34th America’s Cup Design - Mono or Multi Hull ?

:cool:

So, as reported by a French magazine “Voiles” the 34 AC will be run with 22mt multihulls !!!
For me this is the end of a long dream that lasted since 1851 !!!
Pity, I was almost ready to introduce my last design derived from a TP52 stretched up to 22mt !
Cheers
ClaudioD

PS: in attachment the project that was in the pan waiting for !

Yes a long tradition moves into the books of history, the only constant these days is change … something for everybody

//youtu.be/FWINygISxDE

Claudio, albeit the boat on the seas of AC are going multi, I doubt many will be built in RC … MONO’s WILL RULE THE LAKES ! as they are easier to build and transport.

Would love to see you stretched TP or could we pull it in the direction of a V070 ???

Hi Alan,
the sketch above is already a stretched TP52 riduced to and adapted to an RC model of 125cm , 23.8cm and 42cm draft and 4100g - mast and sail plan not yet drawn but could be similar to the AC120.
By the way, Marce l , from Swizerland, bulit one magnificient Alinghi and now one also beatuful AC33. The AC33, accordind to him, is much faster then Alinghi also with less sail surface.
Cheers
ClaudioD

PS: today my 1st AC100, after one hour of “fantastic sailing” (I’m proud of) , at the time I was passing it to the friend in order for me to take pictures and movie, the rudder stock at 45°. One our later, after continuos circling, and 9Kt, the boat went under water. Fortunately this week somebody is going to picked up toghether with the other 3.

Oh no Claudio …to loss a boat on her maiden vovage (and no ice bergs in sight) must have been heart breaking :indiffere I had near similar experience after sailing with one of my 120’s for a few hours in heavy winds, lifted the boat out of the water and the rudder fell out :scared: … I was very lucky that day

Do you think Marcel could be persuaded post some pictures of his AC 33 ? would love to see it, I recall the beautiful construction of his 120. When you have the plans of the TP 52 ready, I would be interested in building a TP 52 as a winter project.

I was very interested in buying a RC VO70 that is built in Hamburg, then when I saw they wanted 3,300 Euro’s my interest dropped faster than my mouth :lol: http://www.stockmaritime.com/modellboote/vo70/allgemein.php

Wishing for a good recovery of the 3 boats lost yesterday.

Cheers Alan

Thanks Alan,
Yes was very sad !
The mould is already laminated this morning for a new hull !
Here the pics of this morning and of last week when I first laminated the mould for “run-in” using a carbon/kevlar of 162g/m² + 80g/m² glass.
Cheers
ClaudioD

Alan
here the Marcel’s AC33 with his Alinghi !
VO70, too large or too short and further the ballast is only at 50% of total weight. Form stability may help, but…The sail surface is small only 58dm² . The AC100 was carrying 55dm² yesterday with 85cm LWL only and 9/10 kn.
My recents boats are generally using bulbs at 60/62% ratio. In the past the M were using 3000g for 4250g boat !
"
The VO7O has a L/B ratio of 3.75, my “New” above, is at 5.25 therefore should perform well for close hauled.

Cheers
ClaudioD

Hello Gentlemen,

I am curious Claudio, why do you think your new AC100 sank? Water intrusion from where?

I am also curious about your TP52 New Design…I have designed and built a 90cm version of a TP, I will include pictures. It sails very well and is personally one of my favorite boats to sail!

For the “nay-sayers” and those who insist a multihull cannot Match Race, the current C Class Championships seem to be proving that “Old Wives (sailors) Tale” inaccurate. For photos, video, interviews, etc. - visit Sailing Anarchy who are covering the event in Newport. [ http://www.sailinganarchy.com/index_page1.php ]

In the meantime, here is a recap of the first day of match racing - with both boats showing the can mix itup like amonohull - but with “speed”.
Canaan = Canda Defender (Fred Eaton/Magnus Clarke)
Alpha = Australia (Glen Ashby/Jimmy Spithill) although it is a Canadian boat they are using

Courtesy/copyright SAILING ANARCHY:

Match racing was in full effect today when two forces collided in Newport, RI for the championship round of the Little America’s Cup (I4C). The Defenders, Fred Eaton and Magnus Clarke, sailing [FONT=Arial]Canaaan faced the Aussies Glenn Ashby and James Spithill, sailing Alpha in a seesaw battle. The story line of the qualifying races has been bigger breeze-Alpha, anything else-Canaan. There was a little bit of both today. [/FONT]

From the onset the action was nonstop. During the two cancelled races of the morning, the prestart fight lasted until the gun, and while Alpha was more aggressive, Canaan attacked when they had the opportunity, pulling their Y-flag during a close downspeed port/starboard cross, and getting a green flag for their trouble. Canaan ended up a mile ahead in the first race by staying in the breeze better than Alpha, although it was rightfully stopped when the Narragansett Bay current was faster than the wind. After Alpha won the second start, the two ended up in the convergence zone between the seabreeze and gradient, and the race was called.

After the seabreeze stabilized at 10-15 knots, racing resumed. Again, the prestart was serious with Alpha continuing to charge and Canaan finding ways to get free. They pushed each other beyond the starboard layline on a wild reach one minute before the start. Fred and Magnus’ tactics worked well until they blew the tack to head to the line. They ended up 38 seconds behind at the top mark as Alpha sped from the line at top speed. Canaan played catch-up for the rest of the race, with Alpha showing their textbook boathandling and great speed. In the end, the margin of victory by Alpha was only eight seconds. Prestart was everything.

The battle raged on in the second prestart with Alpha continuing to attack and Canaan evading. Only in the last 20 seconds before the start did Alpha gain a true advantage, starting underneath Canaan to the left side of the course. Alpha kept gassing the Canadians until Canaan tacked back right. In true match-race style, Alpha tacked straight away and slowly (in catamaran time) rolled over the top of Canaan, forcing Fred and Magnus to tack to the left side of the course. When they met at the top mark Alpha led by 18 seconds. That was the last mark Alpha lead in the race. On the downwind Alpha covered from ahead but Canaan gybed later to starboard for the leeward mark and worked inside with pressure and superior downwind speed and angle. Canaan gybed in front of Alpha at the bottom mark and extended the lead to over three minutes, although the dying breeze after Canaan finished had quite a bit to do with the finishing disparity.

In the end, the prestarts were the key, as Canaan had trouble in the first and stayed clear in the second. The performance differences were minimal upwind, but downwind was another matter, especially in light air. What do you know? Match races with box-rule, technology-driven multihulls, decided by skill. Tomorrow starts in a dead heat, although Canaan has the tiebreak for winning the qualifying round.

Hi, this type of models are rather easy to drive and are very fast. After the AC33 experience I will probably try a more advanced model like the the one above sketched. The width is limited compared to an ‘iron’ to get still good performances when close hauled

I do not know yet, first the rudder stuck at 45° and the boat going in circle, second certanly a water leakage that cause the rest. Next Sunday we are going to try to picked up
cheers
claudioD

Results - final of C Class Championships.

Fred Eaton and Magnus Clarke (Canada 09) repeat and defend the cup fomr challengers from Australia in match racing, and from Great Britain, France and USA in fleet racing.

Well done and thanks for demonstrating the match racing can be done in multihulls.

Final results attached. ** USA crashed and demolished wing first day

So let’s see if the “Big Boys” can follow suit and example?

Hi Dick, simple question !
How it is calculated roughly the sail area for the wingsail like the CClass, comparared with a classic rig Main+jib ?
In others words, assuming that the wingsail is more efficient by 25%, is the total sail area reduced by 25% to ?
thanks
ClaudioD

No Claudio -

Sail area is sail area - and thus there are no longer “soft sail” catamarans competing in this class.

If someone found a way to invent something else that was even more efficient, they could build to the maximum sail area allowed by the rules. In the F-48 R/C Class, solid wing sails are allowed, and sail area is measured by the “surface” exposed to the wind. We do not take into account the thickness and chord of the wing. There are a few R/C land yachts using solid wing sails, and also a few water yachts. Not sure why so few - but I suspect one reason is the inability to twist the wing, and add/removed camber depending on wind and water conditions. Usually, for R/C yachts, the wing can be made smaller/shorter because of efficiency which also helps reduce the tipping action associated with taller, soft sail rigs.

Understood only half.
Let put it in this way : here below the sketch of the same boat, one with a classic rig and the other with a sailwing. difference 28% in surface.
According to your knoledge is the sailwing too high and too big ?
The Wing should be foldable in two parts.like the picture of C class
Thanks
ClaudioD

Thanks Claudio, Marcels is a professional boat builder surely, his beautiful boats not only looks fantastic but looks like it sails really well also, testimony to your brilliant original design concept on the AC 33 again …very impressive.

If you say your TP is more advanced than your AC 33 design, I’m looking forward to the plans when they are ready. Further, I understand what you are saying about VO70 Sail area/ballast ratio’s you quoted, did you take into consideration the canting of the keel ?

RG your TP looks impressive also, well done !

Dick, I guess all the AC fanatics here, like myself, are mono hull guys and we are all still dumb founded or shocked at the change to multi’s for 34th AC, hence the lack of comments on multi’s. I will wait until we start seeing some of the big babies on the water and hopefully I will be wetting my nappies with excitement.

“Change” is it a good thing (most times) I just need some time getting used to it.

Cheers Alan

Hello,

Thanks for the compliments! I can post more pictures if interested?

Claudio, do you think that I can build a AC100 in balsa hull/fiberglass skin and still be close to the weight budget?

thanks,
Brian

I doubt, but you can try, so far the Hull weight is not higher then 160/170g. In the construction of these models you have to stick to the budget of each subassembly.
Cheers
ClaudioD

Claudio - the drawing of both mast’s height of 2375 will provide you with a smaller sail area as you have indicated. I have never tried using a wing (as opposed to a wing “mast”) on a monohull. The reason is that a monohull will only reach theoretical hull speed - while a multihull (much lighter in weight, less wetted surface area) can use the wing to generate more and more efficient power. I know some guys sialing 10 Raters have used a wing mast with soft sail attached with good results. Allowing the mast to turn helps bring the wind in and allows a nice transition between hard wing surface and soft sail surface. If you are calculating performance of your wing to a larger soft sail, you may find it faster. Remember, during the America’s Cup (the big one) the trimaran with it’s wing, outperformed the catamaran with it’s soft sail. This was a very close comparison, even though the trimaran was probably heavier in weight.

You may want to jump over to the multihulls section of the forum where Ray (Nautibuoy) and Magnus Clarke (crew on C Class and wing tender on BMWO during the cup) have traded information. Magnus ( an r/c sailor too) has some ideas about how to make the wing camber adjustable from shore. In our multihull classes, we don’t restrict number of servos - so his ideas might be possible. For your 2 panel wing, you may need to set the camber on shore and let the wing self-tack. This would be like adjusting your outhaul on mainsail before leaving shore. I haven’t seen a monohull comparison, but would be great if you do one to see. I wonder how much smaller a wing could be compared to a soft sail… resulting in a lighter weight rig.

Dick

Claudio -

after posting, I started looking in my archives of sailing information, ideas, photos etc. and found the following. This is not “exactly” like the C Class or America’s Cup wings, but it seems to have been developed and issued a patent. It is a rather simple concept of allowing a form in the middle of two fabric “sails” to move side to side to create camber (or sorts).

Here is the website of these “Soft” wing sails, and I will try to add the PDF file if it isn’t too large. If I can’t load it, you can use the second link to see the U.S. Patent information and how the thing is set up and how it works.

http://www.wingsails.com/WSvsCS.htm is the web site for the soft Wing Sails

U.S. Patent number is 5,868,092
Here is the PDF document - I was able to download it.

If I can’t attach the PDF format patent file, you can download it from here:http://www.pat2pdf.org/patents/pat5868092.pdf

and this link/patent information can be downloaded for free. Many sites will allow text but make you pay for the drawings which are much easier to understand.

I will give it a shot…I will use a very thin skin of balsa. Your plans call for 3mm right? If using the individual sections from the pdf file? Maybe I could enlarge slightly and use a thinner balsa stick.

With all my other projects I just don’t think i will have time for the entire mold making process.

But I always wanted a AC boat…and this seems to be a managable size.

Thanks,
Brian