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poleless spinnaker #170076
03/02/09 02:10 PM
03/02/09 02:10 PM
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waynemarlow Offline OP
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Just a thought but looking for the pros and cons, how much advantage does the spinnaker pole give us over a pole less system such as the Swell Shadow.

In the real race world they aren't that much slower than us downwind and have a huge reliability advantage ( how many times have you had a pole or bridle failure ) plus much less windage particularly as they have a trampoline based recovery system that seems to work.

What is swaying my thoughts a bit is that our front beams are getting further back to probably around 2.6 - 2.7 metres from the bow, our poles are limited to 3 metres so is the 40 cms worth the windage and reliability problems cool

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Re: poleless spinnaker [Re: waynemarlow] #170107
03/02/09 04:06 PM
03/02/09 04:06 PM
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Wouter Offline
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Actually the main reason for having a spi pole is that you'll need one when you fit a spinnaker to a sloop rigged (2-up F16). Having the Jjib luff and the spinnaker luff in the exact same position doesn't seem to work very well for some reason. crazy

We must of course not forget that both sloop rigged (2-up) F16's and cat rigged F16 (like the shadow) constitutes equal shares in our class. Losing the jib altogether is certainly a performance hit for 2-up crew especially in the mixed racing we tend to do.

Additionally, your reading of the F16 spinnaker pole length is wrong. Every F16 design is allowed a maximal pole length of 3.5 mtr. The position of the mainbeam is irrelevant, unlike the way Texel,SHCRS or the F18 class determine maximal pole length. This means the F16 spinnaker is always the distance in front of the mast and mainsail, irrespectibly of the specifics of the platform to which the rig is fitted. This is another performance equalizing feature of the F16 class rules that is not present in for example the F18 class rules. As a result, a boom less spinnaker design can never match this setup as the spi pole will always protrude some distance beyong the bows. So the minimal distance is typically 1.5 mtr. as the (single) forestay bridles really can't be fitted to the extreme ends of the bow.

Of course you can decide to fit your own singlehander to adopt the Shadow setup but I fear that the added result apart from simplicity and dependabilty will be loss of performance with respect to poled F16's. Afterall, The spi triangle will be significantly smaller leading to a significantly smaller spinnaker with a shorter luff. Still, the F16 class rules allow such a thing as this is only unfair to yourself and not to anyone else.

Personally, I have never had a spi or pole failure in the 10 years that I'm using spinakers on cats. I still have one of the most simple spi setups using only 3 mm dyneema lines, figure 8 knots and bowlines with a securing knot in their ends. My poles are non-anodised common hardware store poles costing 30 bucks or so. I use the cheapest all metal Harken small blocks and a single Ronstan plastic cam cleat with a metal eyestrap. All systems are external. My halyards are 4 mm dyneema and I got a AHPC midpole snuffer. My spinnaker is now over 6 years old and I still use it. The only difference with the Shadow system is the pole and the bridlelines. I really don't see these as significant hazzard unless one does things the wrong way, such as using the wrong knots or skimping on the wall thickness of the spi pole.

Have some more work to, C ya !

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: poleless spinnaker [Re: Wouter] #170131
03/02/09 05:44 PM
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waynemarlow Offline OP
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Thanks Wouter, a good reply, just bored and musing differnet ideas. smile

Re: poleless spinnaker [Re: waynemarlow] #170643
03/05/09 11:54 PM
03/05/09 11:54 PM
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CaptainKirt Offline
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Note my avatar to the left I have been using for several years! - I had Gregg Goodall make me a custom "poleless" spi several years ago- I store it in a bag on the tramp and it is great fun out cruising around. Still trying to figure out a good way to retrieve and snuff. I went with this because I was not happy with the (IMO) significantly worse upwind performance of my Taipan with the spi pole/snuffer in place. Boats I could normally outpoint with comparable or better speed were just as high and fast if I added the spi pole etc. Mind you, I am sailing uni only so this impression may not be relevant for the sloops. I really want a simple, fast spi "system" that is quickly/easily mounted, deployed, retrieved and put away AND doesn't detract much if any from straight uni experience. Probably fact I also sail an "A" may have something to do with that!

Kirt


Kirt Simmons
Taipan, Flyer
Re: poleless spinnaker [Re: CaptainKirt] #170663
03/06/09 10:25 AM
03/06/09 10:25 AM
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Any one ever tried mounting the snuffer to one of the hulls?


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

Re: poleless spinnaker [Re: pgp] #170665
03/06/09 10:40 AM
03/06/09 10:40 AM
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MERRITTISLAND, FL
Matt M Offline
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Originally Posted by pgp
Any one ever tried mounting the snuffer to one of the hulls?


Put a hole in the tramp and sew a sock into it. Snuff from the rear. This is on my 20 even though it still has a pole, should no matter either way

Re: poleless spinnaker [Re: pgp] #170669
03/06/09 11:02 AM
03/06/09 11:02 AM
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France
pepin Offline
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Originally Posted by pgp
Any one ever tried mounting the snuffer to one of the hulls?
The Shadow has a well designed snuffer under the trampoline to pull in the poleless spinnaker. I goes from under the front beam I believe to the back of the trampoline.

Re: poleless spinnaker [Re: pepin] #170672
03/06/09 11:16 AM
03/06/09 11:16 AM
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The original Stealth design (2000?) had a trampoline snuffer on the port side but John P decided to abandon it for various reasons.


John Alani
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Stealth F16s GBR527 and GBR538
Re: poleless spinnaker [Re: Jalani] #170731
03/06/09 07:24 PM
03/06/09 07:24 PM
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Mumbles Y.C Wales U.K
Mark P Offline
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I'm Spartacus...well not really but I did have a 2002 Stealth with a "mole in the hole" aka Tramp snuffer. At that time it was ahead of it's time, F18's etc had big spi bags on the tramps with zips that were always seized with salt. Single handing with a spi bag was not possible so the mole was a winner. Yep..it wasn't perfect hence spi pole snuffers but it just goes to show that F16's can and will probably always will be at the forefront of competitive Cat technology.


MP*MULTIHULLS
Re: poleless spinnaker [Re: waynemarlow] #170732
03/06/09 07:29 PM
03/06/09 07:29 PM
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Poleless kite done some time before the Shadow on the Dart 6000. This however had a tramp bag as it was sometime before snuffers became the norm.

Cheshirecatman

Re: poleless spinnaker [Re: Cheshirecatman] #170768
03/07/09 05:46 AM
03/07/09 05:46 AM
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Why would you want a snufferbag under the tramp?
I don't think that a constantly wet spi will be very beneficial to your performance.

Re: poleless spinnaker [Re: Tony_F18] #170776
03/07/09 10:13 AM
03/07/09 10:13 AM
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CaptainKirt Offline
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My latest thought to deal with all these issues is a snuffer "bag" that attaches to a rigid hoop mounted slightly ahead and above the front beam on port side to hold mouth open (cat rig you don't have worry about jib :-) ) and bag that zips onto top of tramp or fits into "pocket" on top of tramp. Only problem with bag on top of tramp is the mast base mounted controls on that side :-( including rotator line or rotator itself. Another option I thought of is a snuffer chute mounted inside the hull- essentially with a deck above and below. Downsides of that- one hull inherently heavier and if you ever stuffed up to the snuffer mouth would probably end up taking a large water sample! I also thought of incorporating a Marstrom type "snail" snuffer either inside a hull or built into a front CF beam (ie shell of "snail" is structural- heck you could even put it right in the middle under the mast to raise mast base).

Kirt


Kirt Simmons
Taipan, Flyer
Re: poleless spinnaker [Re: waynemarlow] #170784
03/07/09 12:29 PM
03/07/09 12:29 PM
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Wouter Offline
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There is one more drawback of a poleless spinnaker.

You have less refined control of the spi luff. I jury rigged a similar setup as Kirt myself one time and found that the tack of the spi would move backwards and forewards with changing sheet tension (acting on the clew corner). The tip of the pole is very much fixed as the top of the spi sail is near the mast. This makes for better control of the spi luff with sheet tension in my opinion.

I had forgotten to include this aspect last time

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: poleless spinnaker [Re: CaptainKirt] #170788
03/07/09 01:41 PM
03/07/09 01:41 PM
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waynemarlow Offline OP
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My doubts about the snuffer out on the end of the pole or mid pole is purely aerodynamic. The A's are a very refined beast and hence getting less and less frontal area ( wind drag ) will give them better and better performance. At wave top ( hull ) height there is very little wind but up around the snuffer ( face height ) there is appreciable wind, enough my guess to affect performance by a small margin.

How do we deal with this blunt hoop and snuffer then. I have done a lot of thinking about this and found no real ideal other than having it run just under the beam or just above ( raise the mast 100mm x 200mm on a hoop should be enough ). Below would be better though but I guess waves and the like would be a real stopper if it got high enough to grab the spinnaker in its sock.

mmm lots of ideas here, any other options then !

Re: poleless spinnaker [Re: waynemarlow] #170792
03/07/09 03:38 PM
03/07/09 03:38 PM
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Wouter Offline
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You have to look at all additions in a different way. There is always a drawback assigned to a benefit. The important question is whether the magnitude of the drawback is smaller then the magnitude of the advantage. In case of the spinnaker the answer is well documented. The benefits on the downwind leg more then compensate for any loses upwind. Just sail a F16 without a spi and boom (A la A-cat) against one with these items, you easily spot the difference (assuming sufficient skills)

The next question is whether using the snuffer adheres to the same principle. This situation is less clear. I've done hand setting and doucing of the spinnaker back in the days and got quite handy with it; even solo. But that is not the main benefit of the snuffer, the snuffer allows me to get through a contested mark rounding noticeably better. I spend less time preparing for my sets and douces and there is less that can go wrong; especially in a blow as I don't have to go the far lee side of the boat to grap the spi cloth myself. For 2-up you can manage, but 1-up with spi you are pretty much hooked to the snuffer in any wind and sea conditions beyond calm.

So you don't really have a choice beyond having a spi or not having a spi. I personally feel the spi setup is faster then the A-la-A-cat setup even with the additional drawbacks of the snuffer. On crowded race courses I feel the benefits are even more convincing. In long distances races ... well the non-spi boats, including the A's can just as well forget about entered unless the vast bulk of the course is a beam reach or upwind leg.

So, my point here is to not hit yourself repeatedly over the head with some small drawback or performance hit without comparing it against the noticeably larger benefit. I mean what is the point ? You are never going to design out all performance hits, that is fundamentally not possible. The only thing you can do it try to entlarge the (benefial) gap between the performance hits and performance boosts. And I dare say that the current midpole snuffer present a pretty darn optimal balancing of these factors already. Many years in Tornado and F18 campaigning have guaranteed that.

Maybe that for a 5 boat race the bag setup or tramp based snuffer is slightly faster but not for a 50 boat fleet. Meaning that a mid pole snuffer alternative maybe slightly faster in SOME specific situations but not over a full spectrum of condition ones encounter over a longer period of racing with many different situations occuring.

But it is always good to keep trying though !

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: poleless spinnaker [Re: Wouter] #170793
03/07/09 03:46 PM
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One more comment

Quote

The A's are a very refined beast and hence getting less and less frontal area ( wind drag ) will give them better and better performance.



I've started to feel that the best qualification of the A's is that they are uphill beasts and downhill dogs with their average over both legs (overall performance) being pretty normal.

Of course the first upwind leg with the start is very important for the overall result and this is driving all the advances in uphill speed even at the expensive of downhill performance. That is a given and also the main argument to not look at the A's for guidance on all things related to catamaran design.

In open class racing they are not king of the hill any more and haven't been for a while (over the full spectrum of conditions). They have excellent racing in their own class because all suffer under the same limits as is the same principle that levels the Hobie 16 playing field. Yet there is no designer who looks at the H16 for guidance on how to design a proper catamaran.

Of course this is with all due respect to our A-cat friends and the A-cat class as a whole.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: poleless spinnaker [Re: Wouter] #170798
03/07/09 06:11 PM
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waynemarlow Offline OP
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Wouters point on the first upwind beat is right and if you can outpoint everyone on that beat then you stand a good chance of being first down the downwind bit.

So are we agreed then that the midpole snuffer is well tried and tested and is the way to go even if it has poor aerodynamic properties, if so that then is saying that the A's on a typical short course can get away on the first beat and then we are following from there on.

Sort of sums up my racing against the A's so far, in their dirty air I always seem to be struggling up the first beat and then catch them up downhill to just repeat it all over again next beat, ah well I've done a lot of thinking on this and its time to come up with a dastardly plan. wink

Re: poleless spinnaker [Re: waynemarlow] #170820
03/08/09 06:04 AM
03/08/09 06:04 AM
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Wouter Offline
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Wayne,

You could one time remove all the spi hardware from your boat and race the A's like that. This could be very telling. I don't except you to gain much upwind, at least not to enough to become competitive with the A's there. On the downwind I predict you'll miss the spi and don't catch up to the leading A's anymore. As such I predict less overall performance then when with the spi setup.

Just an idea to give you a feel of the net benefits or indeed the net performance hits.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: poleless spinnaker [Re: Wouter] #170846
03/08/09 02:33 PM
03/08/09 02:33 PM
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Sebring, Florida.
Timbo Offline
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Hey, here's a thought; somebody design a retractable spinnaker pole, like the monohulls with the asymetrical spinnaker have! You extend it at the A mark, and retract it at the C mark, along with the spinnaker, the whole mess slides under the tramp for upwind work.

Does everyone have their number 2 pencils? Ready? Begin. grin


Blade F16
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Re: poleless spinnaker [Re: Wouter] #170847
03/08/09 02:41 PM
03/08/09 02:41 PM
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CaptainKirt Offline
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Spinnaker bags and pole end snuffers were all the rage when we first started w/ the spis on our Taipan's. Way back- remember Wouter? I still have my first pole end snuffer I put on my 4.9- That's very easy to snuff/deploy but the added weight and particularly windage kills you upwind. And as you have often commented on in the past Wouter, you spend more TIME sailing upwind then down, so a 5% difference in upwind speed between 2 boats, even at the cost of a 5% difference downwind, in a straight windward-leeward course (currently the most common over this side of the pond anyway) will have the upwind advantaged boat first every time. Mayhaps I am a little "different" (many people will confirm that BTW! Probably what helped when we started this F16 circus!) in that I regularly sail both an "A" cat Flyer and F16 Taipan, so I'm quite cognizant of the differences- Getting a good start is also a critical thing and getting clear air up the first beat is important as Wayne mentions, and nothing like being able to start anywhere on the line, like in my "A", and if on time having clear air quite quickly and being able to force anyone above you to tack off or go slow until you "gas" them- also results in an "intimidation" factor in small fleets- they pretty much don't WANT to be above you and will give it to you. Also, on a very short course or in very hectic conditions, the "A" will kill you because they don't have to worry with pulling OR dousing the spi and can more quickly get to their max speed up/downwind.
So of course it's all a trade off- Trick is to trade the least off- That's why spis SO FAR have gone from bags (still commonly used on distance races BTW because there the complexity/weight/windage of any snuffer is not worth it since the spi is rarely launched/doused relative to sailing time), to pole end snuffers, to midpole snuffers.
Another option perhaps worth exploring I've thought of is a retractable pole/snuffer combination- retractable poles are now very common on monohulls- again question is are the tradeoffs in cost/weight/complexity and sailor's time/thought/effort worth the gains??
These are some of the things that are fun when playing in a Formula Class!
If the "A"'s as a class adopted spinnakers I assure you we'd see some interesting developments! Gregg Goodall even suggested a "tacking" spi pole to me- haven't tried that one out yet either.

Kirt


Kirt Simmons
Taipan, Flyer
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