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That is pretty cool looking, but I just want to ask, it looks like you have a daggerboard/centerboard coming from the center of the boat. Would the structure for that not add alot of weight that could be eliminated by just using regeular dagger boards which it looks like the boat has?

Like I said that is a really cool boat and I am definently not an expert, but those are my thoughts.

4.45m wide? Are you counting on the banana boards to stop you from digging the bow in?

I am wondering why there are two snuffer openings, and what looks like an inner forestay? Would be less complex with just one snuffer opening? Why is the 'central pod going all the way to the rear beam? Do you have a target weight, hull volume, mast length and sail area?


It is something new! Hope you get your dream buildt, and that it's not too expensive.

Gree, normally I'd agree with you about the structure and weight, but because of where the mast is (and associated loads)I don't think much as added to accommodate the centerboard. I saw the results of an ansys FEA of the beam/pod arrangement and the largest loads are at the mast step and that area hardly deflects at all, the board loads are minor compared to them. The center location has more to do with the banana boards than anything else and they might be removed soon anyways, they were added as a sort of insurance policy that I don't think is necessary after watching a bunch of LR2 videos. As that boat goes up and down hill and you watch the horizon, the top of the mast is always going forward, the boat just never pitches, even down hill in 12-15 knots and with 8 knot gusts and the crew sitting against the main beam, the bow never goes in more than 40-50mm. Not sure how they do it, but its like watching a train on rails.

Rolf, think I addressed the banana boards above, the 2 snuffers are for the 2 reachers, last I heard the wind can change strength during a race. The centerpod only goes back to the wingmast step, aft of that is a plug in compression tube and forward the prod plugs in also, whats not shown is a small inverted "v" striker under the mast step that is tied to the prod under the forestay and to the bottom of the rear beam. Weights and sail areas are in my first post above, think that the top of the mast is about 10.4m off the water and as I was told, total hull volume is irrelevant to most everything. As for expensive, it already is expensive and I haven't started to build it yet.
Aerynt

Rolf, forgot to mention there is only one forestay and no inner, the extra 2 "stays" shown are actually just the halyard lines for the 2 reacher tack positions
Aerynt

Well, I have already read a few people dogging on your design in the general forum, don't listen to them. That thing looks badass, I am sure that if it is well built it will go like hell!

Has this one been introduced to the forum yet? http://www.tek-kat.co.uk/gallery.html Its pretty scary to see a cat without a bridle supporting the forestay.
The 1st boat is out sailing and looking good at times.

Why not foils?

Too much work or too much stuff to break?

Easier/cheaper to develop planing hull?

Is a wave piercing hull better for a 20 ft. design than the standard shape for coastal use?

Looks very cool.

At a glance the center of effort for your main and jib look too far aft. Unless you are planning on some type of hooter setup for upwind in addition to the main and jib. Still think when it gets windy and the hooter comes down the helm would be very unbalanced.

Good luck with your project!!!

Mike Hill

Mike, the designer uses a 6 deg freedom of motion model, not being a designer I can't tell you how it works, but it does spit out all loads, motions and accelerations and what Ive seen so far tells me it should be easy to sail in any condition thats been modeled so far. The flip side to that is that we are not yet at a final configuration, so it may all change yet.
Aerynt

Thought I might also add that the hull is designed from the waterplane down by some fancy method that I got told I wasn't paying them enough to be told about, but if you look at videos of the A-Class there are no broken waves, no quarter waves and the bow wave is an unusual shape, so I guess it works. From the previous they can get all the pressures on the hull and that in turn is added to all the other forces which is probably why they can make the hull look so damped in pitch irrespective of speed or wind pressure.
Aerynt

Aerynt, I'm looking for insight into why the LR2 appears to be so efficient, care to let us know what you have learnt from working with the designers on your boat ?
Q

Q, I have already said enough, if you want to learn more then I suggest you do what I did and write a cheque.
Aerynt

Is that what these catsailor forum postings are all about ?

Basically we have only seen flat water pictures/video's in what may well have been very stable wind conditions.

An old seaman once told me :"On calm seas, every vessel claims mastery of floatation"

It will take a whole lot more to proof the concept.


Wouter