Planing angles for hiking singlehanders

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Rod
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Planing angles for hiking singlehanders

Post by Rod » Mon Aug 03, 2015 3:17 pm

There is an interesting discussion over on my blog on courses for planing singlehanders when the wind is up.

http://www.earwigoagin.blogspot.com/201 ... sited.html

My question for the astute and knowledgeable members of this forum; What are the best angles to the true wind for hard planing in hiking singlehanders? (Lowrider, narrow Moths which slice and not plane are excluded from this conversation.) My guess is somewhere between 90 to 100 degrees to the true wind. Thoughts? Data?

RLM
Rod M
Annapolis MD USA

http://www.earwigoagin.blogspot.com
http://cbifda.blogspot.com/

Classic Moth: 105
PK Dinghy

Rod
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Joined: Fri May 06, 2005 11:46 pm
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Re: Planing angles for hiking singlehanders

Post by Rod » Mon Aug 03, 2015 3:20 pm

My D Course for planing singlehanders:

Image

RLM
Rod M
Annapolis MD USA

http://www.earwigoagin.blogspot.com
http://cbifda.blogspot.com/

Classic Moth: 105
PK Dinghy

JimC
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Re: Planing angles for hiking singlehanders

Post by JimC » Mon Aug 03, 2015 5:33 pm

We call that a P course over here, which is silly because its more like a lower case q... We'd normally go round the outer distance rather than the committee boat though.

I don't believe there is any common best angle.

Theoretically, in the absence of drag, and with unlimited righting moment, a boat will make its highest speed at 90 degrees plus sheeting angle to the wind. So if the sails can be sheeted to 5 degrees of the centreline you'd get highest speed at 95 degrees to true wind.

In practice both righting moment and drag limit, and as these are highly variable for different boats then the best angle will also limit. If you consider an latest spec International Canoe and a old style classic Moth on a 100 degree reach in a reasonable breeze then the Canoe might be hammering down at over 15 knots with the sails hauled all the way on, and the old style Moth plodding along at 5 knots with the main well eased. The IC can only go higher than 100 degrees by slowing down and letting the apparent come round, but the Moth can turn up and maintain the same speed.

Then of course there's righting moment. Max efficiency and minimum drag is when the sails are fully powered up and set right. If you have to depower drag increases, which is why a high performance boat bears away in the gusts to maintain speed. And again, if we consider on the one hand the IC, and on the other hand the old style narrow classic Moth then the amount of righting moment available means optimum speed will be at widely differing angles.

So what can we say? Optimum angles on a reach will be somewhere between around 95 degrees and something like 150 degrees in most conditions, with the optimum angle increasing with wind strength and intrinsic maximum speed of the boat in question, on the whole though I think more than about 130 degrees is unlikely unless in very fast boats. In my Cherub days we'd sometimes be getting to 90 degree wing marks (ie 135 degrees) at maximum two sail reach speed in strong winds, quite unable to carry a kite.

The other factor to consider is what over here folk call the zone of death, where you can neither point up nor bear away to control heel. This is usually appreciably above 90 degrees unless the wind is very strong. Sailing in that zone is extraordinarily hard work, as the response to gusts can only be to play yards of mainsheet. Probably best avoided.

Rupert
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Re: Planing angles for hiking singlehanders

Post by Rupert » Mon Aug 03, 2015 7:36 pm

I've always found that the quickest point is as close as you can get to the wind without spilling from the main, assuming there is enough wind to be planing. This will change from boat to boat and strength to strength.
Rupert

Rod
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Re: Planing angles for hiking singlehanders

Post by Rod » Thu Aug 06, 2015 7:05 pm

Granted there may not be one "best" angle but given the current technology we should have a better idea for our various classes what angle, depending on wind strength, works best. I must admit I'm one of the guilty as I've never tried collecting that data before. Most hiking singlehanders agree that the normal triangle with a 90 degree included angle at the reach mark does not provide the best planing angles so it has to be reaching angles that are somewhat closer.

There was mention of the Speed Puck, a device that can collect both speed and direction. Never used one but it might be the ticket to getting an idea of what angles work best.

See link.

http://www.velocitek.com/speedpuck/

RLM
Rod M
Annapolis MD USA

http://www.earwigoagin.blogspot.com
http://cbifda.blogspot.com/

Classic Moth: 105
PK Dinghy

Rupert
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Re: Planing angles for hiking singlehanders

Post by Rupert » Thu Aug 06, 2015 7:26 pm

Sorry, I'm a bit of a seat of pants luddite!
Rupert

JimC
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Re: Planing angles for hiking singlehanders

Post by JimC » Thu Aug 06, 2015 9:11 pm

Anything that will log GPS will get you data. The Speed puck will, so will a mobile phone (a waterproof one would be wise!).
So what you could do is to log lots of runs and see what you get. Software like gpsactionreplay will take the log points and give you a polar diagram, which of course will be far more reliable if the wind was steady than if it were shifting all over the place since the software just has to make a guess at average wind direction.
I just looked at a polar from a trace of a morning's racing in my IC, and I was getting the same sorts of speeds roughly in the area 90 - 140 degrees, but dropping off fairly sharply after 140. That suggests that an equilateral triangle (60 degree gybe) would be a better bet than a 90 degree gybe. For a P course I'd be inclined to make one broader and one closer, maybe 100 and 130? BUt then vary it for boat design and wind speed.

Rod
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Re: Planing angles for hiking singlehanders

Post by Rod » Fri Aug 07, 2015 1:42 am

Rupert - Unfortunately I'm a seat of the pants sailor as well but I think it's time to get some hard data. Hiking singlehanders are sort of the exception since they require higher angles to achieve higher speed (then say the two man spin boats or the assyms which are happy with windward-leewards). It's time courses reflected that.

Jim - Maybe you could give us a primer on doing course logging on your smart phone. (I don't own one but I think documenting the procedure to use one in tracking your course would be useful to many.) The International Canoe is a different beast from the ordinary hiking singlehander due to its righting moment. Interesting that you found similar speed over such large angles. I agree that going out in 12-15 and blasting around, getting the angles, then doing the same in 15-18, then 18-20 would help get a more accurate idea of what a fun course would be in that particular singlehander. We just don't have that data at this time. (I expect the Finns and Lasers could give you that data if you talk to one of the Olympic Coaches, though again, what I've seen of the Olympic courses is they don't have hard planing reaches either.)

My experience when I've had hard, fast reaching legs is that, if you are sailing them right, they are up and down - up in the lulls and down in the puffs - and the angles could vary by up to 20 degrees. The technique was to end up slightly high coming into the mark in case there was a puff at the last second forcing you down.

RLM
Rod M
Annapolis MD USA

http://www.earwigoagin.blogspot.com
http://cbifda.blogspot.com/

Classic Moth: 105
PK Dinghy

JimC
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Re: Planing angles for hiking singlehanders

Post by JimC » Fri Aug 07, 2015 12:40 pm

Rod wrote:Jim - Maybe you could give us a primer on doing course logging on your smart phone. (I don't own one but I think documenting the procedure to use one in tracking your course would be useful to many.)
For what its worth, here you are. I'm a raw beginner at this, and have much more to learn.

http://www.devboats.co.uk/gpslogging/

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jpa_wfsc
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Re: Planing angles for hiking singlehanders

Post by jpa_wfsc » Sat Aug 08, 2015 5:48 pm

IMHO, you just need to tape the phone to the mast, with the camera pointing at the helm. Record video as per the GPS system, sailing on various angles, meticulously noting wind speed, etc in a waterproof notebook as you go.

Afterwards, watch the movie. The wider the grin, the more the fun!
j./

National 12 "Spider" 2523
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Rod
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Re: Planing angles for hiking singlehanders

Post by Rod » Mon Aug 10, 2015 1:05 am

Jim,

Thanks for the instructions. I haven't been so geeky to attempt something like that but it does seem the technology is pervasive enough so that anyone could, with some learning of software, construct such a VMG chart.

Back when I was racing the Nethercott IC, my downwind angles were hotter than what you show on your VMG chart. I tried to keep the jib drawing when sailing my downwind angles. Of course you have to figure out the shifts and since hotter angles put you out further from the rhumb line, the penalty for guessing wrong was greater (as it is for digging far out to the wrong side on a beat). I too resisted adding adjustable shrouds. My experience was they added 3-5 boat lengths on a run, but 3-5 boat lengths is 3-5 boat lengths and that is nothing to sneeze at in a race.

RLM
Rod M
Annapolis MD USA

http://www.earwigoagin.blogspot.com
http://cbifda.blogspot.com/

Classic Moth: 105
PK Dinghy

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