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PostPosted: Sat Jul 16, 2011 7:23 pm 
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Location: little Washington, NC
Here is a rough, worst-case computation showing what it takes to right a Hobie. I didn't "cook" the numbers. Frankly, they were a surprise to me. Since I typically sail alone, I'm glad I have a righting bag!

If we use Karl's rigged weight of 37 lbs (does that include all halyards, stays, shrouds, boom, and sails?) we get 18.5 lbs at the tip (it is actually less since more of the weight is closer to the foot of the mast.) We add that to the 2 2/3 (2.66) lb Bob at the top for a total just over 21 lbs applied at the tip. The mast of an H-16 is 27', but the tip is closer to 29' from the point of righting rotation. 21 X 29 = 609 ft-lbs of force RESISTING righting.

I have not included surface tension which will significantly increase that number.

According to Johnny's post, he and his girlfriend, together weigh 305 lbs. My guess is that a reasonable leaning angle will only result in a righting moment arm of no more than 3' to 4'. If both were completely horizontal the moment arm would only be about 5' (feet to shoulders for someone 6' tall). The crew weight is concentrated more at the upper body, but for ease of calculation and since his girlfriend is likely shorter than he is, lets say their combined weight is distributed evenly over 4'. The righting force they are able to create is then 4 X 152.5 = 610 ft.-lbs.! That is not enough to overcome water on top of the sails or surface tension under them.

These are not the numbers you want to see! You need to be much taller or weigh more!

A Hobie righting bag will supposedly hold 150 lbs of water. Using a more reasonable and conservative weight of 100 lbs and the same 4' moment arm (at the shoulder), the bag provides an addition 400 ft-lbs of righting force and should make it much easier to right the boat.

Please don't beat me up because I used some shortcuts, but this gives you a good idea why it can be difficult to right a Hobie, and why following proven procedures, and/or using a righting poll, righting bag, special techniques, etc. may be necessary.

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'86 H16, Sail #89057


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PostPosted: Sat Jul 16, 2011 8:06 pm 
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Location: Northfield Minnesota
37lbs is for my mast, which is an aluminum F16 mast that is just the rigged mast. No shrouds forestay or spinnaker halyard.


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PostPosted: Sat Jul 16, 2011 8:51 pm 
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Location: Clinton Lake Kansas
Karl Brogger wrote:
Also, how much does a H16 mast weigh.
That's a good question, I know the 18 mast weighs close to 60 lbs.

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PostPosted: Sat Jul 16, 2011 11:30 pm 
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My crew and I have a combined weight of 450 pounds (115 kg) we are both 73 inches tall and was practicing righting my boat the other day in 3-5 mph winds. We were able to do it quickly and easily by both of us standing in line with the dolphin striker and pulling on the same part of the righting line. We capsized (on purpose for practice) four times and forgot to uncleat the jib and main sheets. That made a difference of righting the boat in 30 seconds vice righting the boat in 8 minutes. I think it harder to capsize a 16 in no winds that was to right. Just gotta get your ducks in a row and seal your mast.

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PostPosted: Sun Jul 17, 2011 4:05 am 
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Dear Contributors,

Some excellent material being added to this debate....this is literally a whole world of experience coming together on a single page....please keep adding.

I suspect that the solution to my current 'problem' is not a single issue but the culmination of a lot of small issues...e.g, reduce or eliminate the weight of the mast float, better crew positioning on the righting line, a slightly better angle of the capsized cat to the wind direction, cleating the jib on water side etc ect.

All of the contributors are helping to compile this 'refinements' list. Thanks, and keep talking!

Paul


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PostPosted: Sun Jul 17, 2011 6:46 am 
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I think if you are sailing with two people and together you weigh roughly 300 lbs, you both dont really need to get on the hull. Use your crew as your 'righting bag' particularly if she/he is shorter than you. The taller person on the hull with the righting line wrapped around the trap harness and at a suitable angle only has to grasp the hand of their 'righting bag' and pull up while the person in the water lift themselves up. It takes little effort at all. (much easier than fighting with a real righting bag..try it) Also all those bungee big dollar righting line systems only wear you out fighting them. A simple rope tied to the dolphin striker will do.


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PostPosted: Sun Jul 17, 2011 7:14 am 
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Outstanding aschaffter, thanks for the work!

To complicate this further, what about the affect of something like the solo righting system?

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PostPosted: Sun Jul 17, 2011 9:49 am 
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Location: little Washington, NC
Remember, though they are in the ball park, my figures are VERY rough. If I get bored someday, I take some good measurements and do a better job. I can probably even make up a simple formula where all you need to do is enter your weight and height to see whether you can right your H16 solo.

Something I mentioned in an earlier post is that if you can reduce some of the surface tension by getting some air under under the sail by lifting the sail or rocking the boat, that will help quite a bit. Also, righting gets easier as the mast starts coming up since its moment arm gets shorter and the force it applies is reduced.

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'86 H16, Sail #89057


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PostPosted: Mon Jul 18, 2011 4:53 am 
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Location: Saint John, NB Canada sailing on Washademoak Lake
I nearly capsized because my main would not uncleat, told my crew that was the closest I've ever been to capsizing (only 2nd summer with boat). Not 5 minutes later, we were capsized.

So I uncleated the main and traveller, uncleated the jib and could not get it up with just the righting line that came with the boat from under the hull. If I was passing it over the hull, it was only long enough for one of us. So I used my tow line which was attached on the dolphin striker. I passed it over the hull and tied a loop in it so I would have a good grab. That was not enough still.

Then I followed the advice of a fellow Hobier in a Getaway that we were sailing with and unhooked the upper main block from the boom and up she went.

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1978 Hobie 16 Keoke, sail# 36 84
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PostPosted: Mon Jul 18, 2011 9:50 am 
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56kz2slow wrote:
Then I followed the advice of a fellow Hobier in a Getaway that we were sailing with and unhooked the upper main block from the boom and up she went.

Are you saying that the weight of the boom made the difference?
I had not thought of that... :idea:


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PostPosted: Mon Jul 18, 2011 9:55 am 
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Location: Saint John, NB Canada sailing on Washademoak Lake
wildlatin wrote:
Are you saying that the weight of the boom made the difference?



Not the weight of the boom, but the sail/water on sail. When we tried to right it, the sail would not come out of the water.

After unhooking the upper block from the boom, the boom/sail went perpendicular to the boat, it did not seem to want to move all the way out otherwise.

I guess another option would have been to manually force all the main sheet out of the blocks and force the traveler out to get the extra movement. But it was quicker to just unhook the upper block from the boom, I have a snap shackle, so just need to pull the pin and it's off.

It was a breeze to right it with the main unhooked, jib uncleated and righting line over the hull. I'm 5'10" 155 lbs, my crew about the same height, 150 lbs. I also needed to use my tow line as my righting line was not long enough to get lean back far enough to get the required leverage.

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