Wake up Wouter, the posts after your "intellectually challenged" comment talk about the boat you say will be a dog beating a Flyer up wind and thrashing all-comers downwind. Read it clearly then get back to me with your order... of crow that is.
I am saying it is going even more like a dolphin shape than a Flyer. But yes, now that you mention it the Flyer is a lot more dolphin like in shape than the old Taipan style A.

Of course it could be argued that this new boat looks more like a sepository than a dolphin and maybe we should look to a different object of nature for design ideas. : )

Well call me sassafras. That would be why it looks retro. I do say, however, that it appears that the hull volume is placed a bit differently and undoubtedly for the better in the new A.




PS - I'm still glad I'm blocking Wouter. Judging from the responses, he seems to be back in old form.

Doug, there is no website and for prices write to jlindahl_lcd@yahoo.com
RG

Sorry Bob, but we don't intend to ever publish profiles or sections. Instead I have attached a pic of Fred Smiths LR2 on it's first sail.

Wouter,
Do you think before you make coments like this????

<img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" />

Wouter. Arrogance is not a very endearing quality, if we all had the same views and opinions these forums would be insanely boring. Agree to disagree and skip the insults.

D

But if nature is any guide and Dolphin like shapes are superior, wouldn't it then be better to fit the rudders to the stern in a horizontal manner, just like the tails of dolphins ?

Maybe somebody should try to design a hull that looks like a salt water crockodile ?

All very interesting !

Wouter

A comparison is made between this A-cat and the flyer hulls.

Go to : http://www.boatdesign.net/forums/showthread.php?t=18037&page=2

Wouter

Nature should not be a guide. The bit we stick up into the air operates better the more it is like a wing..that would be a BIRDS wing.
Crazy to think that fish or dolphins would have anything to teach us about performance in and on water.
Check the pectoral fins on this boat and the wings!
If a Dolphin did not have pec fins maybe it would not corner so well with just its tail Wouter.
My ideas are based on being open minded and thinking outside the circle. When we don't do that all we can do to upgrade is work with what we have.
So let's just paint the inside of the cave white and live like that.

This "discussion" did not start with a comparison between wings and sails, it was specific about hulls looking more and more like dolphins, which operate under the water and boats which work on the water surface.

So it was pointed out that logically the supposed benefits of a dolphin shaped hull, for the soul reason that it is dolphin shaped, are incorrect. The evolution of dolphins hasn't required them to operate fast on the waters surface.

Now, if you want to have a real debate about the benefits of a hull shaped like it is, you should consider the aerodynamic benefits of such a hull rather than the perceived/marketed hydrodynamic benefits.

It is very clear that it should have less aerodynamic drag than the existing A-class hulls because of its shape. Has anyone else noticed the chamfers America's Cup Class boats have around the deck edge forward of the mast? May I suggest this is for aerodynamic reasons, particular when considering the influence on the lower sections of the jib.

Also, I noticed on the boat design forum (which I haven't read completely) that the LCB (Longitudinal Centre of Bouyancy) of this LR2 A-Class has been moved forward considerably compared with the Flyer. This may also indicate that the LCF (Longitudinal Centre of Flotation, yes it is different to the LCB) has been moved forward considerably, which is a very easy way to improve the forward pitch handling characteristics of a hull, certainly much easier than designing effective wave piercing bows for a sailing yacht.

A wise man once said..."i think wave piercing is fine if you are being propelled by something 1m under the waterline, not 4 m above it."

All I'm saying is that the other benefits of a "wave-piercing" shaped hull shouldn't be overlooked.

Go to Bristol if possible if you want a real barometer on the boat's performance. Lake Hopatcong will be too shifty to make any conclusions about boatspeed differences.

Something must be different about the way I sail. Out at sea in 15 knots and above my boat...the lee boat spends easily as much time in the water as on it.
My cat is actually almost never truely "on" the water. My runnabout is a different story. It is often "on" the water.
I include an image of a fast cat that is not "on" the water.
Before I am told that diving the bow is not the objective, it is a fact and once into the water a dolphin like profile might be exactly what is needed to right the problem.
I stand by my reasoning.

Great post Ncik !

Good point about the LCB and LCF.

I wonder what the result of that will be. In the extreme case such a hull will not dip its bows but rather lift or drag its sterns. Possibly combined with an increased bow wave system.

The bouyancy distribution drawings did indeed clearify some points very well.

Wouter

Wouter & Ncik...just moving LCB & LCF too much opens a can of other worms and it's not the the answer, maybe a partial answer yes, but you need to address a whole host of other things also. The point was not to lift the bows but to keep them as level as possible at all times, even in some moderately large waves...the power is only on if the mast is stationary.
Warbird....much as I like the dolphin likeness comments, I can promise you I never once considered them when designing the boat. I took the trouble to find the most anatomically correct model of a dolphin I could and then sectioned it....and the sections don't look like anything I'd recognise as efficient at high Rn, but then again Im sure we don't understand nature all that well just yet. (see attached pics)
RG

more dolphins

3rd one

last one

I am sorry to post this as a mere "Non-benchmark" A-cat sailor, but I spent actual 5 days on the water tuning and testing against this new design. There were 2 sessions concluding last Monday, in all kinds of Michigan conditions. IMHO, Ian Lindahl was very fast vs a well-sailed Flyer, a well-sailed Auscat, all with new Glaser sails, and my XJ. Its downwind speed was even more impressive, as Ian was clearly fastest- as he smiled-- and went right on by.

Another plus is that it doesn't want to pitchpole. IF personal observation means anything on this forum, I saw with my actual eyes Ian's jibe in heavy air nearby when his traveller line tangled on something (he said): the cat stood on its nose for maybe 7 seconds then came back down and continued at speed. I say that the whaleback, no-deck concept works. Note that there were successful whaleback freighters on the Great Lakes 100 years ago.
Signed, Non-Bristol sailor.

Nothing against the design or anyones relative sailing ability as I have not seen 1 in head to head action, but Ian is a good sailor, and the thing still looks like a suppository.

Its UGLY with a capital U.