Capsize Prevention Devices

Discussion in 'Multihulls' started by brian eiland, Jan 16, 2012.

  1. brian eiland
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    brian eiland Senior Member

    It has been quite awhile since I looked for this subject,...and even my search thru the forum didn't bring up the word in a subject thread titled thusly.

    I was looking thru some material on a new 60' hi-performance cat claiming capabilities of single-handed operation with a hi-aspect sloop style rig, and they mentioned this 'UpSideUp' system with multiple capabilities. I went looking for what equipment was specifically doing the work of safely releasing the loads. Here is what I found:
    http://www.oceandatasystem.com/?mode=developpement-ods-peripheriques

    So I ask, has anyone had personal experience with this equipment? ....or any competing hardware they would like to put forward??
     
  2. Silver Raven
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    Silver Raven Senior Member

    Brian - Ues I have - - back in 1967 - it worked then & still does. Back to you. Ciao, james PS OH by the way it never failed to work. Was to simple so no one was interested. jj
     
  3. basil
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    basil Senior Member

    Hi Brian,

    All the design work that's gone into self righting multihulls over the years just may be for nothing. What a simple solution to an overload situation.

    And a cheap price to pay considering the potential consequences.

    Maybe Doug Lord could combine a version of this system in conjunction with his self righting project. It would be a way simpler system than flotation devices-canting rigs-flooding hulls-water ballast- canting keels- canting amas etc etc.

    Bas
     
  4. hump101
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    hump101 Senior Member

    Vessel capsize is not just down to oversheeting or late sheet release, so whilst these devices are an excellent contribution to safety in many circumstances, would they make you sleep any easier if you are singlehanded lying a hull with bare poles?

    There is a place for these systems, and they probably cover 90% of the dangerous situations, but most of these could be avoided by judicious reefing. Selfrighting still has a place for the remaining 10%, which are much harder to avoid, and thus remains a valid goal, imho.
     
  5. brian eiland
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    brian eiland Senior Member

    Now when I look at the actual devices that are acting to 'release the sail loads' I see two basic themes:

    1) Sheet releasefrom cam cleats
    2) Winch with reversing option
    http://www.oceandatasystem.com/?mode=developpement-ods-peripheriques

    I've never had the occassion to experience the newer winches with backing capabilities, so I can't really comment on their true capabilities of instant release in emergency situations.

    I have however had occassion to use a releasing cam cleat. there was a German company that produced one that I placed on the 'kick-up' centerboard lines onboard a Louisiane 37' catamaran I imported from France, and on the Firefly trimarans I was involved with.

    Basically this releasing cam cleat was mounted on a plate that was allowed to pivot forward in a manner that allowed the sheet line to escape from the top between the cam cleats. The control of that mounting plates 'rotation release' was by a spring loaded detent pin that was adjustable by a micrometer type screw knob. They worked very well.
    http://www.boatdesign.net/gallery/showphoto.php/photo/4907/ppuser/399


    It appears as though the UpSideUp system is making use of this similar arrangement with harkem cam cleats mounted on various plates and/or arms of a certain length.

    My question though is are these cam cleats really capably of carrying the sheet loads of these BIG multihulls??
     
  6. philSweet
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    philSweet Senior Member

    If you want merely a fusible link rather than a management system there are the gadgets climbers use called screamers.

    http://www.rockclimbing.com/Articles/Gear_and_Reviews/Review_The_Yates_Screamer_243.html

    At $12 a pop, they're cheaper than resewing your genny. Simple gadget, can be engineered for any activation load and made at home if you have a sewing machine. Makes sense for a gybe preventer or centerboard holddown or backup CB pennant (to catch a dropped board). Could be built into a genny car control line to slack the car position and reduce lead angle, both of which unload the sail. You would need extra track length for this to work, though. Odd that they don't show any autorelease jammers.

    I wouldn't think it would be too hard to design a jammer and deck organizer combo that would sense and release the lines.
     
  7. eyschulman
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    eyschulman Senior Member

    I secound Brians statement about a pop up load releaseing cam. I had two of these units on my tri back in late 80s. One on rudder and one on the board. They are adjustable simple and they worked for me for 10 years. If used on sails they may be of considerable value but I doubt if they would stop a pitch pole event once the bow gets tripped at speed.
     
  8. Corley
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    Corley epoxy coated

    Well Sodebo uses the upsideup system and it operated on several occasions during his solo round the world attempt including his famous 'plante' in Quessant. Francis Joyon also has the system fitted to IDEC are they big enough tri's for you?
     
  9. pool
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    pool Junior Member

    The easiest way, for a bigger boats/higher loads, would be hydraulic sheet trimming cylinders with an emergency release valve. They would tie easily into the upsideup system.

    Comparable manual systems are common on racing monohulls for boom vangs, for instant release should a boom dip into the water.

    Harken has sheet trimming cylinders for various sail sizes in their regular hardware catalogue.
     
  10. philSweet
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    philSweet Senior Member

    In most cases, I think I would rather have something other than the handed end release. Too easy to get someone sucked into the works if a big jammer pops in the middle of general chaos. The load release should be managed from the fastened end or through an intermediate purchase located out of harm's way. Perhaps a liability issue?

    Thought of another load sensing idea. Fiberoptics in the rope itself. Inject a polarized light source and read the change in polarization a foot or two away.


    found this.- http://en.wikipedia.org/wiki/PHOSFOS

    shine a light on the rope and the reflected frequency would be proportinal to stress.
     
  11. brian eiland
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    brian eiland Senior Member

    Simply System

    I was cruising thru a subject thread on the capsize of Anna (57 Chris White cat), when I ran across this submission;

    "I used to sail a 48ft Paul Lindenberg, plywood cat in the daysailing tourist business.
    The mainsheet was not cleated to a horn cleat, but led thru a block to a pedestal mounted jamb-cleat. The jammer had one fixed jaw, and one pivoting jaw operated by a 12volt solenoid, which itself was powered up by a pendulum operated micro switch. The helmsman could manually snatch the sheet from the jammer, but the electro set-up also worked well. Once a week, me and the boys would fly a hull and test it. It was always interesting.
    This BTW, was back in the early 70's, so what we are discussing here, is nothing new to the game."


    It made me think back to the early multihull days when the use of these pendulum operated switches were utilized...pretty simple and straight forward...not relying on various load sensors for different situtions...nor the complications of these load senors. Then straigth forward release of a pivoting cam/jam cleat.
     
  12. cavalier mk2
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    cavalier mk2 Senior Member

    There is a diagram for those in Jim Brown's book "The Case for the Cruising Multihull."
     
  13. Skint For Life
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    Skint For Life Junior Member

    I have also considered similar devices. From an amatuers standpoint one thing concerns me.

    Is dumping the sheet always the best option?

    I'm thinking of this scenario, sailing a catamaran, running almost directly downwind with all sail up, sail hauled in tight, if the wind gets up and the boat starts to capsize the pendulum swings and dumps the main. All of a sudden the boat is powered up dramatically and launches itself into capsize/pitchpole with added enthusiasm.

    I hope this makes sense. :)
     
  14. Petros
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    Petros Senior Member

    one of the more common capsize is caused by pitch poling (going over straight forward) when pushing hard at speed. This is especially common in cats and tris where the forward volume of the bows is relatively small. Once the bow is buried there is no more floatation as it goes deeper, and all forward momentum stops. Inertia carries you over. I doubt releasing the sheets will stop you at that point.

    There was a thread on this topic a few years ago with a number of dramatic pictures of large tris and cats pitch poling.

    It is not that common to capsize over sideways unless there is one at the helm (which should not happen).
     

  15. cavalier mk2
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    cavalier mk2 Senior Member

    Those devices can be turned off. You could set just the jib to let go. In heavy weather running it makes sense to have the main down and then a jibsheet release would have a better chance. Set 2 jibs with releases to compensate for loss of area, they will also help with any broaching tendencies. Of course a down hill pitchpole release needs to work on a fore and aft axis, maybe one could be set to work at fore and aft and side angles or adjust to wind and boat direction.
     
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