Little America's Cup 2010-C CLass-the real one..

[Doug Lord]

Doug:
Cool your jets. This is not a foiler. It is not intended to fly and will probably crash badly if it does. What you see in this picture is the boat coming out of a small wave and nothing more.
The curved daggerboard and T foils modulate the frequency of how the boat pitches in waves. Which is what I was trying to achieve. When the boat launches out of a wave, it kind of glides back to the surface instead of free falling. This reduces the severity of wave encounters and also the need for volume forward. Only very short time on the boat yet. Much more to learn as we sail.
SHC

==============
Thanks, Steve-I think I realized that after seeing the video...Is it a half-foiler? (just kidding, I think)
At any rate, best of luck-the boat looks real good!

 

[Toro-Mush Knox]

Light came doun, this is the new Jaguar of C Class Catamarans.

This is the Vision from Heaven!!!!
I was watching up close first hand during the filming of the U-Tube clip, of this, Steve Clark's inaugural Atenon's release to the public. It was steady as she goes testing, of the fantastic and phenomenal newly designed C Class Catamaran. I was taken back as the crew blew by my Trac16 "Toro" along with my two Huskies, and my sons Greyhound, as crew with him out on the Trapeze.

Hats off to the great show, it couldn't have gone smother!
The design of the curved dagger-boards, and control offered by them as well as the t-foil rudders was absolutely astonishing, just pure joy to behold. I just loved seing the close up look at the shear control I have never seen possible in chop and heavy current just off Hope Lighthouse.
I am thinking she is like a dream to control in retrospect, just like a winning Formula One Indy Racer. A pure winner! Cud o's to Steve! and his, I hope winning design entry C-Cat, for this years entry, to achieve his dream come true. A win, win combination!

This wonderfully promising entry, US 105, has an unbelievable potential to make it possible for USA, taking it home as #1, the big winner, in this "Little America's Cup" C Class. This will be most notably due to such innovative new conceptual application of truly ingenious design work, brought to fruition from his perfect theory practice, applied!

I am so happy to have been able to be watching, what was a moment I will never forget, as I was going 10 knots and this vision blew by at 22 and reaching 25, and better off the wind. Control was more in moderate and heavier wind's, with the choppy seas, and some big current driven swells than I had ever seen before. Stable pointing to wind, controllable like I have never seen before coming doun off, smooth fast acceleration, and so predictable with every movement, a winning combination in all respects, was all I could think..
My cat was "Toro" (Bull), where this was a "Stealth Fighter" Americas Contender "Cat" (Jaguar). I saw multi-hull adrenalin moving though this one, like never before, yet precisely regulated, as a true Jaguar is seeking it's prey.
Take it Home!!!!

 

[Steve Clark]

SIR,
We were mighty impressed by the "Toro." Three dogs in life jackets enjoying a heads out the window ride, crew on the trapeze enjoying some extra- vehicular activity looked like a high quality family outing. We were hooting our approval.
Thanks for the kind words. We are pretty happy with how things are going so far, but sailing a C Cat around by yourself can lead to delusions of grandeur. We need to get the other boats out to find out where we really are.
SHC

 

[Toro-Mush Knox]

I am a Steve also, and love Yacht Design.
I understand the trepidation you face what with having no match racer to evaluate it by out on the maiden trip tests. If help for a crew to run Cogito is needed to run this earlier Cat, along with your new one, I will be glad to crew.
I built a family modified design off shore Piver 48 footer back in the late 70's with my dad as president of Able Boats, at an India Point warehouse near to the tug boats in Providence. Sadly it succumbed to Brenton's reef damage hitting bottom. I am hoping to follow the team you run. When is the next shake down to happen? Will Cogito be out with her, as this is a pure cutting edge new application in design, and I would love to be there when they both go head to head?

PM me if you don't mind for a next shake down day viewing. SK Jones.

 

[Doug Lord]

Aethon 7/24/10

Another great picture of the non-foiler: (ok,ok, I know)

Aerodynamics of the forward crossarm are very well done-how'd you do it? Have you reached any conclusions about the board cant?

(image from SA/Clark/ click on image and then on image that results for greatest detail)

 

[captainsideburn]

cool rudder/tiller linkage

 

[Doug Lord]

Aethon 7/25/10

Two more-boat looking real good-check out the lee bow:

 

[Doug Lord]

Aethon

From Steve today on SA:

Posted Today, 09:05 PM

With asymmetric boards you achieve 0 degrees leeway. In fact, you can generate +1 or 2 degrees leeway. But as Magnus states, this is slow. On Cogito we knew when we had to pull the board up because the boat would develop lee helm. When the daggerboard overproduces lift the CLR moves aft, and the incoming flow on the bow is coming from the weather side instead of the leeward side. All of which makes the boat want to turn down wind.
We find that with the curved foils we no longer get the lee helm signal. This may be because the boards are further forward than on Cogito, but it is more likely that the surplus lift is going into picking the hull up instead of dragging it sideways. We increase the cant angle when we feel we have enough side force and can benefit from some additional vertical lift. This is some unknown territory and we are treading carefully. It is possible to get the boat actually out of the water if you have too much board down and too much cant angle and go a bit too fast. We are not comfortable in the air because we don't have the controls to manage flight. So we are playing around with the cant angle and board height. Half way up and all the way over is our base setting, the boat seems to trim very well at this setting and we seem to be able to be able to press quite hard with the right foot. But the lift of the board is affected by steering, so I am having to think pretty hard about all the consequences of wiggling the stick around.
Finally you want to pull the windward board to avoid being launched into the sky. If the boards work against each other, there is nowhere for the boat to go but up. This can happen very quickly and be very unsettling. Fredo and Magnus found this out with PLVI. ( Someone post the famous image please.) So something as stupid as the bungee that holds the weather board up is something that we take seriously, and I will pull up pretty fast if I see the windward board slip down.SHC

Beatings will continue until morale improves.

http://forums.sailinganarchy.com/index.php?showtopic=101656&pid=2932553&st=500&#entry2932553

famous pix below:

 

[TTS]

From Steve today on SA:

Posted Today, 09:05 PM

With asymmetric boards you achieve 0 degrees leeway. In fact, you can generate +1 or 2 degrees leeway. But as Magnus states, this is slow. On Cogito we knew when we had to pull the board up because the boat would develop lee helm. When the daggerboard overproduces lift the CLR moves aft, and the incoming flow on the bow is coming from the weather side instead of the leeward side. All of which makes the boat want to turn down wind.
We find that with the curved foils we no longer get the lee helm signal. This may be because the boards are further forward than on Cogito, but it is more likely that the surplus lift is going into picking the hull up instead of dragging it sideways. We increase the cant angle when we feel we have enough side force and can benefit from some additional vertical lift. This is some unknown territory and we are treading carefully. It is possible to get the boat actually out of the water if you have too much board down and too much cant angle and go a bit too fast. We are not comfortable in the air because we don't have the controls to manage flight. So we are playing around with the cant angle and board height. Half way up and all the way over is our base setting, the boat seems to trim very well at this setting and we seem to be able to be able to press quite hard with the right foot. But the lift of the board is affected by steering, so I am having to think pretty hard about all the consequences of wiggling the stick around.
Finally you want to pull the windward board to avoid being launched into the sky. If the boards work against each other, there is nowhere for the boat to go but up. This can happen very quickly and be very unsettling. Fredo and Magnus found this out with PLVI. ( Someone post the famous image please.) So something as stupid as the bungee that holds the weather board up is something that we take seriously, and I will pull up pretty fast if I see the windward board slip down.SHC

Beatings will continue until morale improves.

http://forums.sailinganarchy.com/index.php?showtopic=101656&pid=2932553&st=500&#entry2932553

Steve,

How is the evaluation of the curved daggerboards going? Can't help but notice in the latest pics you are sailing offwind with the leeward board about 50% up and the windward board max up (just enough to fill the bottom of the trunk?). I'm assuming the strategy offwind currently is to use just enough leeward board for lifting/unloading the leeward hull and minimizing the windward board to eliminate drag? That's what I am trying in the ASG3 and I think I am on the right track but I'm getting feedback from a west coast A-Class sailor that Matt Struble is ripping downwind on an EVO with curved boards and never pulls them up when wild thinging.

Boat looks fantastic, you guys seem to be having too much fun!

Bob


The aspect ratio of spray rails makes them lousy for generating lift.
These guys are just to knock the water off and prevent it from re-wetting the hull.
This starts to be a bigger deal as the boats go faster.
I didn't want to try something drastic that would make the boat a woofer in light air, so confined myself to back aft and pretty small.
They seem to help but don't drag in the water when they aren't going to do anything good.
Who knows if they are worth it?
Have to sail some more to get a better opinion.
SHC
I won't speak for Steve, but I know this much for sure, we all pull up our windward daggerboards up because they are assymetric. Having the windward board down only makes the boat produce leeway and go slower due to drag. There is precisely zero to be gained from having both boards down when you have assy boards. As for pulling the leeward one up? Well once you start doing 16 knots, you don't need all that board in the water to produce enough side force to keep the boat going perfectly straight through the water. Having the board down all the way will just make you go to windward, which is not fast because it's just backwards leeway drag on the hulls and if you are going downwind, having a board push you to windward is particularly useless as it kind of hinders your VMG.

On your a-cat do you have sym or assy boards?

Fredo

 

[Doug Lord]

Invictus-last sail before the USA

Video from Larso on SA: http://www.youtube.com/watch?v=zskN0rsdRfc

 

[Doug Lord]

Little America's Cup-design

An interesting sketch from DSmith on SA. Shows a C-Class with the beam CL to CL of the hulls smaller than usual to allow the boat to sail on just two foils--like a Moth with simulated Veal Heel allowing the RM to be very close to a "normal" C Class. The additional benefits are: unloading of the vertical fin, and a lift component to weather from the hydrofoils. Looks like the vertical fins would be canting....
Downside, as I see it, is tacking or gybing but it would not be that much different than the current set up. Possible problem getting started :
a. in light air because there would be four foils in the water,and
b. in heavy air because before the boat flies it would have much less initial RM
than a normal boat.
Very interesting thinking......
---
I'm thinking more about the "Happy Feet" concept: just two foils in total mounted in a module that slides athwartship. Lots of complications to solve..
--
See Steve Killings paper below with details on the hydrofoil C Class "Rocker" and Bill Beavers paper on the Moth which goes into the value of "veal heel(aka windward heel on a foiler):

 

[Doug Lord]

Little America's Cup-----Oh, Canada

The Canadian boat with its new wing:



(click on image then again on resulting image)

 

[TTS]

The Canadian boat with its new wing:



(click on image then again on resulting image)

You beat me to it.

 

[Doug Lord]

Little America's Cup

Tom, its getting close to time to call the race: who's going to win?!

 

[Doug Lord]

Little Americas Cup

Now this is really cool-Adam May's Eagle with wing rig! http://www.boatdesign.net/forums/sailboats/moth-foils-30-7-knots-35-3-mph-11209-73.html#post385768



(click on image then again on resulting image)