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Norbert View Drop Down
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Posts: 351 		Post Options Post Options   Quote Norbert Quote  Post ReplyReply Direct Link To This Post Topic: Cirrus Icon Development
    Posted: 07 Feb 10 at 8:24am
Originally posted by mongrel

I can't see this boat carrying weight
as well as a Tasar does.  You can't just take a
lightweights boat, make the hull lighter, put a big rig
on it and hope it carries weight, the hull's bouyancy and
volume are still the same.  If you were doing this with a
new hull, (similar proportions, but perhaps 15' and and a
bit wider, more bouyancy) then your project might make
some sense to me.  I'm afraid I just see it damaging the
Tasar fleet, and killing off any hopes of NS14 getting a
foothold in the UK.



I was always disappointed that the 59er failed to take
off as a class. If Ovi's were to rebrand and remarket it
without the kite and flog it into the inland market then
its weight carrying ability and undeniably powerful white
sail rig i think that would sell.

But what do i know!
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Slippery Jim View Drop Down
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Posts: 586 		Post Options Post Options   Quote Slippery Jim Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 8:57am
Originally posted by Norbert

Originally posted by mongrel

I can't see this boat carrying
weight
as well as a Tasar does.  You can't just take a
lightweights boat, make the hull lighter, put a big rig
on it and hope it carries weight, the hull's bouyancy and
volume are still the same.  If you were doing this with a
new hull, (similar proportions, but perhaps 15' and and a
bit wider, more bouyancy) then your project might make
some sense to me.  I'm afraid I just see it damaging the
Tasar fleet, and killing off any hopes of NS14 getting a
foothold in the UK.



I was always disappointed that the 59er failed to take
off as a class. If Ovi's were to rebrand and remarket it
without the kite and flog it into the inland market then
its weight carrying ability and undeniably powerful white
sail rig i think that would sell.

But what do i know!


Seriously, the 59er is "perfect" as an entity. Remove the kite and itīs not
the same boat. Depoweringthe rig of an efficient hull is, well, just not
(worth) it. Ok., I admit it - Iīm in love with my boat as she is. Donīt mess
with her "makeup".



Edited by Slippery Jim
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tickler View Drop Down
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Posts: 895 		Post Options Post Options   Quote tickler Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 10:21am
Would it be a stupid idea to build a boat with 3 rigs. All the same area but different aspect ratios. A low one for windy seas, a middle (standard) and a tall one with a very square top and soft topmast for puddle sailing?

"I'll get me coat"
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rs405 View Drop Down
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Posts: 119 		Post Options Post Options   Quote rs405 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 12:12pm
Originally posted by Slippery Jim

Originally posted by Guest#260

I can see merit in
someone trying to establish
the NS14 class in Europe that could lead to a world wide fleet of fast easy
to sail 2 person boats that could enjoy a future world championships.


I'm not to sure about another NS14 SMOD spin out in the UK ....
perhaps you could call it Tasar2010


I am sure the 2010 version would be better than the Tasar but the
difference not worth the splintering of an established class. Tasars get 30
-50 boats at the nats and the worlds in the UK next year will probably be
100 ... not much wrong there ... and they can be brought very cheap and
old boats are still fast.



I canīt see it happening that the Tasar gets swamped by an emergent
NS14-like class either.

Back to the subject of rig, Iīd tend not to have a wing mast, since you
loose the automatic response in gusts (at least with the diamond
spreader setup). The only reason it was developed was to increase the sail
efficiency and thus reduce the sail area, making it easier to manage.

Now itīs clear that manual rig adjustment alone - as in the NS14, Tasar
etc, with wing masts - just doesnīt use the gust wind efficiently above
the design wind.   

I think we have moved on from the idea of manually changing sail profile
in anticipation of a gust/lull - it just isnīt possible in the time available.
Nowadays small diameter carbon masts with their flexibility enable fast
rig gust responses, with minimal aerodynamic losses (just increase sail
top and leach size to solve that problem).

Crews can spend more time looking out of the boat and less time pulling
on bits of string and it leads to much more enjoyable, tactical sailing. Just
set the rig up for the average wind on the day and get out there.


I think you are confused between a wing mast and a rotating/over
rotating one. There is nothing stopping you putting the 'automatic' soft
topmast type rig into a rotating set up. A over rotating, twin spreader
mast was tried in the R-Class some years back.
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Slippery Jim View Drop Down
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Posts: 586 		Post Options Post Options   Quote Slippery Jim Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 2:34pm
Originally posted by rs405

Originally posted by Slippery Jim

Originally posted by Guest#260

I can
see merit in
someone trying to establish
the NS14 class in Europe that could lead to a world wide fleet of fast easy
to sail 2 person boats that could enjoy a future world championships.


I'm not to sure about another NS14 SMOD spin out in the UK ....
perhaps you could call it Tasar2010


I am sure the 2010 version would be better than the Tasar but the
difference not worth the splintering of an established class. Tasars get 30
-50 boats at the nats and the worlds in the UK next year will probably be
100 ... not much wrong there ... and they can be brought very cheap and
old boats are still fast.



I canīt see it happening that the Tasar gets swamped by an emergent
NS14-like class either.

Back to the subject of rig, Iīd tend not to have a wing mast, since you
loose the automatic response in gusts (at least with the diamond
spreader setup). The only reason it was developed was to increase the sail
efficiency and thus reduce the sail area, making it easier to manage.

Now itīs clear that manual rig adjustment alone - as in the NS14, Tasar
etc, with wing masts - just doesnīt use the gust wind efficiently above
the design wind.   

I think we have moved on from the idea of manually changing sail profile
in anticipation of a gust/lull - it just isnīt possible in the time available.
Nowadays small diameter carbon masts with their flexibility enable fast
rig gust responses, with minimal aerodynamic losses (just increase sail
top and leach size to solve that problem).

Crews can spend more time looking out of the boat and less time pulling
on bits of string and it leads to much more enjoyable, tactical sailing. Just
set the rig up for the average wind on the day and get out there.


I think you are confused between a wing mast and a rotating/over
rotating one. There is nothing stopping you putting the 'automatic' soft
topmast type rig into a rotating set up. A over rotating, twin spreader
mast was tried in the R-Class some years back.


No Iīm not. This discussion has been limited so far to wing-mast setups
of the NS14 /Tasar type.

Round (over)rotating masts have been tried and found not to be as
successful as first thought due to aerodynamic inefficiency. It is also not
easy to build a tapering carbon rotating mast (automatic), having similar
problems to making something similar in wing mast form in carbon.
According to the experts, at each 30 cm interval, youīd have to calculate
the stresses in the laminate in order to determine the number of layers to
build in. Lots of calculus for little return.

Thus, a non-rotating automatic mast, carrying more sail area would be
easier to build, but admittedly be a little more difficult for an average
sitting out crew to handle.



Edited by Slippery Jim
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rs405 View Drop Down
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Posts: 119 		Post Options Post Options   Quote rs405 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 5:55pm
Not sure about this. Building a (non wing) rotating flexi tip mast is petty
straight forward in concept. No different to a non rotating mast, but
obviously different shroud and spreader arrangements. Think modern
RS600 mast. Although, admittedly that is a very stiff section.
420, 470, 405, laser 4000
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Guests View Drop Down
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 6:05pm

My opinion on a few points:

The NS14 is an excellent starting point for a new SMOD, but for the UK the sails are slightly too small (lighter winds and competing classes).  The Flight 4.3 is basically a NS with bigger sails and is a great starting point from which to develop the Icon.  I wouldn't be suprised if the Icon ends up very similar, maybe with one or two tweaks to make it more UK customer friendly.

Does it need a kite? In my opinion, no.  These boats reach extremely quickly without a kite due to the low drag and high lift from the rig.  They also run downwind perfectly adequately (better than most as the shrouds can be let forward).  A kite would therefore need to be fairly big to make much difference, but that has several problems: 1. Big kites need more skill and strength - changing the crew profile. 2. Big kites limit the locations the boat can be sailed on. 3. A big kite needs a high halyard and/or a long pole.  A high halyard needs a stiffer mast (or uppers, which are impractical on a rotating rig), which makes it less good in gusts.

Kiteless boats are very popular in the real world (which this forum doesn't represent).  The n12, tasar, Ent and even the RS200 (which basically uses the smallest possible kite) are amongst the most popular classes and show that big kites are not mainstream.

Can wing masts be gust responsive?   Yes - the laminate can be changed above the hounds to make it flexible.  The shape itself does not need to be tapered. 

 

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blaze720 View Drop Down
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Posts: 1635 		Post Options Post Options   Quote blaze720 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 6:18pm
Just think about the facts one moment.  The NS class does not HAVE to use an over-rotating wing section - it is a development class and many decades have gone into refining the boat/rig setup.  They could use round section, and presumably have tried, but they still use an over-rotating wing mast section in either alloy or carbon  - just like many cats, just like camber induced board sails (and Moth) etc.  If they do it at all it is only to have a racing advantage - so they are currently still 'voting' for wing sections. 

We are trying a 45mm diameter tapered carbon tube as well but the clever money is still on the 100x40mm over-rotating wing section here - if round section was best the NS would have switched by now - why pay more for slower ?.  The only way I know to make 'round' work as well is to use camber inducers - but we believe our potential customers simply do not want the hassle of mast-up / mast-down every time they sail and it might still not be as effective.  Simple 'in-line rotation is not too bad and better than nothing but not as good as over-rotation and wing sections imho.

In any test programme you have to try and keep a very open mind - sometimes with difficulty I know.  Received opinion is not always the best guide either.  The acid test is always .... on the water.  We are betting the NS class have got it about right already but I'm still keeping options fully open by trying the round section carbon alternatives.

Are there any N12vers or anyone else out there who have exprience with cruciform rudders ?  We'd like to talk if you are willing to share feedback.. *(Direct messages might be best at this stage  !)

Mike L.
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RS400atC View Drop Down
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Posts: 3011 		Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 7:40pm

The NS14's have evolved within a set of rules.

This would appear to favour a wing mast.

Take away those rules and what is 'best' becomes a whole new question, you are now considering performance against price/hassle/market acceptance etc.

My limited understanding is that there are one or two classes where an over-rotating wing mast would be legal and free sail area, such as the Merlin. I'm sure more than one person has thought about this over the years, perhaps the time is approaching? Or does the kite negate the wing mast? I can't understand why. Perhaps people just like things the way they are and enjoy racing rather than boat development? Perhaps it would be banned if it worked, like foils on 14's?

Also performance is not everything. Some of the biggest fleets are not the best boats. The most enjoyable racing depends on having the right people to race against and some sort of belief that your actions will influence the outcome. So we need boats with a fairly broad appeal if many of us are to be won over to something different.
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blaze720 View Drop Down
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Posts: 1635 		Post Options Post Options   Quote blaze720 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 10 at 8:46pm
The wing mast is definately favoured by the NS and there is no major price premium - we have checked and are now considering extruding alloy here in the UK in partnership with Superspars.  Carbon is very nice but in anything looking remotely like a proper wing section gets pricey very quickly however we will have a round section carbon boom.  The NS allows carbon and a proportion have gone that way though.

I have also had interest from two MR owners but it would be a radical bit of trial and error as their current rigs are so effective and most probably assume carbon is the only option.  Like you I have never understood why the Merlins have not worked out something along these lines but they were probably gaining incrementally anyway with their other developments.  For Icon we are considering both round and wing masts and have both versions avialable now for trial.

Agree with you about absolute performance not being everything.  That is a basis of what we are trying to develop.  'Fast' ... yes of course but much more important to have exceptionally good manners across the full wind range, be practical, 'feel' right, be comfortable and above all be cost-effective.  Some boats just feel right - difficult to describe or define but you know it when you experience it.   And yes if you get too specialised the numbers of those wanting to buy and race never develop - so broad appeal is important.  For this reason we are listening to those who have already said they would like to see a centreboard rather than dagger on Icon.  Technically we might see a modest performance drop but we will be looking into the implications rather quickly. 

Mike L.
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