33rd America's Cup

[Guillermo]

Well said, Randy.
I think all of us will appreciate collaborative and well founded posts from which to learn, not naysaying nor futile digressions. Thanks in advance.
Today I'm going to meet Manolo Ruiz de Elvira and ask him about the new Rule. I'll post here later.
Cheers.

[Guillermo]

(Scuttlebutt)

A LOOK AT THE NEW AC90 RULE
by Britton Ward & Bruce Farr
(November 1, 2007) For the past few weeks we have been involved with the
other members of the Desafio Espanol technical team in the review of the AC90
Class Rule and its many preliminary drafts. The AC90 Rule issued yesterday is
the product of a series of meetings between the Defender and Challengers and
embodies the experience and input of a large number of people. In the next
few weeks the rule will be given close scrutiny by many more people and that
spotlight will highlight areas of the rule that need further refinement and
clarification. These additional refinements will be addressed through minor
rule amendments by December 31st. These amendments will not change the
fundamental concept of the AC90 Class which we feel reflects the need for a
new, exciting, technologically advanced and exceptionally high performance
yacht to contest the America's Cup.

Despite its quick gestation, the new AC90 Rule does a nice job of balancing
the demands of design freedom and closely matched performance for good match
racing. The complex trade-offs between length, sail area, stability and rated
length of the past are gone in favor of a set of fixed limits - a 27.4m
(90ft) overall length limit, an essentially fixed displacement, set upwind
sail area of 475 m2 (5100 ft2) and rig dimensions [mast height of 37.4m (123
ft) above the sheer] and a maximum beam of 5.3m (17.4 ft) and draft of 6.5m
(21.3 ft). At 23,000 kg (50,700 lbs) these boats are very light for their
length, more in-line with a VO70 or an Open 60 than the former V5.0 AC Class.
Combining the light displacement with a substantial sail area increase,
particularly downwind where spinnaker area is unrestricted, and the result is
a much more powered-up boat both upwind and down. These boats will be
challenging to sail to their maximum potential, but promise some spectacular
performance that will be very exciting to watch. -- Read on:
http://www.sailingscuttlebutt.com/news/07/1101a

[nflutter]

this is fun isnt it, from a design point of veiw. out with the old, in with the new. new potential for development in various areas that were not emphasised in the last rule. I feel this is significant because i expect, and hope for all our sakes, some new and flash ideas will come out of this cup. as opposed to last cup. (except of course for the banned? bending keel thing that was pretty cool.) its essentially a design competition, and as such will probably be won and lost on the drawing board, or al least to a larger extent than we've seen lately. I've always argued that americas cup has always been about design and innovation, top class sailing is a given, so i think this is just tops. how about a new rule for the 34th cup! then we can focus on something else, like wingsails, or canting keels, and overlook some things that we already know about, like winglets, trim tabs, etc. then put that in the bag and get a new rule for the 35th, focussing our attention of things that need development not things that are developed that dont really need to be refined to the minute detail in a very specific, un-real-world-like allpication

[Vega]

Originally Posted by RHough

Since the likelihood of the AC ever being sailed in a venue that has 30+ knot wind on a regular basis is very slim (no Yacht Club that I know of has such conditions in their home waters), what relevance does the fact that they aren't designed to do so have?
.

In the last editions there were several days without races for excess of wind. Are we talking of stormy weather? No. Any cruising boat with a decent crew would find the conditions muscled but not dangerous.

There were also several days without racing for lack of wind. There was no wind? No (I was there on one of the occasions) simply not enough wind for heavy racing boats.

On the Americas cup we should have the best sailing boats man can produce, not boats with limited performance. It is not only my opinion, it is, for example de opinion of Juan kouyoumdjam and many top racing sailboat architects.

This new rule will provide better boats. We will see if they can compare with other modern top racing boats, in speed and technologie. I have my doubts.

[RHough]

Originally Posted by Vega

In the last editions there were several days without races for excess of wind. Are we talking of stormy weather? No. Any cruising boat with a decent crew would find the conditions muscled but not dangerous.

There were also several days without racing for lack of wind. There was no wind? No (I was there on one of the occasions) simply not enough wind for heavy racing boats.

On the Americas cup we should have the best sailing boats man can produce, not boats with limited performance. It is not only my opinion, it is, for example de opinion of Juan kouyoumdjam and many top racing sailboat architects.

Perhaps the new rule will provide better boats. I have my doubts, but we will see.

I agree. The agreement for AC32 was to race only under a very limited wind speed range:

"As in the Louis Vuitton Cup, there are no ‘hard’ wind limits, but the Race Committee “intends to conduct races when the approximate average true wind speed is between seven and 23 knots…six metres above the water.”

That was not part of the V5 rule, but an acknowledgement of the fact that under V5, a boat that was built to handle 0-30 would be at a disadvantage in "normal" Valencia conditions. I'd like to see the SI's for AC33 have no upper limit.

The boats have to optimized for expected conditions, that will be true under any rule. I'd like to see the boats be able to sail in 20-30 and not come apart. Unfortunately, unless the scantlings required in the rule or the SI's create boats that are stouter than the V5 boats, building a AC90 strong enough to race in the 20-30 range would reduce it's chance of success in more normal conditions.

Sailing in less than 6-7 does not make for good match racing.

BTW, how was your sailing holiday this summer?

[curridronan]

OK, fair enough. Id say A volvo would've easily beaten them though, Ive seen the VPP outputs for both in similar wind ranges and upwind they are surprisingly similar but you know what happens downwind.
Whatever floats your boat...

[Vega]

Originally Posted by RHough

BTW, how was your sailing holiday this summer?

Short (3 weeks) but muscled (4 to 10).
Sailing mostly on the Gibraltar strait and North Africa coast.

I agree with Vega. I'm very disappointed in this new rule. No canting keel, no canting mast, no rotating mast-this boat will NOT reflect the essence of modern technology
and I think thats terribly unfortunate.

[RHough]

Originally Posted by Doug Lord

I agree with Vega. I'm very disappointed in this new rule. No canting keel, no canting mast, no rotating mast-this boat will NOT reflect the essence of modern technology
and I think thats terribly unfortunate.

Thank goodness designers that have a clue about match racing wrote the rule. The AC hasn't been about "the essence of modern technology" since the 1930's, it has been about good close racing and spending mega-dollars to go (relatively) slowly. J's were cutting edge at the time, but too expensive. The 12's were not cutting edge, and the IACC rule was written to create a match race boat, not the fastest boat for it's size. V5 of that rule produced the best competition since Fremantle.

At 21' plus draft in measurement trim, these boats will have RM's higher than many maxi-boats. With no requirement for accommodation and no offshore ability, there is potential for considerable speed at only 23,000kg on a 90' WL. We might see 18-19,000kg in the bulb ... do the math ... no need for gimmicks that people won't see (canards, canting keels, cbtf), canting or rotating masts won't make a difference as far as the spectacle for TV, so no need to add the complexity or expense. These boats are going to be expensive enough as it is.

[riggertroy]

I've once again seen people saying things along the lines of "isn't the AC meant to be the F1 of yachting" and then saying that the boats cannot handle strong winds. Well if you look at it that way and take the winds to be part of the "race track" then F1 cars are optimised for their racing environment, just think how far a F1 car would get on say the WRC rally.

If people really want to see yachts with all the canards, canting keels and so on, then if there is enough interest maybe a race will develop, set up a group and see if you can get enough interest generated then proceed with developing a race format.

I am looking forward to seeing the result of the court case, I do not believe that in the challenger series the defender should be able to race as then the defender can manipulate the result of particular races it is in, as the defender will not really need to race seriously, they will be able to use the challenger series as a test bed, an advantage that will result in even further advantage to the holder of the AC.

[Roly]

I am looking forward to seeing the result of the court case, I do not believe that in the challenger series the defender should be able to race as then the defender can manipulate the result of particular races it is in, as the defender will not really need to race seriously, they will be able to use the challenger series as a test bed, an advantage that will result in even further advantage to the holder of the AC.

Absolutely!
Who ever heard of a race where one of the participants can't be eliminated?If allowed, it opens up the possibility of all sorts of intrigue.

The idea was to economise.Moving ballast means 1/2 the entrants,or even just two.A protracted tacking duel with canters? Yeah right!

[Guillermo]

Originally Posted by RHough

Thank goodness designers that have a clue about match racing wrote the rule. The AC hasn't been about "the essence of modern technology" since the 1930's, it has been about good close racing and spending mega-dollars to go (relatively) slowly. J's were cutting edge at the time, but too expensive. The 12's were not cutting edge, and the IACC rule was written to create a match race boat, not the fastest boat for it's size. V5 of that rule produced the best competition since Fremantle.

At 21' plus draft in measurement trim, these boats will have RM's higher than many maxi-boats. With no requirement for accommodation and no offshore ability, there is potential for considerable speed at only 23,000kg on a 90' WL. We might see 18-19,000kg in the bulb ... do the math ... no need for gimmicks that people won't see (canards, canting keels, cbtf), canting or rotating masts won't make a difference as far as the spectacle for TV, so no need to add the complexity or expense. These boats are going to be expensive enough as it is.

Very nice post, Randy. Exactly how it is. I'm tired now, but I'll try to post tomorrow on Manuel Ruiz de Elvira's opinions at yesterday's presentation. This weekend he's computing several hull variations for the new BMW-Oracle AC 90 boat, running (remotely!) 180 processors at the same time!

Cheers.

[Guillermo]

Not in an orderly manner, here some notes taken at Manolo's presentation:

- VCOG was around 1,80 m under floatation for the V5 boats. Now it is going to be 4+ m.
- AC 90 boats will have something like 18 to 19 tonnes in bulb, located around 6+ m under floatation. This will flex the long fins a lot and this will have to be specially considered in the performance calculations.
- The new AC 90 will be some 1 knot faster upwind than the V5 boats, topping 11,5+ knots.
- V5 boats were able to deliver 8 knots on 6 knots of wind when beating to winward.
- Beams may increase to around (wild guess) 4,5 m from the actual ones of around 3,5 m
- As designing and developing time is very short, most teams will have only one boat which will face other AC boats just at the race. Quality of design becomes of even more importance and the performance of boats will probably be very different.
- This will threaten the match racing interest, which is at the heart of the present AC race.
- It was proven that the close design of the V5 boats was a key in the success of the AC 32nd edition, building interest up to the last minute.
- The risk of this being not so, is high with the new AC 90 rule.
- 'Poor' teams will have even less chances than before.
- An AC modern boat will always beat any IMOCA 60 boat or the like over an AC race field.
- New AC90 boats will be less forgiving to crews' mistakes.
- Hulls will weight around 2 tonnes only. Structural engineering will be very demanding. Hulls must not flex more than around 30 mm longitudinally.
- The hull is a 'pain in the ass', located between sails and fins....
- The most efficient design team is not the one with the very best experts in each field, but the one in which the experts are able to share knowledge with the rest of the team. Team has to be open to the creative participation of all of its members into each other areas of design.
-He considers around 20 members as the best number for a design team, although AC boats can be (and have been) designed with as small as 4 persons ones.
- Several tenths of hull-rig combinations are CFD tested and then around 4 to 6 physical models run at Canals.
- Canal models are 1:3 sized
- They run canal tests in a Canada Canal (sized 200x8x6), because of the good quality of dynamometer and ability to adjust the canal parameters after each run.
- Computing capacity has become of paramount importance. They have (own) 180 Unix processors working jointly to run the CFD programs. Specialist people in this kind of computing are one of the keys to success.
- VPP programs are not that complicated. What is complicated is to feed them with the appropriate info.
- For sure Alinghi had not developed an AC 90 design or rule before July 2007 (The month Manolo left the designing team).

Well, all the AC 90 thing will happen if the BMW-Oracle vs Alinghi fight doesn't bring the AC to a competion between them in giant catamarans, of course....

Originally Posted by Guillermo

Well, all the AC 90 thing will happen if the BMW-Oracle vs Alinghi fight doesn't bring the AC to a competion between them in giant catamarans, of course....

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Or trimarans. And wouldn't that be specatacular!
+++++++++++++++++++++++
In case anyone has not actually read it:
Deed of Gift(and amendments/interpretations)
America's Cup Deed of Gift
Address:http://www.a3.org/ac2000_DeedofGift.html Changed:11:51 AM on Tuesday, February 29, 2000

[TimClark]

Has anyone here yet tried to take a stab at the rule to get a general idea of what the boats will look like? I have already come up with a hull, but I think I need to add a little more beam and form stability than already exists. Also, I discovered that it will be very hard for teams to design boats to the very minimum for freeboard as the rails will be completely underwater as soon as the boat starts to heel between 25-30 degrees.

TC