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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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On 12/8/2017 at 1:38 PM, ~Stingray~ said:

The New America’s Cup Design

8DEC

Posted by Brian Hancock 

I really don’t want to be negative.  I love innovation and I really appreciate that a lot of time has gone into developing a creative new idea for the 36th America’s Cup. I am not sure what else they could have done, but I do have one idea. They could have stayed with multihulls…:)

http://greatcirclesails.blogspot.com/2017/12/the-new-americas-cup-design.html

From a new entry here, sounds like he will be on live radio shortly: 

http://greatcirclesails.blogspot.com/2017/12/a-blog-is-not-article.html

I will be on a sports talk radio show in New Zealand to defend what I wrote. If you are (remotely) interested you can listen in between 8 and 10 EST at this link or click the radio station pic below

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49 minutes ago, ~Stingray~ said:

From a new entry here, sounds like he will be on live radio shortly: 

http://greatcirclesails.blogspot.com/2017/12/a-blog-is-not-article.html

I will be on a sports talk radio show in New Zealand to defend what I wrote. If you are (remotely) interested you can listen in between 8 and 10 EST at this link or click the radio station pic below

My guess is he has the wrong Radio info, it's more likely to be on Radio Sport live, at https://www.iheart.com/live/Radio-Sport-6194/

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from http://blog.numeca.be/read/article/218

Emirates Team New Zealand (ETNZ) and NUMECA International will be building a close technical partnership over the next four years, continuing their cooperation after this year’s very successful America’s Cup, where ETNZ won the ‘Auld Mug’ and became world champion. Once again NUMECA will bring in the best of their next generation CFD software to help ETNZ in their quest to defend their title in 2021. 

The following interview with Nick Hutchins, CFD Specialist at ETNZ and Benoit Mallol, Product Manager for the marine applications at NUMECA International, reveals some of the main challenges and requirements of ETNZ.

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Found this technical analysis of the AC75 - in French, but quite good:

https://www.uncl.com/2017/12/01/techniques-innovations/nouvel-ac-75-nz-jean/

(TC, what is exactly a "dessalage"?)

As a detail, the author works out a required power for foil actuation below 3 kW (but with 1 t foils and 10" rotation time) and considers an all electric, ball-screw solution as obvious. The weight of the battery pack (700 kg) seems high

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35 minutes ago, Xlot said:

Found this technical analysis of the AC75 - in French, but quite good:

https://www.uncl.com/2017/12/01/techniques-innovations/nouvel-ac-75-nz-jean/

(TC, what is exactly a "dessalage"?)

As a detail, the author works out a required power for foil actuation below 3 kW (but with 1 t foils and 10" rotation time) and considers an all electric, ball-screw solution as obvious. The weight of the battery pack (700 kg) seems high

Nice find! Wish I knew French but here’s a Gtran: https://translate.googleusercontent.com/translate_c?depth=1&nv=1&rurl=translate.google.com&sl=auto&sp=nmt4&tl=en&u=https://www.uncl.com/2017/12/01/techniques-innovations/nouvel-ac-75-nz-jean/&usg=ALkJrhjbPyakvyeGQ-Pt19rfERYZu_CbAw

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1 hour ago, Xlot said:

Found this technical analysis of the AC75 - in French, but quite good:

https://www.uncl.com/2017/12/01/techniques-innovations/nouvel-ac-75-nz-jean/

(TC, what is exactly a "dessalage"?)

As a detail, the author works out a required power for foil actuation below 3 kW (but with 1 t foils and 10" rotation time) and considers an all electric, ball-screw solution as obvious. The weight of the battery pack (700 kg) seems high

Hi X , dessaler means " scuffiare" or capsize for the non italians

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1 hour ago, trucdesign said:

Hi X , dessaler means " scuffiare" or capsize for the non italians

That's what I thought too, but what's then the difference with "chavirer" stressed by the author?

 

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3 hours ago, Xlot said:

Found this technical analysis of the AC75 - in French, but quite good:

https://www.uncl.com/2017/12/01/techniques-innovations/nouvel-ac-75-nz-jean/

(TC, what is exactly a "dessalage"?)

As a detail, the author works out a required power for foil actuation below 3 kW (but with 1 t foils and 10" rotation time) and considers an all electric, ball-screw solution as obvious. The weight of the battery pack (700 kg) seems high

Thanks for the article, the best I read on the AC75 yet. I always used the dessaler and chavirer for the same action, however the author seems to make a distinction between chavirer while sailing and dessaler in a static mode.

- All electrical

- Foils in flexible steel with no possible corrosion

- Fun boats but very difficult to handle

- We will a lot of strange figures, "dessalages", "chavirages" etc.

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8 hours ago, ~Stingray~ said:

I liked his opinion about the actuation of the foils .. he favours an electro mechanical system rather than electro hydraulic using ball screws as used on many aircraft these days .. personally I favour old fashioned gearboxes but I am not up with the play on ball screws .. 

"Foil maneuvers

Point N ° 1: It takes energy to maneuver the two central foils and the foils equipping the saffron. It is easy to understand that the central foils will consume 90% of the energy. The solutions "cyclists" or "winchmen" no longer work. Remember that Christopher FROOME was estimated at 0.436 kW / h during the Tour de France. This is never 2 kW / h for a regatta of 5 hours. To manage to maneuver the central foils, it will take more than the Top Ten of the Tour de France cyclist on the deck, or in the bunkers. The AC75 NZ is no longer a "beach gear" as was the catamaran of the last AC.

The foil maneuvers of this AC 75 NZ, will require:

  • Energy,
  • fast response times,
  • high mechanical, electrical and electronic reliability

To maneuver a central foil from the sailing position (port tack) to the upwind position on the starboard tack (case of a tack), a quick calculation shows that you need to have:

  • Torque: 1000 kg X 2.15 (lever arm at the beginning of the maneuver) = 2150 daNm
  • Angle to go: 66 °
  • Operating time: 10 seconds
  • Angular velocity: 0.105 rad / s
  • Power required: 2,25 kW

At each tack in a regatta (2 maneuvers of foil TB and BB), the consumption is 22500 JX 2, with an electrical efficiency of 0.7: 18 Wh. Or nearly 2 kWh for 100 transfers during the day (2 regattas); It is obviously necessary to add the other maneuvers.

I exclude using as primary energy source, a heat engine that would work permanently. This engine is associated with a generator, a battery of buffer batteries and electric motors coupled to the mechanical parts.

Similarly, I think that a hydraulic system (linear or rotary cylinder) is not appropriate because linear or angular displacements are difficult to control. In addition the hydraulic imposes piping, a large oil reserve and especially a pressure of the fluid at 80 or 160 Bars.

Of course, all-electric technology will be needed. Thus the electric motor of each mechanical system will be associated with a ball screw (low friction, excellent efficiency, reversibility, mass). This is for example a technology widely used on aircraft for the control of exit flaps high lift.

One of the advantages of ball screws is to be reversible, this translates into two transformations of movement:

  1. the screw is driving and the nut moves in translation
  2. the nut is motor (translation) and the screw is rotated.

This allows to "drop" by gravity foil when it is high position and recover the electrical energy provided by the electric motor becomes generator. That's always what's earned, and it's free.

What about batteries: Let's forget the "leaded" technology. A rapprochement with the initiators of Formula E (Electric Formula 1). These cars (250 km / h) are equipped with a lithium battery pack with controller and charger from 50 to 60 kWh, for a unit weight of 320 kg.

It can be seen that the proposal of the NZ will develop the neural work of the teams.

A question of materials

An Archimedean boat is a relatively soft gear. The efforts are not extremely violent. As soon as we approach the navigation in two very different configurations where the Archimedean speed can be doubled and where there are peaks of violent solicitations, the choice of materials becomes paramount.

On this type of boat, the mechanical actions on the foils are of the same type as those to which a landing gear is subjected. At 25 kts, water is a solid obstacle, combined with very strong decelerations, the laws of dynamics generate destructive stresses. On this boat, because there is no ballast in the form of a bulb, there is no problem of weight estimate not to exceed 7000 kg. Designers have no interest in using low density materials (carbon composite type) in the manufacture of central foil supports. This approach is obviously not valid for the design of saffron and its foil and "T" associated.

Then there remains the metal materials with high elastic limit (about 2000 MPa). These are steels, but the counterpart of a high elastic limit is in a very high sensitivity to stress corrosion. The slightest sting of rust can generate a crack which will develop ultra quickly. On the landing gear, these steels are cadmiumed and painted and above all inspected before each take-off. There are also "stainless" that reach 1700 MPa of elastic limit, but these stainless are very expensive. Already forging is complex, finishing machining is far from easy. The beams that support the central foils are embedded in the hull.The bending moment at the embedment is of the order of 30T.m.

I exclude Titanium alloys, although some grades reach 1200 MPa, because the density of Titanium is much lower than that of Steel and corollary Young's Modulus is 30% lower than that of Steel. This means that its elastic deformation will be much greater than that of steel, which would cause problems for a boat that leans on foil via an arm of 3.6m cantilevered."

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17 hours ago, Terry Hollis said:

I liked his opinion about the actuation of the foils .. he favours an electro mechanical system rather than electro hydraulic using ball screws as used on many aircraft these days .. personally I favour old fashioned gearboxes but I am not up with the play on ball screws .. 

"Foil maneuvers

Point N ° 1: It takes energy to maneuver the two central foils and the foils equipping the saffron. It is easy to understand that the central foils will consume 90% of the energy. The solutions "cyclists" or "winchmen" no longer work. Remember that Christopher FROOME was estimated at 0.436 kW / h during the Tour de France. This is never 2 kW / h for a regatta of 5 hours. To manage to maneuver the central foils, it will take more than the Top Ten of the Tour de France cyclist on the deck, or in the bunkers. The AC75 NZ is no longer a "beach gear" as was the catamaran of the last AC.

The foil maneuvers of this AC 75 NZ, will require:

  • Energy,
  • fast response times,
  • high mechanical, electrical and electronic reliability

To maneuver a central foil from the sailing position (port tack) to the upwind position on the starboard tack (case of a tack), a quick calculation shows that you need to have:

  • Torque: 1000 kg X 2.15 (lever arm at the beginning of the maneuver) = 2150 daNm
  • Angle to go: 66 °
  • Operating time: 10 seconds
  • Angular velocity: 0.105 rad / s
  • Power required: 2,25 kW

At each tack in a regatta (2 maneuvers of foil TB and BB), the consumption is 22500 JX 2, with an electrical efficiency of 0.7: 18 Wh. Or nearly 2 kWh for 100 transfers during the day (2 regattas); It is obviously necessary to add the other maneuvers.

I exclude using as primary energy source, a heat engine that would work permanently. This engine is associated with a generator, a battery of buffer batteries and electric motors coupled to the mechanical parts.

Similarly, I think that a hydraulic system (linear or rotary cylinder) is not appropriate because linear or angular displacements are difficult to control. In addition the hydraulic imposes piping, a large oil reserve and especially a pressure of the fluid at 80 or 160 Bars.

Of course, all-electric technology will be needed. Thus the electric motor of each mechanical system will be associated with a ball screw (low friction, excellent efficiency, reversibility, mass). This is for example a technology widely used on aircraft for the control of exit flaps high lift.

One of the advantages of ball screws is to be reversible, this translates into two transformations of movement:

  1. the screw is driving and the nut moves in translation
  2. the nut is motor (translation) and the screw is rotated.

This allows to "drop" by gravity foil when it is high position and recover the electrical energy provided by the electric motor becomes generator. That's always what's earned, and it's free.

What about batteries: Let's forget the "leaded" technology. A rapprochement with the initiators of Formula E (Electric Formula 1). These cars (250 km / h) are equipped with a lithium battery pack with controller and charger from 50 to 60 kWh, for a unit weight of 320 kg.

It can be seen that the proposal of the NZ will develop the neural work of the teams.

A question of materials

An Archimedean boat is a relatively soft gear. The efforts are not extremely violent. As soon as we approach the navigation in two very different configurations where the Archimedean speed can be doubled and where there are peaks of violent solicitations, the choice of materials becomes paramount.

On this type of boat, the mechanical actions on the foils are of the same type as those to which a landing gear is subjected. At 25 kts, water is a solid obstacle, combined with very strong decelerations, the laws of dynamics generate destructive stresses. On this boat, because there is no ballast in the form of a bulb, there is no problem of weight estimate not to exceed 7000 kg. Designers have no interest in using low density materials (carbon composite type) in the manufacture of central foil supports. This approach is obviously not valid for the design of saffron and its foil and "T" associated.

Then there remains the metal materials with high elastic limit (about 2000 MPa). These are steels, but the counterpart of a high elastic limit is in a very high sensitivity to stress corrosion. The slightest sting of rust can generate a crack which will develop ultra quickly. On the landing gear, these steels are cadmiumed and painted and above all inspected before each take-off. There are also "stainless" that reach 1700 MPa of elastic limit, but these stainless are very expensive. Already forging is complex, finishing machining is far from easy. The beams that support the central foils are embedded in the hull.The bending moment at the embedment is of the order of 30T.m.

I exclude Titanium alloys, although some grades reach 1200 MPa, because the density of Titanium is much lower than that of Steel and corollary Young's Modulus is 30% lower than that of Steel. This means that its elastic deformation will be much greater than that of steel, which would cause problems for a boat that leans on foil via an arm of 3.6m cantilevered."

Ball screws....

 

Told ya so :)

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On 12/16/2017 at 5:17 PM, ~Stingray~ said:

 

On 12/17/2017 at 1:40 AM, Terry Hollis said:

I liked his opinion about the actuation of the foils .. he favours an electro mechanical system rather than electro hydraulic using ball screws as used on many aircraft these days .. personally I favour old fashioned gearboxes but I am not up with the play on ball screws .. 

"Foil maneuvers

Point N ° 1: It takes energy to maneuver the two central foils and the foils equipping the saffron. It is easy to understand that the central foils will consume 90% of the energy. The solutions "cyclists" or "winchmen" no longer work. Remember that Christopher FROOME was estimated at 0.436 kW / h during the Tour de France. This is never 2 kW / h for a regatta of 5 hours. To manage to maneuver the central foils, it will take more than the Top Ten of the Tour de France cyclist on the deck, or in the bunkers. The AC75 NZ is no longer a "beach gear" as was the catamaran of the last AC.

The foil maneuvers of this AC 75 NZ, will require:

  • Energy,
  • fast response times,
  • high mechanical, electrical and electronic reliability

To maneuver a central foil from the sailing position (port tack) to the upwind position on the starboard tack (case of a tack), a quick calculation shows that you need to have:

  • Torque: 1000 kg X 2.15 (lever arm at the beginning of the maneuver) = 2150 daNm
  • Angle to go: 66 °
  • Operating time: 10 seconds
  • Angular velocity: 0.105 rad / s
  • Power required: 2,25 kW

At each tack in a regatta (2 maneuvers of foil TB and BB), the consumption is 22500 JX 2, with an electrical efficiency of 0.7: 18 Wh. Or nearly 2 kWh for 100 transfers during the day (2 regattas); It is obviously necessary to add the other maneuvers.

I exclude using as primary energy source, a heat engine that would work permanently. This engine is associated with a generator, a battery of buffer batteries and electric motors coupled to the mechanical parts.

Similarly, I think that a hydraulic system (linear or rotary cylinder) is not appropriate because linear or angular displacements are difficult to control. In addition the hydraulic imposes piping, a large oil reserve and especially a pressure of the fluid at 80 or 160 Bars.

Of course, all-electric technology will be needed. Thus the electric motor of each mechanical system will be associated with a ball screw (low friction, excellent efficiency, reversibility, mass). This is for example a technology widely used on aircraft for the control of exit flaps high lift.

One of the advantages of ball screws is to be reversible, this translates into two transformations of movement:

  1. the screw is driving and the nut moves in translation
  2. the nut is motor (translation) and the screw is rotated.

This allows to "drop" by gravity foil when it is high position and recover the electrical energy provided by the electric motor becomes generator. That's always what's earned, and it's free.

What about batteries: Let's forget the "leaded" technology. A rapprochement with the initiators of Formula E (Electric Formula 1). These cars (250 km / h) are equipped with a lithium battery pack with controller and charger from 50 to 60 kWh, for a unit weight of 320 kg.

It can be seen that the proposal of the NZ will develop the neural work of the teams.

A question of materials

An Archimedean boat is a relatively soft gear. The efforts are not extremely violent. As soon as we approach the navigation in two very different configurations where the Archimedean speed can be doubled and where there are peaks of violent solicitations, the choice of materials becomes paramount.

On this type of boat, the mechanical actions on the foils are of the same type as those to which a landing gear is subjected. At 25 kts, water is a solid obstacle, combined with very strong decelerations, the laws of dynamics generate destructive stresses. On this boat, because there is no ballast in the form of a bulb, there is no problem of weight estimate not to exceed 7000 kg. Designers have no interest in using low density materials (carbon composite type) in the manufacture of central foil supports. This approach is obviously not valid for the design of saffron and its foil and "T" associated.

Then there remains the metal materials with high elastic limit (about 2000 MPa). These are steels, but the counterpart of a high elastic limit is in a very high sensitivity to stress corrosion. The slightest sting of rust can generate a crack which will develop ultra quickly. On the landing gear, these steels are cadmiumed and painted and above all inspected before each take-off. There are also "stainless" that reach 1700 MPa of elastic limit, but these stainless are very expensive. Already forging is complex, finishing machining is far from easy. The beams that support the central foils are embedded in the hull.The bending moment at the embedment is of the order of 30T.m.

I exclude Titanium alloys, although some grades reach 1200 MPa, because the density of Titanium is much lower than that of Steel and corollary Young's Modulus is 30% lower than that of Steel. This means that its elastic deformation will be much greater than that of steel, which would cause problems for a boat that leans on foil via an arm of 3.6m cantilevered."

We tried to translate as best as we could and did propose a post to the anarchy website, 2 weeks ago...

Here attached is our english attempt for Jean's analysis (our IRC rule Guru).

In french, we differenciate a total capsize (keel up) and half capsize (horizontal mast). This last one is "dessaler".

Paperwork AC75v3.pdf

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^ Great work...and thanks for the 'Ros Bif' version

Is there another phrase for 'windward capsize' ? I suspect that one might get used a bit :D

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3 hours ago, nav said:

^ Great work...and thanks for the 'Ros Bif' version

Is there another phrase for 'windward capsize' ? I suspect that one might get used a bit :D

we have "ass over the head" when the nose dive and bottom goes up with wave.

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4 hours ago, etienne.billiet said:

we have "ass over the head" when the nose dive and bottom goes up with wave.

Humm, not sure we use the same words

- nose dive or pitch pole = planter (common word) = sancir (correct word) = cul par dessus tête (old french)

- mast down = faire chapeau (at least on a catamaran)

- capsize = chavirer = dessaler

- and, if the boat goes down = couler

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10 hours ago, nav said:

^ Great work...and thanks for the 'Ros Bif' version

Is there another phrase for 'windward capsize' ? I suspect that one might get used a bit :D

Have been trying to wrap my brain about that possibility too.

Depending how fast the canting can happen it may be as safe from a complete turtle as capsizing to leeward would be, but again.. ?

In the concept video they showed a foil rising at a good clip, somewhere close to the first time the PJM overdub has him murmuring ‘THIS IS DRAMATIC!’ as the boats come together, while apparently upwind. Just an animation but cant from ‘stable’ to ‘normal’ (extended up into the air) happens fast, maybe < 2 secs.

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I expect more than one diagonal flip: gust hits on a low speed mark rounding, rudder foil lets go & boat pivots around the leeward foil, there is no lee-bow to catch it.

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56 minutes ago, Erwankerauzen said:

 

Regarding French translation, I'd prefer

Couler = To sink/sank/sunk 

probably more appropriate than: to go down

Correct Erwan, but we also say "envoyer par le fond", or "s'abîmer".

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2 hours ago, Tornado-Cat said:

Correct Erwan, but we also say "envoyer par le fond", or "s'abîmer".

S'abîmer in the sense of getting damaged or of abîme-abyss (going down the mine)? :)

 

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15 hours ago, ~Stingray~ said:

Have been trying to wrap my brain about that possibility too....

You can capsize a foiler to windward by easing the sheet.  I've also pitchpoled a landyacht backwards when the mast fluttered in a tack.

Before the ease, the leeward foil has an angle of attack that produces enough lift to oppose the heeling moment.  The rig is also producing a bow-down pitching moment that is opposed by the stern foil.

When you ease the sail, suddenly both the heeling moment and he bow-down moment reduce or go away, but the foils are still producing the same lift and thus the same righting and bow-up pitching moments.  Unlike a displacement boat, in which the righting moment drops off as the boat comes upright, the righting moment from a foil doesn't drop off the same way.  And may even get worse as the boat pitches up.  The result is a "High, ho, Silver! Away!" moment as the boat pitches up and heels to windward.

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To the victor goes the toil: Grant Dalton’s daily grind

 

Following today's report into Team New Zealand's quality problem, boss Grant Dalton must balance the responsibilities of both successfully hosting and defending the America's Cup. He talks to Suzanne McFadden. 

https://www.newsroom.co.nz/@sportsroom/2017/12/19/70054/to-the-victor-goes-the-toil-grant-daltons-daily-grind

 

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5 hours ago, Xlot said:

S'abîmer in the sense of getting damaged or of abîme-abyss (going down the mine)? :)

 

Second one. Pretty much old french I would say, but still used. I was in fact partly right in my last post as "abîmer" covers a whole range of possibilities, like sinking, capsizing, losing the boat.

Your understanding of french is more that pretty good :)

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On 12/19/2017 at 3:57 AM, nav said:

^ Great work...and thanks for the 'Ros Bif' version

Is there another phrase for 'windward capsize' ? I suspect that one might get used a bit :D

Here are some suggestions. Keep in mind that we are talking about a 68' hull plus a huge rig dropping from a considerable height above the water on top of a large crew.

catastrophe
kəˈtastrəfi/
noun
noun: catastrophe; plural noun: catastrophes
  1. 1.
    an event causing great and usually sudden damage or suffering; a disaster.
    synonyms: disaster, calamity, cataclysm, crisis, holocaust, ruin, ruination, tragedy, blow, shock;
    adversity, blight, trouble, trial, tribulation, mishap, misfortune, mischance, misadventure, accident, failure, reverse, woe, affliction, distress;
    informalmeltdown, whammy;
    informalcar crash;
    archaicbale;
    archaicmishanter
    "the bush fires were the latest in a growing list of catastrophes"
       

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Yeah we had a big thread with a bunch of references to those jesus lizards & we dubbed the boat the JC75 after it.

But thread got nuked for some reason <_<

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2 hours ago, McGyver said:

I am very happy with the new design because my biggest beef with the foiling catamarans was that 99% of sailors could not relate to them.

^^ Well, you should not be happy with the new design then, because 100% of sailors will not be able to relate to them :D

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1 hour ago, Tornado-Cat said:

^^ Well, you should not be happy with the new design then, because 100% of sailors will not be able to relate to them :D

Well, I'm sure as hell struggling. Don't even want to look at the ugly water walking fucker. 

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from https://mobile.nytimes.com/2017/12/24/sports/sailing/guillaume-verdier-yacht-racing.html?referer=https://www.google.com/

...

The hours have continued to pile up with Verdier committed to many high-profile projects — none more visible than the 36th America’s Cup, scheduled for 2021.

Verdier joined Team New Zealand before the 2013 Cup in San Francisco, where the Kiwis blew an 8-1 lead before losing, 9-8, to the defender Oracle Team USA.

Four years later in Bermuda, Team New Zealand held firm with a new and younger crew, routing Oracle, 7-1. Both those Cups were contested in foiling catamarans, and Verdier focused on the key area of foil design for 2017. But with Team New Zealand and its Italian challenger of record, Luna Rossa, committed to returning to monohulls for 2021, there was concern in the Cup community that the venerable event was taking a step backward in design and adrenaline.

No one feels that way any longer. The proposed new boat looks undeniably futuristic and is expected to be the fastest monohull ever used in the Cup. Instead of a keel to provide stability, it has twin canting ballasted T-foils that have veteran sailors both excited and wary about the challenge of handling it, particularly when it is not hydrofoiling.

Image
merlin_130361427_7a2156de-7169-4711-84b0
A rendering of the new America’s Cup class that was revealed in November: a 75-foot foiling monohull without a traditional keel. CreditVirtual Eye/Emirates Team New Zealand, via Associated Press 

“I’m having trouble connecting the dots in my simple mind,” said Iain Murray, the former America’s Cup regatta director and skipper who will be back aboard Wild Oats XI for the Hobart race. “I do a lot of sailing on these 70- to 100-foot monohulls. I know how fast they go, and I know how fast catamarans have to be going to get onto the foils. They basically need to be doing 15 knots, and I know what it takes for Wild Oats, which is a 100-footer, to do 15 knots.

“I’m sure once the new boat is on the foils with stability, it will be great. It’s just getting on and off the foils is the part I’m struggling with.”

Verdier and Bernasconi say that they have done their “homework” but agree that the proposal is radical.

“If we went out one afternoon and saw one of those foiling down the harbor, having never seen one before, it would definitely be like, ‘What the hell is that?’” Bernasconi said. “And so to actually say that’s going to be the next America’s Cup boat, yeah, it is radical.”

Is Verdier 100 percent certain it will work?

“I’m sure if there are things that are not going to work, we will fix it with the time we have,” he said.

Bernasconi says the boat should foil at 9 knots of wind speed and be capable of hydrofoiling for an entire Cup race in the right conditions. It is still in the conceptual phase: the class rule will not be finalized until March. But before Team New Zealand won the Cup, Verdier said he had already come up with a similar design for a 38-foot monohull for a private client in New Zealand who was brought to Verdier by Ray Davies, a longtime Team New Zealand sailor.

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The initial drawing for that project still had a keel.

“We sat together with the client, and Ray said, ‘Hey, come on! After all we’ve learned, you’ve got to get rid of this keel. It’s looking draggy to have so much in the water,’” Verdier said. “And I said, ‘Yes, but Ray, it’s going to capsize too easily. We need some minimum stability here.’ ”

The solution was to propose putting the weight in the foils instead.

“That is completely counterintuitive because the foil is a lifting surface, so why put lead in a lifting surface?” Verdier said. “We need some stability before we start flying, so we make the foils like canting keels. This kind of boat existed in the past, with twin keels, so I said, ‘Let’s make a kind of twin keel but with foils, not too heavy, just enough so we can right it up at 90 degrees when we cant it the correct way.’”

That 38-footer has yet to be built, but at the end of a very big year for Verdier, he and Bernasconi and Team New Zealand will soon be building a much bigger version with much more at stake.

“Clearly, Guillaume and Dan are brilliant guys,” Murray said. “Whether it’s Comanche or any of these boats, Guillaume hasn’t had too many bad ones. So I think we’ve just got to wait and see. Many times in the past, people have questioned what they’ve done, and they’ve proven themselves.”

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3 hours ago, ~Stingray~ said:

from https://mobile.nytimes.com/2017/12/24/sports/sailing/guillaume-verdier-yacht-racing.html?referer=https://www.google.com/

...

 

“Clearly, Guillaume and Dan are brilliant guys,” Murray said. “Whether it’s Comanche or any of these boats, Guillaume hasn’t had too many bad ones. So I think we’ve just got to wait and see. Many times in the past, people have questioned what they’ve done, and they’ve proven themselves.”

Murray says that the boats will need 15 kts to fly but what does he know ? is he an architect ? did he design the concept ?

Verdier says they will fly in 9 kts, I tend to believe him, even thought it won't be flawless, but that is something else, and there may be the fun, at least for us.

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39 minutes ago, Tornado-Cat said:

Murray says that the boats will need 15 kts to fly but what does he know ? is he an architect ? did he design the concept ?

Verdier says they will fly in 9 kts, I tend to believe him, even thought it won't be flawless, but that is something else, and there may be the fun, at least for us.

Verdier says take-off at 9 kts TWS, while IM talks about 15 kts boat speed. Actually, this jibes with Jean Sans's 16 kts - although I'm still struggling with the two foils being equally loaded.

In any case, this would point to taking off on a beam reach - no idea what will happen going upwind. And if a boat falls off the foils, it's race over

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2 minutes ago, Xlot said:

Verdier says take-off at 9 kts TWS, while IM talks about 15 kts boat speed. Actually, this jibes with Jean Sans's 16 kts - although I'm still struggling with the two foils being equally loaded

^ The difference is even more, IM says what it takes to reach 15 kts with a 100 ft, which is, probably around 15 kts TWS or more, while Verdier-Bernasconi speak of only 9 kts TWS.

I guess the equal loading of the 2 foils is possible depending of the position and rake of the main, but I don't think they can keep it all the time equally loaded as in stronger wind the load moves front. So they may have calculed it for earlier take off only., then it will move.

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13 hours ago, Tornado-Cat said:

Murray says that the boats will need 15 kts to fly but what does he know ? is he an architect ? did he design the concept ?

Verdier says they will fly in 9 kts, I tend to believe him, even thought it won't be flawless, but that is something else, and there may be the fun, at least for us.

I think you forget IM was a successful architect...

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Isn’t it fascinating that nothing like this has ever been done. I’m definitely a multi guy and you could argue these new gizmos are not really a mono, whatevs, but now foiling cats looks so...um...so conquerable. (for the brilliant few with those skills) and yesterday’s hero. 

These newfangled things are just so unlike anything else. Will they work?  Will they be amazing? Will they be a complete joke?  

When’s the first one due to be built and sailing?  

 

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14 hours ago, Tornado-Cat said:

^ The difference is even more, IM says what it takes to reach 15 kts with a 100 ft, which is, probably around 15 kts TWS or more, while Verdier-Bernasconi speak of only 9 kts TWS.

I guess the equal loading of the 2 foils is possible depending of the position and rake of the main, but I don't think they can keep it all the time equally loaded as in stronger wind the load moves front. So they may have calculed it for earlier take off only., then it will move.

What about moving the downwind foil further out, instead of moving the mast rake?  \

So you would have the  boat heeled  in 9 kts of breeze, with the upwind foil adjusted to lift vertically as much as possible, and the downwind foil canted out further to lift up / resist leaning further

 

Or you coul have a Split T rudder, and that thing could also resist ' lean'  in takeoff mode

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On 19/12/2017 at 1:56 PM, Erwankerauzen said:

 

Regarding French translation, I'd prefer

Couler = To sink/sank/sunk 

probably more appropriate than: to go down

for dessalage it's quite the same thing  than a capside but on one side of the boat

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18 hours ago, ~Stingray~ said:

I wonder who the original NZ client was? Curious too if there’s anything to the fact that the 38’ length mentioned is also right at the 12m (non) Surrogate max length. From that article: ...

But before Team New Zealand won the Cup, Verdier said he had already come up with a similar design for a 38-foot monohull for a private client in New Zealand who was brought to Verdier by Ray Davies, a longtime Team New Zealand sailor.

The initial drawing for that project still had a keel.

“We sat together with the client, and Ray said, ‘Hey, come on! After all we’ve learned, you’ve got to get rid of this keel. It’s looking draggy to have so much in the water,’” Verdier said. “And I said, ‘Yes, but Ray, it’s going to capsize too easily. We need some minimum stability here.’ ”

The solution was to propose putting the weight in the foils instead.

“That is completely counterintuitive because the foil is a lifting surface, so why put lead in a lifting surface?” Verdier said. “We need some stability before we start flying, so we make the foils like canting keels. This kind of boat existed in the past, with twin keels, so I said, ‘Let’s make a kind of twin keel but with foils, not too heavy, just enough so we can right it up at 90 degrees when we cant it the correct way.’”

That 38-footer has yet to be built, but at the end of a very big year for Verdier, he and Bernasconi and Team New Zealand will soon be building a much bigger version with much more at stake.

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Similar, from this recently posted Gtran https://translate.googleusercontent.com/translate_c?depth=1&nv=1&rurl=translate.google.com&sl=auto&sp=nmt4&tl=en&u=http://www.tipandshaft.com/americas-cup/ac75-ce-quen-disent-les-designers/&usg=ALkJrhh1wa4Wmfk2YzgqKPJ0mYh1HCEnSQ

... This plan, if it seems revolutionary, is not quite new, since a project has already been studied by Guillaume Verdier , member of the New Zealand design team led by Dan Bernasconi . "With the Ray Davies navigator, we had developed this monohull concept with weighted side foils to offer it to a private client in New Zealand, we have never built the boat, but the project is still in progress," confirms l interested in Tip & Shaft. "Guillaume Verdier had already worked on a project of 39 feet and that's probably why they went in this direction, they do not start from nothing, this boat has already turned in their models , it's reflected" adds Dimitri Despierres , former Oracle, who like Joseph Ozanne and Michel Kermarec , recently committed to the challenge of the New York Yacht Club.

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4 hours ago, dachopper said:

What about moving the downwind foil further out, instead of moving the mast rake?  \

So you would have the  boat heeled  in 9 kts of breeze, with the upwind foil adjusted to lift vertically as much as possible, and the downwind foil canted out further to lift up / resist leaning further

 

Or you coul have a Split T rudder, and that thing could also resist ' lean'  in takeoff mode

Agreed that they may be able to move the foils more than with the AC50.

Regarding the takeoff mode they could use the 3 foils but I don't think they will as the priority they need is speed, which lifts at the square of the lifting surface.

So speed is being the priority, they will diminish immerged lifting surfaces, execepted during tacks and gybes for stability.

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23 hours ago, ~Stingray~ said:

“I’m having trouble connecting the dots in my simple mind,” said Iain Murray, the former America’s Cup regatta director and skipper who will be back aboard Wild Oats XI for the Hobart race. “I do a lot of sailing on these 70- to 100-foot monohulls. I know how fast they go, and I know how fast catamarans have to be going to get onto the foils. They basically need to be doing 15 knots, and I know what it takes for Wild Oats, which is a 100-footer, to do 15 knots.

“I’m sure once the new boat is on the foils with stability, it will be great. It’s just getting on and off the foils is the part I’m struggling with.”

For once, I agree with IM: it's quite possible that, with wind steady over 10 kts, the new boat will foil the course - if anything, it being ballasted inertia should make foiling tacks and gybes easy. The hard part, as IM says, will be getting it on the foils i.e. reaching a speed of 15-16 kts - a bit like the DeLorean car in the Back To The Future films. In fact hull speed for a 68' LWL displacement boat is just 11 kts (IM's WOXI comparison); now the AC75 is not conventionally ballasted, one would have to look perhaps at very lightly ballasted downhill boats like the ULDBs of yore - but in any case reaching take-off speed will be no piece of cake and probably imply taking a reaching course.

The fact remains that accelerating from zero will be painfully slow: up to a speed of around 10 kts (revised calculations piggybacking on Jean Sans'), the weight of the leeward foil will exceed lift, so that probably the foil will not be extended but folded under the hull in the docking position, very low available RM

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2 hours ago, Tornado-Cat said:

Agreed that they may be able to move the foils more than with the AC50.

Regarding the takeoff mode they could use the 3 foils but I don't think they will as the priority they need is speed, which lifts at the square of the lifting surface.

So speed is being the priority, they will diminish immerged lifting surfaces, execepted during tacks and gybes for stability.

Maybe so, but if we are comparing a single foil vs double foils, your still going to get massive reduction in takeoff speed.

 

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4 hours ago, Tornado-Cat said:

Regarding the takeoff mode they could use the 3 foils but I don't think they will as the priority they need is speed, which lifts at the square of the lifting surface.

If the video is at all accurate they will be 3 foiling in takeoff mode, raising the ww foil only once they are flying. That’s what it seems to show, beginning around 1:45

 

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15 minutes ago, ~Stingray~ said:

If the video is at all accurate they will be 3 foiling in takeoff mode, raising the ww foil only once they are flying. That’s what it seems to show, beginning around 1:45

 

You might be right, but watching the video it shows in fact :

1) the boat flying on 2 foils

2) tacking or gybing on 3 foils, as speculated in my post above.

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Discussing these boats with some moth mates we had the same thoughts as Iain. Huge drag at the take off stage. 

If Murray is right and the teams do not iron out the lift off bugs, we may see the boats needing big support boats to tow them up to foiling speed before the prep sygnal. And then the racing will be just a tactical event to see who can slow their oponent enough to drop off the foils first. Followed by a boring low rider prcession to the finish.

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36 minutes ago, Phil S said:

Discussing these boats with some moth mates we had the same thoughts as Iain. Huge drag at the take off stage. 

If Murray is right and the teams do not iron out the lift off bugs, we may see the boats needing big support boats to tow them up to foiling speed before the prep sygnal. And then the racing will be just a tactical event to see who can slow their oponent enough to drop off the foils first. Followed by a boring low rider prcession to the finish.

 

Or they could drop off the foils during the race. These boats have soft sails, so they won't have the precise trim that the cats had with their wingsails. A mistake by the trimmers could result in a splashdown that effectively ends the race.

One statement from Verdier sounds a bit ominous:

"Verdier believes there is time to make adjustments if required in what will be a design race for 2021.

"I'm sure if there are things that are not going to work, we will fix it with the time we have," he said of the new boat he continues to work on."

https://www.stuff.co.nz/sport/other-sports/100172415/team-new-zealand-designer-a-bit-nuts-as-radical-new-boat-is-rated

A much better process would be to build a prototype and get the major bugs out first, before you waste all the teams time and money. Verdier's approach could end up with the teams effectively redesigning the class in the middle of the competition. Sounds a bit like AC34 all over again.

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2 hours ago, Phil S said:

Discussing these boats with some moth mates we had the same thoughts as Iain. Huge drag at the take off stage. 

If Murray is right and the teams do not iron out the lift off bugs, we may see the boats needing big support boats to tow them up to foiling speed before the prep sygnal. And then the racing will be just a tactical event to see who can slow their oponent enough to drop off the foils first. Followed by a boring low rider prcession to the finish.

I don't think so:

- the moth has a small sail surface vs weight ratio, AC75 will have huge sails, mainly to take off

- the Qwant proved to fly in light wind with a heavy queel, AC75 will have ballasted foils

At the end it is a question of speed at take off which will depend of a few well known factors:

- weight

- power = sails, I guess they will take off downwind with huge front sail if necessary

- RM = width of the boat + length of the foil arms

- drag of the hull = design + width + weight

Basically they have a few months to design a rule allowing a boat with a flat planing hull, narrow enough to limit the drag in choppy water. And the rule should allow a maximum width of the foils not depending on the width of the hull.

The very difficult conditions for these boats will be choppy water with low wind, the winner will be the first to fly and...not fall. Catamarans narrow hull are not bothered by chops, wide mono are, and the drag can be huge.

I may be wrong, but...

BTW, I am pretty sure they will test the concept within the few months on a smaller boat, before writing the rule in march.

Ah, .....on an other level, TNZ is a competitor as per some chapters of the protocol, and they are not allowed to test non surrogate yacht isn't it ??? :)

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Where's Douguie Lord to stuff up a perfectly good load of reasonably qualified opinions?  Come on Dougie we need you to expound to us your views on why this will/wont work with your neverending load of unquantified opinion of 30 years of research of bullshit foiling in toy boats.

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Sounds like it could be closest to 18footer racing with differing concepts, multiple rigs, massive gains and losses at times and lots of swimming.

Let's hope the extra size and weight doesn't result in extra hospital visits

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1 hour ago, nav said:

Sounds like it could be closest to 18footer racing with differing concepts, multiple rigs, massive gains and losses at times and lots of swimming.

Let's hope the extra size and weight doesn't result in extra hospital visits

Correct, RM requires weight + width. On AC75 ballasted foils will replace the crew outside the boat. The advantage of a the cat is to allow width, with a hull in order to come back to normal archimedian sailing, while these boats will "dessaler" winward. I d'ont think it will be difficult to fly  them, even in light wind, it will be difficult to fly them without capsizing.

If that is true, the question is not to know if Verdier is a nut, and if his concepts works, but how sailors can sail it. Then, some may hate him :)

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On 12/21/2017 at 1:13 AM, Tornado-Cat said:

^^ Well, you should not be happy with the new design then, because 100% of sailors will not be able to relate to them :D

Was a sarcasm emoticon REALLY needed...?

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Catching up on this thread and wow are we in for an engineering technology development show. As in you have to think it will be amazing or terrible. The  comments above suggesting maybe they should have built that 38 footer described in the article or at least prototype something before committing to this design are spot on, though this position is also kind of obvious and shared by pretty much everyone here I'm sure.  Contrast this approach with the recent development of foiling Ultime Trimarans where there was a progression of Macif, then Gitanta, then BPXI, then Macif going back  in the shed to get more foily, then a new Sodebo and so forth. They've crept up on full ocean foiling learning along the way. It's just so crazy to set this AC  rule and then build a whole lot of boats with no precedent whatsoever. I know we have to have monos this time because of the Italians etc and I know conditions off Auckland are not flat water cat friendly,  but what if by 2021 the French foiling tris are fundamentally faster in strong offshore conditions as well as being extremely seaworthy and relatively affordable? It will make the JC75 seem an even more weird voyage into an odd place.

ps. Rather than darkly refer to "certain stainless steels" I'm gonna say right now, look for these appendages to be made out of 17-4, finishing in the H900 condition. It can be forged, welded and machined and is nice and corrosion resistant. And it has an ultimate tensile strength of 1445 MPa. I love 17-4 and it's not desperately expensive.

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On 25/12/2017 at 11:06 PM, Phil S said:

Discussing these boats with some moth mates we had the same thoughts as Iain. Huge drag at the take off stage. 

If Murray is right and the teams do not iron out the lift off bugs, we may see the boats needing big support boats to tow them up to foiling speed before the prep sygnal. And then the racing will be just a tactical event to see who can slow their oponent enough to drop off the foils first. Followed by a boring low rider prcession to the finish.

By association, from Wikipedia:

"Taking off is one of the main times albatrosses use flapping to fly, and is the most energetically demanding part of a journey."

Hmm, not a good omen ...

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12 hours ago, Foiling Optimist said:

Catching up on this thread and wow are we in for an engineering technology development show. As in you have to think it will be amazing or terrible. The  comments above suggesting maybe they should have built that 38 footer described in the article or at least prototype something before committing to this design are spot on, though this position is also kind of obvious and shared by pretty much everyone here I'm sure.  Contrast this approach with the recent development of foiling Ultime Trimarans where there was a progression of Macif, then Gitanta, then BPXI, then Macif going back  in the shed to get more foily, then a new Sodebo and so forth. They've crept up on full ocean foiling learning along the way. It's just so crazy to set this AC  rule and then build a whole lot of boats with no precedent whatsoever. I know we have to have monos this time because of the Italians etc and I know conditions off Auckland are not flat water cat friendly,  but what if by 2021 the French foiling tris are fundamentally faster in strong offshore conditions as well as being extremely seaworthy and relatively affordable? It will make the JC75 seem an even more weird voyage into an odd place.

ps. Rather than darkly refer to "certain stainless steels" I'm gonna say right now, look for these appendages to be made out of 17-4, finishing in the H900 condition. It can be forged, welded and machined and is nice and corrosion resistant. And it has an ultimate tensile strength of 1445 MPa. I love 17-4 and it's not desperately expensive.

 

- the relative performance of a multi is irrelevant if, for whatever reason, COR/D is committed to a single hull.

- ETNZ feel they have tools that predict performance close enough to trust

- they seem confident they can engineer what they have imagined - and control it

- it is possible to 'correct' any glaring miscalculations before the Match

- etnz is already conversant with solid steel foils

- design and construction proficiency is an integral part of the AC challenge

 

 

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2 hours ago, nav said:

- it is possible to 'correct' any glaring miscalculations before the Match

 

Yes, it is. Take the lead out of the foils and add flotation. Squint hard and call it a monohull. One shouldn't trust fundamental design decisions to billionaires.

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Oh ye of little faith...:lol:

ETNZ (and the rich Italian) have earned the right (and have the track record) to give this a go - as least as much, if not more, than the last 2 rich dudes who put their stamps all over things...

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I think there are two risks here. The first is there is a risk that only one team solves the technical challenges so there isn't much of a contest. One reason the last two ACs were interesting was the most innovative team wasn't the best funded, so forced the others to catch up but they had the resources to do so, especially in 2013.  From what one can glean reading this forum, It doesn't look right now that there are any very well funded challengers for the next Cup. The second risk is that multihull foiling continues to rapidly develop so that the JC75 is obsolete in terms of speed and cost before it even gets there. That won't be bad for the competition itself but it might well reduce international sponsor and team interest.  You are right Nav that they have earned the right to try, and I sincerely hope they succeed, but compared to sticking with the AC 50 or doing foiling tri of some sort, it is a risky strategy for America's Cup indeed.

 

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If the computer is showing the lizard can get up and run, then it can. Same as the all time statement, 'I can draw it, so engineers can build it'. Force = mass X acceleration. 

How much force will need to be applied to the centre of pressure point on an 'open design hull', (and that's the important bit to remember) to get the lizard running? 

What will the hull look like? What shape will offer the least wetted area and the most lift to encourage lift-out to foiling?

Me Thinks this is gonna be nothing like the cartoon of concept. 

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8 minutes ago, nav said:

^ well he seems a bit keener about the whole thing than some here....

laughing all the way to the bank

 

Some of that segment was in a previous month’s WSS but yes, the extras included this time do add to that ‘keener’ sense. His point about the light weight combined with all that RM may be obvious to most but it definitely is worth repeating. The Boat is a Beast.

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The cartoon shows a double surface main sail fitted to a mast that has shrouds and spreaders.

i wonder if they plan to lay the boat on its side to install the mainsail. i think there are some patents involving double surfaced sails out there too.  They are a design problem in themselves, one problem being that they can weigh twice as much as a regular sail.

i wonder if they have some breakthrough design for a giant double surfaced sail, or if they still need to figure out how the mainsail will look.  

 a 90' boat with a soft sail doing 50 knts. may a little bit wishful.

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