I am no expert on the A-class but I haven't seen a bow shaped like this before.
[img]http://www.boatdesign.net/forums/attachment.php?attachmentid=15049&d=1185441096[/img] [img]http://www.boatdesign.net/forums/attachment.php?attachmentid=14632&d=1183894884[/img]

see http://www.boatdesign.net/forums/showthread.php?t=18037&page=2 for more details.

Gareth

I hope that is not the future - It looks like a suppository.

Return of the SIZZLER!

Is made of aluminium?

I believe that is a custom A being built for a few people by John Lindal in (MI?). One of the guys here is getting one. I will post some pics when I see it.

IT does look like a sizzler!

Is it John or or his son, Ian. Last time I saw Ian, he was talking about building a A-Cat.

It is being built by both John and Ian Lindal. The first one is on the water now and the second should be this weekend. The construction is carbon/foam/carbon.

I'll give it another 5 years till they chop off the front 0.49 mtr altogether and make it a 16 footer ! <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />


Wouter

I shared the photos with Pete Melvin. His reply was, "The Penetrator!"

I have often wondered why cat designers have not payed more attention to Dolphins in their design ideas. These animals must have wonderful hydrodynamic shape. I have sailed at ten knotts and had a dolphin pacing me a metre off my bow for several ks and not even look like its tail is moving. Their energy to speed level is legendry. I have thought the Flyer is almost there but make the beak shape low and still the rising hull. I also think a more radical attitude to the rear of the boat being a planing surface is important.
As to looks. ?????

Dolphins also speed most of their life UNDER the watersurface, instead of on the watersurface as sailboats do.

Otherwise surface ships would look like submarines do and they don't.




He was riding the pressure zone of your bow wave. In effect, the portion of water directly in front of your boat moves forward with almost the same speed as the hull. The dolphin "feels" like he is just hovering in his particular volume of water while he and the volume of water are pushed along by the boats hull. Dolphin cover many many many nautical miles like in front of oceans freighters, with a minimum in effort..

Wouter

Yeah, dolphins don't have to worry about losing energy by creating waves.

Plus I've also heard a rumour that they ooze a liquid out of their skin that reduces their skin friction. Let's see if the A-classes will try that!

I'd like to know the theory behind that bow design...it could be a nightmare to sail downwind in a blow without any reserve bouyancy! But it could reduce the windage upwind to the point that it adds up to a positive advantage.

In general, dolphins aren't designed to swim on the surface of the water in displacement mode either.

And....they are very difficult to steer..........

You are right, we shouln't pay any attention to nature but do you know what. The latest A shapes are a lot closer to a dolphin in shape than a brick. Wave piercing is that...not wave riding. The latest a shape has a positive boyancy attitude low down in the shape. It is down low and already working rather than old shapes that put more boyancy in when it was too late and created more hobihorsing and pitch-poling. So, the boyancy is already working and the top of the boat is shaped like a dolphin....rounded to help shed water. Flat deck of Tornadoes and whatever...flat....NOT like a dolphin. Of course it is dreadful to sail down wind....that is why As don't sail downwind.....could do to remember that to beat an A downwind a spinny is needed...providing lift for the bows.....But the A copes without that lift.....is there a pattern here?....
Maybe we should look at bird wings for sail development...oh, no, that's already been done...nature wrong again.

Wouter this is of course correct but the jury is out on them and their energy to power ratio. No clear understanding is in on how they turn the energy expended into to speed created. While yes they ride at my bows we are talking a 14 or 16 foot boat and a 600lb 14 foot animal....my crappy little boat just isn't providing that much push....not to talk about the other three or ten around the boat. what's driving them?

It looks like the opposite of the Blade, perhaps a Butter Knife, or a Spatula.....

It's too light. Even with the increased rigging you would need 30-60 Lbs ballast.

Seriously, look at the drawing comparing it to the Flyer. That is a very small hull volume. I am not sure you could make that concept work as an F16. After you scaled it down to 16 ft, made the hulls bigger to accomodate the increased platform and crew weight, accomodated the different center of force for the jib and spin,...... it would be a different boat. Maybe a lower volume Blade.

I seem to remember a brief conversation with Lindahl and I thought he mentioned that Richard Roake had a major hand in the design. Eg... Super Lube back in the unlimited worrell 1000 days... the planing catamran hull that Randy Smythe sailed.

I could be complete wrong about this one though... would love to see some close up pictures.

The flyer hulls' take along time to adjust your down wind sailing style to.... Those things look like you are trying to sail a moth !

Every sensible racing yacht looks more like a dolphin than a brick...It doesn't look that much like a dolphin anyway, I've never seen one with a sharp pointy head.

Nature has other things to contend with that also influence its design, like catching food. Not every aspect of nature can be applied to making boats go faster. Do you see dolphin nose like appendages on the front of keels? No, because it is inefficient for racing yachts, but very good for dolphins that need to catch food.

I'm all for reverse engineering nature, but common sense should be incorporated into the design process.

My personal opinion is that it could be a great light weather boat in the hands of a skilled skipper. Probably will be a handful off the wind in a blow and waves, because it has little reserve bouyancy in the bow.