, then you can buy it, in most cases.

 

Unless of course, shes also a sailor, and then she will probably clearly understand the difference in designs, and you two, will look at many different multihull designs, before the choice is made. 

 

The finer sailing, cruising multihulls are few and far between. But if you want one, their out there to get, but can you get your wife to agree?? 

 

Lets compare a Gunboat, or Schoining, or Outremer design to a similar size, Lagoon, Foutain Pagot, or any other purpose designed, charter cat, that is later sold into the cruising market, as a "cruising cat". 

 

These designs are completely different.



#49 Peccadillo

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Posted 11 September 2013 - 04:57 AM

Lot of talk here about foils. Seems to me that is the least likely area of trickle down into cruising from AC72s. At most we may see some foil assist. But foil assist is not from AC72s - has been around for a while, just not in standard cruising designs.

 

I like Evil Gnome's comments about the jibs - I reckon we'll start to see those soon enough, just like we've seen with square-head mains on cruisers.

 

What about other areas of trickle down? Well I think the success of buoyant wave piercing hulls on ETNZ may influence cruising design and may also influence purchasers to be confident about this design trend - but is also already happening (new Gunboat, MC60). Wing sails - well no, but maybe wing masts will get explored more (not just normal masts with a wing section but real wing masts like Chris White's Mastfoils). And I bet we see a few horizontal foils on the rudders of performance cruisers - coz they wd look cool :P . And they may even help with downwind control ...



#50 Frassld

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Posted 11 September 2013 - 06:20 AM

Lot of talk here about foils. Seems to me that is the least likely area of trickle down into cruising from AC72s. At most we may see some foil assist. But foil assist is not from AC72s - has been around for a while, just not in standard cruising designs.
 
I like Evil Gnome's comments about the jibs - I reckon we'll start to see those soon enough, just like we've seen with square-head mains on cruisers.
 
What about other areas of trickle down? Well I think the success of buoyant wave piercing hulls on ETNZ may influence cruising design and may also influence purchasers to be confident about this design trend - but is also already happening (new Gunboat, MC60). Wing sails - well no, but maybe wing masts will get explored more (not just normal masts with a wing section but real wing masts like Chris White's Mastfoils). And I bet we see a few horizontal foils on the rudders of performance cruisers - coz they wd look cool :P . And they may even help with downwind control ...

I know a guy after some new rudders, would those horizontal foil thingys help down wind on a Chris White 46?

#51 Peccadillo

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Posted 11 September 2013 - 09:40 AM

Now there's a thought Frassld!



#52 Peter Hackett

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Posted 11 September 2013 - 10:14 AM

Nice props when you dry out, less pressure on the soldier crabs will please the greens and the front 12 tonnes rests on minikeels, see you in Hill Inlet again next year Shaun!



#53 eric e

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Posted 11 September 2013 - 10:33 AM

M+M

 

designers for etnz

 

and designers of the new olympic multihull

 

the nacra17

 

i think you will find them quite keen to trickle down as much as commercially possible

 

nacra17Europeans2013e.jpg



#54 BalticBandit

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Posted 11 September 2013 - 10:37 AM

I don't see how you can fit lead into that kingpost...



#55 eric e

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Posted 11 September 2013 - 11:34 AM

I don't see how you can fit lead into that kingpost...

 

wasn't designed by oracle



#56 Wess

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Posted 11 September 2013 - 12:31 PM

Yea but this is not about cruising boats.  Heck, a fully foiling SL33 with modest shelter meets the criteria I outlined.  The California does as well, other than price.

 

The funny thing about this conversation is that 95%+ of cruising cats built don't even have daggerboards because the market is willing to sacrifice upwind performance for the sake of simplicity.

 

Think about this for a moment.  There are indeed many cruising cats that simply put are dogs.  Granted.  But some significant prcentage of the market also said I want better performance and I will to give up comfort to get it.  Think how many Corsairs have been sold.

 

Maybe I should ask the question(s) differently...

 

*  Could you make an SL33 or XS35 fully foiling?

*  Would the foiling version be faster?

*  What would it add to the cost of the boat to do this?

*  Could the weekend warrior racer handle the boat... would it be the same, more or less twitchy than a Moth?



#57 Chris O

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Posted 11 September 2013 - 03:03 PM

Maybe I should ask the question(s) differently...

 

*  Could you make an SL33 or XS35 fully foiling?

*  Would the foiling version be faster?

*  What would it add to the cost of the boat to do this?

*  Could the weekend warrior racer handle the boat... would it be the same, more or less twitchy than a Moth?

 

 

Wess, I think the answers to all of your questions, save for maybe the last one about twitchiness, have already been answered within the body of the overall discussion above. Steve Clark spoke to the complexity and cost realities of AC style lifting foil manufacturing and I shared a few of the pragmatic ideas regarding overall conceptual issues that divide racing from cruising in a broader sense.

 

The answer to your questions directly, would be:

 

Yes, you could probably make an XS, or SL fly, but with the assumed, even minimalist, level amount of stuff to make it a cruiser, they would need larger foils to generate the lift needed. The SL is carbon, but the XS is, as far as I know, a vinylester/glass boat that would need to go all-carbon to be a consistent, fully flying boat. As it is, right now, it uses foil assist.

 

The foiling version would, no doubt, be faster in some conditions. Slower in others

 

As to added cost, you'd have to ask Randy and the boys at SL Performance for the exact numbers, but it's gonna be a whopping price tag no matter how you want to carve it up.

 

After watching the driving patterns and understanding the skill sets involved with controlling the AC boats, I'd say that the boats you are asking about in full fly mode would be well above the typical skill sets of the "weekend warrior" guy you mention.

 

Me, I just don't se why one would want to go this far into the bleeding edge of design for a cruising boat.



#58 BalticBandit

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Posted 11 September 2013 - 03:17 PM

Well you could get an SL 33 foiling quite reliably, but it would cost a lot of money.  Because you are talking about a beefed up set of CB trunks,  much  much much stronger DBs,  and all the mechanics of autosensing the ride height.



#59 SL33_SF

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Posted 11 September 2013 - 04:37 PM

*  Could you make an SL33 or XS35 fully foiling?

*  Would the foiling version be faster?

*  What would it add to the cost of the boat to do this?

*  Could the weekend warrior racer handle the boat... would it be the same, more or less twitchy than a Moth?

 

Answers:

1) Yes (see picture at bottom), plus the three SL33 of ETNZ and LR have been foiling for almost two years.

2) will let you know in three weeks, after SF Big Boat Series. We know ETNZ's answer...

3) Additional cost is marginal; add a tip to the existing daggerboards (pic below), some control to the db heads and off you go...
   Trunks etc are wide and strong enough and remain unmodified
   Luckily M&M thought a few years ahead when they designed the SL33...

Attached File  New_DB_Tips_sml.jpg   392.92K   75 downloads

4) will let you know in three weeks, after SF Big Boat Series. I am a  pure weekend warrior, plus don't pay crew to sail.

Yes, at some point we will crash and everybody will have 'warned us'. Except that they 'warned us' already two years ago and we have happily and safely raced the SL33 in SF Bay ever since, including last years Big Boat on Citi Front (finished 2nd on corrected, smoked the other cats plus the TP52's up- and downwind).

Choose your 'experts' wisely...

 

SL33 derivative 'FOILED' in NZ:

Attached File  Foiled_Jumping.jpg   28.01K   111 downloads
Should qualify as fully foiling, I can see air underneath the hulls... ;-)

Not very fast yet, though.

 

As a general comment: What I am not looking forward to are the hundreds of designs with 'lifting foils' which won't work properly.

Choose your 'experts' wisely...



#60 Chris O

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Posted 11 September 2013 - 06:04 PM

Interesting response, SL, but what about the included cruising component of the discussion? And I truly do like that controlled foiling photo. ;-)

 

How much does an SL33 cost, landed, and ready to sail? How much cash would it require to add the cruising amenities most folks accept as necessary? What would that do the foiling capabilities once the extra weight is added?



#61 Doug Lord

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Posted 11 September 2013 - 06:30 PM

This is a design that is working to develop a foil system specifically tailored to rough water-it may have greater potential for cruising applications than trickle down from the AC:

http://www.youtube.c...h?v=lEqYTrzaHsc



#62 SL33_SF

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Posted 11 September 2013 - 06:35 PM

Interesting response, SL, but what about the included cruising component of the discussion? And I truly do like that controlled foiling photo. ;-)

 

How much does an SL33 cost, landed, and ready to sail? How much cash would it require to add the cruising amenities most folks accept as necessary? What would that do the foiling capabilities once the extra weight is added?

I don't see fully foiling happen for cruising anytime soon either. Some foil assist for sure.
Foiling performance is hugely weight sensitive, so adding a condo on the hulls will never be a good idea.

Most cruisers suck at going upwind (or any sailing, for that matter). Let's fix the simple problems first...



#63 BalticBandit

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Posted 11 September 2013 - 08:34 PM

Doug did you notice how wet that boat was?

Did you notice how light that boat was? 

 

Do tell how that has applications to "cruising"?



#64 TheFlash

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Posted 11 September 2013 - 08:37 PM

BB, Doug's link looks exactly like the boat I'd like to take cruising up the delta with the wife and kids...

 

 

 

 

 

 

 

 

 

 

 

 

(What's the sarcasm font again?)



#65 BalticBandit

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Posted 11 September 2013 - 08:42 PM

Be careful OR... next Dougie will be quoting this post as support for his ideas! 



#66 piv

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Posted 23 September 2013 - 01:22 PM

Its possible to build a moderate cost foiling multihull. We ( BDG, Windrush and an enthusiast ) did it in 2001 with Spitfire. It was 12m LOA, balsa core glass hulls, really solid, unstayed carbon masts and carbon foils, mini cabins and sleeping room in each hull. It was designed for the Brisbane - Gladstone race but for various reasons we never got there. The hulls and foils worked great. We got 32 knots in 15kts of wind. Way easier to control than a smilar sized wave hugging multi. It had surface piercing foils, no real adjustment required to fly it. The ride was smooth and stable and dry. We sailed it quite a bit in guage roads off Fremantle. We were probably a bit ambitious with the biplane rig with a double luff kind of soft wing sail system. It worked but was painfull. A lot more work on the details of the rig and it would have been good. Light air performance needed a bit more sail area, ie code zeros, that we didnt have. It was about 90% good, 90% to sort out. It needed a lot more development to become an all round "good boat" but was pretty good as it was and certainly showed what could be done. Light air performance was OK but the difference between floating and foiling was so great, you just wanted to foil in less and less wind. Id love to have a second crack at this kind of boat or get enough resources to develop the Spitfire concept a bit more. Thanks to all those who made the project possible. It can be done and it is worth doing. Fast, low sailing effort, smooth, dry, stable, quiet. Its kind of like the difference between galloping on a horse or riding in a car.

#67 Wess

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Posted 23 September 2013 - 01:45 PM

Interesting to watch the ICCC stuff.  Not the most stable foiling!  Groupama system seems close to set and forget (other than rake on main foils / nothing adjustable on rudders afaik) but quite unstable.



#68 phillysailor

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Posted 24 September 2013 - 12:01 AM

I don't think insuring a foiling catamaran is going to be possible. Puts limits on the cruising applications.
 
You could have almost no fuel or water stores in a foiling cat (let alone an engine or anchors). You'd have to support their weight on the foils, remember, so they'd end up being considerably more robust than those used on the AC72s.
 
If Artemis's crash was a lesson to anyone, it's to those considering adding foils to their production catamaran, be they for racing or racing with bunks & a bucket.
 
The wings are the things. If telescoping wings were achieved at appropriate weight/strength/cost then bridge clearance, reefing, efficiency and durability over soft sails would quickly prove their worth. The boat I want to examine at Annap Boat Show is the MastFoil 47.
 
I'd rather have skegs and tabs (also on the Atlantic 47) than daggerboards, let alone crazy-ass foils. Robust, simple and not a boat-killer if run aground, rather a boat-saving element. That's a cruising underbody to sell to an investor. Y'all are nuts if you think there is actually a market for foils in the cruising market.

#69 lesburn1

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Posted 24 September 2013 - 12:07 AM

who is this Doug guy, and why are people " " him?



#70 Doug Lord

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Posted 24 September 2013 - 12:26 AM

I remember Spitfire-I thought it was an impressive boat!

 

Its possible to build a moderate cost foiling multihull. We ( BDG, Windrush and an enthusiast ) did it in 2001 with Spitfire. It was 12m LOA, balsa core glass hulls, really solid, unstayed carbon masts and carbon foils, mini cabins and sleeping room in each hull. It was designed for the Brisbane - Gladstone race but for various reasons we never got there. The hulls and foils worked great. We got 32 knots in 15kts of wind. Way easier to control than a smilar sized wave hugging multi. It had surface piercing foils, no real adjustment required to fly it. The ride was smooth and stable and dry. We sailed it quite a bit in guage roads off Fremantle. We were probably a bit ambitious with the biplane rig with a double luff kind of soft wing sail system. It worked but was painfull. A lot more work on the details of the rig and it would have been good. Light air performance needed a bit more sail area, ie code zeros, that we didnt have. It was about 90% good, 90% to sort out. It needed a lot more development to become an all round "good boat" but was pretty good as it was and certainly showed what could be done. Light air performance was OK but the difference between floating and foiling was so great, you just wanted to foil in less and less wind. Id love to have a second crack at this kind of boat or get enough resources to develop the Spitfire concept a bit more. Thanks to all those who made the project possible. It can be done and it is worth doing. Fast, low sailing effort, smooth, dry, stable, quiet. Its kind of like the difference between galloping on a horse or riding in a car.

 

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#71 Keith

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Posted 24 September 2013 - 12:28 AM

I don't think insuring a foiling catamaran is going to be possible. Puts limits on the cruising applications.
 
You could have almost no fuel or water stores in a foiling cat (let alone an engine or anchors). You'd have to support their weight on the foils, remember, so they'd end up being considerably more robust than those used on the AC72s.
 
If Artemis's crash was a lesson to anyone, it's to those considering adding foils to their production catamaran, be they for racing or racing with bunks & a bucket.
 
The wings are the things. If telescoping wings were achieved at appropriate weight/strength/cost then bridge clearance, reefing, efficiency and durability over soft sails would quickly prove their worth. The boat I want to examine at Annap Boat Show is the MastFoil 47.
 
I'd rather have skegs and tabs (also on the Atlantic 47) than daggerboards, let alone crazy-ass foils. Robust, simple and not a boat-killer if run aground, rather a boat-saving element. That's a cruising underbody to sell to an investor. Y'all are nuts if you think there is actually a market for foils in the cruising market.

Actually dagger boards and kick up rudders, take cruising to a new level, IE,  shallow anchorages where, anyone with deeper draft, isn't going to hit you when they drag, and yeah they will, drag that is.. Ocean passage making in extremely rough conditions, dagger-boards let you slide sideways... and are very forgiving,  but my choice will always be boards, as they allow me a better sailing catamaran.



#72 Wess

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Posted 24 September 2013 - 12:57 AM

Oh for gosh sakes.  Read!  I want a boat for racing that has minimal but some shelter below. Many comments suggest it can be done.  Designer/buiulder discussion at ICCC suggest it can be done.  Folks on the Fill Your Hands team did not get to a next step I would lkove to see.

 

As for comments on cruising boast, I suggest you go read Scuttlebutt and current M&M/PJ fight.  Shame that PJ can't chill.  Gather M&M know of what they speak, no.  What is the harm in development if a well qualified design team and owner want to give it a go.

I don't think insuring a foiling catamaran is going to be possible. Puts limits on the cruising applications.
 
You could have almost no fuel or water stores in a foiling cat (let alone an engine or anchors). You'd have to support their weight on the foils, remember, so they'd end up being considerably more robust than those used on the AC72s.
 
If Artemis's crash was a lesson to anyone, it's to those considering adding foils to their production catamaran, be they for racing or racing with bunks & a bucket.
 
The wings are the things. If telescoping wings were achieved at appropriate weight/strength/cost then bridge clearance, reefing, efficiency and durability over soft sails would quickly prove their worth. The boat I want to examine at Annap Boat Show is the MastFoil 47.
 
I'd rather have skegs and tabs (also on the Atlantic 47) than daggerboards, let alone crazy-ass foils. Robust, simple and not a boat-killer if run aground, rather a boat-saving element. That's a cruising underbody to sell to an investor. Y'all are nuts if you think there is actually a market for foils in the cruising market.



#73 carcrash

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Posted 24 September 2013 - 02:04 AM

Trickle down to close-to-shore racing boats: I think we see the trickle up from Hobie Tri-Foiler (the firs wand controlled hydrofoil), moths, C-class. I think the next AC 72s will have at least mechanically active (wand) controls, if not full electronic.

 

How much trickle down do we get from Formula 1? Not much.

 

Fast is not necessarily attractive. I know, I know, it kinda is. But for absolute speed, hop on a Boeing, a motorcycle, a Cigarette, or Virgin Galactic. Don't mess around with sailboats.

 

We sail because its fun, not because we set the a record for human speed.

 

Foiling is physically dangerous. Its just that simple. Regardless of control system or lack thereof, of size, mass, carbon, whatever. When you crash -- and you do crash -- it hurts, at best, and injures or even kills. Like riding a motorcycle to commute to work. If you have kids, you probably don't do it (statistically, this is very clear).

 

So, I would not be surprised to see boats like F-18 develop foils. Kinda like the Moth.

 

But I am not at all surprised that nobody has advanced beyond, say, Cherokee Monkey, and made a full foiling F-32. It could easily be done, absolutely nothing preventing it. Would be an excellent foiling platform. And its been possible for decades before the first F-27. And there are exactly zero.

 

Cruising? Its about enjoyment, relaxation, enjoying the sights, friends and family. Not danger, pain, injury, and death.



#74 Doug Lord

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Posted 24 September 2013 - 02:39 AM

Just a point: the Rave was the first production wand controlled foiler designed by Dr. Bradfield. The Hobie trifoiler designed by Greg Ketterman used "feelers" that stuck out in front of the boat and moved the whole foil where the wands moved flaps on the main foils. A version of the wand system on a three foil cat(single main foil,windward foil+wand retracted) is a good bet for an automatic system.

And just one more thing once again: Wiliwaw cruised over 20,000 miles in the Pacific in the old,old days. We can do better these days. Many people have sailed thousands of hours on foilers w/o death dismemberment or serious psycological problems-except for an inordinate need for speed...

 

Trickle down to close-to-shore racing boats: I think we see the trickle up from Hobie Tri-Foiler (the firs wand controlled hydrofoil), moths, C-class. I think the next AC 72s will have at least mechanically active (wand) controls, if not full electronic.

 

How much trickle down do we get from Formula 1? Not much.

 

Fast is not necessarily attractive. I know, I know, it kinda is. But for absolute speed, hop on a Boeing, a motorcycle, a Cigarette, or Virgin Galactic. Don't mess around with sailboats.

 

We sail because its fun, not because we set the a record for human speed.

 

Foiling is physically dangerous. Its just that simple. Regardless of control system or lack thereof, of size, mass, carbon, whatever. When you crash -- and you do crash -- it hurts, at best, and injures or even kills. Like riding a motorcycle to commute to work. If you have kids, you probably don't do it (statistically, this is very clear).

 

So, I would not be surprised to see boats like F-18 develop foils. Kinda like the Moth.

 

But I am not at all surprised that nobody has advanced beyond, say, Cherokee Monkey, and made a full foiling F-32. It could easily be done, absolutely nothing preventing it. Would be an excellent foiling platform. And its been possible for decades before the first F-27. And there are exactly zero.

 

Cruising? Its about enjoyment, relaxation, enjoying the sights, friends and family. Not danger, pain, injury, and death.



#75 Chris 249

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Posted 24 September 2013 - 04:07 AM

 We shouldn't let the "coolness" of these boats stop us from enjoying more practical boats.  

 

Good post, but doesn't history show that the "coolness" of extreme craft DOES stop a lot of people from enjoying more practical boats?

 

In windsurfing people enjoyed big boards until the industry started pushing cool shortboards and then the whole thing collapsed. In cat sail down here, there were huge fleets until the emphasis went on "cooler" bigger and faster cats and then the whole thing collapsed. Same thing in dinghies; in the UK the scene exploded when the emphasis was on slow boats like Enterprises and GP14s and then it declined once the "cool" boats like 505s became more popular in the mid '70s.

 

If we can have cool AC72s and still respect the slower boats that most people can actually buy and sail, things could be great. But doesn't history tell us that a noisy minority of dickheads will now start abusing practical boats like Farriers and F18s, just like they abuse practical boats like Flying Scots and Lasers? 

 

History seems to show that if people have the choice between sailing something uncool and sailing something they cannot afford or sail like a carbon foiler, they will often drop out of the sport altogether.



#76 piv

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Posted 24 September 2013 - 01:22 PM

A few things about Spitfire. We had an outboard on it and motored in and out of the marina ourselves. We had an anchor on board. We carried all that junk plus a heap of eskys, drinks, and the stuff you normally take out sailing. It was designed to fly with four people aboard and on her maiden voyage we flew it with 7 on board. We sailed in winds up to about 25knots, just never had stronger winds while we were sailing her. Never crashed, never had a scary bear away. Never even looked like putting the bows in. Part of that is due to the foils and part due to the hulls being designed to fly with flared bows, so any landing is gentle and skimming and not putting the bows in. The hulls were Not hulls designed as wave piercing, which to me seems completely ridiculous for a foiler. If you come off the foils you dont want to pierce the waves and go down the mine, you want to plane and skim over the surface. So a short handed near shore racer with some accomodation is possible, its moderately practical and its been done and of course could be done even better next time.

#77 Wess

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Posted 24 September 2013 - 02:14 PM

A few things about Spitfire. We had an outboard on it and motored in and out of the marina ourselves. We had an anchor on board. We carried all that junk plus a heap of eskys, drinks, and the stuff you normally take out sailing. It was designed to fly with four people aboard and on her maiden voyage we flew it with 7 on board. We sailed in winds up to about 25knots, just never had stronger winds while we were sailing her. Never crashed, never had a scary bear away. Never even looked like putting the bows in. Part of that is due to the foils and part due to the hulls being designed to fly with flared bows, so any landing is gentle and skimming and not putting the bows in. The hulls were Not hulls designed as wave piercing, which to me seems completely ridiculous for a foiler. If you come off the foils you dont want to pierce the waves and go down the mine, you want to plane and skim over the surface. So a short handed near shore racer with some accomodation is possible, its moderately practical and its been done and of course could be done even better next time.

How much breeze was needed to fly?



#78 Chris O

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Posted 24 September 2013 - 02:42 PM

So, piv.... where are the photos and the video clips of this outrageous, ahead of its time, beast?

Surely you knew what you had in your hands when you accomplished all these things you mention? I'm just surprised that you didn't record it for posterity, so that announcements of this type could be supported by real imagery of Spitfire doing its bad thing.

Lastly, if it was such a wonderful thing... and I have no reason to doubt the truthfulness of the reports, then why in the world did not someone with means take up the bridle and bring that beautiful horse home for the good of the sailing industry?

#79 harryproa

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Posted 25 September 2013 - 07:42 AM


So my question for multihull designers is... is there any realistic potential for trickle down from this foiling AC class?

Wess

 

 

Harryproa people who want to go faster are more interested in planing biscarphs and inclined (unstayed) rigs, which have proven to be as fast or faster (MI and SR2) than foils,  with neither the damage potential or the cost.  There is also a project using a single air foil section beam to lift (but not fly) the hulls.  

 

We also have 3 wing rig projects happening.  One is a telescoping 2 element wing for a 60'ter (prototype for a 30'ter being built this northern winter), one is a pair of vane operated rigs on a 50'ter and the other is an NDA.    The other interesting area is a telescoping tube rig, which should be in the water 'soon'.  

 

Some of the above is direct trickle down from the AC.  The rest is the realisation, from watching the cup, that there is still a lot to be done to make boats better.  

 

Lots of fun, it is a great time to be a boat designer, if you are able to think outside the box.  Not such a great time to be a kiwi, although this might change tomorrow!

 

Re your cruising cat: If they can get a Laser with 96 kgs on board foiling in 12 knots breeze at mid teens boat speed, then it can't be too difficult to get a minimal cruising cat foiling.  

 

Spitfire is/was an awesome boat. Mark Pivac, Brett Burville and the guys who put it together really knew what they were doing. I don't have any videos, but did see it being built and sailing/flying in Perth.  Way ahead of it's time, then.  Probably still is.

 

rob



#80 Chris O

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Posted 25 September 2013 - 01:56 PM

So, Rob... where is Spitfire now? Do you know? If not yourself, who would know the condition and the whereabouts? At the very least, it would seem that there are some really powerful lessons to be learned from the boat, even if it is not working right now.

 

I'd like to know more about this machine.



#81 piv

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Posted 25 September 2013 - 02:36 PM

Chris O, sometimes you can be onto a good thing and the rest of the world just doesn't get it. There were photos in Seahorse and Yachting World, the Australian Multihulls magazine, local newspapers, local TV (channel 7 I think). Ive got lots of video on tape that I should probably now get onto you tube (anyone know how to get 8mm tape onto you tube when your camera has gone for swim and no longer works?). There is more info on the BDG website www.bdg.com.au. This was all pre you tube. I had to snail mail a CD to Seahorse so they could use the digital images. Like I said before, there were lots of reasons why it wasnt taken up. I cant speak for the general public as to why they didnt bust our door down, but from our side of things, we (me, Brett Burvill (Windrush), John Illet (FastaCraft)(and his brother Garth who wasnt involved in Spitfire) had already spent a lot of time developing the Moth foiling systems and tried lots of stuff. That was easy on an 11foot boat. Everything on Spitfire was a mission and expensive compared to a Moth. We had a good budget (well fractions of a percent of an AC type budget, about the same as some C class budgets, but big compared to a windsurfer budget!) thanks to those involved, but the budget (and then some) ended and so did development. My business supports my family and some develpment projects, but it cant feed this hungry beast. Id say we were 10 years too early. Its probably still 10 years too early. Even though foiling Moths are successful beyond even what we thought might happen, in commercial terms, they really are not that great a business. Hats off to Amac for making that work. We all tried and had a hard time. The reality is that most people dont have the means or inclination (and you need both) to play in development classes. Most people go with the flow. In my street there are 40 houses with pitched roofs, mine is the only one with a curved roof. Brett still has Windrush, but unless someone comes along with some decent funding, I dont think she will be on the water again any time soon. Brett is pretty busy with F18s and Tornados. Im not saying that Spitfire was a perfect boat, far from it. What it did show was that a moderate tech mid size sailing hydrofoil could be built and used, was fairly safe, fast, comfortable and with more development could probably become practical for a keen "weekend sailor" with deep enough pockets. The foil layout was a success but the rig turned out to be a bit painfull, a bit underpowered in light air and a bit too twisty in heavy air, mainly due to a few details that would require major mods to correct. Foils probably cost about the same as making a boat 10 feet longer (eg a moth foiler costs about the same as an F18, Spitfire was a 40 footer that probably cost about the same as a 50 footer). But if cost is an issue, dont play the game.

#82 samc99us

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Posted 25 September 2013 - 02:50 PM

Pictures of Spitfire here: http://marine.bdg.co...re_gallery.html

 

Looks like a weapon in the right hands, pre-cursor to Hydroptere in many ways it seems. Maybe forces could be joined?



#83 piv

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Posted 25 September 2013 - 02:57 PM

I think you would see the most foiling development by encouraging some kind of class rule to encourage it. Most of the class rules either unintentionally or purposefully discourage foiling. Even the AC72 rule is framed to make it real hard, but it is such an advantage that ways around the restrictive rules have been found. One side effect of the restrictive rules is that "outlying solutions" get tried and sometimes they work, far better than anyone expected. I remember writing in Seahorse that I would like to have only two foils, or even just one penetrating the surface rather than three as Burvill and I were using on Moths at the time but I didnt think it was possible. Well the Moths changed the rule interpretation to effectively make foils penetrate the surface on only one longitudinal plane (notionally to stop catamarans), everyone thought that would stop hydrofoils being used. So the Moth guys just went ahead and made them work within the rules and look at the solution that has developed. Same thing with the L semi surface piercing AC72 foils, on paper, free of rules its unlikely you would go to that exact solution (as far as I know, no one did before) but look what happened with a tight rule and $100m thrown at it. With a blank sheet and an open box rule or no rule, the sky could be the limit. Probably Groupama or some French bank will come up with a budget to build an offshore foiler to break the round the world record and Frank will show us what can be done. Thats what I wanted to do back before Spitfire with a boat to enter "The Race" (remember that!) but my vision was a bit long distance. Hats off to the AC guys for getting this technology into the gaze of the general public.

I think hydroptere was around before Spitfire.

#84 piv

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Posted 25 September 2013 - 03:02 PM

Spitfire would reliably fly in about 12 knots of breeze from memory. That was chosen as a reasonable compromise windspeed for takeoff, pretty common windstrength in summer Australia.

#85 Wess

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Posted 25 September 2013 - 03:25 PM

Spitfire looks to be a pretty interesting boat.

 

PIV - If doing it today, what would you do differently in terms of hulls, foils, and rig?



#86 Doug Lord

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Posted 25 September 2013 - 04:47 PM

Spitfire would reliably fly in about 12 knots of breeze from memory. That was chosen as a reasonable compromise windspeed for takeoff, pretty common windstrength in summer Australia.

 

If I remember correctly, didn't you guys use some ballast on the boat?

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#87 mathystuff

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Posted 25 September 2013 - 11:35 PM

anyone know how to get 8mm tape onto you tube when your camera has gone for swim and no longer works?

 There are companies specialized in digitizing out of date media. I bet google would find one near you with acceptable prizes.

 

 

On topic: Why not control foil AoA by a system similar to a cars suspension that would decrease AoA based on lift created. Should be possible to get a foil decent over a wide range of speeds this way, while also reducing the risk of a foil induced pitch pole as negative lift would reduce negative lift.



#88 piv

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Posted 26 September 2013 - 08:40 AM

Yes we had design provision for water ballast on the windward hull as it is less drag than creating foil down force (gravity has no drag, but we never sailed with it, we didn't get to that point of development. If we were to do the next generation, the major changes would be: 1. Probably inclined dagger boards rather than the folding foil system (it was heavy, expensive, and structurally heavy on the boat to deal with the point pin loads), mainly to save cost. 2. Lighter structure, mainly to save cost rather than weight. Less material, less labour, smaller foils for the same takeoff speed. It was super bullet proof. Could be done in glass again but the price of prepreg carbon has come down a lot so would have to look at the trade offs. 3. The rig. More sail area for light winds. Better sail tracks to ease hoisting. Maybe go to a stayed wingmast to save cost (there was a truck load of carbon in the unstayed masts) and simplify leach twist control. Id be happy with an aluminium wing mast. If the logistics and budget was available (cranes etc) then I would think about solid wings, depending on the intended use of the boat. For Spitfires coastal racing I wouldnt go solid wings. Maybe go to a single mast as there is no competition yet to warrant the biplane rig. That said though, the whole boat was a lot nicer with the masts out on the hulls. So its a tough call. Otherwise work on the sails to get the leaches and double luffs working better. But really its very expensive to experiment at this scale. My aim is to sort things out on a smaller boat, say A cat size or even 14 foot size first. A lot of people bang on about weight being a big issue for foilers, its not. It does affect the take off speed, but thats only important if you are racing in marginal conditions against someone else who is lighter. There is so much less pitching (basically none) that rig weight and weight in the ends of the boat is far less significant. I am fairly interested in a moderate cost foiler that can utilise extruded aluminium foils, aluminium cross beams and masts and glass hulls. Sure it might be a few % slower than a carbon boat, but it will still be about 100% faster than a lowrider and even with foils and control systems would come in cheaper than a similar sized but much slower carbon multihull. One of the rare occasions where you can have better, cheaper and faster at the same time.

#89 Wess

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Posted 26 September 2013 - 01:09 PM

Really cool program and ideas PIV.  Wish you guys much success with Spitfire, or a Spitfire II.

 

Foils for future... surface piercing J, or L or T with elevators and auto height wand type system, or other?



#90 Chris O

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Posted 26 September 2013 - 02:19 PM

While I wish you much success in whatever you choose to pursue in the future, there is something within your last post where I would suggest somewhat different perspectives.

 

When you say, "...A lot of people bang on about weight being a big issue for foilers, its not. It does affect the take off speed, but that's only important if you are racing in marginal conditions against someone else who is lighter...."

 

I would suggest that weight is always an issue. It's an issue for all boats, one way, or another and its especially so for foiling machines that are dependent on lifting that weight in order to achieve their design fulfillment. If weight is not an issue, then why not a Spitfire with a full, bridgedeck cabin, toilets in each hull, full journey water tanks, fuel for in-harbor maneuvering and electrical generation, stores and bunks, storage and galley facilities for a crew for however long the cruising journey would last...?

 

I suspect that the boat would soon leave behind any notion of being able to get up and out of the water without much bigger rigs and bigger foils... and the lift function necessary to not only lift it, but to keep it lifted, would change dramatically. In essence, say hello to the dreaded design spiral and be prepared to shell-out major dollars in order to feed it.

 

Yes, you could go to full, Spartan-esque cruising amenities with a design aesthetic that parallels that of an ultra-light backpacker, or a couple of guys who are attempting to scale a major, big wall rock climb, where each and every component that one brings is a component one must lift, over and over again. I suspect that Wess is leaning somewhat in that direction, but it certainly is not the norm within the sailing community when one hears the term, cruising boat.

 

If I were doing a boat of this type, I'd go for foil assist in a limited application, rather than fully flying. I'd keep the weight way down through careful use of materials and functions and create a solution that addresses some of the current mentality for creature comfort cruising, while trimming the condo-on-the-water thing to a tiny trickle for specific needs. With these approaches, one could get a faster, more stable, cruising boat, and still have a decent connection to the stuff that makes for a bit better  experience while at anchor at the cruising grounds of your choice.

 

It would be good to work-through the design issues you mention on a smaller scale. Problem with that process when looking to do what Wess is after, is that the relationship of the human scale of things on a tiny boat is way out of whack compared to what is needed and how to design it for a boat that IS human scale for the necessary functions. As a one-off for a specific application, why not?  As a functional product which depends on sales to a broader base of customer thinking.... not in this marketplace. I realize that nobody said "commercial product" here, but at some point, the boat will be sold and that process brings with it all the issues mentioned.

 

Lastly, speed is not a terribly critical component for what the business has grown to accept as a cruising paradigm. Comfort afloat is a much bigger issue, as is ease of use, safety and user friendliness of operational systems. I didn't create the reality, but racing boats do not, typically, make for good cruising solutions.

 

I'd love to hear your comments, Piv.



#91 Doug Lord

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Posted 26 September 2013 - 03:12 PM

Yes we had design provision for water ballast on the windward hull as it is less drag than creating foil down force (gravity has no drag, but we never sailed with it, we didn't get to that point of development. If we were to do the next generation, the major changes would be: 1. Probably inclined dagger boards rather than the folding foil system (it was heavy, expensive, and structurally heavy on the boat to deal with the point pin loads), mainly to save cost. 2. Lighter structure, mainly to save cost rather than weight. Less material, less labour, smaller foils for the same takeoff speed. It was super bullet proof. Could be done in glass again but the price of prepreg carbon has come down a lot so would have to look at the trade offs. 3. The rig. More sail area for light winds. Better sail tracks to ease hoisting. Maybe go to a stayed wingmast to save cost (there was a truck load of carbon in the unstayed masts) and simplify leach twist control. Id be happy with an aluminium wing mast. If the logistics and budget was available (cranes etc) then I would think about solid wings, depending on the intended use of the boat. For Spitfires coastal racing I wouldnt go solid wings. Maybe go to a single mast as there is no competition yet to warrant the biplane rig. That said though, the whole boat was a lot nicer with the masts out on the hulls. So its a tough call. Otherwise work on the sails to get the leaches and double luffs working better. But really its very expensive to experiment at this scale. My aim is to sort things out on a smaller boat, say A cat size or even 14 foot size first. A lot of people bang on about weight being a big issue for foilers, its not. It does affect the take off speed, but thats only important if you are racing in marginal conditions against someone else who is lighter. There is so much less pitching (basically none) that rig weight and weight in the ends of the boat is far less significant. I am fairly interested in a moderate cost foiler that can utilise extruded aluminium foils, aluminium cross beams and masts and glass hulls. Sure it might be a few % slower than a carbon boat, but it will still be about 100% faster than a lowrider and even with foils and control systems would come in cheaper than a similar sized but much slower carbon multihull. One of the rare occasions where you can have better, cheaper and faster at the same time.

 

Piv, what are your thoughts on surface piercing foils vs wand controlled fully submerged foils? Thanks for taking the time to discuss this stuff!



#92 Lohring Miller

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Posted 26 September 2013 - 03:21 PM

Actually, the AC 72 is trickle up from the C class.  Multihull development owes a lot to work done in the A, B, and C classes starting in the 1960s.  New Zealand was defeated a long time ago in the AC with a much smaller catamaran that owed its wing design to Dave Hubbard and Duncan McClain (sp?)  based on their work on the C class wing.   Burt Rutan provided additional refinement, I believe.  It was obvious then that multihulls were faster than traditional monohulls.  Before and since, ocean racing multihulls have proven themselves in all levels of sailing.  As was pointed out, there is always more danger with speed in any type of boat.  Try racing in 2 meter seas at 40 knots in a planing boat for 6 hours. I was in Dry Martini in 2010.   Please give me foils.   Today, the cutting edge of 25' sailing dingy designs is on display in Falmouth with the ICCCC races.  The French and Swiss are applying lessons they have learned in all sizes of boats.  I'm sure the results of this racing will find its way into fast, European ocean racing multihulls.  That includes foils.  Even ballasted monohulls are using foils to enhance stability.  Wings have been a harder sell, but are starting to appear in autonomous sailboats where durability in bad conditions and ease of control are critical.  Race boats will always be at the edge of what is possible.  Cruising boats have much less power and speed.    Lohring Miller



#93 Airwick

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Posted 26 September 2013 - 07:03 PM

I think the bottom line is that the technology has been around for quite a while but the demand wasn't. There have been a few niche products and many one-off projects but none that really took off.

 

However it looks like this version of the AC might change the balance a bit...

 

I would expect to see a few more "mainstream" options available in the next couple of years from small foiling cats (A or F18 "type" boats) or an updated version of the tri-foiler and more focus on foiling options for things like the M-32, SL-33, GC32 and the like. 

 

Full foiling seems unlikely to happen any time soon for "cruisers" as there are just too many compromises between weight/power/wind/safety. More weight requires more power to fly at a given wind speed which means less safe when the wind is up (easy to overpower and low capsize wind limits). A few will be willing to do the necessary sacrifices to get the speed boost but I would expect it to remain a small niche.

 

A foiling beach cat or tri (either a new class or an evolution of an existing class) seems the most likely to be commercially successful on anything above small scale.



#94 Chris O

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Posted 26 September 2013 - 08:14 PM

I think the bottom line is that the technology has been around for quite a while but the demand wasn't. There have been a few niche products and many one-off projects but none that really took off.

 

However it looks like this version of the AC might change the balance a bit...

 

I would expect to see a few more "mainstream" options available in the next couple of years from small foiling cats (A or F18 "type" boats) or an updated version of the tri-foiler and more focus on foiling options for things like the M-32, SL-33, GC32 and the like. 

 

Full foiling seems unlikely to happen any time soon for "cruisers" as there are just too many compromises between weight/power/wind/safety. More weight requires more power to fly at a given wind speed which means less safe when the wind is up (easy to overpower and low capsize wind limits). A few will be willing to do the necessary sacrifices to get the speed boost but I would expect it to remain a small niche.

 

A foiling beach cat or tri (either a new class or an evolution of an existing class) seems the most likely to be commercially successful on anything above small scale.

 

 

A well-reasoned and concisely written take, Airwick. Nice work.

 

Other than for specific, all-out racing applications, I just don't see serious foil use making much of a dent in recreational, or cruise oriented sailing, at all. Sure, there will be the odd, t-foil rudder setups and occasional angled, or curved, foil assist adaptations here and there, but as a standard functional element, there are just too many issues to deal with that will take them out of the mainstream of everyday boaters. I've listed those reasons several times before on these pages, so I'm not going to do it now.

 

Racing boats... sure. I've always felt that there was a place for lifting foils for that slender market niche and I expect that interesting things will develop in the coming years for that application.

 

As far as this thread's topic, I also see the appearance, every so often, of foil equipped, bare bones cruiser style boats that have been specifically modified to accept the technology and are aimed for a very unique style of sailing that is not at all mainstream in nature. I expect the prices to be quite a bit higher and the resale values to be marginalized because of the limited scope of the design. This marginalization will be especially true as newer technologies, which are inevitable, make their way into the sandbox. If you are value conscious in your boat ownership, lifting foils are probably not a good direction.

 

I think that you are partly right about the AC changing the balance of things within the sailing community, but It's my opinion that the change is mostly about awareness and it will not make large changes in the way boat builders look at the market, especially the cruising market. A really small, quick response style of builder, like Randy Reynolds, could present a somewhat affordable foiling cat based on an existing platform that could be adapted for enhanced cruising, if that is the way one wants to go with their boating. What is not known, is how much more that boat would cost over the stock product now available.



#95 BalticBandit

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Posted 27 September 2013 - 08:14 AM

I think the bottom line is that the technology has been around for quite a while but the demand wasn't. There have been a few niche products and many one-off projects but none that really took off.

 

However it looks like this version of the AC might change the balance a bit...

 

I would expect to see a few more "mainstream" options available in the next couple of years from small foiling cats (A or F18 "type" boats) or an updated version of the tri-foiler and more focus on foiling options for things like the M-32, SL-33, GC32 and the like. 

 

Full foiling seems unlikely to happen any time soon for "cruisers" as there are just too many compromises between weight/power/wind/safety. More weight requires more power to fly at a given wind speed which means less safe when the wind is up (easy to overpower and low capsize wind limits). A few will be willing to do the necessary sacrifices to get the speed boost but I would expect it to remain a small niche.

 

A foiling beach cat or tri (either a new class or an evolution of an existing class) seems the most likely to be commercially successful on anything above small scale.

Well the moths showed off the ability to do  a multi-piece wing (disassembled for transport) some years ago. So I wonder if any of the beach cat classes have loose enough rules that you might see a wing get introduced.  The gothcha of course with the wings is that they are more fragile than a carbon mast with cloth.  and Beach cats tend to be pushed more.  But I dunno, could you put a wing on a F18 class boat?  And if you can you might see it as a light to medium air alternative



#96 Doug Lord

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Posted 27 September 2013 - 04:26 PM

As far as wings go both for the AC and certainly for AC "trickle-down", I think Gino Morrelli said it best in this interview:

http://www.sailingwo...riting-the-rule

 

 

GM: I think the excitement that has been generated in this Cup has way more to do with foiling and flying than the wing. If we used the same platform with soft rigs and rotating masts with fully battened sails, then first you can reef them, second you can launch them at your leisure like a normal boat, and third you eliminate the wing-building team and the problem with the handling of the wing, the hydraulics, and control systems. In reality the difference between the performance of the boats with a wing on foils and without the wing on foils, won't be much. They’ll still sail at 40-plus knots. Maybe they don’t sail at 165 degrees downwind, but at 163 to 160, and they’ll probably still fly in as little wind.

 



#97 W111GBR

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Posted 27 September 2013 - 05:51 PM

Here in Falmouth I had the pleasure of interviewing Nigel Irens, I asked pretty much the main question for this thread..

In short, it's unlikely to see the foiling action on anything other than short course racers..

I will get Mr Clean to add the interview here ASAP..

#98 BalticBandit

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Posted 27 September 2013 - 05:58 PM

As far as wings go both for the AC and certainly for AC "trickle-down", I think Gino Morrelli said it best in this interview:

http://www.sailingwo...riting-the-rule

 

 

GM: I think the excitement that has been generated in this Cup has way more to do with foiling and flying than the wing. If we used the same platform with soft rigs and rotating masts with fully battened sails, then first you can reef them, second you can launch them at your leisure like a normal boat, and third you eliminate the wing-building team and the problem with the handling of the wing, the hydraulics, and control systems. In reality the difference between the performance of the boats with a wing on foils and without the wing on foils, won't be much. They’ll still sail at 40-plus knots. Maybe they don’t sail at 165 degrees downwind, but at 163 to 160, and they’ll probably still fly in as little wind.

 

Well given that this is being argued by you Doug, my money is on wings.



#99 W111GBR

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Posted 27 September 2013 - 06:05 PM

Ok, here you go. 1 small one, it's not Billy Besson, just getting that changed now! 1 big one, I got the boat the wrong way round with Idec and Sobedo, sorry about that.. Here you go!



#100 BalticBandit

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Posted 27 September 2013 - 08:13 PM

Um wrong thread I think






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