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Thread: Small Shallow Draught Self-Righting Sailer

  1. #71
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    Default Re: Small Shallow Draught Self-Righting Sailer

    This reminds me of a Parker Dawson.
    Photo coming......
    I love the smell of fresh cut plywood in the morning.

  2. #72
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Has anybody publish an accessible study of windage and its effects on a small sailboat? Especially its effect on windward courses. The fore- and aft-cabin look very useful for righting, but how do they effect one's day-to-day experience? -- Wade

  3. #73
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    Default Re: Small Shallow Draught Self-Righting Sailer

    This guy makes some " can lean pretty far and come back up " boats.

    Kark Stanbaugh
    Chesapeake Marine Design
    basil

  4. #74
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by Daniel Noyes
    ...I would be interested to hear from Craic about the Bay Raider if he gets around to it, maybe start it's own thread...Has your Mag article run yet? can you tell us any more? this is a permanent version of my idea of strapping inflated Gloucester ball to the deck bow and stern... lots of bouyancy up high. Is the self righting achieved with bouyancy and hull weight alone or is there ballast involved? water or permanent? in the centerboard or internal?

    looks like a very capable craft, similar size and weight, little larger transom but very much along the lines of how I envision Centennial...
    Daniel,

    I never submitted the article. I wrote it, but then found it sounded all too self-important, and I did not want that publicity.
    I now have the boat I wanted, and that is enough for me.

    And in earnest, I today think the issue is not really of general interest. There are very few people who need a boat as tough as mine, and those who want one are perfectly able to fend for themselves, or otherwise do contact me privately.

    My starting point was the ocean rowing boats for single rowers. Only, minus too much of the rowing.
    I sent a brief to a few designers for an "oceanable" small shallow draught sailer.
    They came back with big numbers, in money, and especially in terms of timeframe.

    I then looked at making an ocean rowing boat sailable. Got nowhere, they are too tender. So I then looked at making a small shallow draught sailer oceanable.

    That was quicker, more economic, and much easier. I ended with having an already bullet-proof little sailer made practically bomb-proof by a yard with vast expertise in ocean rowing boats.

    Converted stowage area under the cockpit floor level into airtanks, fillable on demand to increase waterballast load, sealed the cabin watertight, added the watertight buoyancy structure over the stern, and reinforced the tiller and the rudder fastening.
    Built a stronger standing rig, modified the sails, and added handrails and fastening points, proper VHF and solar charging.

    I am not looking at crossing an ocean with it, presently, but I now have a boat well suited for my everyday tasks, i.e. mostly Mackerel and big Pollack fishing, and drinking cider on the way home, and which I could also take out much much farther.

    It's really a boat for everyday use, singlehandable of course, and fun to sail in challenging conditions too.

    The biggest benefit I enjoy from it, is the centre cockpit feeling of protection and comfort, and the feeling of having a boat more capable than I am myself. C.

  5. #75
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by Craic View Post
    Thank you for mentioning John Welsfords Penguin and Francois Viviers Meaban in this context. And thanks to Ian McColgin for mentioning Phil Bolgers Birdwatcher.
    Would you know, have they been designed to be, or in practice already proven themselves to be self-righting from any angle i.e. a roller?

    These are cabin boats. Are there open boats out there yet to be selfrighting from any angle?

    As open sailers all I found are the ancient Stromness Lifeboats Good Shepherd and John A Hay at http://www.stromnesslifeboat.org.uk/...n-history.html , and one Phil Morrison designed ocean-rowing boat converted to a sailer.
    Any boat, even the self righting motor lifeboats, will have a range of stability when inverted. Some will have such a narrow range of stability inverted that they take only a little to start them rolling back so they're effectively self righting from any angle.
    To do that with an open boat is difficult, it requires narrow beam and a lot of very high up bouyancy, so you end up with what is effectively a "closed" boat with a big open cockpit in the middle and a lot of ballast as low down as possible.


    To get an open boat that will self right from 90 Deg though is much easier, same as above but less extreme. Note that only in very extreme circumstances will a small boat be rolled past that by wind alone, if she's designed to be able to right from that angle it normally takes wave action to keep her going over.

    I was in one of my 6M Whalers out on a mountain lake a few weeks ago when we were caught flat footed by a 30 knot gust, were knocked flat, and the boat self righted from mast parallel with the water. We had some bailing to do but carried on and won the race. She came up on her own, I was able to get the owner back aboard as she came up and she was stable when upright and swamped. Thats almost as important as being able to right her.

    John Welsford
    An expert is but a beginner with experience.

  6. #76
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by WI-Tom View Post
    John Welsford's Pilgrim was designed to be self-righting from 90 degrees even when half full of water. Might be worth a look.

    http://www.duckworksbbs.com/plans/jw/pilgrim/index.htm

    Tom
    Yes, thats the case. The prototype has been tested and comes back up without assistance.
    Thanks Tom.

    John Welsford
    An expert is but a beginner with experience.

  7. #77
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by john welsford View Post
    Yes, thats the case. The prototype has been tested and comes back up without assistance.
    Thanks Tom.

    John Welsford
    John,
    I applaud you wholeheartedly for making your designs so safe. In Europe minimum safety is a legal requirement for all production boats. Home-builts are still exempt, unless they are to be sold on. Beats me why many designers and home-boatbuilders still ignore even the most basic safety regulations re angle of vanishing stability and self-righting. They are there for good reason, and, if cleverly adapted, can still result in excellently performing boats. C.

  8. #78
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by Craic View Post
    John,
    I applaud you wholeheartedly for making your designs so safe. In Europe minimum safety is a legal requirement for all production boats. Home-builts are still exempt, unless they are to be sold on. Beats me why many designers and home-boatbuilders still ignore even the most basic safety regulations re angle of vanishing stability and self-righting. They are there for good reason, and, if cleverly adapted, can still result in excellently performing boats. C.
    Thanks Craic. I get to go sailing in quite a few of my boats, so its not only the safety of my customers thats a factor in the designing of my boats, but also my own hide is on the line.
    I was away cruising with a group of four boats in the Marlborough sounds a couple of weeks ago, a 6M Whaler, a pair of Navigators and a SCAMP. We had some challenging conditions, and a great deal of fun. Look up "Kenepuru Capers" on Weebly, we're going to try and do it again next year.

    John Welsford
    An expert is but a beginner with experience.

  9. #79
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Most boats naturally meet the requirements in the ISO standards for their intended purpose. In this case for open boats it would be Design Category 'D' (.5 metre seas and F 4 or up to 17 knots wind) , or possibly 'C' ( 2.0 metre seas and F 6 26 knots wind). A small expedition boat should be easily righted or self righting from a mast in the water knockdown. It is not really that difficult but it does require intent.

  10. #80
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by gilberj View Post
    Most boats naturally meet the requirements in the ISO standards for their intended purpose. In this case for open boats it would be Design Category 'D' (.5 metre seas and F 4 or up to 17 knots wind) , or possibly 'C' ( 2.0 metre seas and F 6 26 knots wind). A small expedition boat should be easily righted or self righting from a mast in the water knockdown. It is not really that difficult but it does require intent.
    I find that to meet 'C', or "Small Expedition Boat" its much easier to start with a blank sheet of paper and the intention to design to that than it is to try and modify an existing boat. That might sound obvious but a lot of people try.

    John Welsford
    An expert is but a beginner with experience.

  11. #81
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by Craic View Post
    Daniel,

    I never submitted the article. I wrote it, but then found it sounded all too self-important, and I did not want that publicity.
    I now have the boat I wanted, and that is enough for me.

    And in earnest, I today think the issue is not really of general interest. There are very few people who need a boat as tough as mine, and those who want one are perfectly able to fend for themselves, or otherwise do contact me privately.

    My starting point was the ocean rowing boats for single rowers. Only, minus too much of the rowing.
    I sent a brief to a few designers for an "oceanable" small shallow draught sailer.
    They came back with big numbers, in money, and especially in terms of timeframe.

    I then looked at making an ocean rowing boat sailable. Got nowhere, they are too tender. So I then looked at making a small shallow draught sailer oceanable.

    That was quicker, more economic, and much easier. I ended with having an already bullet-proof little sailer made practically bomb-proof by a yard with vast expertise in ocean rowing boats.

    Converted stowage area under the cockpit floor level into airtanks, fillable on demand to increase waterballast load, sealed the cabin watertight, added the watertight buoyancy structure over the stern, and reinforced the tiller and the rudder fastening.
    Built a stronger standing rig, modified the sails, and added handrails and fastening points, proper VHF and solar charging.

    I am not looking at crossing an ocean with it, presently, but I now have a boat well suited for my everyday tasks, i.e. mostly Mackerel and big Pollack fishing, and drinking cider on the way home, and which I could also take out much much farther.

    It's really a boat for everyday use, singlehandable of course, and fun to sail in challenging conditions too.

    The biggest benefit I enjoy from it, is the centre cockpit feeling of protection and comfort, and the feeling of having a boat more capable than I am myself. C.
    "I then looked at making an ocean rowing boat sailable. Got nowhere, they are too tender. "

    interesting, this is just the route taken by Johanson, the banks dory has very little initial stability but loads of reserve once the rail gets down near the water... though to be fair the dory men were avid sailors of their banks dorys, which could even go to windward a little once half full of fish.

    I'd be interested to hear how you like the cabin set up you have, what would you do differently if given the opportunity.

  12. #82
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by Daniel Noyes View Post
    , ...
    I'd be interested to hear how you like the cabin set up you have, what would you do differently if given the opportunity.
    Inside the cabin no standard mattresses, but two giant outdoor bean bags filled with styrofoam pellets, for extra buoyancy. The bean bags are great, they adapt to any heeling of the boat or body position from sitting to lying, and can be stuffed aside without ado for getting at the hard stowage compartments underneath. For dry small stuff stowage only canvas pockets along the outside walls, nothing edgy protruding.
    There will be anchoring points for strapping me down in rough seas.C.

  13. #83
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    Default Re: Small Shallow Draught Self-Righting Sailer

    very interesting... Im liking the bean bag idea... can these just be lashed down over gear and water bottles to hold them in place?

  14. #84
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Someone I know has a small bean-bag cushion (plastic pellets) for putting on a thwart during sailing, and it seems to be a great little thing but the store that sold them doesn't carry any more, and I can't find one elsewhere. -- Wade

  15. #85
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by wtarzia View Post
    Someone I know has a small bean-bag cushion (plastic pellets) for putting on a thwart during sailing, and it seems to be a great little thing but the store that sold them doesn't carry any more, and I can't find one elsewhere. -- Wade
    Try Ebay: http://www.ebay.com/itm/In-Outdoor-L...BdkXY9qjIgycUA

    My giant size ones were about € 50 incl. postage, each.

    Yes, the bean bags instead of the usual mattresses are a cheaper and better solution. You're welcome to it.

    I got the idea initially because I spent some time sleeping on sailbags of a big yacht when I was young. And slept like a log there. So the idea to get me bean bags was not so far off for me. The styrofoam pellets inside are a bonus buoyancy feature. There are several small boats out there relying solely on styrofoam for safety buoyancy. I think the extra fixed buoyancy reserve from my two giant bean bags is near 0.4 tons, which is about the dry weight of the hull and centerboard. Meaning, my boat would still float even if all its airtanks would have been flooded. C.
    Last edited by Craic; 03-28-2017 at 03:07 PM.

  16. #86
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    Default Re: Small Shallow Draught Self-Righting Sailer

    wow yes, i'm imagining the bean bag might nestle in nice between the side and the centerboard trunk... they could be relatively easily pushed out of the way to get at gallon water bottles etc that I plan on storing low down either side of the CB trunk...

    certainly worth serious consideration, thanks.

    have you spent any nights at sea in your craft? have you slept aboard often?

  17. #87
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    Default Re: Small Shallow Draught Self-Righting Sailer

    This may sound ridiculous ! But the addition of a modern cars airbag with a sensor for submersion , atop the mast , a good or bad idea ? Even an automatic PFD type CO2 canister inflation device packed in a small aerodynamic teardrop shaped container like tiny mast float . So as to keep sail rig from going under . Would this idea possibly help the vessel able to easily right itself . Also if the vessel had twin side ballast tanks , the lowest tank (when boat is capsized ) could drain automatically therefore assisting /causing the boat to swing upright . I am very new to the sailing scene .
    Last edited by WAGrunter; 04-05-2017 at 06:53 AM.

  18. #88
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Simpler and more reliable are masthead floats, which have been around for decades. Also been done are foam sheets sewn into the top panel of a small boat's sail. It doesn't take much buoyancy at the end of a mast to stop a small boat from going completely over. The first masthead float I ever saw was on the now antique AquaCat, the first popular production catamaran. That was back in the '60s.

    But a CO2 triggered unit, of course. I wouldn't be surprised if it's not been marketed somewhere already. But there's a big jump in expense with that and the reliability would be less than fixed flotation. If you're not in a race, the drag isn't a big deal. More currently, the G32 catamaran has them, and they are very fast, float and all.

    -Dave

  19. #89
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by Woxbox View Post
    Simpler and more reliable are masthead floats, which have been around for decades. Also been done are foam sheets sewn into the top panel of a small boat's sail. It doesn't take much buoyancy at the end of a mast to stop a small boat from going completely over. The first masthead float I ever saw was on the now antique AquaCat, the first popular production catamaran. That was back in the '60s.

    But a CO2 triggered unit, of course. I wouldn't be surprised if it's not been marketed somewhere already. But there's a big jump in expense with that and the reliability would be less than fixed flotation. If you're not in a race, the drag isn't a big deal. More currently, the G32 catamaran has them, and they are very fast, float and all.
    --- Seems as if the drag could be almost negligible if the float were tear-drop-shaped rather than spherical. -- Wade

  20. #90
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Quote Originally Posted by WAGrunter View Post
    This may sound ridiculous ! But the addition of a modern cars airbag with a sensor for submersion , atop the mast , a good or bad idea ? Even an automatic PFD type CO2 canister inflation device packed in a small aerodynamic teardrop shaped container like tiny mast float . So as to keep sail rig from going under . Would this idea possibly help the vessel able to easily right itself . Also if the vessel had twin side ballast tanks , the lowest tank (when boat is capsized ) could drain automatically therefore assisting /causing the boat to swing upright . I am very new to the sailing scene .
    --- I have seen some designs on small trimarans where the amas are open at the transom. While sailing, the water direction keeps water out. In capsize, they flood, allowing a relatively easy righting event, and then they drain.

    I think the trick is to design the ama interior to drain the water without being left with an inefficient hydrodynamic form and volume-distribution. That is to say, a modern ama tends to have its deepest point near the middle or a bit forward of the amidships location, then the rocker curve sweeps up more sharply to the stern than it does to the bow. This would tend to allow water to pool inside the ama before it reached a level that would drain from the open transom. You can build a "ramp" (floor, sole) inside the ama angled to constantly drain the water out the stern, but then you have an enclosed volume that, if too large, interferes with righting from a 180 (ignoring issues from having yet another enclosed space you have to air-out between cruises).

    Alan Stewart designed and used a small-ish trimaran, Mosquito, for the Watertribe Around-Florida endurance race. His transoms were open, and when I asked him about them, he did have a method to drain them, something like a ramp or perhaps form-fit foam, but I forget the details, and also do not know to what extent the flotation volume due to the draining geometry would affect righting. I am guessing that, if we sketched it all out, the result would be that the weight of a crew person would be adequate to overwhelm the small enclosed volume inside the ama during righting.

    I built a "safety ama" for my single-outrigger after I added a taller mainmast and discovered that if I were lazily sailing inside the main hull during a day of bad wind, a dragon-fly fart would still knock-down the boat -- and that is with an 80 pound ama 6 feet out from the centerline of the canoe hull! Nobody was more surprised than I was. So I built a simple V-hull safety ama suspended over the water during flat sailing, and on a relatively short set of telescoping tube-cross-beams, with both an open transom and a kayak-drain-plug at the bottom of the rocker curve. The transom hole has a plastic cover pulled tight against the transom with an internal bungee cord to ward off water entry from astern (in rough coastal water the safety ama is pretty much as wet as any trimaran ama, so I guess the outrigger suddenly becomes an asymmetric trimaran when in salt water :-) ).

    At the end of the afternoon cruise I open the drain plug and generally a pint of water comes out. The first iteration had a simple hole at the bottom of the rocker curve, on the theory that while in motion the ama would generally drain. I tested this in the lake, heeling the canoe over to make sure the ama was pressed down. When released on the other tack, some water did drain out (there goes the hard version of my theory) but really, the safety ama still did its job and I didn't have to worry about remembering to open the drain to air out the ama later. I added the plug after getting out on the coast in the usual 2-3 foot chop and noting that the ama was usually enveloped in waves. I could raise it higher, as on the Hawaiian sailing OC's, but then, windage. Such is life.

    On the new outrigger I am designing/building, I think I want to have a strip-built ama (for nice shape) but just make it hollow with a Beckson port in the transom, and if I capsize 180,then I will have to open the port to flood it (the main ama will probably be solid foam glassed over, light enough to cause no real problem in rotating it over as I sink the safety ama). -- Wade
    Last edited by wtarzia; 04-07-2017 at 01:04 PM.

  21. #91
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    Default Re: Small Shallow Draught Self-Righting Sailer

    Better close this thread before the thread drift gets worse. Thanks to all contributors who kept focus over the years.
    Feel welcome anyone to open a new thread about small shallow draught sailers NOT self-righting unaided from every angle of inversion. There should be lots. Craic

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