Micro cruiser (sailboat).

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

  1. Tiny Turnip
    Joined: Mar 2008
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    Tiny Turnip Senior Member

    For perspective:

    I have three boats.

    First boat is a Winklebrig: http://www.jegsweb.co.uk/boats/winklebrig/winklebrig1.htm

    It is a tiny, but very chubby (16ft) lead ballasted gaffer. We have slept 2 adults and two children on board, but that was extremely cosy. I regularly sleep me and my two boys (11 and 9.) It displaces 650kg unladen, and launches and recovers from the trailer. The launch/recovery, raising/dropping the mast, rigging, stowing etc takes the best part of an hour, without hurrying.

    My third boat is a Solway Dory trimaran
    http://www.solwaydory.co.uk/videos/17 - in effect a 18ft twin outrigger canoe with a modest unstayed main and mizzen.
    two people can carry it, (it weighs perhaps 100kg rigged) the trailer is unbraked. It is just about car toppable.

    In sailing performance, it totally trounces the WB on every front, dispite carrying less than half the sail area. It is nearly 3 times as fast, Points much higher, is stable to the point of being virtually uncapsizeable, (dangerous words, I know!) virtually sails itself. really. tacking and gybing without touching a sheet, and once on a bearing, a little trimming of the mizzen and you can take your hand off the tiller. You could sleep two on board at a pinch, with the addition of a tent, but it is really designed as a camping cruiser for beach hopping. A totally different boat from the WB, of course, and I dearly love the WB, but, with the exception of sleeping on board, (and with a microcruiser/trailersailer, how far away from the shore are you going to be without a tender anyway) I struggle to find *anything* my little chubby ballasted microcruiser wins on. Cuteness perhaps.

    Oh, and the nearly new Solway Dory tri cost me half what I paid for the 20 year old WB.

    BTW, the WB website owner swapped his own WB for a water ballasted Swallow Baycruiser a few years ago...

    http://daisygracebaycruiser20no1.blogspot.com/
     
  2. Petros
    Joined: Oct 2007
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    Petros Senior Member

    The problem with water is it is not very dence, so it makes for a bulky slow hull. Concrete ballast would be removeable if you designed the chamber with proper releif, coated it with wax or polyethene sheets before you put in the concrete. You just need a hand winch or hoist to remove it (you could even rig something up from the on-board equipment to lift it out). And it is cheap enough to leave behind, you can add it to the local jetty or breakwater.
     
  3. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    All this is very true for multihulls - the only downside is the lack of carrying capacity.

    I was very interested in Jarcats
    http://www.duckflatwoodenboats.com/mainpages/gallery?KID=63

    which are a capable, robust and trailerable catamaran - but by the time you try to stow 3 peoples wet gear, snorkelling kits, food, spare clothes, toiletries, bedding, fishing gear, etc, there is no room to sleep, let alone a decent head.

    And somewhere not too cramped to get out of the elements is imperitive to avoid sunburn or hypothermia. Light canvas shelters just dont do the job as well as solid decking.

    Fairly reluctantly, I have decided on a monohull, just for the room and comfort.
     
  4. lumberjack_jeff
    Joined: Oct 2010
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    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    Sugar

    Sugar is readily available, non-toxic and has a solubility of 2kg per liter (1kg) of water @25c. The resulting syrup has a specific gravity of about 1.4 and thus weighs 1.4kg per liter. (11.6# per gallon)

    For 1000# of ballast, pour 660# of sugar in the 87 gallon-capacity bilge and add about 40 gallons of water.

    (the sugar would cost about $300 or so... probably best to make arrangements with the costco nearest the launch site ;) )

    Pump it out when done.

    Is the economics better than trailering the ballast and/or renting a travel lift? I dunno.

    Probably the economical approach is rocks or (sea) water.

    Thought exercise. Please check my logic/math.
     
  5. eyschulman
    Joined: Jul 2011
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    eyschulman Senior Member

    Re; carrying capacity of a tri. Modern tris can have lots of extra boyancy. The weight will hert the performance to the point where it might be as bad as a very good micro mono. Both concepts are poor alternatives regarding creature comfort. If you choise to live in a hole the size of a big drainage tube you might as well go light and have excelent performance with the tri. The modern molded folding tris at 28ft with moderate WL beam and multiple widening flares of main hull actually have decent living spcace as much as many of the older mono designs of the same lenght. The tri also gets the bonus of all that net and ouside room to allow for steching out. For ten years I owned a 26ft Danish micro tri that fit in this catagory.
     
  6. rwatson
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    rwatson Senior Member

    Unfortunately, any multihull will always have a lot less room for a given amount of material.

    And also, you have two, if not three hulls to build.
     
  7. river runner
    Joined: Jul 2011
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    river runner baker

    tris, removeable ballast

    By this point in the discussion I would have thought it was obvious that by removeable ballast, we meant ballast you wouldn't take home with you. In the case of water, you'd pump it into the nearest storm drain. If you increased it's desity with salt (salt is much heavier than sugar), I'm not sure what the legal issues would be, if any. I'd think pumping it int any river that was entering the ocean would work.
    I was just looking at trimarans a few days ago. I've always liked tri's as a trailerable option. One issue is that if I were building it myself, building three hulls and connecting them seems like more work than building a monohull. Monohulls can also carry more weight, though ballast could offset that. One large hull has more useable living space than than three small hulls. Some the tri's I looked at had a central hull that was nearly has fat as a monohull, but it seems to me this defeats the whole concept of the multihull, which is hulls so narrow that "hull speed" doesn't apply to them. I'm looking at something a bit more substantial than a canoe with outriggers. That's a young mans boat. I want to sit in the cockpit and sip a sherry while watching the sun set.
     
  8. troy2000
    Joined: Nov 2009
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    troy2000 Senior Member

    If you're looking for a lot of trailerable microcruiser in a small space, you could do worse than Bill Short's Pelican family of sailboats. They were designed for San Francisco Bay, which means they're fairly seaworthy, and they're well-proven.

    http://www.platypusboats.com/pplans.html

    The attached picture is the Great Pelican: 16' overall, 8' beam, weight 950 lbs. You could probably extend the cabin back, if you wanted more space out of the weather.

    Plans, parts, kits, or finished boats are available from Platypus Boats.
     

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  9. philSweet
    Joined: May 2008
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    philSweet Senior Member

    yep, my kind of pocket cruiser.

    First two- Mac 14 in the Florida Keys. Probably the only one in the US. Used a Jet 14 rig.

    The rest are of my 16' skiff which I started as a teenager and eventually finished 9 years later. Both served long and well and proved to be remarkably versatile. 3.First sail. 4. Ten years later. 5. Twenty years later, and showing a bit of wear and tear.
     

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  10. lumberjack_jeff
    Joined: Oct 2010
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    lumberjack_jeff Sawdust sweeper

    Salt is heavier than sugar (72# per cubic foot vs 53#), but its relative lack of solubility reduces the specific gravity of a dissolved solution.

    A gallon of brine weighs about 3# less than a gallon of syrup. That said... solubility may be a non-issue. Who cares that if salt is completely dissolved? (it'll take a lot of water to wash it out, though)

    Rock salt is cheaper, too. Pour it into the bilge at the ramp and shovel it out on the way back.
     
  11. rwatson
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    rwatson Senior Member

    All in all, I think sand in sand bags, strapped to the bottom of water ballast tanks would be the most flexible arrangement. It has the weight of the cement that has been suggested, without the awkwardness of rocks and their sharp protrusions and potential unavailability, and is easier and cheaper to source than sugar and salt in commercial quantities :p

    You could make the bags small enough to carry really comfortably, and they would bend through small openings. If any escapes, you can do a high pressure flush through the water ballast exit.

    You are virtually guaranteed to be able to find sand not far from a launching place, and you wont mind leaving it behind on the return journey.

    Can you imagine the tooth decay in the local fish population if you released 1000 litres of sugary water ? ;)
     
  12. rwatson
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    rwatson Senior Member

    I really like that trailer sailer - a very useful little boat.

    They are a bit light on with their info, like the ballast type (if any)
     
  13. eyschulman
    Joined: Jul 2011
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    eyschulman Senior Member

    What about a S&S lightning with a small cabin and a kick up rudder. Now you have a beachable boat with lots of used boats and parts available.
     
  14. Seafarer24
    Joined: May 2005
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    Location: Tampa Bay

    Seafarer24 Sunset Chaser

    My 1974 Seafarer 24 was realistically trailerable, and it was the fixed-keel model drawing 3'9" and weighing 3,910#s. The first owner trailered it down to FL from the factory in Huntington, NY behind a 6-cyl minivan and ramp-launched it for years. He eventually bought a water-front home and kept it in the canal behind his house (by this point the trailer had rusted away to nothing and was discarded). When I bought it from him I bought a new trailer for it and used a travel-lift to load the boat so the trailer wouldn't get wet and so the bottom could be pressure-washed by the yard. The trailer had two axles with hydraulic disc brakes on the front axle, and an extendable tongue. I hauled it across FL with a diesel F250 that I borrowed from work, but I moved it around town with my 1/4-ton 6-cyl (4.0L) Jeep Comanche 4x4 and occasionally (carefully) my buddies Suzuki Samurai!

    I've seen someone trailer-launch their fixed-keel sailboat off a beach with an 80's station wagon... and recover the boat later! It wasn't pretty, and the car was a rusty hulk due to putting it seat-deep in salt-water, but it wasn't a particularly steep beach, either.

    A 1,000# - 1,500# boat with a 2.5'-3' draft is definitely trailerable and can be ramp launched with the right trailer and some fore-thought. Extendable tongues and high-tides can keep your car out of the water during the process.

    I'm currently thinking about a 16' fixed-keel cruising sailboat...
     

  15. alan white
    Joined: Mar 2007
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    alan white Senior Member

    Your hull design has no chance. Not to discourage you, but "plank-on-edge" hulls are not very trailerable due to depth and weight. They depend almopst entirely on ballast for stability so they tend to sail "on their ear" (layed down when going to windward).
    Your design is exaggerated (slack-bilged) even for a plank-on-edge model).
    I think it's a good exercise for a novice designer to play with ideas. It is good to make mistakes while learning though it can be costly. Of course, the liklihood of coming up with something truly better is very remote. Others have tried almost every conceivable idea and modern builders are very open-minded (see "Peep Hen" or "Bolger Micro" et al.
    I would suggest you take an existing hull design/sail plan and build on that. The Bolger Micro series (15 and 19 ft), Martha Jane, and other boxy designs combine several features taht you are looking for. Maximum interior space for length, water ballast, simple construction, easy trailering, low cost, etc., etc..
    Look up those designs and see if something appeals.
     
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