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  #1  
Old 06-02-2005, 03:24 PM
im412 im412 is offline
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stabilization at anchor

i have a 20' v hull that rolls at anchor....like they all do
i have been thinking of ways to minimise this effect, without buying another boat

1 water balast to fill at anchor,making a greater mass and empty to motor
2 small outriggers with a bouy on the end to lower at anchor making it a tri and lift up when motoring
3 sailing wooden center boards, externally on each side of gunnels which are lowered at anchor

what are your views of the above and does anyone have an efficent means of reducing roll
i know someone here will have a good idea
cheers jack
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  #2  
Old 06-02-2005, 06:08 PM
tom28571 tom28571 is online now
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Locally we use an old Navy 26' whaleboat as a race committee boat. It can and will roll your guts out at anchor. Has actually tossed (and injured) a crew across the boat in in a beam wake from a passing boat. Our solution is to drop a string of three "flopper stoppers" over each side. Not perfect but much safer and more comfortable. They would be better if hung from outriggers. Cheap and pretty effective.
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  #3  
Old 06-02-2005, 10:21 PM
im412 im412 is offline
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thanks for helping, tom
i've seen the flopper stoppers on the net and they do work and stow very neatly
sorry, forgot to mention i fish in spencer gulf australia and there are some really fast rips
i think it would take too much weight to keep them vertical
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  #4  
Old 06-04-2005, 03:07 AM
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Guillermo Guillermo is offline
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Jack:
Have a look at: http://banjer37msclub.tripod.com/motorsailers.htm Follow the link there for "roll dampening".

In my opinion, for a 20' boat, you can hang a bucket with a weight into it from a pole at the side, keeping it a couple of m depth. It works nicely enough. A more sofisticated version is an stainless steel isosceles triangulum hanged flat from the pole, instead of the bucket. I use two of those in my 37' motorsailer, one on each side. They are cheap, long lasting and work great!

Regards,
Guillermo.
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Old 02-20-2006, 08:21 PM
bilbobaggins bilbobaggins is offline
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You could try rigging a couple of sizeable poles sticking out laterally, the way beam trawlers do, with simple fore/aft guys. Those beams stabilise the trawlers, as a side-effect, and should stabilise you. Something to do with 'radius of gyration', I believe. It has a similar effect on roll stability to a sailboat masted/dismasted.....
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  #6  
Old 02-20-2006, 10:37 PM
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Willallison Willallison is offline
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Jack - what kind of boat is it?
Early Haines Hunters used to have a substantial sized hole in the transom (where the bung would normally be), so that when the boat was at rest the underfloor area would fill with water. as you took off, this would empty. The boats were true 26 degree deep-v's but were light enough such that when at rest the chines were well clear of the water - hence the propensity to roll so badly.
Having said that, hanging a couple of weighted buckets over the side would probably work at least as well!
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Old 02-21-2006, 02:41 PM
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safewalrus safewalrus is offline
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For roll dampening either try the methods as shown by Guillermo above or (depending on the shape of the vessel i.e. if it's flat bottomed forget it) try a small sail at the backend, nor enough to drive her but enough to take the bite out of the roll, this also works whilst moving - slowly! The buckets wont, incidentally if your going to use buckets remember that the average bucket bail (handle) ain't very strong, you may want to beef it up a bit or buy a few buckets!
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Old 02-21-2006, 02:56 PM
TimClark TimClark is offline
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I recently saw an item in the new Cruising World that was a rectangular piece of metal that was hinged at the middle and at the sides that would stop the rolling of a boat by drag not weight. I forget what it was called but it looked like it would work very well.

Tim
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  #9  
Old 02-21-2006, 04:29 PM
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Guillermo Guillermo is offline
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A technical paper on this issue:
http://www.cmst.curtin.edu.au/publicat/2002-08.pdf

Plastic flopper-stoppers:
http://www.setsail.com/dashew/rollcontrol.html

Hinged ones:
http://www.magmaproducts.com/R10-702_707_Assembly.PDF

You may try also a Sea Gyro for a mere $8.999 AU
http://www.webace.com.au/~sea_gyro/
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Old 02-21-2006, 05:01 PM
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Willallison Willallison is offline
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'tis true, your average plastic bucket is unlikely to be up to the job. It may seem unlikely, but they will work better if you put holes in the buckets too....
You could simply, cheaply and more space and weight efficiently make up a vertical equivalent of a sea anchor - a simple cone shaped piece of fabric - sailcloth or similar - with the end cut off, and some weights to keep it pointing in the right direction...
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  #11  
Old 02-21-2006, 06:05 PM
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Guillermo Guillermo is offline
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Quote:
Originally Posted by Willallison
'tis true, your average plastic bucket is unlikely to be up to the job...
I've tried plastic buckets for small boats. They work. And very nicely with some minor surgery at the bottom, making it a flapping valve. Cheap and efficient.
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  #12  
Old 02-21-2006, 07:45 PM
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safewalrus safewalrus is offline
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Conversely don't anchor! Just sail slowly along (motoring is back to square one unless you stem the waves and motor gently into it - then you pitch! if of weak disposition you will still lose your breakfast!
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