AC 72 Design

[TimW 1]

I have looked at some of the Oracle photos on their FB page today, there seems to be a lot of twist in their platform.

 

When flying a hull the windward hull appears very nose down.

 

Design fault or intentional?

 

Come on guys they wanted it to twist that way so that if they fit foils on the rudder the leeward one will lift the lee ama and the windward one will increase their righting moment making their boat more powerful.

It is not so obvious that every platform has to be super stiff at all. There is more than 1 way to skin a cat.

[Guest]

Yes their platform has allot of twist. This is not a good thing.

 

ETNZs platform is super stiff

 

 

 

 

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

[Guest]

Yes their platform has allot of twist. This is not a good thing.

 

ETNZs platform is super stiff

 

 

 

 

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

 

Well thats probably the best explanation I have heard so far

 

Very interesting indeed the differences between the boats. I sill like ETNZs one better.

[Battleship 100]

IRC the rule states that the windward dagger board must be raised except for about 30 seconds whilst tacking and gybing so that sort of rules out any down force from it.

[Guest]

IRC the rule states that the windward dagger board must be raised except for about 30 seconds whilst tacking and gybing so that sort of rules out any down force from it.

 

I think he was talking about the foils on the rudder

[Guest]

Yes their platform has allot of twist. This is not a good thing.

 

ETNZs platform is super stiff

 

 

 

 

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

 

Well thats probably the best explanation I have heard so far

 

Very interesting indeed the differences between the boats. I sill like ETNZs one better.

 

 

and to think someone was calling this guy oceancruiser a troll

 

Stiffness is great if your wanting maximum power and lift in your rig and foils (or you're Dirk Diggler) but can be a liability and cause stress and loading issues and failure if not designed and constructed properly due to a lack of understanding of new ideas etc...

 

Oracle wil; have a handle on all this and it will be a fast boat they start the AC with.

[Guest]

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

 

Well thats probably the best explanation I have heard so far

 

Very interesting indeed the differences between the boats. I sill like ETNZs one better.

 

 

 

 

Stiffness is great if your wanting maximum power and lift in your rig and foils (or you're Dirk Diggler) but can be a liability and cause stress and loading issues and failure if not designed and constructed properly due to a lack of understanding of new ideas etc...

 

Oracle wil; have a handle on all this and it will be a fast boat they start the AC with.

 

 

 

For a lot of racing multi's, stiff is better.

 

 

However, think about it. For a flying hull the difference in drag as air flows around it is just plain insignificant.

 

For the very special cases where you never intend to run with more than one hull in the water, the question comes down to how it will handle in turns and how it behaves in the transitions (hull skimming the surface, hull lifting out of the water or splashing back into the water). As long as it does OK in the turns and transitions, a platform prone to twist can be tolerated.

 

The boat that can slow the fastest, turn the fastest and regain lift the fastest and be into full speed the fastest will have a definite advantage, but will it be enough if there is a boat that can sail at almost the same speed as the world sailing record holder, do the turns, tacts, and keep the boat upright to fin.

 

Stiff would still be preferred by most, but if you are pushing light weight as a priority, they may be better off learning to deal with twist.

 

These boats have one VERY SPECIAL design feature that you will rarley find on other boats. They are built for a very specific venue and they are generally discarded after competing once. The disposable nature and sheltered waters competion of an AC boat lets them tolerate stuff that no one would put up with on a more "normal" boat.

 

If you accept this arguement where is the trickle down benefit for the cruising sailing vessels and normal cruising boat builders.

 

 

 

 

 

But will it be faster than???

 

 

Who was the Kiwi legend that

 

•Developed first ‘tin-sail’ panel geometry software •America’s Cup

 

•Developed first leech-cut genoas •America’s Cup

 

•Sail trimmer, sail designer, on Swuzzlebubble, 1st boat Admiral’s Cup

 

•Developed first tri-radial genoas

 

•Sail coordinator Australia II, Winner America’s Cup

 

•Southern Cross Cup

 

Change the course of America’s Cup history in 1983 when he designed the sails for Australia II, the wing-keeled wonder that snatched away the Auld Mug from the New York Yacht Club. The first yacht to take the America's Cup away from the USA, breaking the Defenders' 132-year-grip on the Cup and turning the America's Cup world upside down. Although it was the radical wing keel that was credited for being the magic bullet that made Australia II, Skipper John Bertrand preferred to give greater credit to the advanced composite sail designs developed by their sail designer.

 

 

•Was in several match-racing wins as tactician

 

Involved in the winning •12 metre Worlds •Kenwood Cup 1984.

 

1986: •Developed first modern 12m gennakers

 

1989: •Admiral’s Cup

 

1990: •Kenwood Cup

 

1992: •Olympic Games (Coach)

 

2000: •Winner America’s Cup •Olympic Games (Coach) •Design coordinator, navigator,‘Black Magic’, NZL-32, NZL-60

 

Designed the wind tunnel for team New Zealand that gave team New Zealand superior boat speed and higher pointing ability.

 

Inductee 2000 Americas cup hall of fame.

 

In 2000, the challenge was for Team New Zealand to become the first non-U.S. syndicate to successfully defend the Cup. Once again, as design team coordinator and navigator the man played the pivital role in doing so.

 

The man Grant Dalton definitely did not want.

 

Involved with the design on the new fastest sailing machine with the new world record tri !!!

 

Now in the design mix with a new radical design similiar to the new world speed record holder sailing vessel except it,s a AC 72.

 

This could be the winning boat in 2013! with a KIWI LEGEND connection.

 

 

[OYSTR 1]

http://artemis-racing.americascup.com/team/management/tom-schnackenberg

[Guest]

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

 

Well thats probably the best explanation I have heard so far

 

Very interesting indeed the differences between the boats. I sill like ETNZs one better.

 

 

 

 

Stiffness is great if your wanting maximum power and lift in your rig and foils (or you're Dirk Diggler) but can be a liability and cause stress and loading issues and failure if not designed and constructed properly due to a lack of understanding of new ideas etc...

 

Oracle wil; have a handle on all this and it will be a fast boat they start the AC with.

 

 

 

For a lot of racing multi's, stiff is better.

 

 

However, think about it. For a flying hull the difference in drag as air flows around it is just plain insignificant.

 

For the very special cases where you never intend to run with more than one hull in the water, the question comes down to how it will handle in turns and how it behaves in the transitions (hull skimming the surface, hull lifting out of the water or splashing back into the water). As long as it does OK in the turns and transitions, a platform prone to twist can be tolerated.

 

The boat that can slow the fastest, turn the fastest and regain lift the fastest and be into full speed the fastest will have a definite advantage, but will it be enough if there is a boat that can sail at almost the same speed as the world sailing record holder, do the turns, tacts, and keep the boat upright to fin.

 

Stiff would still be preferred by most, but if you are pushing light weight as a priority, they may be better off learning to deal with twist.

 

These boats have one VERY SPECIAL design feature that you will rarley find on other boats. They are built for a very specific venue and they are generally discarded after competing once. The disposable nature and sheltered waters competion of an AC boat lets them tolerate stuff that no one would put up with on a more "normal" boat.

 

If you accept this arguement where is the trickle down benefit for the cruising sailing vessels and normal cruising boat builders.

 

 

 

 

 

But will it be faster than???

 

 

Who was the Kiwi legend that

 

•Developed first ‘tin-sail’ panel geometry software •America’s Cup

 

•Developed first leech-cut genoas •America’s Cup

 

•Sail trimmer, sail designer, on Swuzzlebubble, 1st boat Admiral’s Cup

 

•Developed first tri-radial genoas

 

•Sail coordinator Australia II, Winner America’s Cup

 

•Southern Cross Cup

 

Change the course of America’s Cup history in 1983 when he designed the sails for Australia II, the wing-keeled wonder that snatched away the Auld Mug from the New York Yacht Club. The first yacht to take the America's Cup away from the USA, breaking the Defenders' 132-year-grip on the Cup and turning the America's Cup world upside down. Although it was the radical wing keel that was credited for being the magic bullet that made Australia II, Skipper John Bertrand preferred to give greater credit to the advanced composite sail designs developed by their sail designer.

 

 

•Was in several match-racing wins as tactician

 

Involved in the winning •12 metre Worlds •Kenwood Cup 1984.

 

1986: •Developed first modern 12m gennakers

 

1989: •Admiral’s Cup

 

1990: •Kenwood Cup

 

1992: •Olympic Games (Coach)

 

2000: •Winner America’s Cup •Olympic Games (Coach) •Design coordinator, navigator,‘Black Magic’, NZL-32, NZL-60

 

Designed the wind tunnel for team New Zealand that gave team New Zealand superior boat speed and higher pointing ability.

 

Inductee 2000 Americas cup hall of fame.

 

In 2000, the challenge was for Team New Zealand to become the first non-U.S. syndicate to successfully defend the Cup. Once again, as design team coordinator and navigator the man played the pivital role in doing so.

 

The man Grant Dalton definitely did not want.

 

Involved with the design on the new fastest sailing machine with the new world record tri !!!

 

Now in the design mix with a new radical design similiar to the new world speed record holder sailing vessel except it,s a AC 72.

 

This could be the winning boat in 2013! with a KIWI LEGEND connection.

 

 

 

 

In a Team with Dalton in it there is only room for one ego maniac, controll freak....

 

Grant Dalton....

 

...he leads by fear, arrogance, intimidation and one rule...

 

 

we work as a team and do things my way.

 

i like Blakes, Coutts approach.

[Guest]

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

 

Well thats probably the best explanation I have heard so far

 

Very interesting indeed the differences between the boats. I sill like ETNZs one better.

 

 

 

 

Stiffness is great if your wanting maximum power and lift in your rig and foils (or you're Dirk Diggler) but can be a liability and cause stress and loading issues and failure if not designed and constructed properly due to a lack of understanding of new ideas etc...

 

Oracle wil; have a handle on all this and it will be a fast boat they start the AC with.

 

 

 

For a lot of racing multi's, stiff is better.

 

 

However, think about it. For a flying hull the difference in drag as air flows around it is just plain insignificant.

 

For the very special cases where you never intend to run with more than one hull in the water, the question comes down to how it will handle in turns and how it behaves in the transitions (hull skimming the surface, hull lifting out of the water or splashing back into the water). As long as it does OK in the turns and transitions, a platform prone to twist can be tolerated.

 

The boat that can slow the fastest, turn the fastest and regain lift the fastest and be into full speed the fastest will have a definite advantage, but will it be enough if there is a boat that can sail at almost the same speed as the world sailing record holder, do the turns, tacts, and keep the boat upright to fin.

 

Stiff would still be preferred by most, but if you are pushing light weight as a priority, they may be better off learning to deal with twist.

 

These boats have one VERY SPECIAL design feature that you will rarley find on other boats. They are built for a very specific venue and they are generally discarded after competing once. The disposable nature and sheltered waters competion of an AC boat lets them tolerate stuff that no one would put up with on a more "normal" boat.

 

If you accept this arguement where is the trickle down benefit for the cruising sailing vessels and normal cruising boat builders.

 

 

 

 

 

But will it be faster than???

 

 

Who was the Kiwi legend that

 

•Developed first ‘tin-sail’ panel geometry software •America’s Cup

 

•Developed first leech-cut genoas •America’s Cup

 

•Sail trimmer, sail designer, on Swuzzlebubble, 1st boat Admiral’s Cup

 

•Developed first tri-radial genoas

 

•Sail coordinator Australia II, Winner America’s Cup

 

•Southern Cross Cup

 

Change the course of America’s Cup history in 1983 when he designed the sails for Australia II, the wing-keeled wonder that snatched away the Auld Mug from the New York Yacht Club. The first yacht to take the America's Cup away from the USA, breaking the Defenders' 132-year-grip on the Cup and turning the America's Cup world upside down. Although it was the radical wing keel that was credited for being the magic bullet that made Australia II, Skipper John Bertrand preferred to give greater credit to the advanced composite sail designs developed by their sail designer.

 

 

•Was in several match-racing wins as tactician

 

Involved in the winning •12 metre Worlds •Kenwood Cup 1984.

 

1986: •Developed first modern 12m gennakers

 

1989: •Admiral’s Cup

 

1990: •Kenwood Cup

 

1992: •Olympic Games (Coach)

 

2000: •Winner America’s Cup •Olympic Games (Coach) •Design coordinator, navigator,‘Black Magic’, NZL-32, NZL-60

 

Designed the wind tunnel for team New Zealand that gave team New Zealand superior boat speed and higher pointing ability.

 

Inductee 2000 Americas cup hall of fame.

 

In 2000, the challenge was for Team New Zealand to become the first non-U.S. syndicate to successfully defend the Cup. Once again, as design team coordinator and navigator the man played the pivital role in doing so.

 

The man Grant Dalton definitely did not want.

 

Involved with the design on the new fastest sailing machine with the new world record tri !!!

 

Now in the design mix with a new radical design similiar to the new world speed record holder sailing vessel except it,s a AC 72.

 

This could be the winning boat in 2013! with a KIWI LEGEND connection.

 

 

 

 

In a Team with Dalton in it there is only room for one ego maniac, controll freak....

 

Grant Dalton....

 

...he leads by fear, arrogance, intimidation and one rule...

 

 

we work as a team and do things my way.

 

i like Blakes, Coutts approach.

 

 

Disagree re Blakes approach. No offence intended.

[Guest]

[

 

 

 

 

In a Team with Dalton in it there is only room for one ego maniac, controll freak....

 

Grant Dalton....

 

...he leads by fear, arrogance, intimidation and one rule...

 

 

we work as a team and do things my way.

 

i like Blakes, Coutts approach.

 

 

Disagree re Blakes approach. No offence intended.

 

 

i,ll re phrase that.

 

Blakes in initial approach in 94. to me he is a bit like mark todd. More an englishman using NZ as a port of convenience.

 

When he left the team in the lurch (with Sefton and co), he really went down in mine and many TNZ members good books. Which is why Coutts and co left.

[Guest]

http://artemis-racing.americascup.com/team/management/tom-schnackenberg

 

So your telling me Artemis boat has a hula?

[OYSTR 1]

http://artemis-racing.americascup.com/team/management/tom-schnackenberg

 

So your telling me Artemis boat has a hula?

Nah, just linking to where the original text came from.

[Guest]

Yes their platform has allot of twist. This is not a good thing.

 

ETNZs platform is super stiff

 

 

 

 

Well, they think they know that the rudder t-foil will support around 20% of the boats weight at initial takeoff with that load going down as the boat goes faster. So that gives a concrete figure of what the download force from a negative angle of attack could be. they also know that foilers designed to utilize negative lift work and are fast(Rave, Osprey, Hobie Trifoiler, Skat, Long Shot)-in other words the drag produced by the negative lift is offset by the increase of RM on those boats. They use dual altitude controlled main foils with the windward main foil pulling down. The rudder t-foils on these boats lift about 20% of the boat at initial takeoff and go to pulling down as the boat goes faster.

 

 

What this means is that the Oracle system could be getting around the rule that says the main foil can't pull down by allowing the twist to change the angle of attack of the windward rudder foil. They would have to adjust the windward main foil so that it was neutral if the windward hull was immersed while it was twisted.

 

And royale 780 that puts a whole new twist on things .

 

Well thats probably the best explanation I have heard so far

 

Very interesting indeed the differences between the boats. I sill like ETNZs one better.

 

Here is another observation,

 

 

In the current Professional Boatbuilder magazine Sam Bradfield is quoted saying "hydrofoils need to flex some". He's apparently learned from experience that overly rigid foils are prone to failure.

[Guest]

The latest from San Fran is Oracle have tested a hinged foil two days ago.

 

Moving the goal post dramaticaly!

 

Just wonder which way they have moved them?

[Guest]

Are you sure your not talking about Artemis?

 

If you ask me, Oricals 72 was never meant to fly. It will be very interesting when and if they do.

 

It doesn't matter anyway. Luna rosa will be in the water soon and we can test if foiling or not is faster around a course, hone our 72 skills and build better boats while the competition are repairing theirs

[Grinna 2]

Well, we're just slaughtering the sacred cows tonite aren't we.

 

You lot sound like school kids "My dad can beat up your dad!" and it all amounts to as much as if you guys were peeing in the wind. The proof of the pudding is in the eating and it'll be time to actually find out whose pudding is best soon enough.

 

In the meantime, Justin and Oceancruiser, what do you really gain from tearing down the latest Kiwi yachting hero du jour? By all means talk up the likes of Coutts and Schnacks and whoever else you want .... but when you're throwing mud all you're doing is losing ground. You guys may well be proven right, but NZ yachting has been missing people of significance to inspire youngsters. For all his faults, Grant Dalton is the closest thing we've got at the moment .... though its good to see the likes of Jo Aleh and Pollie Powrie being lifted that way.

 

By pissing on the parade so vehemently you just make yourselves look like churlish, petty little spoiled brats.

[Guest]

Thanks Grinna

 

Felt like 2 against one there for a while

[Guest]

Well, we're just slaughtering the sacred cows tonite aren't we.

 

You lot sound like school kids "My dad can beat up your dad!" and it all amounts to as much as if you guys were peeing in the wind. The proof of the pudding is in the eating and it'll be time to actually find out whose pudding is best soon enough.

 

In the meantime, Justin and Oceancruiser, what do you really gain from tearing down the latest Kiwi yachting hero du jour? By all means talk up the likes of Coutts and Schnacks and whoever else you want .... but when you're throwing mud all you're doing is losing ground. You guys may well be proven right, but NZ yachting has been missing people of significance to inspire youngsters. For all his faults, Grant Dalton is the closest thing we've got at the moment .... though its good to see the likes of Jo Aleh and Pollie Powrie being lifted that way.

 

By pissing on the parade so vehemently you just make yourselves look like churlish, petty little spoiled brats.

 

 

WTF! Geez grinna.

 

With an "out of context" aggressive post like that you deserve a reciprocal reply.

 

if kids look up to a corporate such as ETNZ they must be either thick or desperate when they can look up to Valerie Vili, our Rowers, and other non corporate "NZ sponsored" sports stars That actualy Win something.

 

We also are not bagging anything but backing our corner and who we think will win and for what reason ( that is both Royal780 and me).... as opposed to you who is offering nothing and bagging Both sides of the argument just to boost you own pathetic ego. I appreciate royals comments and the discussion.

 

If Dalton is all NZ has got..... we'll then NZ Is Fucked!

 

Thank god we have great sailors doing great things on all the other teams such as a 49r silver medalist on the Korean team....

 

 

... not that grinna would know that.

 

Geez this forum is full of idiots that post dumb stuff. Between you, pwederell, and wheels, plus a few hanger on's,- you guys are a real blight on this site and I believe really stop a lot of good people from posting through fear of being bagged for having an opinion that is not in agreement with yours and the Mob.

 

Sad really and this is not making posting here enjoyable at all.

 

I can see the reason why so many view the forum. But offer verry little. The Mob will eat them up!

 

Compared to other sites this site is becoming a niche for about twenty people who group together to bag people like me and ocean cruiser and in doing so alienate the viewers that May want to post.

 

I'Ve had enough of this rubbish.

 

This is the last post for me. You tossers can carry on stroking you're own penis's.

 

Carry on.

[Changed 10]

Good.