Micro cruiser (sailboat).

Discussion in 'Boat Design' started by river runner, Oct 20, 2011.

  1. river runner
    Joined: Jul 2011
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    river runner baker

    A seaworthy cruising sailboat that is realistically trailerable, has been a dream probably since the invention of the auto. There have been a lot of attempts at it, some pretty good, most haven't been very successful. I've seen people towing their twenty seven footers with their pickup, but I think that is crazy, specially if you live in Colorado and need to pull it over mountain passes to get to Puget Sound or whereever. I'm thinking much smaller. Under twenty feet.

    I'm picturing a small boat that, rather than a keel, has a very deep V shaped hull (like an axe head). This would increase the interior volume, especially head room. In the bottom of the V I'd pour lead shot, and over that I'd pour epoxy. Howard Chapelle suggests a Chinese Junk or punt bow to increase space. I'm not a fan of blunt bows, as you may know from my previous posts, but I can see where it might help here. I'd try to strike a balance between maximizing waterline length and giving it good performance in rougher water.

    My question is, would it be possible to get such a design to perform decently.
     
  2. Manie B
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    Manie B Senior Member

    No never
     
  3. michael pierzga
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    michael pierzga Senior Member

  4. rwatson
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    rwatson Senior Member

    Shackleton did one of the epic Micro Cruises - from Antarctica. Historians have ranked the James Caird's voyage as one of the greatest open boat journeys ever accomplished.

    This 23 footer used stones off the beach for ballast - and was definitely towable.

    The use of water ballast is common practice these days, if you cant find enough stones.

    However, the big issue isn't just 'seaworthy' enough ?

    Things like 'sanity preserving', 'enjoyable', 'family friendly' are all equally important.

    A glass net float can travel around the world, so its 'seaworthy', but would you want to do the trip on one ?
     

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  5. river runner
    Joined: Jul 2011
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    river runner baker

    images

    Here are some images of a rough draft. Chapelle suggested a Junk or punt bow to increase room in a small cruiser. I was having trouble getting it to come out right so this one is a "normal" bow.
    I was trying to think of a way of adding the ballast when I got to my destination. I don't think water is dense enough, but something to consider. Rocks off the beach might work if they don't throw me in jail and I could figure a way of keeping them from shifting if the boat got knocked down. I could also keep the lead shot in the back of the truck or buy it at my destination.
    My big concern is performance to windward with this design. Is there any chance winglets or something could save a design like this?
     

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  6. gonzo
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    gonzo Senior Member

    A design like that will be impossible to launch in most places. You may be able to do it with a trailer extension to get it into deep enough water.
     
  7. river runner
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    river runner baker

    I know a place in Port Townsend, Washington that will lift a boat off the trailer and put it in the water. I would think any place where sailboats are popular would have a yard that will do this. I have no idea how much that costs, but I don't imagine it's cheap. I don't know if there are any places in colorado that do that, but there are some pretty good size boats on Lake Dillon and they got in the water somehow. Something else to consider and look into.
     
  8. gonzo
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    gonzo Senior Member

    When you originally posted "realistically trailerable" it would include being able to launch from the trailer. Otherwise, any boat can be transported. If you depend on a crane or travelift, a proper boat will be much better than a contraption compromise.
     
  9. river runner
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    river runner baker

    Gonzo, your point is well taken, but I also want the boat to be seaworthy and I don't think this boat is as deep as you think. The difference in height between the lowest point and the tip of the bow is less than five feet. Put a nice cabin on it and you are probably still at only 6 to 6.5 feet. Draft is around three feet or less. That sounds pretty reasonable for a sailboat. I'm sure a Fallmouth cutter or such would be as much.
     
  10. philSweet
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    philSweet Senior Member

    What you have drafted is a lot like Monroe's Presto boats (not the recent production "Presto" which has nothing to do with the originals). It seems to work ok over a fairly narrow size range around forty feet LOA. His used stones and sand. If you can get the ballast density up a bit, it might work ok on a smaller craft. There are high density liquids used in mineral separation. Kind of expensive, but maybe you could find a 1000# of tired, contaminated stuff cheap at a lab. Pump it into a tank in the truck for transport. I'm kind of surprised I've never seen high density liquids used on boats, I guess they feel the ability to dump the seawater overboard is of greater value. It really doesn't take much time to shift 1000# worth of 50# lead sheets to the truck either. If everything is organized on the boat in containers you won't tie up the ramp much. I agree with Gonzo that when you draw the trailer you will find you need a lot of water and a steepish ramp. You could put a small flat on the bottom to create a guppy belly and reduce your draft by a few inches. Extend a deadwood skeg aft with some drag to it. Once you are aft of the axle, it can drop some more. Overall, I get the impression that this type is a bit fussy to set up well, but yes, they can work. And FWIW, I'm a fan of pram bows. I think they let you power up small boats a bit more. You want enough reserve buoyancy to stand on the bow of your boat and a pram bow delivers this. You are familiar with Wright-Potters and Peep Hens/Marsh Hens?

    I lived on Dillon reservoir for three summers. Worked for the USFS and stayed at Peak 1.
     
  11. rwatson
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    rwatson Senior Member

    Lets see, that's 20 blocks of 22 kilos each. I just bought 6 x 20 kilos of mortar mix, and it wasn't all that big a job.

    But that's only 453 kilos of ballast. That's less than a MacGregors water ballast. An ocean going yacht would might have a lot more than that, say 1000 kilos.

    By carrying a Tonne on the truck, you increase the cost/size/fuel consumption of the prime mover. The standard 4wd pickups (utes) in australia have 1 tonne carrying limit, and that then doesnt allow much capacity for people, gear etc.

    I think water ballast is definitely the way to go if you want towability as well as verticality.

    My ideal is to have water ballast tanks that store fresh water in collapsible containers (you need fresh water at sea you know), that can be topped up with salt water as they get used, and replenished with rain water while out at sea. If the tank hatches are big enough, you could also drop in some of whatever is free at the launch ramp. Sandbags, rocks, old iron, empty glass bottles, or a mixture of all of them.

    No need to tie up the launching ramp either - just flood the tanks, motor over to the nearest quiet beach or industrial wasteland, and start dropping weighty material into the tanks, displacing the seawater. I suppose you could get one of those alluvial pumps they use for gold fossicking, and suck sand and small rocks off the ocean floor. If you used plastic milkcrates or similar, you could packs the sandbags, rocks etc in them to stop them shifting.

    If you are planning an extended ocean voyage, a day or so pottering around getting the ballast right is a small price to pay. Its a bummer if you just want to do a bit of fishing.

    The reality is though, very few people spend a lot of time at sea in a small boat. Its too uncomfortable, and costs a lot in lost wages.
     
  12. Petros
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    Petros Senior Member

    Rather than buying lead shot at your destination why not just buy ready mix concrete, much cheaper and not toxic.

    It could work like this: you have a short and thick hollow keel (perhaps with winglets, or a daggar board), you get to your destination but your next to the last stop is a concrete plant. Fill the keel and stab a couple of steel rebar loops in the top, in a few hours you secure the new ballast through the loops so it can not fall out in a capsize, lay down the floor and launch the boat. When you return to your trailer you can hoist the ballast out by the metal loops and dump it, and you drive home. 4000 lbs of ballast will only cost you about $60. Concrete weighs about 150 lb/cubic foot and cost about $60 a yard if you pick it up yourself (pay cash for a discount ;-)).
     
  13. river runner
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    river runner baker

    Water ballast does seem to have a lot of merit. And with my thick "keel" design might work OK. I'd lose some head room. I'm wondering how much you could increase the density with salt. You wouldn't be able to drink it, but as rwatson says, you wouldn't want to stay out too long on a boat this size. I'm thinking more of cruising the San Juan Islands (Puget Sound can get pretty rough) or some of the islands off both coasts.
    I considered cement too. The problem with cement (or epoxying lead shot in place) is you can't remove it for the trip home. I think removeable ballast sounds like the way to go and water would be the easiest.
     
  14. gonzo
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    gonzo Senior Member

    Removing the ballast from the boat and putting in the back of the pickup is like taking money from one pocket, shifting it to the other and thinking you now have more money. The overall towing weight will be the same. Your chiropractor bill may increase though.
     

  15. eyschulman
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    eyschulman Senior Member

    Why get all tangled up with ballast issues keep the boat light. Go to a folding tri. At 26-28ft you can trailer and launch in shallow water. Good to excellant performence and if you are conservative with how much sail you fly in a breeze a safe platform.
     
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