The new sailing twin skin setup

Kiwing

Super Anarchist
3,280
505
Bay of Islands
I am thinking this new engine is not nearly as powerful or controllable as the AC35 wing.

Being over 70 and the highest performance boat I have sailed is a paper tiger cat my opinion is hardly up there.

However I am in software and am aware of how good simulation software is these days so I am speculating partly on the figures put out by ETNZ from their simulations.

Does any one want to discuss this (preferably without character assassination!)

 

rh3000

Super Anarchist
3,693
1,725
Auckland, New Zealand
I am thinking this new engine is not nearly as powerful or controllable as the AC35 wing.

Being over 70 and the highest performance boat I have sailed is a paper tiger cat my opinion is hardly up there.

However I am in software and am aware of how good simulation software is these days so I am speculating partly on the figures put out by ETNZ from their simulations.

Does any one want to discuss this (preferably without character assassination!)
I don't think twin-skin will ever be as efficient as a rigid wing, surface area for surface area.

But I also can't see a twin-skin being used if it offers no performance advantages over regular sail.

So if what we get is a new and better type of soft sail, that can be used and hoisted in 'regular' boats, I'd see that as win. 

 

Boybland

Super Anarchist
2,904
387
Morioka, Japan
I don't think twin-skin will ever be as efficient as a rigid wing, surface area for surface area.

But I also can't see a twin-skin being used if it offers no performance advantages over regular sail.

So if what we get is a new and better type of soft sail, that can be used and hoisted in 'regular' boats, I'd see that as win. 
I agree, I can't imagine they would bother with the complexity if the simulations didn't show a significant performance gain, you wouldn't go there just for fun, especially not with the other obvious gamble with the foils.

Whats the current numbers for a wing versus a soft sail these days? would be nice to know what the range of possibilities we are looking at.

 

rh3000

Super Anarchist
3,693
1,725
Auckland, New Zealand
What do you mean new? You do know that this is not new. It dates back to at least 2015. Glenn Ashby first saw it in Western Australia last year.

Look at THIS
Given the Egyptians were sailing boats 4000 years before Christ rocked up, I'd regard something that appeared 24 months ago, and has yet to be used in any mainstream racing comp as "new"... if you'll let me  ;)

 

A Class Sailor

Anarchist
970
127
On the water
Given the Egyptians were sailing boats 4000 years before Christ rocked up, I'd regard something that appeared 24 months ago, and has yet to be used in any mainstream racing comp as "new"... if you'll let me  ;)
The way you worded it suggested that it was because of the AC that we would get a new type of soft sail. Let's give credit to where credit is due, and its actually been 36 months :p .

Just because it's used in the AC doesn't mean it will get global acceptance and be adopted by many. For most, the question that should be asked is what problem this solves. In the case of the AC, it is yet another attempt to match the performance of the last 2 types of boat while trying to pretend it is something else. Going away from solid wing masts creates a significant problem of how do you generate enough power in the light winds while being able to significantly depower when you get up and foiling. The last 2 AC boats had the ability to produce righting moment from the top of their solid wings through inverting the top, so not only did they have very fine control over the camber of the rig at different points to produce low drag, they were actually able to get some benefit from the rig when depowered. They also were able to maintain airflow over the wing through tacks and gybes which is incredibly efficient compared with a flapping sail.

The interesting thing is that this type of rig has been tried on Moths and it was no better than the current rigs, which are very highly developed.

 

rh3000

Super Anarchist
3,693
1,725
Auckland, New Zealand
The way you worded it suggested that it was...
Only in your head...

183d17bd856b9e273d5454b3238a6ecd.gif

 

Terry Hollis

Super Anarchist
The way you worded it suggested that it was because of the AC that we would get a new type of soft sail. Let's give credit to where credit is due, and its actually been 36 months :p .

Just because it's used in the AC doesn't mean it will get global acceptance and be adopted by many. For most, the question that should be asked is what problem this solves. In the case of the AC, it is yet another attempt to match the performance of the last 2 types of boat while trying to pretend it is something else. Going away from solid wing masts creates a significant problem of how do you generate enough power in the light winds while being able to significantly depower when you get up and foiling. The last 2 AC boats had the ability to produce righting moment from the top of their solid wings through inverting the top, so not only did they have very fine control over the camber of the rig at different points to produce low drag, they were actually able to get some benefit from the rig when depowered. They also were able to maintain airflow over the wing through tacks and gybes which is incredibly efficient compared with a flapping sail.

The interesting thing is that this type of rig has been tried on Moths and it was no better than the current rigs, which are very highly developed.
Comparing the softwing to the hardwing it is easy to see what "problem this solves".  You need to understand that the Hauraki Gulf is significantly larger than the Bermuda puddle. 

You may recall that when some boats were disabled at Bermuda they had to be towed sideways at very low speeds to get back to base where they could be repaired.  Given that the soft rig can be lowered any need for return to base can be accomplished at speed.

If you are advocating a conventional single skin soft sail instead of a double skin sail I can only suggest that the AC does pour lots of money into developing their craft so it is just possible that they will come up with something a bit more advanced than what one lonely chap was able to achieve with the International Moth class.

 

rh3000

Super Anarchist
3,693
1,725
Auckland, New Zealand
The interesting thing is that this type of rig has been tried on Moths and it was no better than the current rigs, which are very highly developed.
You've declared that the current state-of-the-art SRW was no better than single-skins, and has not been adopted further as a result - fair enough.

The way you worded it suggested that it was because of the AC that we would get a new type of soft sail. 
So if the AC75 does have a double-skin rig that performs better than single skin, and then we see double-skins get adopted by other sailing rigs then you will have to concede that it was because of the AC that we would get a new type of soft sail, given your stated position above.

I look forward to waiting and watching :)

200w_d.gif


 
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Kiwing

Super Anarchist
3,280
505
Bay of Islands
........

The interesting thing is that this type of rig has been tried on Moths and it was no better than the current rigs, which are very highly developed.
Wow so ETNZ is barking up the wrong tree?  It's that case again "why use bikes we done the numbers and there is no advantage."???

Can you use a single skin main in AC36?  I guess we will see where they all go in due course.

But speculation Anyone?

 

Groucho Marx

Anarchist
842
217
auckland, nz
The French did the double luff main on both the Langevin designed trimaran foilers Gautier 11 and 111 way back in the early 1980s.  You somewhat angry boys here are way behind the times.

gautier2 copy.jpg

gautier3.jpg

 
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Monkey

Super Anarchist
10,376
2,045
I am thinking this new engine is not nearly as powerful or controllable as the AC35 wing.

Being over 70 and the highest performance boat I have sailed is a paper tiger cat my opinion is hardly up there.

However I am in software and am aware of how good simulation software is these days so I am speculating partly on the figures put out by ETNZ from their simulations.

Does any one want to discuss this (preferably without character assassination!)
I think this is the only major part of this class that will trickle down. It may not be a new idea, but it’s never seen the sort of R&D money it’s about to. This is what’s great about the AC. 

 

Woolfy

Anarchist
750
251
Waiheke Island
Got to agree with Monkey, one real benefit to the rest of the sailing community the AC has consistantly given is that ideas old and new have always had far more money thrown at them by AC teams. Some ideas have proven to be lemons or just not worth the expense, others have been developed to an extent that the transferance to main stream sailing has been relatively cheap. Were it not for the AC I don't think a huge range of things seen on yachts today would be nearly as refined as they are, think deck hardware, keels, rigs and rigging, sailsetc all have had millions thrown at them by AC teams accelerating development. No doubt the development would have occured without the AC but at a much slower pace. Bit like a major war encourages development as cost is less of factor, at the beginning of WW2 single engine monoplanes were still a new thing, by the end we had jet fighters, were it not for the war jet planes would undoubtedly been developed but as quickly?

 
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