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      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  
pacice

Foiling Monohull - what would it look like?

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2 minutes ago, ~Stingray~ said:

^ Good stuff, SHC

At http://www.sailingscuttlebutt.com/2017/10/11/americas-cup-catamarans-many-negatives/

Andy Claughton, who has been Land Rover BAR’s chief technical officer, shares a less flattering opinion of the 15-meter AC Class seen in Bermuda. An excerpt below is from Claughton’s column titled ‘Cut!’ in the October 2017 edition of Seahorse Magazine.

Sour grapes? [That was too easy :D ]

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30 minutes ago, Steve Clark said:

 

It is reasonable to suggest a big canting  keel day racer will be faster than Rambler, or Wild Oats,  but that is about half as fast as the AC 50.  Rambler, Wild Oats and CQS have made pretty serious efforts to enhance their performance with DSS foils with very minimal success.   These boats had deisel engines, which is a bit of a stumbling block.  But what about batteries and electric motors?   [/b]I believe this foiling monohull concept is far from a slam dunk.  In order to gain performance, the boats may well gain many of the negative aspects of multihull. They may not right themselves after a capsize, Isn't that a requirement for offshore canters? It certainly is for IMOCAs they may have deck spreaders or foil arrangements that make then as ungainly lay and difficult to manage ashore as the big catamarans. If they have to be craned in and out of the water every day, they will be just as costly to manage, Surely the travelift compatibility will be maintained and if they are engineered to the limit of materials, they will be fragile when sailing above their "design conditions."  The first thing a design team will do is try to understand the prevailing conditions in order to optimize the boat for those conditions. If this isn't City Front, boats will break.  Much of this can be addressed in the design rules and sailing instructions. I have no desire to return to the days when multimillion dollar racing boats would not race in more than 18 knots of wind because they would burn trough their tissue paper jibs too fast.  

In short, expect something far more like a V5 IACC than an AC 50 and come to grips with racing at less than 1/2 the pace of the last Cup.

I actually believe that the way forward was to permit some additional design freedom around the foils ( including flaps and surface sensor systems) which would have lead to develop,meant of true rough water foiling, and possibly advanced seafaring.  But that is just me.

SHC

 

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4 hours ago, rh2600 said:

 

They actually sailed in a very small sheltered area on the Tamaki Strait in the Inner Gulf - this it not a great place to race due to traffic and distance from the city.

Please also note the mention of weather at that specific time of year being an important factor.

In any event, enjoy them apples.

Thanks for the interesting info rh.

However they started the Coastal classic and did not break their AC50 into pieces. They could also have modified the rule to reinforce it for the AC36, authorized flaps to prevent to sailors to work like slaves and authorized a mechanical wand to replace the dot on the screen.

So, I don't believe GD explanation 1.

I don't believe explanation 2 either, that they did not want to take too much advance over the competitors, how pretentious...

No, we are in the AC and the only logical explanation is that LR imposed a mono because they would have been 4 years late with the same class of boat or any foiling multi. So P$B leveled the playing field against the defender and any other teams.

The rest is PR, and that is acceptable, like it was with Oracle before, same spin turning the other way around. :)

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1 hour ago, Tornado-Cat said:

Thanks for the interesting info rh.

However they started the Coastal classic and did not break their AC50 into pieces. They could also have modified the rule to reinforce it for the AC36, authorized flaps to prevent to sailors to work like slaves and authorized a mechanical wand to replace the dot on the screen.

So, I don't believe GD explanation 1.

I don't believe explanation 2 either, that they did not want to take too much advance over the competitors, how pretentious...

No, we are in the AC and the only logical explanation is that LR imposed a mono because they would have been 4 years late with the same class of boat or any foiling multi. So P$B leveled the playing field against the defender and any other teams.

The rest is PR, and that is acceptable, like it was with Oracle before, same spin turning the other way around. :)

I'll leave you to it then ;-)

34-june-2014-them-apples.jpg

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4 hours ago, Steve Clark said:

In short, expect something far more like a V5 IACC than an AC 50 and come to grips with racing at less than 1/2 the pace of the last Cup.

I actually believe that the way forward was to permit some additional design freedom around the foils ( including flaps and surface sensor systems) which would have lead to develop,meant of true rough water foiling, and possibly advanced seafaring.

I think you're right.

Still think a displacement or semi-foiler multihull would have been best.

 

Quote

However they started the Coastal classic and did not break their AC50 into pieces.

Thing is that was a Southerly.

The famous AC72 waves vid was with a big Nor'Easter coming home from out by Tiri which is near the AC course area.

 

Yellow lines time!

XRFIRST.jpg

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Would a foiling monohull use a spinnaker?  I'm thinking the center of effort would be too far forward to mitigate through foil design...

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15 hours ago, Tornado-Cat said:

Ah, ah, amazing how some can change their discourse in a few months.

I am sure these guys did not know what they were talking about a few months ago. :)

"After 21 days of sailing in the Hauraki Gulf, Emirates Team New Zealand has lowered its bold red wing sail....
The sailing conditions in Auckland have been ideal for testing and putting the race boat throughout the range of conditions it will race in once in Bermuda....."
"The conditions have almost been more ‘Bermuda-like’ than in Bermuda.” said Skipper Glenn Ashby. “We have probably been the team that has had the chance to sail more days on their America’s Cup Class catamaran than anyone to date as the weather at this time of year in Auckland is perfect for sailing"

Try to keep up .. ETNZ did not do the bulk of their training in the Hauraki Gulf.

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11 hours ago, Steve Clark said:

I actually believe that the way forward was to permit some additional design freedom around the foils ( including flaps and surface sensor systems) which would have lead to development of true rough water foiling, and possibly advanced seafaring.  But that is just me.

Not just you. 

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The worst Gulf conditions in hard north easterly winds is nearing Rangitoto Light, in the channel with tide outrunning. And that is on the Waitemata harbour/Hauraki Gulf boundary and also the area, if the race courses are presumably to be set for spectator viewing, close to Takapuna and East Coast Bays - where keelers running for home in the channel in hard north easterly winds have been observed to broach to in numbers and lie on their sides with sails in a mess.

Expect to see the (presumably) very deep draft, 75 foot AC monohulls stay out of this area not only because of the "minor" point it is the main shipping channel but also because of the can-be-savage wind against tide conditions. Although the proposed monsters should be able to handle said wind/tide mess.

But where do they race, further out in the Gulf presumably - where no one on shore can see them?

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7 hours ago, Groucho Marx said:

.Expect to see the (presumably) very deep draft, 75 foot AC monohulls stay out of this area ....

But where do they race, further out in the Gulf presumably - where no one on shore can see them?

Which reminds me - about the canting keel pros/cons - that one should consider draft limitations not just in AKL but also in the five Preliminary Races locations. As well as in the Challengers' home bases, of course

 

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10 hours ago, Groucho Marx said:

The worst Gulf conditions in hard north easterly winds is nearing Rangitoto Light, in the channel with tide outrunning. And that is on the Waitemata harbour/Hauraki Gulf boundary and also the area, if the race courses are presumably to be set for spectator viewing, close to Takapuna and East Coast Bays - where keelers running for home in the channel in hard north easterly winds have been observed to broach to in numbers and lie on their sides with sails in a mess.

Expect to see the (presumably) very deep draft, 75 foot AC monohulls stay out of this area not only because of the "minor" point it is the main shipping channel but also because of the can-be-savage wind against tide conditions. Although the proposed monsters should be able to handle said wind/tide mess.

But where do they race, further out in the Gulf presumably - where no one on shore can see them?

Auckland has a small fleet of multihulls who also sail through this area, and most of them are still the right way up.

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35 minutes ago, jaysper said:

Bermuda America's Cup catamarans 'could not be safely raced in the Hauraki Gulf'

https://www.stuff.co.nz/sport/other-sports/97838645/bermuda-americas-cup-catamarans-could-not-be-safely-raced-in-the-hauraki-gulf

 

Ok, so I guess he should know plus he doesn't seem to have any reason to be biased.

awww cmon man - he's clearly biased because his point of view happens to support what GD has been saying!

I mean when has the AC not been raced in what is essentially a lake!? Oh that's right, every other fucking time

:-)

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2 hours ago, pacice said:

Auckland has a small fleet of multihulls who also sail through this area, and most of them are still the right way up.

Correct. But usually not in the conditions described? When I saw near a dozen keelers broach and lie on their sides I was single handing a multihull - which didn't broach - but helm was hard up to steer down - a close run thing though.

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2 hours ago, rh2600 said:

awww cmon man - he's clearly biased because his point of view happens to support what GD has been saying!

I mean when has the AC not been raced in what is essentially a lake!? Oh that's right, every other fucking time

:-)

You need to use your <sarcasm></sarcasm> or #sarcasm tags next time as I didn't quite catch on to it initially :D

I have to say that I was sceptical about the "not being able to race AC 50s in Auckland", but this pretty much settles it for me.

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4 hours ago, jaysper said:

Bermuda America's Cup catamarans 'could not be safely raced in the Hauraki Gulf'

https://www.stuff.co.nz/sport/other-sports/97838645/bermuda-americas-cup-catamarans-could-not-be-safely-raced-in-the-hauraki-gulf

 

Ok, so I guess he should know plus he doesn't seem to have any reason to be biased.

Biased ? where is that ? with a boat built for a lake ! :)

OK, it was southwesterly but just imagine the same boat a bit reinforced, reefable sail, flaps on the foils, machanical wands.

OK, I stop , i am repeating myself. How could have P$B won with such a boat, we know he prefers one the mono in the photo, the only ones able to cross the gulf.  :):):)

 

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5 minutes ago, Tornado-Cat said:

Biased ? where is that ? with a boat built for a lake ! :)

OK, it was southwesterly but just imagine the same boat a bit reinforced, reefable sail, flaps on the foils, machanical wands.

OK, I stop , i am repeating myself. How could have P$B won with such a boat, we know he prefers one the mono in the photo, the only ones able to cross the gulf.  :):):)

 

Ok, so I gotta be honest here and say that you seem to be spinning out of control right now TC, so much so that I am really not sure of what point you are trying to make here any more.

I am assuming (but not 100% sure) that you are asserting a greater level of expertise than Claughton on this manner, in which case you have strayed well into Doug Lord territory.

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2 minutes ago, jaysper said:

Ok, so I gotta be honest here and say that you seem to be spinning out of control right now TC, so much so that I am really not sure of what point you are trying to make here any more.

I am assuming (but not 100% sure) that you are asserting a greater level of expertise than Claughton on this manner, in which case you have strayed well into Doug Lord territory.

No, he is talking, we have the proof of the contrary :)

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1 minute ago, Tornado-Cat said:

No, he is talking, we have the proof of the contrary :)

Ah I see, so you having a video of the ETNZ AC50 blasting across the gulf is a proof that it is suitable for an entire regatta there?

Even the Great Sound which is a relative mill pond proved too much for the AC50s on at least one day.

*yawn* I think now you are straying into the realms of Indio.

 

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Jaysper, I accept that those conditions would not be suitable for an AC50, but how often have you seen those conditions in an AC ?

For the rest, you chose to believe GD, I chose to believe P$B when he spilled the beans.

Large_15_65714_MONO60EDMONDdeROTHSCHILD.JPG

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4 minutes ago, Tornado-Cat said:

Jaysper, I accept that those conditions would not be suitable for an AC50, but how often have you seen those conditions in an AC ?

For the rest, you chose to believe GD, I chose to believe P$B when he spilled the beans.

Large_15_65714_MONO60EDMONDdeROTHSCHILD.JPG

To be clear:

 

1. I have as recently as about 2 days ago stated that I didn't think there would be a problem with AC50s in the gulf (you can look back for the post), but this release from Claughton is enough to remove any doubt for me.

2. I don't believe this is the reason that they are going monos (as they could have gone with other multis that aren't so fragile).

3. I believe that there was a prearranged agreement to go monos and I am perfectly fucking ok with that. If you are not, I don't actually give a shit.

4. Even if this deal hadn't existed, I have little doubt they would have gone with monos anywho.

 

However, your recent posts have looked a lot more like the rants that I so gleefully ignore than your normal posts which, whilst quite off centre, are generally rational.

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When you say it would be too windy for the AC50, I guess you are assuming they would not build new boats? Or that they couldn't possibly change the rule at all? They could have done whatever they wanted with the rule and the boats, and made them fine for the range of conditions in the gulf. And they can certainly create a monohull rule and design(s) that will work fine.The monos will likely be slower in most conditions. But I will still watch. If it floats Bertie's boat, more power to them.

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1 hour ago, nroose said:

When you say it would be too windy for the AC50, I guess you are assuming they would not build new boats? Or that they couldn't possibly change the rule at all? They could have done whatever they wanted with the rule and the boats, and made them fine for the range of conditions in the gulf. And they can certainly create a monohull rule and design(s) that will work fine.The monos will likely be slower in most conditions. But I will still watch. If it floats Bertie's boat, more power to them.

its not the wind, its the wave height

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Something thats bothering me is the 40min race bit.

Displacement upwind would mean something like only 1.5 times round a Bermuda length course or 2 laps round a silly little Extreme Sailing Series course

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It's not a limit - like you know say SF - 1 sec over and you lose the Cup.

More a ball park 40-60 mins was mentioned as well, perhaps depending on conditions

Could be fun if there is a hard limit on any day and the boat behind is sailing the other all over the Gulf trying to run the clock down - the more tactical options the better

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There has always been an upper and lower wind limit in the Amercias Cup.

There will be no racing in 35 knots, and most of the time, the conditions are the 8 to 15 knots.

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On 10/13/2017 at 1:18 PM, Tornado-Cat said:

Jaysper, I accept that those conditions would not be suitable for an AC50, but how often have you seen those conditions in an AC ?

For the rest, you chose to believe GD, I chose to believe P$B when he spilled the beans.

Large_15_65714_MONO60EDMONDdeROTHSCHILD.JPG

Nice photo, but the boat is reaching at approx 90 degrees to the wind. What does it look like doing a Windward/leeward course?

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51 minutes ago, pacice said:

Nice photo, but the boat is reaching at approx 90 degrees to the wind. What does it look like doing a Windward/leeward course?

Yes, nice photos. Good questions, these foils were conceived to help them gain 2 or 3 kts downwind but do not help upwind.

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2 hours ago, Tornado-Cat said:

Yes, nice photos. Good questions, these foils were conceived to help them gain 2 or 3 kts downwind but do not help upwind.

No they are hindered by drag and poorer VMG. Several of the pre-dali IMOCA 60 vintage are quicker uphill.

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13 hours ago, Sailbydate said:

No they are hindered by drag and poorer VMG. Several of the pre-dali IMOCA 60 vintage are quicker uphill.

Why no ? I said it does not help upwind, and you are right it may even increase drag upwind.

That explains why foil assist is mainly good in some races only, and would not be of great help in the AC.

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Translated:

THE NEW MONOCOQUES OF AMERICA'S CUP

by François Chevalier and Jacques Taglang

 

In a few years, it was enough that the America's Cup put its nose in catamarans so that they become flying objects badly identified. The wings have replaced the sails and the useless hulls have flat bottoms, the crew, disguised as a helmeted robot, spends its time to ensure pressure in the hydraulic circuit ... The next Cup promises to revolutionize the monohulls. 75 feet, or 22.86 meters long, is one meter longer than the Mini Maxi 72, but these are blocked by the IRC gauge.

AC75b.jpg

AC75a.jpg

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On 10/1/2017 at 3:31 PM, Doug Lord said:

NZAC Sailplan ,version one
Based on these calcu-guestimates:
A) At 90 degrees the force holding the boat there is 171,926 ft.lbs.
The force trying to right the boat is 483,800lb
1-keel weight 19782 lb @ 20'
2-buoyancy from pod-4608lb @20'

3- Wing mast 115' above deck

4-SA=3191 sq.ft./ CE 59' above center of lift of keel/foil combo
-----
-b Weights----
1) hull weight-8572 lb
2) keel weight 19782lb
3) rig weight 2915lb
4) crew weight 1900lb
5)TOTAL DISPL.= 33168 lb
-----
C) RM on Foils:
1) HM at 59' with 2.5lb/sq/ft. pressure= 470,672 ft.lb.
2) RM, boat slightly heeled, mast vertical=569,418 ft.lb.
-----
D) Foil Loading one main foil in the water supporting 80% of the load=
18' X 2.5' chord foil fully immersed=589lb/sq.ft.

E) Fully retractable main foils for lightest air sailing.

F) Upper third of main could possibly be designed as a solid sail with two panels. When the whole sail is reefed this section would slide down. Needs study but may be effective.

G) From my analysis the thing may need a canting keel-not for ultimate RM but to start out. Needs much more study. Probably has great potential IF the target weight is within about 6000lb  of the 31268lb total boat weight( for this first run) including keel.

NZAC SAILPLAN, version 1,  9-29-17 004.JPG

NZAC revised   9-7-17 003.JPG

NZAC ONE     9-25-17  dl 002 - Copy.JPG

Compare the specs to Chevalier's boat . His  guesstimate is MUCH lighter than NZAC but guaranteed not to be self-righting which NZAC is. It also appears to have more upwind SA(with a shorter mast than NZAC)-but where does the RM come from ? This boat would surely foil whereas Chevaliers boat looks like it might at a major angle of heel-his render shows rudder t-foils which is mandatory for full flying and the main ingredient of full flying missing from the IMOCA's like Hugo Boss. Chevaliers renders are always gorgeous.....

Chevaliers specs:

 

Mise à l’eau : 31 mars 2019
Longueur : 22,86 m                                                 LOA: 75'
Flottaison : 22,86 m                                                LWL: 75'
Bau : 6 m                                                                Beam: 19' 7'' (hull)
Bau foils sortis : 15 m                                            Beam with foils: 49' 4''
Tirant d’eau : 5,50 m (si une quille est prévue)     Draft: 18' (if keeled)
Déplacement : 7 t                                                   Displacement: 7 tons
Tirant d’air : 33 m                                                 Air draft: 108' 4''
Surface de voiles au près : 400 m²                        SA (windward): 4305 sq. ft.
 
Surface de voiles au portant : 750 m²                   SA (downwind): 8073 sq. ft.

 

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Neither of Chevalier and Taglang's boats are suitable for close-quarters match racing because the foils extend outside the beam of the hulls.  The boat has to be able to sideswipe another boat without hooking the foils or the shrouds.  For example, the AC50 Design Rule limited how much the retracted foils could extend outside the beam so they couldn't hook another boat's shrouds.  I think you'd need to have a similar kind of envelope for the foils on the new monohull. I don't see Dali or DSS foils fitting into that envelope.

To get the power to foil, you need righting moment, and that means putting the foils out wide, whether it's a multihull or a monohull.  You can draw the rig and foils flying independently, then draw the boat that encloses the foils and mast step.  I think a more suitable approach would be put L foils on something like a 75' KZ1 with wider wings - a scaled up version of Mark Pivac's Moth that Brett Burville sailed (and was subsequently classified as a multihull).

The restriction on moving parts for the foils in the AC72 and AC50 Design Rules was a bit silly.  I realize they didn't want to get into an arms race designing radical morphing structures, etc., but they forced the control systems to be unwieldy and inefficient.  It would be sufficient to only allow moving parts in, say, the aft 40% of the chord with all parts at their maximum extension.  That would ensure the load-bearing structure is fixed and flaps are allowed for control, which make for a much simpler, lower power control system than moving the entire foil.  It would also allow Fowler flaps so the crew could change the wetted area between upwind & downwind, or to tune for different wind speeds.

I would also eliminate the use of electrically controlled valves.  This would force the use of hydromechanical controls similar to the state of the art in aircraft flight control systems of the 1960's to early 1970's.  The only stored energy would be hydraulic accumulators and mechanical springs.  Other than those restrictions, anything goes.  The big drawbacks to this are today's controls engineers aren't proficient at designing systems that don't use digital controls, and it's more expensive to machine close tolerance parts to make changes than it is to load modified software.  But it would eliminate the notion that the computers are sailing the boat and the crew is just following the bouncing ball.  If there are fewer things that can be programmed, then the crew has more things they need to do and are more involved with the sailing.

As for sail handling, physics says that if the boat is fast - meaning able to sail at some multiple of the true wind speed - then lots of different sails are a detriment rather than an asset because you can't stand the drag of all the extra wetted area.  So no matter what kind of boat it is, if it's a fast boat it just doesn't need more than a mainsail/wingsail and a jib.  Which means you need a helm and one or two wing trimmers.  Everyone else on the boat is doing some kind of auxiliary function, like grinding, making fine adjustments, or rail meat.  If you want to see a return to classical sail handling, setting and dowsing of downwind sails, the boats have to be slow.  

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^ Do you believe the ‘spirit’ of the Rule was violated by ETNZ through their use of what GD called a ‘super-computer’ to enable their automated flight control system, when ‘manual input’ was specified in the Rule? GD claims that he is amazed that nobody else did it, as if it was an obvious path that only the foolish missed.

 

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1 hour ago, ~Stingray~ said:

^ Do you believe the ‘spirit’ of the Rule was violated by ETNZ through their use of what GD called a ‘super-computer’ to enable their automated flight control system, when ‘manual input’ was specified in the Rule? GD claims that he is amazed that nobody else did it, as if it was an obvious path that only the foolish missed.

 

No, I believe they followed the rule.  I'd rather see a different rule.  

I don't think salt water and electrons play well together.  Trickle-down technology from the AC has a tremendous influence on all of sailing.  I'd like to see the development of hydromechanical technology that would be applicable to other forms of sailing.  

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2 hours ago, ~Stingray~ said:

^ Do you believe the ‘spirit’ of the Rule was violated by ETNZ through their use of what GD called a ‘super-computer’ to enable their automated flight control system, when ‘manual input’ was specified in the Rule? GD claims that he is amazed that nobody else did it, as if it was an obvious path that only the foolish missed.

 

I don't believe etnz  violated the spirit of the rule but certainly the AC50s violated the spirit of sailing IMO. Ridiculous oil slaves, peeps dedicated to maintaining ride height, unable to sustain sailing for more than about 30 minutes, banging the boundaries. Yuck! 

Only problem is that if etnz want a fast boat, they may well end up specifying a class rule that includes many of the same problems including banging.

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3 hours ago, ~Stingray~ said:

^ Do you believe the ‘spirit’ of the Rule was violated by ETNZ through their use of what GD called a ‘super-computer’ to enable their automated flight control system, when ‘manual input’ was specified in the Rule? GD claims that he is amazed that nobody else did it, as if it was an obvious path that only the foolish missed.

 

Not the rule, the spirit perhaps, but remember the discussions on this forum about about enhanced reality in 2013....

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7 hours ago, Basiliscus said:

Neither of Chevalier and Taglang's boats are suitable for close-quarters match racing because the foils extend outside the beam of the hulls.  The boat has to be able to sideswipe another boat without hooking the foils or the shrouds.  For example, the AC50 Design Rule limited how much the retracted foils could extend outside the beam so they couldn't hook another boat's shrouds.  I think you'd need to have a similar kind of envelope for the foils on the new monohull. I don't see Dali or DSS foils fitting into that envelope.

To get the power to foil, you need righting moment, and that means putting the foils out wide, whether it's a multihull or a monohull.  You can draw the rig and foils flying independently, then draw the boat that encloses the foils and mast step.  I think a more suitable approach would be put L foils on something like a 75' KZ1 with wider wings - a scaled up version of Mark Pivac's Moth that Brett Burville sailed (and was subsequently classified as a multihull).

The restriction on moving parts for the foils in the AC72 and AC50 Design Rules was a bit silly.  I realize they didn't want to get into an arms race designing radical morphing structures, etc., but they forced the control systems to be unwieldy and inefficient.  It would be sufficient to only allow moving parts in, say, the aft 40% of the chord with all parts at their maximum extension.  That would ensure the load-bearing structure is fixed and flaps are allowed for control, which make for a much simpler, lower power control system than moving the entire foil.  It would also allow Fowler flaps so the crew could change the wetted area between upwind & downwind, or to tune for different wind speeds.

I would also eliminate the use of electrically controlled valves.  This would force the use of hydromechanical controls similar to the state of the art in aircraft flight control systems of the 1960's to early 1970's.  The only stored energy would be hydraulic accumulators and mechanical springs.  Other than those restrictions, anything goes.  The big drawbacks to this are today's controls engineers aren't proficient at designing systems that don't use digital controls, and it's more expensive to machine close tolerance parts to make changes than it is to load modified software.  But it would eliminate the notion that the computers are sailing the boat and the crew is just following the bouncing ball.  If there are fewer things that can be programmed, then the crew has more things they need to do and are more involved with the sailing.

As for sail handling, physics says that if the boat is fast - meaning able to sail at some multiple of the true wind speed - then lots of different sails are a detriment rather than an asset because you can't stand the drag of all the extra wetted area.  So no matter what kind of boat it is, if it's a fast boat it just doesn't need more than a mainsail/wingsail and a jib.  Which means you need a helm and one or two wing trimmers.  Everyone else on the boat is doing some kind of auxiliary function, like grinding, making fine adjustments, or rail meat.  If you want to see a return to classical sail handling, setting and dowsing of downwind sails, the boats have to be slow.  

Excellent, common sense. A thing that is missing in most of us.

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9 hours ago, Basiliscus said:

Neither of Chevalier and Taglang's boats are suitable for close-quarters match racing because the foils extend outside the beam of the hulls.  The boat has to be able to sideswipe another boat without hooking the foils or the shrouds.  For example, the AC50 Design Rule limited how much the retracted foils could extend outside the beam so they couldn't hook another boat's shrouds.  I think you'd need to have a similar kind of envelope for the foils on the new monohull. I don't see Dali or DSS foils fitting into that envelope.

To get the power to foil, you need righting moment, and that means putting the foils out wide, whether it's a multihull or a monohull.  You can draw the rig and foils flying independently, then draw the boat that encloses the foils and mast step.  I think a more suitable approach would be put L foils on something like a 75' KZ1 with wider wings - a scaled up version of Mark Pivac's Moth that Brett Burville sailed (and was subsequently classified as a multihull).

The restriction on moving parts for the foils in the AC72 and AC50 Design Rules was a bit silly.  I realize they didn't want to get into an arms race designing radical morphing structures, etc., but they forced the control systems to be unwieldy and inefficient.  It would be sufficient to only allow moving parts in, say, the aft 40% of the chord with all parts at their maximum extension.  That would ensure the load-bearing structure is fixed and flaps are allowed for control, which make for a much simpler, lower power control system than moving the entire foil.  It would also allow Fowler flaps so the crew could change the wetted area between upwind & downwind, or to tune for different wind speeds.

I would also eliminate the use of electrically controlled valves.  This would force the use of hydromechanical controls similar to the state of the art in aircraft flight control systems of the 1960's to early 1970's.  The only stored energy would be hydraulic accumulators and mechanical springs.  Other than those restrictions, anything goes.  The big drawbacks to this are today's controls engineers aren't proficient at designing systems that don't use digital controls, and it's more expensive to machine close tolerance parts to make changes than it is to load modified software.  But it would eliminate the notion that the computers are sailing the boat and the crew is just following the bouncing ball.  If there are fewer things that can be programmed, then the crew has more things they need to do and are more involved with the sailing.

As for sail handling, physics says that if the boat is fast - meaning able to sail at some multiple of the true wind speed - then lots of different sails are a detriment rather than an asset because you can't stand the drag of all the extra wetted area.  So no matter what kind of boat it is, if it's a fast boat it just doesn't need more than a mainsail/wingsail and a jib.  Which means you need a helm and one or two wing trimmers.  Everyone else on the boat is doing some kind of auxiliary function, like grinding, making fine adjustments, or rail meat.  If you want to see a return to classical sail handling, setting and dowsing of downwind sails, the boats have to be slow.  

Why couldn't Welbourns "Q" foils be used on a boat with wide racks that act as a sort of "shield" for close quarters racing as well as providing tremendous righting moment?

NZAC ONE     9-25-17  dl 002 - Copy.JPG

NZAC revised   9-7-17 003.JPG

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FFS, that is at least the 15th time that has been posted or reposted in this thread alone. If you want to discuss it, reference a previous post.

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1 hour ago, RobG said:

FFS, that is at least the 15th time that has been posted or reposted in this thread alone. If you want to discuss it, reference a previous post.

And it still presents a trimaran, which he still calls a monohull with buoyancy pods.

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