I've only met Ian once and have a shoddy memory - but isn't he larger than the "average" A sailor? Would that reflect how well this design carries weight?

First of all, the boat was designed for Ian and Fred Smith. Second, it may be ugly to some and great to others, but the point of the project was to produce a fast, well built A at a reasonable price point. While the testing is still continuing, the early results look good.

Lovely dolphin images and I take your comment about not using dolphins as a starting point. I would be interested to see a front profile.
I regret the fact that people feel the need to tell you how ugly your boat is. It is not a style my likes warm to but I have found in life that sometimes it takes time to understand the beauty of different and new things.
Go well with your work.

Is this boat going to be sailed at the Worlds in November down in the FL Keys? That would be the ultimate benchmark.

Still according to the info posted, seems like a fast design with a good nut on the tiller.

Good luck.

Robi,

RG and Ian both have stated that 2 boats will be at the worlds in November earlier in this thread. Ian Lindahl and Fred Smith both have LR2's on the water and have been testing against each other, dave Carlson, Fred eaton and a couple of other A-cat sailors. They hope to have the third boat ready for the worlds as well. I do not know how far along #3 is though.

Boats 3 & 4 will be started shortly
The video link is Ian out practicing today
http://www.youtube.com/watch?v=MRdBQY8YHj0
RG

Are any of them going to be the design #2 for the bigger sailors?

Doug

Doug, #3 will be the same as the previous 2, but #4 could be either hull depending on who buys it.
Another video
http://www.youtube.com/watch?v=ChjMGsAWQCk
RG

RG,

It would be great to see a closer and clearer look at what is happening with the wake, wave, q-wave patterns as they leave the hulls.

Tom, these are the only 2 that are anywhere to close by the camera. There is not much you can see from these.

http://www.youtube.com/watch?v=f4riWfj5u2o

http://www.youtube.com/watch?v=ECJWys1ZCvE
RG

All the video's so far are :

http://www.youtube.com/watch?v=f4riWfj5u2o

http://www.youtube.com/watch?v=ECJWys1ZCvE

http://www.youtube.com/watch?v=ChjMGsAWQCk

http://www.youtube.com/watch?v=MRdBQY8YHj0


In one you can just see the water coming over the bow in one of these video's but this is mostly because the resolution is so poor. Even the bow and sterns waves are obscured by the poor resolution.

On thing that does strike me in these video's are the laboratory like conditions on this pond. Winds are 6 to 8 knots at least as the skipper can be seen to lift the hull while trapping but the water looks as flat as a pancake. When you look on the inside of the leeward hull you can see how small the chop really is, my guess about 4 inches. It is difficult to tell what the wind is doing.

Basically it is hard to tell anything from these video's, probably intentionally.

If the designers are playing around with pressure distribution along the waterline length of the hulls, much like the designers of larger freighters did with the bulb keels, then I would expect this design to have sweet spots and not-so-sweet spots. Basically the pressures along the hull vary with different boat speeds, crew weights and conditions (weather and water surface).

If they can pull it off to have a hull that manages to minimize to wave system over a wide range of conditions and crew weights then they will have achieved something remarkable. The big word here is of course "if".

I still would like to see this hull in some real chop.

Wouter

Wouter, look at
http://boatdesign.net/forums/attachment.php?attachmentid=15093&d=1185616592
http://boatdesign.net/forums/attachment.php?attachmentid=15092&d=1185616592
http://boatdesign.net/forums/attachment.php?attachmentid=15091&d=1185616592

not a hydro expert, but those shots look like very light air and a huge bow wave for the speed, Aerynt observed in the F20 forum, the bow wave is quite different, so how do you get from that to zero bow wave at other speeds? seems a bit backwards to me, but then its hard to ignore how clean it looks on the water otherwise (the videos's).
Also noted in an earlier post that they thought the optimum crew position was further aft than shown in most shots, seems they don't move from upwind to downwind.
Whats hard to ignore is that the mast seems to be stationary in any of the video's, have never seen that before.
And last of all, who the hell is Retired Geek ?

I don't know, I haven't done in depth analysis of the pressure (wave) situation around an A-cat hull.

Mostly because I think that the drag from the wave system is far smaller then some other components and therefor it is most smart to try to optimize these either components first. Afterall most my experience comes from F18's and F16's. Here rig development is still a major component; notice the difference between the Ullman and Glaser F16 suit of sails. The A's may already have exhausted this avenue.

I do know however that a huge bow wave can have at least two causes. One is high speed the other is a blunt entry at the bow. I can't tell from a still photograph which one is too blame.



That is one reason why I like to see some video in real chop. It is my opinion that the A-cat is relatively long for its width and overall weight. In flat water you can indeed move the bouyancy all down to the waterline and to the front and thus really cut down on the bows dipping in. I'm not saying that this is what they have done but if someone were to do this then it will work great in flat water, but in chop it will oscillate very strongly as so much bouyancy is in the bow at such a large leverage to the centre of rotation/weight.

I'm a firm believer that what is claimed can be achieved for a narrow set of conditions, but the real trick on the race course is to have a design that goes sufficiently well in a range of different conditions. Otherwise you've designed yourself a single gear race car. I'm not saying that the guys with the LR project did this, but without seeing shots and video spanning a range of conditions we won't know what they have achieved.

I think retired Geek is either Ian Lindahl himself or that other guy who is involved, can't remember his name.

It just occured to me that the same stability of the rig can also be achieved by a set of carefully trimmed T-foils on the rudders. It is because of the A-cat class rules do not allow such T-foils that the development is now geared towards changes in the hulls design to further reduce pitching of the rig. As such an interesting question arises. Is this development really a step forward or just a whole lot of effort because the class rules prohibit an easier and cheaper solution. Compare this situation to that which led to the yacht rigs with a very large Genua sail and a small triangular mainsail. This setup was not at all an efficient use of total sailarea but rather it was the most efficient use of the sailarea given a handicap rule set with an obvious oversight coded into it. Explanation, the overlapping area of the Genua was not considered efficient in the rules and was completely disgarded from the total.

It will be sad day when some enthousiast goes against the rules of the A-cat class and puts T-foils on and just sails along side this new development like a mirror image.

Wouter

[quote
Tom, these are the only 2 that are anywhere to close by the camera. There is not much you can see from these.

http://www.youtube.com/watch?v=f4riWfj5u2o

http://www.youtube.com/watch?v=ECJWys1ZCvE
RG [/quote]

RG,

Thanks. The boat still looks great. I am waiting to hear from Fred this weekend on how he likes his new LR2. I have his Boyer MKIV. It is sailing well, but sometime at the beginning of the year, I will contact Ian about the larger format hulls.

[quote And last of all, who the hell is Retired Geek ? [/quote]

RG is the boat's designer. Maybe he will share his name, but so far in all of the posts, he has not, so I will not out it.

There are a few foiling A's out there right now. Not class legal, but sailed nonetheless as experiments. I know that some in the Bristol fleet have been playing with foils and canted daggerboards. I do not know though how serious the development is. Fred Eaton's foiling C-Class cat will make an apperance at the ICCC in Toronto this month. Team Inviticus is also building a foiling C to compete. I do not know weather or not the foiling C will race in the series, but I assume that it will.

Wouter, here are a couple of pics that show the waterline in slightly choppy water, sorry but I don't have anything in huge chop, although the boat has sailed in that kind of water and Im told its still not pitching.
As for the bow wave, yes its there when going slow but it disappears after the boat gets past about 3-4 knots and you never see it again.
RG

another pic

3rd pic

last pic, sorry some are blurry, but they were cropped from larger pics