Here’s what I know about the America’s Cup: At the end of the last cup, a panel of designers were asked to comment on the state of the IACC rule. They felt that all the boats had migrated into a small corner of the design space (narrow, heavy boats). small loopholes in the rules were being exploited to give various teams ceratin advantages (the double knuckle bow and the Hula as unmeasured waterline length, for example). The Swiss and the challenger of record made some overatures to modify the IACC rule to remove the corner of the box and allow for more experimentation of the design space.
So when Ernesto comes out and says that they are contemplating “turboing” the IACC, what he is referring to is changing the measurement rule to allow for more sail area, taller rigs and deeper keels. but fundamentally, the IACC rule will still look the same. The main difference will be in the formula used to measure the boats.
CBTF is not allowed under the existing IACC rule. Remember, the IACC rule is not a box rule. You can add waterline length but if you do, you need to take away sail area or displacement. As such, the rule does not allow for canting ballast of water ballast or other forms of increasing the righting moment without increasing the displacement. For good or bad, CBTF is not allowed under the IACC rule. It would require a major change to the rule to allow it and if that is what Ernesto had in mind, he would have come right out and said it. That is a major change and would have been major news. Instead he indicated that the boats were going to be merely turboed which menas they are just shifting the measurement rules to favor taller rigs and more draft.
I agree… I don’t think they’ll put CBTF on the AC boats either. What’s the point? So you have a swingy keel and 2 rudders… the boats go 3 or 4 kts faster. BFD.
I don’t think taking the existing boats and making them slightly faster will all of a sudden spark the interest of the general non-sailing public.
As for sailing the AC on 60’ foiled multis… well, now you’re on the left field warning track.<g> Great to watch going in a straight line, but pre-start battles?? Tacking duels?? With multis??? That would be like using top fuel dragsters for the Grand Prix of Monaco.
Personally I think Bartarelli is blowing smoke.
I guess we’re all in agreement that they probably won’t do CBTF but Dick the speed difference would be a hell of a lot more than 3-4knots!!!
An aside for a second:-many big multihulls can tack as fast(or faster) as a mono ,point higher and go 2-3 times as fast!
What a blast to watch them duel it out–but just fantasy for now…
When you go back to the article the key thing is “current trends in monohulls” or words to that effect.The biggest current trend in monohulls is canting keels/ CBTF(Open 60’s, Open 50’s, 40’s, mini6.5’s, Schock 40, Volvo 70’s,
maxZ86’s,Mari Cha,Genunine Risk, Smak 30 etc) so while it is highly unlikely one can still hold out hope! I challenge anyone to show a more modern, more pervasive,faster and more powerfull trend in big monohulls than canting keels and CBTF!! Cain’t be done!
Doug, as I understood your origional idea in this thread, you were talking about the possibility of putting CBTF on basically the existing AC boats. Lets say you put a canting keel on the current boats, big enough to double the sail area. It’s still a displacement hull. Do you really think the current AC hull form (or similar) is capable of going much faster? I think the potential speed gains for the existing hulls are minimal at best. The current boats aren’t going to pop out no matter what you do to them.
You got that right Dick. MC IV is about the sexiest thing that floats.
So Doug… why you still fooling around with those wimpy assed single masted slugs. Lets see… 140’ long, 9550 sq ft of SA… hhhmmmmm 1/12 scale would be too big to fit in the truck. Doug, how bout a 1/24 scale Mari Cha IV. A little less than 6 ft long with about 4770 sq in of sail area. Now that’ll impress the schooner crowd.
Dick, do you have any shots that show the whole sail plan. I still haven’t seen the top of her masts.
Mr. Lemke, you failed the challenge miserably since I mentioned Mari Cha in the posting where I issued the challenge! No way a ketch rig is a trend in modern big monohulls! No way that Mari Cha would be as fast without the canting keel! Canting keels/CBTF are a TREND as I pointed out…
Mr. Carver- if the IACC boats adopted canting keels /CBTF they would have to be entirely different boats and according to Bill Burns of CBTF,Inc. in big boats it has proven faster to reduce displacement rather than increase sail area compared to equal size boats. But as long as you can shorten sail increasing sail area works because the canting keel boat develops MAX righting moment independent of wind strength,ie, you can have big light air sails-bigger than “normal” for a given size boat but you’d have to shorten sail as the wind picks.
I’m going to build at least one 86" maxZ86 with CBTF and a spinaker…
Doug Lord microsail.com monofoiler.com
High Technology Sailing/Racing
Ok 1.8 m long (6ft) with 2 swing rigs??? and of cousre CKTF.
Here’s my design
a blank sheet of paper at this stage, it will give my something to do on the 14 hr flight to LAX.
Could even go with a retrival tube on the forward mast for gennaker, now we talking!!!
Oh… now he likes it cuz the mains are squared off. :-0
First off: You can call me Dick.
Second: Barti blows a little sunshine your general direction about the AC boats getting “turboed”, and you go into a 3 day fantasy rant on at least 2 different forums about “this can only mean one thing… CBTF”.
I’m just saying… NOT.
Third: If MC IV sets a new record crossing the pond, it could spark an arms race (trend) among billionairs.
Lastly but not leastly… thanks Dick! (I need a bigger monitor)
BTW Doug, don’t take it too seriously… just poking fun.
Dick previously I was writing to two Dicks at once so I thought that ,to more personally direct my barbs, I should use the more formal appellation.
I’ll say it again: there aint no way to go faster in a big monohull than doing it with CBTF!!! Believe it or not. Two maxZ86’s with CBTF are about to be launched as is Genuine Risk so it won’t be long before the records start to fall right and left. Putting that technology on IACC boats would double the speed( not in every condition and not on every point of sail); multis would triple the speed(same pin head disclaimer) but I digress.
That other forum was an experience with a lot of real hostility to CBTF; what many do not understand is that this is NOT an experimental technology it is proven having been tested in and ocean and short course environment for over 8 years: it is fast–very ,very fast and significantly superior around a course than any other canting keel technology and in another world compared to an equal sized fixed keel leadbelly…
Double the speed??.. in the same wind? uuuuhhh can I bet UNDER?
Refresh my memory… what were they doing? About 10 or 12 kts in about 10 true? You’re saying they could do 20 to 24 kts in 10 to 12 true, with CBTF?
Well, we’ll never know, but I’m very skeptical. Nothing against the technology. It has it’s place… offshore. Where has it proven to be vastly superior around the cans? Schock 40’s? They don’t seem to be all that…
Mt point: it doesn’t add anything to the AC match racing format… except something else to break.
Geeez Doug… I get the impression that you won’t be satisfied till we hang a great big swingy thing off Antarctica and CBTF the whole planet.
I happen to have a polar for the Schock 40. I was thinking of buying one a few years back and they sent me a bunch of material on it. At the time I was driving a C&C 41 so the two boats were similar in size and sail area. The biggest difference was the displacement. The C&C was over twice the displacement of the Schock 40.
Looking at the polar, several things become aparent pretty quickly.
The Shock 40 sails at a much higher percentage of her hull speed in a light wind than the C&C 41. The target boatspeed upwind in 6 knots of breeze is 5.8 knots. The C&C would have been hard pressed to break 4 knots in 6 knots of breeze.
The schock 40 does not really break through her hull speed upwind in even the highest breeze. In 24 knots true, the target boatspeed is 7.35 knots. The C&C upwind in the same wind conditions would push 7.2 knots - the difference being the hull shape here, not the CBTF. However, the Schock 40 would get to that hull speed with 5 people on board (only 2 or 3 sitting on the rail) whereas the C&C 41 needed 12 people with 10 on the rail and a lot of reefing to stay in control in 24 knots true.
Downwind is where the Schock 40 shines. In 18 knots of wind, the downwind target speed is 12.4 knots. The fastest speed we ever saw on the speedo on the C&C 41 was 10.5 knots and that was surfing down a pretty big wave while on the verge of broaching. The average speed on that same run was more like 8 knots. In 24 knots of wind, the target boatspeed for the Schock 40 is almost 15 knots - double the hull speed. That is pretty darn impressive. And you are sailing pretty deep at that speed, so your VMG is over 13 knots. No 40 footer without CBTF can touch that.
So the bottom line is that the boat is still a displacement boat. It will be limited to its hull speed under moderate wind conditions and therefore will not be massively faster than the other 40 footers. However, in light winds the boat will sail at a higher percentage of hull speed given the lighter weight of the boat. Off the wind the boat will sail consistently faster across the speed range. In heavy winds, she will plane be able to really pull away.
From what I have seen, this boat is performing up to her polars. Accordingly, she has been given a PHRF rating of 25 for around the can racing and -15 for offshore downwind races. The C&C 41 rated 66. So on around the buoy racing the Schock 40 would need to beat the C&C 41 by 41 seconds per mile and on downwind offshore races it would be 81 seconds per mile. Those PHRF ratings are close to what your the TP 52 are racing at.
For some reason, I cannot post the polar. I have asked Doug to post it for me if he can.
Actually, on the Schock 40, you would only sail with 4 or 5 guys. That is about the minimum that I would sail with to try and handle spinnaker sets and douses. Upwind you could get away with 2 or 3 guys, but when you throw in a mast/pit man to hoist the sail and a foredeck to reel in all that cloth on the takedown, you end up being much happier with 5 on board. I might add one or two more for distance racing.
The C&C 41 was a different story. 10 guys was not uncommon for around the can racing - 12 if it is really blowing. And definitely 12 for distance racing.
And no new technology is faster if the application isn’t right. If the hull form is wrong; if the fins are in the wrong place or the wrong shape; if the sailplan is poorly designed or in the wrong location; if the mechanical systems don’t work right, etc., you don’t get a boat that wins on the race course. That’s the huge difference between theory and practice.