pacice

Foiling Monohull - what would it look like?

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2 minutes ago, rgeek said:

Ah that explains it then. They are going to have 6-8 galley slaves cycloring away inside the hull

But the whips used on the galley slaves will be traditional to the (whatever) nation! :)

GD said yesterday he expects his nationality rules to lower the cost of sailor salaries; there has to be an analogy there.

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9 minutes ago, ~Stingray~ said:

His nose? :)

It's an interesting suggestion that despite the move 'back' to monohulls, these boats may - like the foiling monohulls - have very little resemblance to what old 'traditionalists' are pining for..

Or... to what most monohull sailors use

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4 hours ago, Doug Lord said:

Anyone who thinks a monofoiler can't be as fast as a multifoiler need just look at the Moth vs most other small boats under 20'. "Jaw-dropping" sounds good.....

As usual, you are well out of date. The top A Class sailors are now far quicker than the moths. The best A's are "cruising" upwind at around 20 knots with extended bursts over 22 knots  all at a higher angle than the top moths who are achieving 18 knots while downwind, they are a a bit slower (26-7 knots) but lower. Although we will find out for sure later in the year. the belief is that the top A's are now quicker around the course than the top moths and when the A's start to foil gybe and maybe even tack, they will be significantly quicker.

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1 hour ago, Doug Lord said:

 


 

 

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

NZAC revised   9-7-17 003.JPG

NZAC ONE     9-25-17  dl 002.JPG

this would seem to make a whole lot of sense, the profile view especially has got to be well inside the ballpark. my initial take was going wide for hull form stability but that would be draggy and wrong for inshore use, wouldn't be surprised if buoyancy pods were excluded due to weight. I'm looking forward to these boats, they're going to be insane.

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So, how different is the 75 going to be from this decades old type design - but with the odd foil sticking out and maybe wing mast/partial soft sail rig?

gardaracer.jpg

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If the new boat is as advanced as Burling seems to think it is -it will fly--probably upwind and downwind-if the Italians go along with it.

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1 hour ago, A Class Sailor said:

As usual, you are well out of date. The top A Class sailors are now far quicker than the moths. The best A's are "cruising" upwind at around 20 knots with extended bursts over 22 knots  all at a higher angle than the top moths who are achieving 18 knots while downwind, they are a a bit slower (26-7 knots) but lower. Although we will find out for sure later in the year. the belief is that the top A's are now quicker around the course than the top moths and when the A's start to foil gybe and maybe even tack, they will be significantly quicker.

Thats just BS-no A cat that can't tack on foils will beat a Moth that can in foiling conditions. You bury yourself in bullshit when you say "Moths are achieving 18 knots while downwind".

They did that in 2005, 6 ,7 etc. They're top speeds downwind are much faster now.......

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49 minutes ago, Groucho Marx said:

So, how different is the 75 going to be from this decades old type design - but with the odd foil sticking out and maybe wing mast/partial soft sail rig?

gardaracer.jpg

If something like that becomes an AC sailboat I will feel like I've been hit in my nuts with a hammer

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5 hours ago, Doug Lord said:

Anyone who thinks a monofoiler can't be as fast as a multifoiler need just look at the Moth vs most other small boats under 20'. "Jaw-dropping" sounds good.....

Anyone who thinks a 75' monofoiler is possible need just look at the smallest crewed International class, the first & only properly successful monofoiler, with really stupid ballast ratio, all in fully mobile crew.

Because that'll definitely scale-up to 75' without any problems at all & nobody ever tried to make a bigger Moth ever before :rolleyes: Guaranteed success!

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9 minutes ago, 3to1 said:

I thought I read 1-2 years ago a Moth touched 30 knots?

The Moth speed record is 35.9 knots according to "Moth on Foils! " on boatdesign-the largest Moth thread anywhere.....

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10 minutes ago, hoom said:

Anyone who thinks a 75' monofoiler is possible need just look at the smallest crewed International class, the first & only properly successful monofoiler, with really stupid ballast ratio, all in fully mobile crew.

Because that'll definitely scale-up to 75' without any problems at all & nobody ever tried to make a bigger Moth ever before :rolleyes: Guaranteed success!

It's science that shows what can be done: problems get solved and speed goes up and up and doubters fall flaying by the wayside. TNZ did it in 2012 and 13 and they may do it again.

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Oh well, the Lord of Fools has yet again taken over an interesting thread and polluted it with his endlessly repetitive and bonkers defecation ... over a dozen times LoF has already posted the same or similar crude, lunatic renderings in this thread. Why don't you stone cold crazy, daughter of fire arrow and wolf, (can you believe this shit?) just stay in your basement and make your asinine toys and leave us out of your horse manure circuit of insanity?

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7 hours ago, Doug Lord said:

Thats just BS-no A cat that can't tack on foils will beat a Moth that can in foiling conditions. You bury yourself in bullshit when you say "Moths are achieving 18 knots while downwind".

They did that in 2005, 6 ,7 etc. They're top speeds downwind are much faster now.......

Try reading and stop quoting out of context, fuckwit. I did not say that moths are achieving 18 knots downwind. if you cannot understand basic English fuck off.

To be clear. the top Moths are doing 18 knots upwind. The top A's are doing steady 20 with sustained bursts of over 22 knots. That is fact. When looking at VMG including tacks. the A will still get to the top mark ahead. The only problem which i readily admit is that the number of A class sailors who can do that at the moment are very few. Give it another year and there will be more.

As for downwind, top recorded speed is meaningless. they are always achieved in perfect conditions without any reference to VMG. What you need to do is check the data from the Moth worlds because what counts is the speed in a race. There was enough of it around. Most of the top Moths were achieving about 27-28 knots. There were 1 or 2 instances of more during the whole regatta. the good A's are doing 26-27 knots sustained but they are going lower than the moths. Downwind, the ability to foil gybe means the Moths more than make up what they lose on the depth.

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9 hours ago, Groucho Marx said:

Oh well, the Lord of Fools has yet again taken over an interesting thread and polluted it with his endlessly repetitive and bonkers defecation ... over a dozen times LoF has already posted the same or similar crude, lunatic renderings in this thread. Why don't you stone cold crazy, daughter of fire arrow and wolf, (can you believe this shit?) just stay in your basement and make your asinine toys and leave us out of your horse manure circuit of insanity?

He talks like Mr T.

"Doug Lord says it's so"

"Doug Lord is the baddest"

"Doug Lord pity the fool!"

 

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4 hours ago, A Class Sailor said:

Try reading and stop quoting out of context, fuckwit. I did not say that moths are achieving 18 knots downwind. if you cannot understand basic English fuck off.

To be clear. the top Moths are doing 18 knots upwind. The top A's are doing steady 20 with sustained bursts of over 22 knots. That is fact. When looking at VMG including tacks. the A will still get to the top mark ahead. The only problem which i readily admit is that the number of A class sailors who can do that at the moment are very few. Give it another year and there will be more.

As for downwind, top recorded speed is meaningless. they are always achieved in perfect conditions without any reference to VMG. What you need to do is check the data from the Moth worlds because what counts is the speed in a race. There was enough of it around. Most of the top Moths were achieving about 27-28 knots. There were 1 or 2 instances of more during the whole regatta. the good A's are doing 26-27 knots sustained but they are going lower than the moths. Downwind, the ability to foil gybe means the Moths more than make up what they lose on the depth.

 

13 hours ago, A Class Sailor said:

As usual, you are well out of date. The top A Class sailors are now far quicker than the moths. The best A's are "cruising" upwind at around 20 knots with extended bursts over 22 knots  all at a higher angle than the top moths who are achieving 18 knots while downwind, they are a a bit slower (26-7 knots) but lower. Although we will find out for sure later in the year. the belief is that the top A's are now quicker around the course than the top moths and when the A's start to foil gybe and maybe even tack, they will be significantly quicker.

Riiight........

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Doug

Maybe there is something about american English, but read it again because  to me, ACS is pretty clear and you are misreading it. That does not say Moths are doing 18 knots downwind. I will give you a hand and show you how it should be read, because your way of reading it doesn't make any sense.

13 hours ago, A Class Sailor said:

As usual, you are well out of date. The top A Class sailors are now far quicker than the moths. The best A's are "cruising" upwind at around 20 knots with extended bursts over 22 knots  all at a higher angle than the top moths who are achieving 18 knots while downwind, they are a a bit slower (26-7 knots) but lower. Although we will find out for sure later in the year. the belief is that the top A's are now quicker around the course than the top moths and when the A's start to foil gybe and maybe even tack, they will be significantly quicker.

 As I say, it seems pretty obvious to me so either there is a common language usage issue between versions of English or you are having your usual your struggle with anything that disrupts your view of the world. 

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7 hours ago, Team_GBR said:

Doug

Maybe there is something about american English, but read it again because  to me, ACS is pretty clear and you are misreading it. That does not say Moths are doing 18 knots downwind. I will give you a hand and show you how it should be read, because your way of reading it doesn't make any sense.

 As I say, it seems pretty obvious to me so either there is a common language usage issue between versions of English or you are having your usual your struggle with anything that disrupts your view of the world. 

Based on past events I believe door #2 holds the answer to your question. 

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I skipped through a few Veitch segments yesterday and now remember forgetting to post that after hearing Ashby in one of them, I am fully convinced the boats will have foils, as he actually said, 'of some kind..'

Which leads to a pretty fast boat on one or more points of sail, obviously.

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PMSL! Woke up to this. Thanks, TGBR, but don't waste your time arguing with the "special" one on something like this. He will only ever read things how he wants to in order that his little world stays spinning the way he thinks it should. If he hadn't misread what I wrote, he would have challenged me another way. He knows that I know Moths don't  only go 18 knots downwind but rather than speak about the main issue f how fast A's are relative to Moths, something he has no data on but doesn't want to believe, he attempts to correct this disruption to his world by trying to discredit, because he cannot join in with any meaningful facts.

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1 hour ago, ~Stingray~ said:

I skipped through a few Veitch segments yesterday and now remember forgetting to post that after hearing Ashby in one of them, I am fully convinced the boats will have foils, as he actually said, 'of some kind..'

Which leads to a pretty fast boat on one or more points of sail, obviously.

"Of some kind" could mean dagger boards too

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4 minutes ago, jonas a said:

"Of some kind" could mean dagger boards too

Yes, could mean anything. Daggers would be my hope too for close-in racing safety reasons.

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2 minutes ago, Tornado-Cat said:

I want long, thin, wide, exterior foils in Hauraki stadium gulf with Romans and barbarians.

 

:D:D:D

Great movie clip, thank you!

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3 hours ago, A Class Sailor said:

PMSL! Woke up to this. Thanks, TGBR, but don't waste your time arguing with the "special" one on something like this. He will only ever read things how he wants to in order that his little world stays spinning the way he thinks it should. If he hadn't misread what I wrote, he would have challenged me another way. He knows that I know Moths don't  only go 18 knots downwind but rather than speak about the main issue f how fast A's are relative to Moths, something he has no data on but doesn't want to believe, he attempts to correct this disruption to his world by trying to discredit, because he cannot join in with any meaningful facts.

Just one question. What would anyone compare relative speeds of a Moth and a A Class Cat anyway?

Might as well compare TP52's and MOD70's - it would make about as much sense.

 

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Sure be nice to see a very close winded displacement mode to weather and tacking duels

A screaming reaching machine with DSS foils and a course to make em work, and a way cool jibe mark

Displacement mode downwind to cause jibing duels

 

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Dream on, Kenny, about displacement mode up and downwind; from ear to ground rumours (which may or may not be BS) the new boat is going to be beyond extreme and an arse-kick to traditionalists hoping for old world looks and performance. So that means when beating (let alone reaching) the new creatures will be close to foiling flying. If this happens to be true that means lead ballast is going to be minimal?

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4 hours ago, Sailbydate said:

Just one question. What would anyone compare relative speeds of a Moth and a A Class Cat anyway?

Bragging right! :D  and to wind Doug up because it disturbs his world when the apparent order he believes in is changed. The reality is that a few sail both but in reality, they are different enough that they aren't in competition. We have the Australian national titles of both classes at the same location this year, one after the other and I am sure it will be a great opportunity to exchange views and ideas.

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15 hours ago, ~Stingray~ said:

Yes, could mean anything. Daggers would be my hope too for close-in racing safety reasons.

Did you not get that that was all 'tongue in cheek',

foils of some kind, they don't sail too well without them - all with a cheeky grin?

So mono with a rudder, maybe a keel, maybe wait and see!

 

Personally: 1 T rudder, 1 U keel, flaps all over place :D

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19 hours ago, ~Stingray~ said:

Can someone interpret this Italian for us?

http://www.lastampa.it/2017/09/30/societa/mare/sport/la-suggestione-di-unalleanza-tra-americas-cup-e-volvo-ocean-race-4w75xAbMbC1Ux4p2g30ySO/pagina.html

It seems to be suggesting a confluence of AC75 and AC36-following VOR75 boats.

Did you try google translate? It has gotten better in the past year or so, with machine learning. I tried. It didn't seem to say much. Perhaps something was lost in the translation, but I guess it just didn't say much.

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2 hours ago, nav said:

Did you not get that that was all 'tongue in cheek',

foils of some kind, they don't sail too well without them - all with a cheeky grin?

So mono with a rudder, maybe a keel, maybe wait and see!

 

Personally: 1 T rudder, 1 U keel, flaps all over place :D

Yeah, when someone who is just echoing the new keywords asks someone who understands the physics asks about foils, it is a little funny. Sails are foils. Rudders are foils. Keels are foils. Etc... But in today's parlance, when you say "foils", people are generally talking about those that make the hull(s) fly. So we should really ask if the new monohulls will fly and in what conditions and at what true wind angles.

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25 minutes ago, nroose said:

Yeah, when someone who is just echoing the new keywords asks someone who understands the physics asks about foils, it is a little funny. Sails are foils. Rudders are foils. Keels are foils. Etc... But in today's parlance, when you say "foils", people are generally talking about those that make the hull(s) fly. So we should really ask if the new monohulls will fly and in what conditions and at what true wind angles.

Yes, clearly he was playing with words. I think that eg in kite surfing the word "foil kite" is used for  non-inflatable kites

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19 hours ago, Tornado-Cat said:

I want long, thin, wide, exterior foils in Hauraki stadium gulf with Romans and barbarians.

 

Time for a bit of thread drift: Makes AC small time.

 

The Fifteen Billion Dollar Athlete

An ancient Roman chariot racer stands alone as the richest athlete to ever live and the story behind his incredible wealth has not been lost to time.

 

https://sports.vice.com/en_us/article/nzpgaq/the-fifteen-billion-dollar-athlete

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18 hours ago, Sailbydate said:

Just one question. What would anyone compare relative speeds of a Moth and a A Class Cat anyway?

Might as well compare TP52's and MOD70's - it would make about as much sense.

 

comparing two small flying boats makes much more sense than comparing a conventional mono and a conventional tri.

the two small foilers are both extreme and extremely fast. just sayin'

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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

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5 minutes ago, nav said:

Metrics flylord...heard of it?

Surely such a brilliant person as you can do the conversions?! Don't have the time or interest to do it for you......

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19 hours ago, Sailbydate said:

Just one question. What would anyone compare relative speeds of a Moth and a A Class Cat anyway?

Because it is the nearest we can get to comparing the potential performance of the AC50's and the proposed monohull AC75. It's not really a very good comparison for that, but it is fun particularly when it throws Doug's world into chaos! 

The reality is that there is no way that the AC75 will be anywhere near the speed of the AC50's. So what! They aren't trying to come up with a mono rule that will produce boats that fast and I am pretty certain that speed compared with the AC50's is the last thing on their minds. My hope is that they come up with a rule that produces close match racing and the boats need to be a handful to sail so that it puts a premium of teamwork and IMO, fixating on foiling won't do that.

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Just now, Doug Lord said:

Surely such a brilliant person as you can do the conversions?!

Heard of it, but your use of imperial measurements tells us everything we need to know about you and your relevance. Do you think any AC team or any serious designer of high performance yachts works in imperial measurements? They haven't for years. Your use of imperial measurements just shows how out of step you are.

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14 minutes ago, Doug Lord said:

Surely such a brilliant person as you can do the conversions?! Don't have the time or interest to do it for you......

 

although no one knows what it looks like yet – other than it will be 22m long,

 

 but you stick to your guns - keep your 100% record

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18 hours ago, Kenny Dumas said:

Sure be nice to see a very close winded displacement mode to weather and tacking duels

A screaming reaching machine with DSS foils and a course to make em work, and a way cool jibe mark

Displacement mode downwind to cause jibing duels

 

God no!

The desire for displacement mode downwind is exactly what made the old 90 footers such overweight pigs!

They had better be at the very least planing flat out downwind.

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2 hours ago, Barnyb said:

Time for a bit of thread drift: Makes AC small time.

 

The Fifteen Billion Dollar Athlete

An ancient Roman chariot racer stands alone as the richest athlete to ever live and the story behind his incredible wealth has not been lost to time.

 

https://sports.vice.com/en_us/article/nzpgaq/the-fifteen-billion-dollar-athlete

Thanks Barnyb, amazing story, he would have made 15 billions now, I wish sailors could make a fraction of it and finish their carrer saying:

"I am Scorpus, the glory of the roaring Circus, the object of Rome's cheers and her short lived darling. The Fates, counting not my years but the number of my victories, judged me to be an old man."

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:D Fun subject.

RG brought up the possibility of 'Ben Hur' chariot style racing during his webcast with TE but someone else conjured up the exact same term before or after that. Maybe one followed the other or maybe it was independent but regardless, if it comes down to danger like that then: Let's hope the winning helm gets very effing rich! :)

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1 hour ago, Team_GBR said:

Because it is the nearest we can get to comparing the potential performance of the AC50's and the proposed monohull AC75. It's not really a very good comparison for that, but it is fun particularly when it throws Doug's world into chaos! 

The reality is that there is no way that the AC75 will be anywhere near the speed of the AC50's. So what! They aren't trying to come up with a mono rule that will produce boats that fast and I am pretty certain that speed compared with the AC50's is the last thing on their minds. My hope is that they come up with a rule that produces close match racing and the boats need to be a handful to sail so that it puts a premium of teamwork and IMO, fixating on foiling won't do that.

+1 Agree. Especially the bit about DL ;)

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So how different will the new AC class be compared to eg a minimaxi 72? For good match racing, canting keels, water ballast and extra appendages are just a distraction   

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What about something like CQS? Second over the line in the Fastnet race isn't too shabby. Maybe it needs a 25% trim length–wise, but the deck–spreaders (or whatever they're called) reduce the chance of slicing open the windward boat's belly.

Or maybe it's irrelevant…

?format=750w

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It's foil assist-not full flying, I don't think Burling would endorse that configuration. And it certainly isn't "jaw dropping" as the new boat was described by someone who has seen the specs,,,,,

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3 hours ago, Doug Lord said:

It's foil assist-not full flying, I don't think Burling would endorse that configuration. And it certainly isn't "jaw dropping" as the new boat was described by someone who has seen the specs,,,,,

Dougie forget about a full foiling monohull around the cans,  high seas, and high windspeed limits, it's not going to happen (text comprehension in advance: not saying it's not possible)

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This might be relevant to what Burling may endorse. After all, his NZ olympic success is in the 49er. 

I made some poor assumptions myself concerning the apparent wind machine that RNZYS would create for Burling and Tuke. And yes, of course they will have an apparent wind machine, but - apparently - the 49er is no moth.

49er polars.png

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Images of multiple foil/swing keel impressions have been posted on various medias but the proposed boat can be savagely simplified; toss a number of those draggy appendages and have water ballast for stationary stability - which is then dumped once sailing, conventional dagger with T and no lead for anti-leeway, windward/leeward angled out Ts or Js for stability and flight and single T rudder ... and no monstrous rig, 10-20-30% wing? - this boat will be light, won't need a football field of sail? And something quite different for the traditionalists to comprehend?

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here's another flail; an extreme foil ASSIST design for light/medium conditions, racks, no lead, no hull form stability and pushing the boundaries of weight reduction. a pure apparent wind machine.

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8 hours ago, ~Stingray~ said:

Crazy as he is, DL's doodles could actually be close to it.

Yeah, right, maybe if he didn't nauseously repeat his crappy art we might take more notice.

Dougsboat copy.jpg

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1 hour ago, Groucho Marx said:

Yeah, right, maybe if he didn't nauseously repeat his crappy art we might take more notice.

Dougsboat copy.jpg

I took notice, they made sense.

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7 hours ago, sclarke said:

Some really interesting bits in there. Most of Bernasconi quotes suggests the boat won't be as radical as the behind the scene quotes from the Protocol. 

"Some degree of commonsense has to come into it,"

"what people can sail at a lower level than the America's Cup. That's a primary reason for going away from cats"

"We don't want to go too crazy."

"It's not just making the highest performance boat we can, it's making a boat that is good for match-racing."

The other thing that struck a chord was this: "I talked to the public about what sort of boat they wanted, there was a real split between people saying they would love it to go back to a real traditional boat and people who absolutely love the foiling boat," 

People like either the ultimate performance of foiling cats or match racing qualities displacement monos. No one is calling out for a miss mash of the two.  I fear is ETNZ try to satisfy both parties they will end up with a dog of a boat which compromises the benefits of each without realising their benefits. 

"It is going to be a high-performance monohull so we are trying to get the best of both worlds there." For me, that's the most concerning quote. I rather something just be the best in one world. 

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I for one would't wring my hands if the thing went back to (mostly) displacement mode, it has produced some nail biting finishes, like AC32 for example, by all the sailing GODS a 180 degree shift!

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Okay so the brilliant AC50 cats were too advanced for their own good?

And so we're aiming for a watered down performance monohull ... but maybe half a step up from what we consider is monohull norm.

So half the viewers can understand what they're looking at.. And the other half, or third or whatever, will be pissed off.

But wait, we read that the hot AC50 crews, knowing what is coming, or think they know what is occurring, have been quoted as being very impressed.

Okay, early days, but there are some pretty wishy-washy things being uttered at this time.

And sounds like whatever appears is not going to impress anyone.

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On 9/30/2017 at 2:37 AM, Doug Lord said:

Thats just BS-no A cat that can't tack on foils will beat a Moth that can in foiling conditions. You bury yourself in bullshit when you say "Moths are achieving 18 knots while downwind".

They did that in 2005, 6 ,7 etc. They're top speeds downwind are much faster now.......

True - but the real technology is with the kite foil design.

 

They have all the lift minus the drag, manual height control, 40 kts downwind, 21-22kts upwind at higher angles than most monos

 

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8 hours ago, mozzy656 said:

I fear is ETNZ try to satisfy both parties they will end up with a dog of a boat which compromises the benefits of each without realising their benefits. 

+1000

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9 minutes ago, jorge said:

+1000

I don't think we should worry too much. They do have people who know what works. Obviously not everyone will be happy.

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On 9/30/2017 at 5:46 PM, Sailbydate said:

Just one question. What would anyone compare relative speeds of a Moth and a A Class Cat anyway?

Might as well compare TP52's and MOD70's - it would make about as much sense.

 

they are both single handed foilers. Kind of fun from that point of view, and it looks like - from reports above - the A class is closing in on the moth.

A class is fun to follow as the foiling cat was borne of AC34 - although the A class subject to its own set of rules and restrictions hence they developed their own style of lifting foils.

And now with AC36, perhaps something yet again new will be born.

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5 hours ago, floater said:

they are both single handed foilers. Kind of fun from that point of view, and it looks like - from reports above - the A class is closing in on the moth.

 

I think it's inevitable that the A Class will be faster around a course than Moths, they have 60% more sail area on a taller rig to start with. A Class are significantly faster than Moths in displacement mode, it was only foiling that put Moths ahead of other performance boats.

The A Class don't need to foil tack if they have 4kn more boat speed and can just bang the corners.

Moths probably represent the pinnacle of mono T foilers, but the advantages of mulits in being able to carry more sail works for foilers just as well as floaters. If you restricted a foiling kite to 8.25m, how fast would they be in 8kn of breeze?

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15 hours ago, dachopper said:

20 kts upwind, 25 degrees off the breeze..... beat that!

Thats polars for an A or a Moth? :wacko:

 

Dougsboat copy.jpg

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56 minutes ago, hoom said:

Thats polars for an A or a Moth? :wacko:

 

Dougsboat copy.jpg

I think it was for a kite foil with a foil kite

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The first fundamental disadvantage of a moth or a cat, or any boat over a kite is that not only do they have to lift and overcome the aero drag of a human, but they have to lift and overcome the aero drag of a hull which has enough buoyancy to support said human. 

The foiling kites are beautifully paired back and as a result fast and efficient. 

But, they do have a design weakness! The force from the sail (kite) has to go through the human to get to the foils.  Humans can only be so strong.

As long as the moth and the A cat have their box rules they will never go faster than a foiling kite. The leverage of the moth is probably limited by the practical length of foil and width / height of racks.  The A cat is leverage limited by width. If you removed those limitations, you would have to use material which could take the forces are design sails which don't stall at the incredible apparent wind angles and speeds.

But crucially, neither A Class or Moth are limited by the strength of a human, which is their advantage over a kite.

The A Class and Moth are interesting to talk about, but I don't see them being totally related to the problems the a foiling mono would face. I think the time AC sailors spend in them  more for understanding race dynamics and strategy than engineering. The issue for mono's I believe would be moving lifting surfaces and ballast around over such a large platform. 

The only way I see a foiling mono working, would be if they had a small canting keel, enough to keep the boat upright at rest, and enough to promote foiling when canted. Then the real leverage would be added by sailing with windward heal. That would be really radical, and dangerous. But it would eliminate the issue of moving foils around and it would start to put them back on terms with cats where the weight of the boat is all to windward of the fulcrum, so creating leverage. . 

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What about a shuttle ballast/shuttle keel?

Lead weight with an embedded electric motor running on an internal track. It would keep the bulb out of the air/water flow. It could run on a track with a rack and pinion system, travel out into deck spreaders at its furthest extension and down into the bottom of the hull for stability when the boat isn't powered up. The track would be essentially V shaped. 

It could bring some of the benefits (perhaps not all) of a canting keel without much of the drag...

It would require fairly sizable bulbous wings(or could be incorporated into hull shape perhaps) but would allow the shifting of lead ballast without dragging it through the water, allowing the possibility of maneuvering whilst foiling???

Thoughts?

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On 04/10/2017 at 3:11 AM, dachopper said:

Kablaaaam.

 

20 kts upwind, 25 degrees off the breeze..... beat that!

Kitefoil Polar.jpg

So how do those kitefoiler speeds compare to an AC50's speeds?

If the foilers are hitting 40 knots then even with the foiling cats we were back to the same situation we had with surfcats and 12 Metres in the 1960s and '70s, when a cheap "beach craft" was faster than an AC boat. Obviously the speeds are utterly different, but back in the day many people felt that it was ludicrous that the AC boat was slower and they ignored that the two boats were completely different beasts. From some angles it seems as if we are back in the same situation but now it's the cat that is the bigger and slower craft.

 

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1 hour ago, Costro said:

What about a shuttle ballast/shuttle keel?

Lead weight with an embedded electric motor running on an internal track. It would keep the bulb out of the air/water flow. It could run on a track with a rack and pinion system, travel out into deck spreaders at its furthest extension and down into the bottom of the hull for stability when the boat isn't powered up. The track would be essentially V shaped. 

It could bring some of the benefits (perhaps not all) of a canting keel without much of the drag...

It would require fairly sizable bulbous wings(or could be incorporated into hull shape perhaps) but would allow the shifting of lead ballast without dragging it through the water, allowing the possibility of maneuvering whilst foiling???

Thoughts?

If they want boats which are relevant to the sailing community they will go for water ballast or a conventional fin keel.

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How light could you make a 75' mono with any combination of foils?

Could you hold it up without lead with foils only?

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11 hours ago, Costro said:

What about a shuttle ballast/shuttle keel?

Lead weight with an embedded electric motor running on an internal track. It would keep the bulb out of the air/water flow. It could run on a track with a rack and pinion system, travel out into deck spreaders at its furthest extension and down into the bottom of the hull for stability when the boat isn't powered up. The track would be essentially V shaped. 

It could bring some of the benefits (perhaps not all) of a canting keel without much of the drag...

It would require fairly sizable bulbous wings(or could be incorporated into hull shape perhaps) but would allow the shifting of lead ballast without dragging it through the water, allowing the possibility of maneuvering whilst foiling???

Thoughts?

It could work. The white boat is a concept model for a 16' singlehander. The whole wing moves side to side with ballast running very quickly inside. The wing is sealed and each half has the buoyancy to support the lead in the inside sliding cart. A small amount of ballast is used on the daggerboard and the thing is self-righting.

The 20 year old scow model uses a Trapeze Power Ballast System in combination with a small fixed keel and is also self-righting.

On-deck movable ballast can work if it is designed well-and can produce a self-righting boat with loads of RM-significantly more than a fixed keel or canting keel and much faster than a canting keel in maneuvers.

Crossbow fl-primer 006.JPG

Super  Scow with PBS 3 - Copy.JPG

Scow PBS 001.JPG

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9 hours ago, Sailabout said:

And batterys 

And solar panels

And dinghies, and lazy jacks

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9 hours ago, Sailabout said:

How light could you make a 75' mono with any combination of foils?

Could you hold it up without lead with foils only?

That's what I've been looking at, and what I think ETNZ's preference is. 

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29 minutes ago, MR.CLEAN said:

That's what I've been looking at, and what I think ETNZ's preference is. 

Libera class style, 17 guys on a rack/trapeze?

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12 hours ago, The Jay said:

So how do those kitefoiler speeds compare to an AC50's speeds?

If the foilers are hitting 40 knots then even with the foiling cats we were back to the same situation we had with surfcats and 12 Metres in the 1960s and '70s, when a cheap "beach craft" was faster than an AC boat. Obviously the speeds are utterly different, but back in the day many people felt that it was ludicrous that the AC boat was slower and they ignored that the two boats were completely different beasts. From some angles it seems as if we are back in the same situation but now it's the cat that is the bigger and slower craft.

 

Pure Speculation, but I think the kitefoils in the light would probably beat an AC50, say a Banga light wind foil under 15 kts, and a moses foil 20-30 kts.

 

In the medium / heavy, i think they would be close .

 

Seaway would become an issue for both , the kiter more than the cat  i would be almost positive towards 30kts.

 

they have developed quite a bit over the last couple years, and are going more and more towards higher aspect, ultra high modulus thinner solid Carbon sections. 

 

I think some of the race foils may only have 9 to 10mm mast in the water, on foils a similar thickness up front, and maybe 5 - 6 mm at the rear.

 

 

Just as was revealed by the AC50 crews, the rear kite foil stabilizer is tuned to match the hydro-dynamic drag, so that the more there is, the more downforce it provides, this stops the balance point of the kitesurfer from shifting due to the foil speed through the water, instead it only shifts due to sail shape reference apparent wind and groundspeed. 

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2 hours ago, Sailabout said:

Libera class style, 17 guys on a rack/trapeze?

At least the cyclors were doing excercise

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1 hour ago, jorge said:

At least the cyclors were doing excercise

Remember that the class is being developed in conjunction with the Italians.

Its hard to draw on your ciggy while blowing hard on a bike.

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Thanks Chopper.

7 hours ago, dachopper said:

Pure Speculation, but I think the kitefoils in the light would probably beat an AC50, say a Banga light wind foil under 15 kts, and a moses foil 20-30 kts.

 

In the medium / heavy, i think they would be close .

 

Seaway would become an issue for both , the kiter more than the cat  i would be almost positive towards 30kts.

 

they have developed quite a bit over the last couple years, and are going more and more towards higher aspect, ultra high modulus thinner solid Carbon sections. 

 

I think some of the race foils may only have 9 to 10mm mast in the water, on foils a similar thickness up front, and maybe 5 - 6 mm at the rear.

 

 

Just as was revealed by the AC50 crews, the rear kite foil stabilizer is tuned to match the hydro-dynamic drag, so that the more there is, the more downforce it provides, this stops the balance point of the kitesurfer from shifting due to the foil speed through the water, instead it only shifts due to sail shape reference apparent wind and groundspeed. 

Interesting. Thanks for the info..

 

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