Flopper stoppers

FrancisRutter

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I have been trying to make a flopper stopper. I have a rectangular piece of 3 sixteenths ply, 12 by 15 inches with a string at each corner. On one long side I crewed a weight. It proved to be far too much at 5lbs so I took it off and recast it at 9 oz. The board goes down happily enough on the weighted side, but then comes up again still on its edge, so not providing any resistance to coming up. I have cut down the weight again to 7oz without improvement.
How do you make these things work?
 
The ply needs to triangular. I quote Hiscock' It should consist of a traingular piece of ply, with a weight at it's centre to act as ballast and another weight at one corner; a line from each corner is taken to shackle to make a three legged sling and the whole affair is uspended below water from the end of spinnaker boom. When the yacht rolls toward the damper the strain comes off the sling and weighted end will dive; when the yacht rolls the other way the triangle on its sling resumes a horizontal posture and thus offers strong resistance'. The dimensions depend upon the yachts length - the one he made for Wanderer IV (49ft) was 2ft along each side, but it could have larger with advantage. They do work, but perhaps only reducing roll by half.
 
With lots of rolly anchorages around here, I've been thinking about the same, but is there I wonder a fabric bag or similar version that just packs away neatly? Anyone know?
 
The triangle is the one, exactly as stated, Im know they work, but bigger, better!
I made some from steel galvanised grating, square suspended at each corner, with rubber mat covering the top, held on around the edges with tie wraps, then took a knife and split the rubber diagonally, both ways, almost like a joker valve, suspended from spinny poles, two of them, one each beam, when rolling, grid goes down, flaps open, pulling up flaps close, lots of resistance, mine are a meter square and stop her rolling dead! 57' 48 tons and she rolls on wet grass!
You can just suspend them over the sides, made fast to a good cleat, well under the water, but the "torque arm" of the spinny poles makes a huge difference. Stops folk anchoring near you as well.
 
LakeSailor may be able to help you out on this one. Certainly, he'd have pictures of how they are rigged!! ......hopefully!

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
 
Sorry folks, but can someone please explain to me what Flopper Stoppers are, and what/when they are used for?
Cheers, Non understanderflopperstopper. /forums/images/graemlins/blush.gif
 
Ah Yes.

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Read about them http://www.cmst.curtin.edu.au/news/fsc/index.html
 
They stop the boat rolling at anchor when the waves are on the beam. You can buy ready made ones which look just like the cones you see on the motorway, or you can make more or less elaborate ones as the original poster is attempting. I think his dimensions, 12" x 15", are way too small.
In a recent PBO there is an article by Andrew Simpson, I think, explaining how he made his, which he claims is quite effective.
I've never bothered with them myself. I use a bridle from anchor rode to a stern quarter to bring the bow into the swell when it is on the beam and the boat is lying to the wind. If this doesn't do the trick, I move.
 
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I use a bridle from anchor rode to a stern quarter to bring the bow into the swell when it is on the beam and the boat is lying to the wind. If this doesn't do the trick, I move.

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Worth a try if there's enough wind or tide to hold her in one position. We're off to Tenby this week with a bit of luck, and it's well known for its rolliness in flat calm. God knows where it comes from! I was intending to drop a stern anchor to line us up and get a quiet night, but will have a go at the bridle idea. Bucket from the boom-end is plan B.
 
Mine are also used to stop her rolling when peeps come screaming by in motor boats and those effin ferries all over the bollyolics!
 
It has usually worked for me but you're right that you need something, tide or wind, to influence how she lies. The easy way to set this up is, after you are settled on your anchor, attach a line to your anchor rode, I use a rolling hitch, take the line to a stern cleat or winch, then let out more anchor rode and the bow will shift round as the anchor rode lead moves aft. There's a sketch on my website in the 'Happy Hooker' article under cruising resources.
 
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