New Design for a 17' Daysailer/Racer

The original post called for a "daysailer/racer between a dinghy and a sportboat". And with a spec like that a canting keel most certainly does fit in! In fact there is no other way ,without using trapezes, to get the two person performance that you want in a boat this size. Cleve, be wary of asking a designer with no canting keel experience to design a state of the art canting keel daysailer/racer. You've seen here on this forum how some people behave when confronted with new technology. One designer has already made disparaging remarks about the performance of a canting keel 17 footer on a race course. One thing for sure: if they don't understand it and don't believe in it they can't design it! I can put you in touch with at least one west coast designer associated with CBTFco that could help you get the performance two person boat you're after.

Originally Posted by Lorsail

In fact there is no other way ,without using trapezes, to get the two person performance that you want in a boat this size. .

Hang on a sec.. Did you say trapeze?

Seriously Doug, What cost estimate would you put on your canting keel design with all the proper engineering and how does this compare to a set of trapezes consisting of a few bits of wire, shockcord and harnesses? For simplicity, please assume that we already have a bulb keel.

Brett ...trying to stick to some facts...

I already made a very rough estimate of $1500(this is the cost of the canting keel mechanics above a fixed keel-not a design fee estimate of any kind).
It was my understanding that Cleve didn't want trapezes but did want a relatively high performance boat that could be easily sailed by two people. The canting keel with KFOIL for xtra lateral resistance fits the bill to a tee.
It has the advantages of a keelboat with close to the RM of a dinghy-no lead sits in the keel doing nothing. It can be trailered since overall beam is limited to 8'. The hull would be narrow and light. The electrically controlled canting keel would move side to side even at max extension as fast as a human could and you could tack for 8 hours again at max extension every 14 seconds(!) on just one 15 pound battery.Excelent design would prevent the keel from moving around freely(loosely) no matter what happened. A back up hand crank and keel lock assure safety in any situation.The keel could be adjusted to sail at 4 or 5' deep an would fully retract.Rudder would kick up or vertically retract if a t-foil was used(Bieker type). The rig would be carbon and would feature a square top main -and maybe squaretop jib. The boat would carry a masthead asy spin...

[Paul B]

Brett, It's no use talking to an uninformed zealot. Sadly, he'll continue to hijack every sailing design discussion with "it needs to be a foiler", "it has to be a canting keeler with my never-tried theory". Of course he does not attempt to answer any of the points brought up, just faith, faith, faith...

Someone should ask this expert to state the number of times he has sailed ON a canting keel boat.

How many times has he sailed AGAINST a canting keel boat?

How many times has he seen, in person with his own eyes, a canting keel boat sailing?

How many times has he sailed on a monohull that "flew" on Foils?

How many boats in the size range of this project have ever been built with a canting keel?

Oh, and NOT counting model boats. Real boats with human flesh on board. My bet is we would see a load of zeros. Faith, faith, blind faith and zealotry.

But YOU are not qualified to design such a boat because you haven't done so in the past, and question the validity of using this mechanism on this particular type of project.

Of course I am not qualified to have an opinion, even though I've worked in the design office of one of the most successful racing yacht designers ever. I also must know nothing about canters since I've only raced against them often, watched many of the myths exposed, and was in fact present during the first day of trialing the canting mechanism of perhaps the most famous canter to date (see one of the photos I took that day http://www.boatdesign.net/forums/att...&stc=1&thumb=1).

I'll wager I have more real world experience with canters than our resident zealot. But I lack faith. Knowledge is the enemy of faith.

"Paul B", why are you afraid to use your real name? Your method of discussion by personal attack and ridicule must be a good part of the reason.
You have not been able to come up with a single viable reason why this type of system would not work on a boat like this.
Again, Cleve, I can put you in touch with a top notch west coast designer (or two) that may be willing to help you make this boat a reality.

[Paul B]

Would that be Zero, Zero, Zero, Zero, and Zero? Not much to pin self-proclaimed expertise on, is it now? Maybe you'll post some engineering drawings of your solution to eliminating the hull bump, or a BOM for your "cheaper than a stock keel" canting system.

Better yet, why don't you contact one of your West Coast design pals and pay them to design and engineer this Super 17 (TM) for you to build for yourself?

[Tactic]

Hi Jonc,
Yes I have plans almost complete.Complete enough for me to build anyway.Full construction plans could be ready soon enough if required.
I was going to use 6mm cedar glassed in and out for the hull and plywood for the decks etc on the proto.
And if it ever reaches production glass fibre would be used.
I have speced an alloy rig and dacron sails to keep costs down,though that is not set in stone.
The skipper weight is set at 100kg..so if you weigh 75kg for example you carry 25kgs under the seat.
I think you would see very tight tactical racing in this type of boat,ideal for sailing schools,disabled sailors and older sailors who miss the buzz of tight racing.
The keel and rudder are retractable so the boat is easily launched and retrived.
Cost should be reasonable at around 15k (estimate only)
All in all it seems like to me a good way to have close racing without physical prowess being a concern for a reasonable outlay.What do you all think?
Cheers
Brett

[mistral]

Hi guys, the air is becoming quite hot in this room :-)))))
I'm curious.....si I'll ask one or two question to Cleve:
-How much your state-of-the art dinghy will cost (rigged and equipped)????
-I guess that in a such high-tech boat you will use just hi-tech deck hardware, no "out-of-date" aluminium or steel , just carbon blocks and spectra, pbo and dyneema sheets and ropes; i even guess that sails will be made in pentex or mylar at least...........

mmmm, maybe this tricky game is going to be a little too much expensive...i get back on my laser 2 regatta :-))))))

fair (and unexpensive) wind to everybody
Mistral

P.S: I've seen canting keel boat sailing; she was a mini 6.50, proto class, who is training for 2005 minitransat; she's an impressive boat, but in a tipical mini race you seldom tack more than one-two time in a hour......

I don't think it has to be inordinately expensive and with the powered canting keel a tacking duel would be no problem-and alot of fun.
-------
Check this out: http://www.marinetechs.com/projects/..._article9.html
It is a 20 footer designed with a canting keel; looks like it might be suitable for homebuilders. It could be improved by losing the daggerboard and replacing it with fixed wings(similar to ACC wings) or by using retractable wings like the kFOIL™..Opens up more inside room...

Um - whilst those pics are all very nice and all, do we have any small round the buoys canting keel raceboat designs (excl. mini transat types) that have made it past the back of a cigarette packet and actually floated?

Brett

PS .No offence to the authors of that site intended. I know it was under the sketches section.

I know of one that is on the way-18'. I found the site above doing a search but nothing else.
In my opinion what has prevented designers from considering this idea in boats under 20' is the pesky problem of the extra lateral resistance required by a canting keel-especially a performance keel that cants 45-55 degrees.
With the proven(lateral resistance) performance of wings affixed to the bulb and the advent of retractable bulb mounted wings that concern is out the window. For the first time you can consider a high performance canting keel without taking up any interior space with a daggerboard etc. This reduces construction difficulty, adds livable space nearly equivalent to a fixed keel boat and reduces cost and complexity while sailing.It's a major change in the viability of canting keels in small boat applications.
Once these concepts are understood more widely you can bet there will be more boats in this size range and smaller taking advantage of the unique advantages of such a keel.
In my opinion this will usher in a whole new series of canting keel equipped boats that will transform small keel boats into real performance machines with all the advantages of a keel but with performance closer to that of a dinghy.
It's just a matter of time....

[Tactic]

Have a look at
www.colsonyachtdesign.com
He has a 5.5m traileryacht/ sportsboat that might fit the bill.

On the canting keel issue...why bother on yachts that use human ballast as their major source of righting momment? Surely a crew member on wings or trapeze is more effective and much much simpler than a canting keel?
Or am I missing something?

Cheers
Brett

[Paul B]

We may never know what the real design brief was intended to be, but Cleve mentioned the RS K6 as his starting point. He wanted to look at a smaller version of that boat. The RS K6 weighs in at 260 kg and is about 6 feet wide.

The Colson boat doesn't list the weight, but it looks like a substantial item. The Marinetechs artwork claims a weight of 650 kg. That's 2.5 times the weight of the RS K6 for one foot more length. Cleve was concerned that the Thompson boat was too heavy, so that means the Marinetechs boat is way out of the ballpark. Maybe canting stuff does add weight? I'm still waiting to see a BOM and sketches for the previously proposed canting mechanism (battery, electronics, hydraulics, shock absorbers, back up system, super secret wing deployment devices, etc). There's no doubt it will add cost, with fabrication, electrical, plumbing, etc at US$60.00/hr boatbuilder rates. No need to mention the upkeep issues of these systems in a salt water environment.

The 17 footer should weigh in somewhere around 230 kg to mirror the RS K6 type. That brings us back to a simple, daysailor/dayracer. No traps, although I like them, so a nice dagger keel with bulb of maybe 50 kg. Keel span could be up to the 6 feet that has been suggested, but I don't think that is required and might make things a bit difficult in the retracted/trailer mode.

So maybe the boat should look somewhat like the attached sketch. Something like 17 feet long by 5 feet wide. Of course the deck can be pumped out to form "wings" to add some more crew RM. You could add a bit of a cuddy cabin to add some storage.

[mistral]

ok, i spent my few bucks, take a look at this; http://www.nautikit.com/Idea19.htm ; she's intended to be a very simple boat to build, suited for little shipyards and homebuilders; she's clearly out of range concerning weights (approx. 700 "all-in" displ.); she has a very high RM due to a long fin with bulb (RM is about 620 kgm at 65 degrees); first one is gonna be launched at the end of 2004, it would be interesting to use it as a test boat for a canting keel sistem, although it will brake the project philosophy: "keep it simple"

fair wind
Mistral

Brett(nz) one of the main reasons to bother is that the "customer' didn't want trapezes and wanted to be able to double hand this size boat for racing or daysailing. At this length there are different ways to achieve the goal-trapezes would be going very much toward the "dinghy" type while the canting keel allows the advantages of a keel with the power to carry sail of an extra person.
On other performance keelboats in this length range-boats designed to be sailed close to flat-the ballast does no good until you get a knockdown whereas on the canting keel version the keel is always ready to add power with no change in angle of heel.That can allow a small net lowering of allup sailing weight as compared to other keelboats.
There may still be illustrations of the kFOIL on the front page or page 2 of sailinganarchy.com (and on this site but I forget where). The illustration only shows one version of the retractable wings and there are three... Dovell's solution with fixed wings used for lateral resistance has been illustrated in "Australian Sailing" August of last year and pictures of the boat sailing have appeared in Seahorse magazine. The fixed wings have the advantage of simplicity but the disadvantage of breaking when they hit something and of being there when you don't need them. Retractable wings automatically retract if they hit something and can be automatically or manually retracted downwind or in light air...
Both systems allow the keel to be lifted for trailering and take up no more interior space than a fixed keel.
-----------------------
Mistral, thats a good lookng little boat! I see you opted for the "traditional" type swing keel(retracts like a centerboard). I'm curious why not retract vertically and eliminate the wire from the backend of the keel? In my experience(86 18 footers of my design) the wire was a bitch to keep from breaking too frequently.
Too my eye it seems that the boat may not be wide enough aft to require twin rudders but the installation looks good.
I wish I could read Italian(?) but I can't. What is the designed crew weight? Looking forward to seeing sailing pictures!