pacice

Foiling Monohull - what would it look like?

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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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That's not going to foil in a zillion years, unless you deploy jumbo wings and a turbo fan engine. So change the name of the thread

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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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I wrote a while ago that the only interesting monos would be a narrow pod with foils or a wide mono with L foils. I am not good artist but just found image of how it could look like. Chevalier draws amazing designs but I don't agree with his vision of what would be a good foiling mono, too conservative for me.

portada-mw-680-1.thumb.jpg.9186e4ad9ea71f4adfd4486cd456ea5d.jpg

https://wilson-marquinez.com/

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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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2 hours ago, NotSoFast said:

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

That is false. You probably don't realize that Moths have buoyancy on each side-approx. one cu.ft. buoyancy in airbags.

The NZAC buoyancy pod is never sailed on-its there just in case of a knockdown to help the keel right the boat.

picture by Thierry Martinez:

Moth buoyancy pix by Thierry Martinez.jpg

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On 18/10/2017 at 10:38 PM, Tornado-Cat said:

I wrote a while ago that the only interesting monos would be a narrow pod with foils or a wide mono with L foils. I am not good artist but just found image of how it could look like. Chevalier draws amazing designs but I don't agree with his vision of what would be a good foiling mono, too conservative for me.

portada-mw-680-1.thumb.jpg.9186e4ad9ea71f4adfd4486cd456ea5d.jpg

https://wilson-marquinez.com/

What if we had the same boat with L foils inward, like those used for last AC, with flaps.

If wide enough to provide sufficient RM, and not too heavy., it could fly.

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17 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.  

GREAT post!  As always you are a huge blessing to this board.

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1 hour ago, Tornado-Cat said:

What if we had the same boat with L foils inward, like those used for last AC, with flaps.

If wide enough to provide sufficient RM, and not too heavy., it could fly.

You've started quoting yourself?  Like Doug Lord Xenu?

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NZAC, version two foils (tc) :

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.

 

--About the same RM as Version One---

--UptiP* foils OR manually controlled  "L" foils---

* like SuperFoiler---

NZAC Version Two Foils (TC) 002.JPG

 

Version One Foils:  ( "Q" foils)

 

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

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15 minutes ago, Doug Lord said:

NZAC, version two foils (tc) :

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.

 

--About the same RM as Version One---

--UptiP* foils OR manually controlled  "L" foils---

* like SuperFoiler---

NZAC Version Two Foils (TC) 002.JPG

 

Version One Foils:  ( "Q" foils)

 

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

Holy Crap - That’s Amazing!

Where have you been all my life??

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FFS Dougie, that last weasel piss drawing is a trimaran with foils. Also again, this is a 75 foot craft not a Moth. So your spindly foil/float? connections are going to snap off in 5 knots apparent. Better make that 3. And how many times have you posted your ridiculous concept; has to be approaching 2 score now? Repetition makes reality, eh?

 

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1 hour ago, Doug Lord said:

NZAC Version Two Foils (TC) 002.JPG

 

Your first version was a mono, I guess this would be considered a tri, a bit like the successful super foiler. However, I wonder if a wide hull with these kind of foil was part of their studied concepts. But they will chose much more classical.

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Stranger things have happened.. Read Basiliscus where he describes drawing a boat around the mast step and the foils, the general concept could (yikes) actually look something like that.

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9 minutes ago, Tornado-Cat said:

Your first version was a mono, I guess this would be considered a tri, a bit like the successful super foiler. However, I wonder if a wide hull with these kind of foil was part of their studied concepts. But they will chose much more classical.

How could a buoyancy pod that can't effectively  be sailed on make the boat a tri??!! I bet the proportion of pod volume compared to total displacement would be around the same as the buoyancy pods on a Moth. If the pod isn't used to sail the boat, it can't be considered part of a trimaran!!! 

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2 minutes ago, Doug Lord said:

How could a buoyancy pod that can't effectively  be sailed on make the boat a tri??!! I bet the proportion of pod volume compared to total displacement would be around the same as the buoyancy pods on a Moth. If the pod isn't used to sail the boat, it can't be considered part of a trimaran!!! 

I am not the one to decide, but I think they consider the superfoiler as a tri.

 

3412d0f73db2882731f98769e2c40152.jpg

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14 minutes ago, ~Stingray~ said:

Stranger things have happened.. Read Basiliscus where he describes drawing a boat around the mast step and the foils, the general concept could (yikes) actually look something like that.

Like this ?

89dbd1ac706b4d97bed016a6f9654287.jpg

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10 minutes ago, Tornado-Cat said:

I am not the one to decide, but I think they consider the superfoiler as a tri.

 

3412d0f73db2882731f98769e2c40152.jpg

The SuperFoiler IS a trimaran! Those hulls are used to sail the boat before its on foils-they are stepped planing hulls to reduce drag in incidental hull contact at speed. The pods on the NZAC would NEVER be used to sail the boat, not in light air , not ever. Viewed from the side the NZAC pods are more similar to a tube than to a hull designed to support any portion of the displacement.

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38 minutes ago, jorge said:

FFS stop it Doug. You've posted your idea zillion times. Give us a break we aré all aware. 

You gave your self away jorge! What I posted tonight was an entirely different version of the foils!!!  Obviously, you're right on top of these forums and the discussions going on! Congratulations........

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You are insufferable to beyond the point of bonkers.

Isn't it time you used your energies to actually build a boat large enough to carry your fat posterior? And stop your incessant and insane postings here?

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33 minutes ago, Doug Lord said:

You gave your self away jorge! What I posted tonight was an entirely different version of the foils!!!  Obviously, you're right on top of these forums and the discussions going on! Congratulations........

The problem dougie is that i really don't read your posts anymore. I only read the ones of people who  know what they are talking about. Cheers!

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3 hours ago, Doug Lord said:

How could a buoyancy pod that can't effectively  be sailed on make the boat a tri??!! I bet the proportion of pod volume compared to total displacement would be around the same as the buoyancy pods on a Moth. If the pod isn't used to sail the boat, it can't be considered part of a trimaran!!! 

In fact you could avoid the pod boyancy, as the stability is provided by the keel, then it could perhaps be a mono. But the boyancy may be a good idea for safety.

Anyway, I don't ind whether it's mono, tri or cat as far as it goes fast. As I often pointed out, what is an ice boat: mono, cat or tri ? I don't mind.

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6 hours ago, jorge said:

The problem dougie is that i really don't read your posts anymore. I only read the ones of people who  know what they are talking about. Cheers!

Not to put too finer point on it, jorge you'll be finding fuck all worth reading here abouts then. ;)

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4 hours ago, Sailbydate said:

Not to put too finer point on it, jorge you'll be finding fuck all worth reading here abouts then. ;)

Sometimes,  Basiliscus, or SHC,  to name only two, puts some good insights. I was taught to listen to everyone's opinion, even those who seem  dumb and ignorant, because they too have something to say, but Dougie here, has raised the bar too high for me

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8 hours ago, hoom said:

Monohulls by definition used by some here

 

 

gitana-11-2.jpg

 

 

Cute but completely wrong: trimaran amas and main hull are all used to sail the boat. The NZAC buoyancy pods are NEVER used to sail the boat-only for capsize recovery.

NZAC Version Two Foils (TC) 002.JPG

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4 hours ago, Doug Lord said:

Cute but completely wrong: trimaran amas and main hull are all used to sail the boat. The NZAC buoyancy pods are NEVER used to sail the boat-only for capsize recovery.

NZAC Version Two Foils (TC) 002.JPG

So your foils shown are not used to sail the boat? Just a fashion accessory? 

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A foil does not an ama make........

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So would your boat be disqualified if, during a race one of the "bouyancy pods" touched the water and suddenly provided more righting moment when needed?

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20 hours ago, Doug Lord said:

How could a buoyancy pod that can't effectively  be sailed on make the boat a tri??!! I bet the proportion of pod volume compared to total displacement would be around the same as the buoyancy pods on a Moth. If the pod isn't used to sail the boat, it can't be considered part of a trimaran!!! 

So you are claiming AC50 used by ETNZ was not in fact a cat, as none of its hulls were used to provide buoyancy while foiling 100% of race time.

Wrong claim, a cat is a cat and a tri is a tri regardless of hulls touching water or not.

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44 minutes ago, See Level said:

So would your boat be disqualified if, during a race one of the "bouyancy pods" touched the water and suddenly provided more righting moment when needed?

The buoyancy pods on NZAC would not be designed to support any proportion of the boats displacement when it is moving at any speed-they are only there to help the keel right the boat from a knockdown. They would never be sailed "on". Not a trimaran.

You don't have to be a rocket scientist to understand this: in a knockdown or capsize when the pod hits the water it acts like a brake because the fore and aft rack supports and foil reinforcing struts* also hit the water. BUT the buoyancy assists the keel in preventing the boat from going over 90 degrees. The pods make the boat safer while allowing the keel to be lighter than it otherwise would be. 

* look at the right side of the sketch

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33 minutes ago, NotSoFast said:

So you are claiming AC50 used by ETNZ was not in fact a cat, as none of its hulls were used to provide buoyancy while foiling 100% of race time.

Wrong claim, a cat is a cat and a tri is a tri regardless of hulls touching water or not.

Thats false. It shows that you either don't understand the concept or don't give a shit. Either way it's one of the silliest comments I've read that didn't come from the Frog Man......

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39 minutes ago, Doug Lord said:

The buoyancy pods on NZAC would not be designed to support any proportion of the boats displacement when it is moving at any speed-

Guess what. The hulls on AC50 of ETNZ were not designed to support any proportion of the boats displacement when it was moving at any speed during a race.

According to your definition quoted above, it was thus not a catamaran!

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"You don't have to be a rocket scientist to understand this: in a knockdown or capsize when the pod hits the water it acts like a brake because the fore and aft rack supports and foil reinforcing struts* also hit the water. BUT the buoyancy assists the keel in preventing the boat from going over 90 degrees. The pods make the boat safer while allowing the keel to be lighter than it otherwise would be."

 

Well your right on one point, you don't have to be a "rocket scientist" to understand this. 

That might be because they deal in the science of Zero to One atmosphere.

Whereas your pods become INSTANTLY bouyant at  slightly above ONE atmosphere and continue to gain bouyancy to around 2 atmospheres.

And we're not talking displacement we're talking RIGHTING MOMENT.

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Blue Arrow has been mentioned before, it didn't have buoyancy pods, amas, floats, whatever and likely passes the tests for a monohull. At 65' it's getting close to the right length for AC36, and at just 1.5t displacement makes a mockery of a foiling mono carrying a 9t keel. It also used one person to manually trim the foils, cyclers need not apply. Maybe the first upgrade will be adding ailerons to the crossbeam.

How did it end? Destroyed in a pitch pole at just 30kn.

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Latest goss from the docks of the EXSS is that while no decision has been reached, momentum is building inside the ETNZ camp towards something with a lot less lead than anyone's ever seen in a big boat.  Maybe a whole lot less.  :)

 

 

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7 hours ago, Doug Lord said:

The buoyancy pods on NZAC would not be designed to support any proportion of the boats displacement when it is moving at any speed-they are only there to help the keel right the boat from a knockdown. They would never be sailed "on". Not a trimaran.

You don't have to be a rocket scientist to understand this: in a knockdown or capsize when the pod hits the water it acts like a brake because the fore and aft rack supports and foil reinforcing struts* also hit the water. BUT the buoyancy assists the keel in preventing the boat from going over 90 degrees. The pods make the boat safer while allowing the keel to be lighter than it otherwise would be. 

* look at the right side of the sketch

They also make the boat very stable when inverted.

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5 hours ago, MR.CLEAN said:

Latest goss from the docks of the EXSS is that while no decision has been reached, momentum is building inside the ETNZ camp towards something with a lot less lead than anyone's ever seen in a big boat.  Maybe a whole lot less.  :)

 

 

fingers crossed

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May be they will suss out an ultra-light monohull which requires water-start like windsurf with minimal bouyancy.

An inflatable wing sail would avoid "turttling"  after capsize, and would allow the crew to put the boat back using the same "water start" technics

What do you think Dougy  ???

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9 hours ago, MR.CLEAN said:

momentum is building inside the ETNZ camp towards something with a lot less lead than anyone's ever seen in a big boat.  Maybe a whole lot less.  :)

The problem with that is nobody has ever made such a thing previously, you wouldn't want to find out too late that the concept basically doesn't work.

 

Sure, nobody had made a big foiling multihull before ETNZ either & that worked out OK but in that case the rule was supposed to create semi-foiling big multis and there had already been plenty of those and ETNZ had semi-foiling available as a fall-back if the full foiling didn't work out.

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  ^ To a T. Plus it's not just the concept, they have to pen down a box rule. And it must be suitable for match racing and stable while going backwards during dial-ups

 

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12 hours ago, RobG said:

Blue Arrow has been mentioned before, it didn't have buoyancy pods, amas, floats, whatever and likely passes the tests for a monohull. At 65' it's getting close to the right length for AC36, and at just 1.5t displacement makes a mockery of a foiling mono carrying a 9t keel. It also used one person to manually trim the foils, cyclers need not apply. Maybe the first upgrade will be adding ailerons to the crossbeam.

How did it end? Destroyed in a pitch pole at just 30kn.

Blue Arrow AC monohull---Scuttlebutt photos(archives)  1988  :

Blue Arrow-scuttlebutt.jpg 2.jpg