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JimC View Drop Down
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    Posted: 11 Mar 10 at 12:21pm
Originally posted by Peaky

As soon as you add a kite (like the Tasar 2 was going to have),


That's definitely not my memory. Chris will remember better, having been much more at the centre of events, but I'm pretty sure that the spinnaker experiments were quite separate to the Tasar 2 proposal, which was all about making a 21stC version of the two person spinnaker free boat.

Originally posted by Peaky

I don't see how you can have a fixed mast that is flexible above the hounds for upwind work but then stiffens when reaching? With the rotating mast, the mast bend varies as the mast rotates.


I reckon its easier with a fixed mast than a rotating one. To make the mast stiffer on a reach than upwind you increase the laminates in the layup on the side of the tube and leave them the same on the front and back. Upwind when the kicker loads etc are fore and aft the tube is more flexible, because the thicker laminates are off axis and hardly contribute to stiffness. With the boom squared off the thick laminates are now on axis and the mast is stiffer.

I reckon the big difference with a catamaran is that the roll inertia is so much greater, so power is proportionally more important and gust response proportionally less. The desirability of gust reponse is going to be far greater on an inland/restricted water boat than in more open water situations where so much NS racing occurs. I've raced a wing masted Cherub on the River Thames: there's some real life experience behind this!

Edited by JimC
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 1:21pm
Graham

Hands up I also had an ISO. Kites are fun, but I guess the question for
Mike was where is there a market hole. The answer to him must have been
Parent child/ Family boat that was fast but light and uncomplicated. Kites
add complication., scare a few and are unsuited to many locations where
restricted water and tides mean that dead downwind will often be faster.
In space an asymetric on a trap boat can be faster, but even a Musto or
700 is not much use if you are ditch crawling or reaching out into a 4 knot
foul tide.
In class sailing this is irrelevant, but round the cans club sailing is often
better served by a symetrical or no spinnaker boat. The kite will only be up
on my 100 on true downwind legs with space as it will be faster to white
(clear) sail on the reaches.

The Icon is, as Mike has noted, a more developed version of the NS14 hull
from post Tasar days.

I was actually looking to sail something that my wife would sail with me
and it needed to be   a) Simple b) light to pull up the slip and c) fast as we
are tidal. Conclusion was pretty easy, Tasar. Tasars a remarkable quick in
a breeze PY 1023 (see speed thread). If Mike can produce a boat which is
light, has better than 200 stability, reasonable weight carriage and works
in the light (hence bigger rig and wing mast), then I think he has a market.
What other simple two sail boat is up to date and appealing new?

I suspect that keeping it simple and price under control will be the
challenge. Nothing wrong with alloy wing masts, as Dragonfly 800 owners
would tell you. My view would be stick with the alloy mast, centreboard/
standard foils, Epoxy, not carbon, simple fit out, no mast rams etc, very
few bits of string.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 1:28pm

Hi Jim,

Not sure about the T2 - wasn't aware there was a look at modifying it without a kite.  I know the Bethwaites now favour shoving as much rag on as possible and having a flexy tip to take out the gusts.  As much as I admire the Bethwaite work, I do sometimes wonder if they aren't a little blind to practicality at times. The 59er is an example.  The hull is great, but the rig, even though in theory it is a 'gust responsive' one, is just too powerful.  I think the T2 may have been looking at going this route - big sails, flexy mast tip.  However, there is more than one way to skin a cat. 

One of the really interesting, but seldom discussed, bits of HPS1 is the part about gust harshness and what I think he called the (wind) stability index.  Depending on the weather type and relative temperature of the water and air above it, the gusts come and go more quickly, more frequently and more predictably.  In the steady winds it could be argued that you barely need a responsive rig at all - the crew can predict and have time to adjust manually.  In unsteady winds, you want the rig to do some of the work for you.  The Bethwaite way is (was) to have a flexible mast tip that opens the leach from the top down i.e. it is the mast, not the sail, doing the work.  The new 49er rig has a squarer head and a stiffer mast, and a smoother ride by all accounts.  In this case it is the sail doing the work, not the mast (as much).  The ICON, and other modern wing mast rigs with very squareheads (as opposed to just fat heads) work in a similar way.  Pull the downhaul on to take out leach tension and watch it fall open.

I think you're not too far from Burghfield?  Come down and try it.

BTW is it leach or leech?
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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: 11 Mar 10 at 1:43pm

Originally posted by JimC

Originally posted by Peaky

As soon as you add a kite (like the Tasar 2 was going to have),


That's definitely not my memory. Chris will remember better, having been much more at the centre of events, but I'm pretty sure that the spinnaker experiments were quite separate to the Tasar 2 proposal, which was all about making a 21stC version of the two person spinnaker free boat.

I' d tend to agree there. The Tasar 2 was going to be a modern version of the Tasar with a hull rebuild (lighter) and a more automatic rig including a carbon stick mast.It was apparently dropped, owing primarily to fears that the Tasar class might be internally split and/or the class canibalised.  Looking back, I remember reading somewhere that Frank's conclusion is that they spent a long time comparing the relative performance of different types of wing mast for the Tasar, whilst forgetting that everywhere else significant performance gains were being attained by changing conventional mast / rig geometry.

The Tasar asymmetric story was another, earlier issue, stremming from an enquiry probably stimulated  from within the Tasar class by the emergence of the NS14 breakaway, the Manley Graduate, which can use either a symmetric or asymmetric spinnaker.

 



Edited by Slippery Jim
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Posts: 586 		Post Options Post Options   Quote Slippery Jim Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 2:09pm
Originally posted by Peaky

Hi Jim,

Not sure about the T2 - wasn't aware there was a look at modifying it without a kite.  I know the Bethwaites now favour shoving as much rag on as possible and having a flexy tip to take out the gusts.  As much as I admire the Bethwaite work, I do sometimes wonder if they aren't a little blind to practicality at times. The 59er is an example.  The hull is great, but the rig, even though in theory it is a 'gust responsive' one, is just too powerful.  I think the T2 may have been looking at going this route - big sails, flexy mast tip.  However, there is more than one way to skin a cat. 

One of the really interesting, but seldom discussed, bits of HPS1 is the part about gust harshness and what I think he called the (wind) stability index.  Depending on the weather type and relative temperature of the water and air above it, the gusts come and go more quickly, more frequently and more predictably.  In the steady winds it could be argued that you barely need a responsive rig at all - the crew can predict and have time to adjust manually.  In unsteady winds, you want the rig to do some of the work for you.  The Bethwaite way is (was) to have a flexible mast tip that opens the leach from the top down i.e. it is the mast, not the sail, doing the work.  The new 49er rig has a squarer head and a stiffer mast, and a smoother ride by all accounts.  In this case it is the sail doing the work, not the mast (as much).  The ICON, and other modern wing mast rigs with very squareheads (as opposed to just fat heads) work in a similar way.  Pull the downhaul on to take out leach tension and watch it fall open.

I think you're not too far from Burghfield?  Come down and try it.

BTW is it leach or leech?

Firstly, neither mast nor sails might be treated as individual entities. Secondly, there was no intention to rig the T2 with a kite e basta. As far as I lknow, the work on the Tasar kite, came before the proposal by Frank B. for the T2. The T2 was to be simply a mroe efficient progression of the tasar 2 sail, hiking boat principle of the Tasar. The result of the tasar kite experiment was to show Frank that the hull/rig combination of the Tasar was not efficient enough to allow for a successful conversion to asymmetric across the wind range. Partly hence the 59er.

As for the 59er, I don't find its rig overpowered, esp. now that she sails with a wire. Others within my class don't find that either.

Re. the square rig on the 49er, 29er XX. The mast is stiffer on both, since the square head sail is more powerful. It induces more mast flex and therefore needs a stronger mast section up top. The ride is smoother, a function of both mast and sail characteristics. It also carries weight far better (+10Kg ). the new 29er XX rig is similar, but does not carry as much extra weight. Certainly I suspect the old 29er XX rig (actually the 59er rig) was replaced by the new one partly due to the increase in bending stress in the mast from twin trapezing.

 
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JimC View Drop Down
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Posts: 6662 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 2:09pm
Originally posted by Peaky

but the rig, even though in theory it is a 'gust responsive' one, is just too powerful.

But I think you'll find it has smaller white sails and more beam than an RS400...
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 2:22pm
I suspect the waterline beam is less on the 59er. At any rate, no one
would think of putting a trapeze on a 400!
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Posts: 187 		Post Options Post Options   Quote cad99uk Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 4:00pm

Mike L

What are the capsize characteristics of the Icon. I would be looking for a boat that did not have a tendency to invert, or with the centreboard high in the air.

These 'bad characteristics often caused by large side tank volume I guess.

Would the choice of mast have any bearing in this area.

I currently sail a 29er and RS800 and I find these fine for capsize recovery.
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Posts: 2143 		Post Options Post Options   Quote getafix Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 4:25pm
Originally posted by SimonW99

Graham

Hands up I also had an ISO. Kites are fun, but I guess the question for
Mike was where is there a market hole. The answer to him must have been
Parent child/ Family boat that was fast but light and uncomplicated. Kites
add complication., scare a few and are unsuited to many locations where
restricted water and tides mean that dead downwind will often be faster.
In space an asymetric on a trap boat can be faster, but even a Musto or
700 is not much use if you are ditch crawling or reaching out into a 4 knot
foul tide.
In class sailing this is irrelevant, but round the cans club sailing is often
better served by a symetrical or no spinnaker boat. The kite will only be up
on my 100 on true downwind legs with space as it will be faster to white
(clear) sail on the reaches.

The Icon is, as Mike has noted, a more developed version of the NS14 hull
from post Tasar days.

I was actually looking to sail something that my wife would sail with me
and it needed to be   a) Simple b) light to pull up the slip and c) fast as we
are tidal. Conclusion was pretty easy, Tasar. Tasars a remarkable quick in
a breeze PY 1023 (see speed thread). If Mike can produce a boat which is
light, has better than 200 stability, reasonable weight carriage and works
in the light (hence bigger rig and wing mast), then I think he has a market.
What other simple two sail boat is up to date and appealing new?

I suspect that keeping it simple and price under control will be the
challenge. Nothing wrong with alloy wing masts, as Dragonfly 800 owners
would tell you. My view would be stick with the alloy mast, centreboard/
standard foils, Epoxy, not carbon, simple fit out, no mast rams etc, very
few bits of string.


in the same camp as you on the Icon, I liked what I saw at the show and think this provides an excellent <potential> alternative to what I see as the current two-sail, two-handers available

Enterprise/Albacore - old designs, heavy-ish, <comparitively> slow to accelerate
N12 - fast, tippy, arms-race = £££££
Tasar - had it's day and undercanvassed for two 'average' size crew (or one fatty and one child/wife)
Grad - like the Rooster update and looked very sorted, but bit slow, possibly same weight issue as Tasar
NS14 - fine if you live in Oz and some issue with weight carrying according to the above posts
Firefly - bit slow, small, old design, same weight issue again?

wouldn't even contemplate Icon if open-water with 300m+ legs were on offer every weekend, but they aren't....
Feeling sorry for vegans since it became the latest fad to claim you are one
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Posts: 750 		Post Options Post Options   Quote Hector Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 10 at 5:52pm

Originally posted by getafix

Originally posted by SimonW99

Graham

Hands up I also had an ISO. Kites are fun, but I guess the question for
Mike was where is there a market hole. The answer to him must have been
Parent child/ Family boat that was fast but light and uncomplicated. Kites
add complication., scare a few and are unsuited to many locations where
restricted water and tides mean that dead downwind will often be faster.
In space an asymetric on a trap boat can be faster, but even a Musto or
700 is not much use if you are ditch crawling or reaching out into a 4 knot
foul tide.
In class sailing this is irrelevant, but round the cans club sailing is often
better served by a symetrical or no spinnaker boat. The kite will only be up
on my 100 on true downwind legs with space as it will be faster to white
(clear) sail on the reaches.

The Icon is, as Mike has noted, a more developed version of the NS14 hull
from post Tasar days.

I was actually looking to sail something that my wife would sail with me
and it needed to be   a) Simple b) light to pull up the slip and c) fast as we
are tidal. Conclusion was pretty easy, Tasar. Tasars a remarkable quick in
a breeze PY 1023 (see speed thread). If Mike can produce a boat which is
light, has better than 200 stability, reasonable weight carriage and works
in the light (hence bigger rig and wing mast), then I think he has a market.
What other simple two sail boat is up to date and appealing new?

I suspect that keeping it simple and price under control will be the
challenge. Nothing wrong with alloy wing masts, as Dragonfly 800 owners
would tell you. My view would be stick with the alloy mast, centreboard/
standard foils, Epoxy, not carbon, simple fit out, no mast rams etc, very
few bits of string.


in the same camp as you on the Icon, I liked what I saw at the show and think this provides an excellent <potential> alternative to what I see as the current two-sail, two-handers available

Enterprise/Albacore - old designs, heavy-ish, <comparitively> slow to accelerate
N12 - fast, tippy, arms-race = £££££
Tasar - had it's day and undercanvassed for two 'average' size crew (or one fatty and one child/wife)
Grad - like the Rooster update and looked very sorted, but bit slow, possibly same weight issue as Tasar
NS14 - fine if you live in Oz and some issue with weight carrying according to the above posts
Firefly - bit slow, small, old design, same weight issue again?

wouldn't even contemplate Icon if open-water with 300m+ legs were on offer every weekend, but they aren't....

Me too.

Given my current club I won't be looking to buy, but I can see that if I had to sail on a more resticted water, I'd be hugely under-inspired by any of the established 2 sail classes. There may be compensations such as good flleet racing so never say never, but the Icon seems to me a great concept that if got right could have a significant impact and rosy future.

On the mast front - still think a simple(ish) carbon pole would be the best seller, as it matches the modrn appeal of the boat, is light so easy to rig, simple and just seems right. When I sailed a Tasar (20yrs ago) I found the rig just pointless and was entirely unconvinced it added anything to performance. If the Icon is meant as a small venue flyer then is a wing rig really appropriate?

But as I said, no open chequebook here so I'm not your target market.
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