Affordable, long-term liveaboard?

Discussion in 'Projects & Proposals' started by Filmdaddy, Aug 4, 2005.

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  1. Yobarnacle
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    Yobarnacle Senior Member holding true course

  2. Yobarnacle
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    Yobarnacle Senior Member holding true course

    I'm licensed Master of Towing Oceans up to 3000 tons. Issue 8 of my license. Renewed every 5 years. (8x5=40 years plus) :D Uh, that's a 3000 ton TUG. Any size on the towed vessel.

    Will it give me an aggregate waterline length and greater hull speed?
    Don't know. Suspect not. The hulls aren't contiguous. if the bow of the pusher matched the stern of the barge and bottom was flat from one hull to other, MAYBE it would be, regards hydrodynamics, a single hull.
    But breaking the flow of water along the hull, I suspect I'll have TWICE the wave making resistance.
    But the whole point of having trailersailors is, if I want to go FAST? I take the highway! :)
    otherwise, I'm content to poke along leisurely.
     
  3. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Since I won't be towing commercial, and everything together is under 20 meters in length over all? I don't think a license is required. unless you have an accident, God forbid! Then, you maybe guilty of infractions you never imagined! If you are the cause of an accident, the Coast Guard is NOT your friend! :(
     
  4. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Oh, in reference to the Hobbyking motor urled above.
    The voltalge, 3000kv isn't kilo-volts. In RC speak, that lower case k = RPM.
    the motor turns 3000 RPM per volt input. And max volts 14.8v, times 3000 = FAST!
     
  5. Sailor Alan
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    Sailor Alan Senior Member

    Now i look back i see my ‘post’ was in reply to a ‘post’ from 2005. Oops.

    I would use open topped, not evacuated (too expensive) reflectors, but they might need a glass top, for air insulation. This glass, or the mirrors, would need to be washed every day, hence the water-maker on board.

    Each small section would have its own turbine, re-purposed from a car or truck ‘Turbocharger’, the turbine bit, cheap and available. I imagine perhaps 20+ of these independent steam cycle circuits. I would consider using naphtha (cheap) for the operating fluid, or similar, to keep total temperature down.

    Each turbine would have an alternator re-purposed from a car or truck alternator, with the diodes cut off. i think these produce 3 phase, 55V ‘free’ and are still rated for their original amps. These would run very fast, being direct coupled to the turbine.

    The large number is a direct result of re-purposing ‘found’ materials.

    I suppose it could derive DC from each alternator, as in the original car, but i am suspicious of current eddies and reverse flow in the DC buss.

    Rectifying the multiple frequencies at one place is simply so this energy can be stored in regular Lead acid batteries, cheap and efficient, if heavy. If you don't need to store the electricity, you still need a completely different frequency for the drive motors.

    Finally, the DC from the batteries is inverted into 3 Phase AC for the main motors, 2, or perhaps 4 of them, one at each end of the hulls.

    AC motors with a very thin plastic membrane, or sheet between the rotor and stator have been around for a while. I installed dozens nearly 40 years ago in Germany, they were called “Kiwi Pumps” and may well have been made in New Zealand. I used them to pump water, hot water, radiator water etc in high rise buildings. The thin ‘liner’ allowed the rotor to run in the fluid, water in this case, and the bearings to be lubricated by it too. With hot water, or radiator water, the rotor was hardly ‘cooled’ by it though.

    Today, Grundfoss, seem to use the same technology for their deep well pumps, and i suspect the motor units on large cruise ships use it too. No bearing seals, the rotor and propeller run in water. http://net.grundfos.com/doc/webnet/versaflo/benefits.html

    Clearly slightly less efficient than a regular motor, the air gap must be bigger, by the thickness of the liner at least, but clearly an advantage in some circumstances.

    I was working backwards from the stated 1,000sq/ft, hence the 30’ beam and 60’ length. At 20’ high, not tooo tall, but i didn't want any wave slap on the underside of the bridge deck. i have no idea of the operating region required, but at 30’ wide, waves can be an issue.

    In a previous job, (I'm retired), i studied the Hydrolance quite hard. It is impractical as drawn in the advertising, but has the seeds of possibility. All the proportions in the advertising are completely misleading, as are the proposed speeds, but the principle is fine. This is not helped by the only examples so far, ferries in the Caribbean, are far too short to work as advertised.
     
  6. Sailor Alan
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    Sailor Alan Senior Member

    To answer some of your other questions.

    Steam turbine/electric drive was quite popular during the late 30’s for cruise liners at least. Nobody had yet learned to build high power quiet gearboxes, so they put a 2 pole alternator on the steam turbine, and ran it at 3,000+ rpm. They used a Cyclo-converter, using mercury filled glass vacuum tubes (valves), to reduce the frequency to a 12 pole motor running 100 rpm for the propeller shaft.

    For the same reason, ships, usually small warships, have been fitted with diesel/electric drives, for a long time. The US navy had a class of small anti-submarine vessels with Diesel/electric drive. High speed diesels, low speed drive motors, though these were DC i think.

    The reason above is still valid, high speed diesel for efficiency, very low speed propeller for efficiency, and electric drive might be cheaper/lighter/more convenient than a classic gearbox. It allows remote engines and/or motors for a start, one engine, multiple motors, or vis-versa.

    Apart from the odd ‘Honda’ generator driving several trolling motors, or other electric driven propellers, for dockside maneuverability, i have not heard of cheap diesel/electric propulsion, but that doesn't mean they don't exist. There are electric ‘thruster’ motors, in tunnels, or ‘pods’, out there powerful to drive a small boat or barge quite well.

    http://www.westmarine.com/electric-...water-motor-and-propeller-4-2kw-48v--12998613

    Not a recommendation though.
     
  7. Sailor Alan
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    Sailor Alan Senior Member

    You are correct, the hulls need to be contiguous, and fairley smooth in transition, ie no 'gaps' to get an artificial length.

    I think the question might have been about towing on the road?

    Wonderful idea, running the ’lazy’ propeller at neutral speed. Excellent thought, wish i’d thought of it.

    Having two vessels really helps solve the ‘visitor’ problems, and being able to ‘get away’ at times as well. Brilliant. Equally, rafted boats are always a ‘party’ even if they are ‘related’.

    I know you have thought about this a lot, but a couple of points.

    People used to “tow’ dinghies behind sailboats all the time, so why not ‘tow’. You are concerned about getting equivalent ‘heel’ on both boats (good point i might add) , but if you ‘tow’ the ‘dumb’ boat, heel will not matter. Use a ‘link’ so it doesn't surge. I’m thinking of something about 3’ or shorter, with ball joints either end, and a very stiff coil spring in the middle. Pinch something off a farm tractor perhaps.

    Equally, under power, pushing in any waves must be hard on the connection, again, why not pull, or tow. Im sure you have a reason I'm not seeing here.

    In puget sound, we hardly ever see a push barge train, usually pull. Apparently this is because of wave motion, the barge and tug rising independently. A very few tugs here have vertical bars on a blunt bow so they can ‘push’ and the vertical bars are meant to slide up and down on the barges stern so little damage is done. They might slide a bit sideways too, but they are usually held by hawsers.

    Note, we only see ‘push’ tugs in the extreme south sound, i assume because it is much calmer there.

    If you ‘fly’ a sail with the tack on one vessel, and the clew on another, i suspect you will get a force trying to ‘jack-knife’ the boats all the time. Trying to resolve this force might be quite a trick, trying to ‘brace’ the boats in exact train. Perhaps having the rig on one vessel or the other might be best. Another reason i suggest ‘towing’ might be easier.
     
  8. Yobarnacle
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    One of the big advantages to electric drive on sail vessels, is the ability to run the prop just a couple RPM faster than sail speed, I like your term NUETRAL, eliminating drag with out expensive CP or folding props. And so little current demand at such minimal speeds that it could be provided by todays solar panels.

    I intend to set up 'Stowaway' as a hawser tug, to tow 'Intrepidos', and 'Intrepidos' set up to push 'Stowaway'. In addition, each serves as a life boat if the other boat is lost or wrecked.
    Regards pushing VS towing. It's not convenient to tow close astern. So the tow is comparatively long with several boat lengths of hawser out, at minimum.
    Control is much easier pushing. Even hawser or winch tugs go on the hip to dock the barge. I have landed barges (6 in tandem tow) on towline (couldn't hip 6 of them), but had an assist tug on the stern backing against me as we walked the whole affair sideways into dock.
    Not likely to have assist tugs. :)
    The concept of pushing under sail, is problematical. Interesting to think "could you and how?'. As I hinted at before, IMHO, best tactic is voyage to new locale by road. Even two round trips to deliver both boats, is faster by highway and more economical than voyaging on own bottoms. Once both are re-launched, make up in notch and push to ultimate destination, 5 to 10 miles from launch point. Burn a little juice. Leave one boat anchored as BASE, while you explore, sail, go fishing, ect with the other boat. This let's the men folk do their thing while the ladies tint their hair or why-ever it was they didn't want to go with the men. :D
     
  9. Sailor Alan
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    Sailor Alan Senior Member

    Im still impressed at the double boat, one called “HIS” the other “HERS” and together called “Joint Custody”.

    Why is it “not convenient’ to tow close astern. Please explain, preferably in simple terms.

    I understand control is 'easier' when pushing, but isn't the boats rolling differentially, and rising differentially a big issue? or is the connection, through the "V" dock, really solid, trying to hold the boats nearly ridged?

    Will both boats have both forms of motive power? i thought from my first reading that one would have both forms of power (sail and Diesel), the other only electric, and batteries. Was i wrong?

    The tugs in Puget sound use several barge lengths of Hawser between tug and barge in this area, but use perhaps a mile or more on the way to Alaska. Much of Alaska's freight seems to go by barge, and not freighter, perhaps unusual. As a sailor in Puget Sound, we need to be very aware of the tow line, usually deep underwater.
     
  10. Yobarnacle
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    Yobarnacle Senior Member holding true course

    My boats are in Florida. Two important advantages (there are many) of trailersailors is, hurricane coming? Head for the hills, with boats.
    Florida has two great coasts. Gulf and Atlantic. Just a few hours drive east or west to change coast. But a long, long way around to sail! :D
     
  11. Sailor Alan
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    Sailor Alan Senior Member

    Another approach for your consideration.

    If you were to set up on the hip for power AND sailing. Say port hip for port tack, stbd hip for stbd tack. That way the sails would not really interfere with each other.

    Unfortunatly the boats might be rolling against each other, so need a serious pad between them, foam mattress or a 'real' piece of cargo net perhaps.

    Alternately, a pair of 3' long links with a ball joint either end, and a strong coil spring in the middle, might hold the boats parallel off one another's hips in a suitable way. Actually you would need 3 links, the 3rd as a 'spring' or diagonal thrust link. A bit mechanical, or agricultural, but it should work. Then the boats will not touch side to side, or hull to hull. There is no reason the links could not be wood, with metal ends if necessary for appearances sake.

    Note; one of the links could also be wide enough to walk over, instant physical communication between boats.
     
  12. Yobarnacle
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    Yobarnacle Senior Member holding true course

    The reasons for scope of hawser are several. The vessel astern doesn't have brakes. If the tug stops, it gets run over, UNLESS there was sufficient length of hawser for the 'barge' to fall off to one or other side. Also, if shallow enough, say tug stopped by running aground, the hawser makes a mud loop and anchors the barge before it climbs on top of the tug.
    It's inefficient to pull on a tow while it's being pushed away by your prop wash, so towing close astern is dead slow for minimal prop wash.
    Surge is also a problem. Needs sufficient hawser out as shock preventer, so not JERKING on fittings.
    Steering is difficult , if tow is close astern. Tug needs to be able to pivot under the towline. That's why towbits are about 1/3 forward of the stern and well ahead of props and rudders.
    Barge too close astern 'REINS' you. Inhibits your ablity to turn.
    So, it's not convenient short coupled on hawser. :D
     
  13. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Sounds like a catamaran, with short fat hulls.

    Pushing ahead is the best arrangement. Easy to make up and break out and best control. Minimum gear. But I don't plan to make any rough water tows with these boats. They're for pleasure. I'm not a masochist or out to prove anything. If it blows up and I'm caught? Drop the hook and ride her out. :D
     
  14. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Right now one boat has a working diesel. I have a second diesel (froze up and I'm trying to free). Eventually, in a perfect world, BOTH boats will be diesel electric. but one diesel CAN charge all the batteries, but that limits range under power for the electric only dependent boat.
    Of course, a 600 lb diesel, if not installed, allows an additional 600 lbs of batteries for greater range.
    Compromises and priorities, and using what's available.
    If this old diesel isn't salvageable, maybe i'll just load up on batteries.
    The fuel tank can remain. Reserve for the other boat WITH an engine.
     

  15. goodwilltoall
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    goodwilltoall Senior Member

    Greetings,

    This is an idea that came to mind and space wise it would be the minimum that I would consider for long term liveaboard.

    PS: there are two files in pdf- it is the 66'.
     

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