C Class Catamaran Design

[Doug Lord]

Found this on the A Class thread. Its a new design by Team Invictus using a single wand controlled main foil and a single rudder T foil.

http://www.yachtsandyachting.com/news/186458/Team-Invictus-launch-new-C-Class-Cat

They gain a lot of RM from VealHeel and appear to have enough flight altitude designed to allow the thing to heel quite a ways to windward. On a Moth, here is a substantial gain in RM with Veel Heel and there would be here too if they start out high enough:

 

[Steve Clark]

Encouraging news.

It's an evocative image, but I'm not sure the physics work in anything but pastel.

These guys can do good work, and it will have to be all of that if they are to build wings that weigh 60% of the best built to date.

I hope this announcement is that they are reallystarting, rather than announcing the intention of starting once they have raised the money.

SHC

 

[Catnewbie]

The trampoline looks strange, just if there are a lot of telltales to show the air flow ?

 

[basildog]

Come on Dougie,

Let it rip - go on - you know you want to say it - "Just like the mighty Fire Arrow's centre foily thing".

 

[multitranslation]

Another pipe dream...

 

[blunted]

Having done that round of math before I can assure you that it requires really long foils to make it work properly. Leaves you are a decent disadvantage in intermediate conditions and take off.

Ambitious standing rigging locations and angles.

See how it goes I guess

 

[Poseidius]

Looks familiar !

 

[Cunningham]

It will loose some of the righting moment advantage a cat has over a mono hull. maybe better vmg off the wind?

 

[invictus]

Having done that round of math before I can assure you that it requires really long foils to make it work properly. Leaves you are a decent disadvantage in intermediate conditions and take off.

Ambitious standing rigging locations and angles.

See how it goes I guess

Rigging?

Encouraging news.

It's an evocative image, but I'm not sure the physics work in anything but pastel.

These guys can do good work, and it will have to be all of that if they are to build wings that weigh 60% of the best built to date.

I hope this announcement is that they are reallystarting, rather than announcing the intention of starting once they have raised the money.

SHC

 

[invictus]

Unfortunately we haven't found anyone willing to part with cash without seeing what they are buying.

One thing is certain: we cannot win against Franck without taking risk!

 

[Doug Lord]

It's a damn good idea and I hope you can pull it together!

 

[DSmith]

It looks like you will loose a lot of righting moment and probably won't be able to heal to windward enough to get the force vector to line up with the vertical foil so that only the fully submerged foil is lifting ....unless the vertical foil is ridiculously long.

What about the idea in the attached sketch? It gives maximum righting moment and aligns the force vector. It just has the complexity, weight and time required to rotate and lift'/lower the foils at each manourvre.

 

[invictus]

Ok, the picture doesn't show everything clearly. Rigging - there isn't any (the lines u see are trapeze lines, but I forgot to draw the rings etc on the leeward ones), and RM, well the racks, hulls and beams slide on curved tracks on the inside faces of front and rear beams. Yes, the foils are a bit long, but not ridiculously so; our RM is not compromised.

The drawing shown is v similar to Will Sunnucks Vampire conversion which appeared at Foiling week.

 

[Steve Clark]

Rigging - there isn't any (the lines u see are trapeze lines, but I forgot to draw the rings etc on the leeward ones), and RM, well the racks, hulls and beams slide on curved tracks on the inside faces of front and rear beams. Yes, the foils are a bit long, but not ridiculously so; our RM is not compromised.

THAT IS DIFFERENT! and much more conceptually valid. You will have a good time building it, I believe your structural team will be burning a lot of computer time because the mechanism is not trivial and the consequences are pretty unpleasant if it goes even slightly wrong.

Good Luck.

SHC

 

[DSmith]

So you ease the whole platform over over the foils to get it near the windward hull and then tack. That's some innovative thinking!.

 

[invictus]

Rigging - there isn't any (the lines u see are trapeze lines, but I forgot to draw the rings etc on the leeward ones), and RM, well the racks, hulls and beams slide on curved tracks on the inside faces of front and rear beams. Yes, the foils are a bit long, but not ridiculously so; our RM is not compromised.

THAT IS DIFFERENT! and much more conceptually valid. You will have a good time building it, I believe your structural team will be burning a lot of computer time because the mechanism is not trivial and the consequences are pretty unpleasant if it goes even slightly wrong.Good Luck.

SHC

Rigging - there isn't any (the lines u see are trapeze lines, but I forgot to draw the rings etc on the leeward ones), and RM, well the racks, hulls and beams slide on curved tracks on the inside faces of front and rear beams. Yes, the foils are a bit long, but not ridiculously so; our RM is not compromised.

THAT IS DIFFERENT! and much more conceptually valid. You will have a good time building it, I believe your structural team will be burning a lot of computer time because the mechanism is not trivial and the consequences are pretty unpleasant if it goes even slightly wrong.Good Luck.

SHC

 

[invictus]

Thanks Steve, we have made the tooling for hulls and beams and foils, and a few sponsorship leads following the show.

 

[invictus]

DS

for tacking/gybing, yes, as you say, I think centralise, execute manoeuvre, then reset to opposite tack. We need some tips from canoe sailors!

N

 

[dorox]

It looks like you will loose a lot of righting moment and probably won't be able to heal to windward enough to get the force vector to line up with the vertical foil so that only the fully submerged foil is lifting ....unless the vertical foil is ridiculously long.

What about the idea in the attached sketch? It gives maximum righting moment and aligns the force vector. It just has the complexity, weight and time required to rotate and lift'/lower the foils at each manourvre.

Hmm... Reminds me something