Wave-Piercing, Pitching damping or marketing?

I do not want to address the designs today because time is short for the next couple of weeks. What was shown more clearly than anything else at the regatta was the old adage, "time on the water". You can state that the more traditional hulls did better, but that is not correct either. None of these hulls were of traditional designs. What was dominate were the 2-3 platforms that were dominant in the class over the prior 2-4 years. Ben's boat is a further evolution of the XJ platform designed by Peter Cogan. What made Ben's boat interesting was the rigid wing. In terms of wing technology, it was a simple rig and more refinements can be made to improve it's performance. Again, time on the water was critical with this boat. It would have been great for Ben to have had 12-18 months on the water with it. Randy had less than a month on the LR2 before the worlds. The top sailors in the class were the top finishers.

 

I'll post my own thoughts shortly, but the following is John Lindahl's thoughts

Comments on the LR2 A design:

This new design is one of the best feeling boats I have ever been on. From the first time I sailed it there was a unique feel that separated it from any other boat I ever built and/or sailed (and that includes over 25 different A's and 18 Squares).These hulls have the ability to stabilize the platform and give it a most solid feel, with the fear of pitchpole nearly eliminated. This design kept the surface area very low, which led to the lightest weight boat at the Worlds (150 pounds). The only down side to the design that I can see is the possible increase in wave drag on the hull topside when it gets into the heavy chop conditions that were prevalent in Islamarado. All of our sailing had been done in flat water lake conditions and the wave drag was not evident there. Since there is plenty of buoyancy forward I think the nose could be fined up some for a sharper entry as long as the flow remains attached.There is an upwind feel of the boat being pulled to weather and downwind it likes to be driven low.

The boards and rudders contribute in an "effortless" way. There is a "no-load" feel, with no cavitation or stall characteristics. This "no-load" feel allows the board to be easily raised, even when sailing upwind. The boards all weighed less than 3 pounds. The only problem with the boards is the tapered tip does not allow for weed removal when the boards are raised. But the boat can sit on the start line and jump into point mode very quickly.

The hull cross section, with no apparent deck allows the sailor to get out on the trap very easily as it's just a slide down the hull and there is a very comfortable feel when on the wire because of the hull side angle to the feet. The "no deck" design, with the resultant egg shaped cross section is structurally superior to anything else and provided the builder natural strong points to make tang and tramp attachments. The minimal area forward sections were not blown around when the wind piped up, so aero drag was dramatically reduced. A condition that has not been encountered yet is the ocean swell and I would anticipate this platform just loving that (going both uphill and down).

The boat build was exceptionally strong and stiff. Hull design (the egg) contributed a lot to that.The hulls were built with 9mm Corecell 5.5# density foam, which I'm sure is the thickest core of any, and then sheathed in and out with Hexcel 5.8 oz. carbon bedded with West System Epoxy. Hull weight averaged 31 pounds prior to primer and paint. Standard Hall beams were attached with carbon and epoxy which gave the platform a very solid feel, with no racking or twist. Integrated rudder gudgeons, recessed tramp hooks and minimal tangs presented an extremely clean appearance, especially when the beams were recessed into the hulls. Even when the beams were recessed there was no evidence of wave slap on the beams or even the dolphin striker. I feel the profile height could be reduced slightly.

For a boat that did not come out of a machined female mold the fairing and finish was excellent. Attention to detail was evident in the appearance. The fact that this design did not get a lot of trial time leads me to believe it has an excellent future.

 

Lr2

Congratulations RG, thats quite a testament!

 

RG & TTS

Thx for comments!

Bob

 

Bob,
here is what Fred Smith had to say about his LR2

MY problems and I emphasis my.

1. I did not sail the boat enough prior to the worlds.

2. I should have used the old sail

3.Just to many new things to learn in a short time.

4.Not in good enough shape.(to much work not enough sailing)

5.Start of the regatta accident didn't help.

Wednesday of the regatta I started to sail better.I was reaching the first
mark in the top 25.I just sucked downwind.Boards are excellent I could
outpoint most everyone.I will experiment with pulling up the boards next
spring going downwind.

Thursday ,the boat was even faster upwind,I rounded in front of Pete Melvin
,Ben Hall,I think I was in the top fifteen,couldn't keep up on the downwind
but I was getting faster on the run.

 

FOLLOW UP ON THE LR2

After finishing the A Class Worlds an evaluation of the LR2 was made by builder, John Lindahl; builder/sailor, Ian Lindahl; designer, Richard Roake; sail maker/sailor Randy Smyth; and sailor, Fred Smith. Input was also received from several others and the conclusions are noted here.

For a brand new boat (both design and build) there was a general feeling of success. The boat itself performed very well, for as little time as the sailors had to learn it and tune. Roakes hull shape put some lift in the bow and got the weather hull out of the water very quickly. Everyone commented about the fact that this design does not want to pitchpole. There is plenty of volume forward. One nice attribute of the design is the boats ability to go into “point mode” and maintain speed. The best VMG downwind seemed to be achieved by heading down rather than doing the “wild thing”. The unique bows did not dive and trip, like a lot of people thought they would. Instead they stabilized the platform and at times there was a feeling of too much bow. This was felt in the accelerations coming out of a wave or when a gust hit you. The hull shape above the waterline reduced air drag, so you didn’t feel the bows getting pushed around in the wind. Boards and rudders were excellent with extremely good getaway from the starting line and a no drag feel when underway. It was possible to easily pull them up, even when “loaded” on an upwind beat.

When the building project began there were two overriding parameters: integrity and weight. The platform had to be strong and light. Hull panel stiffness was achieved by using a much thicker core than anyone else (9mm). The thick core was shaped by strip-planking the foam core inside CNC cut female frames. The core was then carefully laminated with carbon and epoxy inside and out. Beam junctions were glued and carbon wrapped for an exceptional joint. The first three LR2’s built are all under class minimum weight, with the third boat being 15 pounds under). Minimal fairing and attention to resin use kept the hull weight very low, as well as there only being 63 sq.ft. of surface area on a hull. The platform was stiff, strong and surprisingly light, with the added bonus that the boats finished out looking good.

All agreed that time on the boat is all that’s needed to put this boat up at the front of the fleet. All also agreed that the rig tune (mast-sail combination) was the area that needed the most attention. This of course goes back to time on the boat. There was also a feeling that the platform could take on more power.

This exercise was intended to get some new ideas in design and building technique introduced to the A Class community. We feel successful in doing that and will continue custom work on the boat. Complete boats are available as well as kits for those interested in doing their own. Board and rudder speed kits are available as well. R & D will continue with Richard Roake in the New Zealand design studio and Lindahl Composite Design here in Michigan.

A website is in the works but for now information is available from:

John Lindahl
LINDAHL COMPOSITE DESIGN
6002 Cedar St.
Fennville, MI 49408
269.650.5900
jlindahl_lcd@yahoo.com

 

Any further update / views on the design