90% boat-10% vehicle amphib

Discussion in 'Boat Design' started by Squidly-Diddly, Jun 17, 2015.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

    I'd like to see an amphib design of a "real" boat (not Sealegs inflatable, some sort of cabin cruiser or even motorsailer) that is a real boat (not an Army surplus "Duck-Truck".

    Basically close a normal boat as far as performance and seaworthiness, it would just lose some cargo/living space to the road gear.

    Should be barely street legal.

    Main purpose would be things like cruising the Great Loop, while able to venture somewhat off water without needed to find secure docking and be able to 'camp' on any street, take the craft into the shop instead of the shop coming to you.

    Also, with mild street legal status, it might create several new Great Loop type navigations. Able to drive around dams anytime. Retrace Lewis and Clark.

    Probably something like the Option One concept, but with fold down wheels, normally under hull-conforming fenders. Maybe have the whole system hybrid, maybe 4X4 electro-wheels.


    PS-Maybe "self portaging" more than "amphibious", but to me being street-legal is 80% of the reason for the concept at all. Maybe even as what they call in the USA "agricultural equip". I don't think govt regs REQUIRE you be able to absorb a certain level of pot holes for what would be classed as a 'truck'. IIRC most truck regs are about brakes. Too me, if you are only going to haul out at private yards or even public launch points at parks, but carry your own gear to do so, you might be better off with inflatable rollers and a winch.

    I'm thinking less beach assault off road ability, and more crawling up nice concrete ramp but then able to carefully drive unlimited distances on streets and hwys at speeds up to 55mph on good straight roads.
     
  2. Rurudyne
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    Rurudyne Senior Member

    You and I are thinking (dreaming?) alike. Principally for crawling ashore, with or without a boat ramp, or get around water obstacles such as sandbars (in the water) or no longer functioning locks that break up some otherwise navigable rivers. But also to assist is getting on a flatbed for transport longer distances overland.

    Though I'd personally not try for street legal at all because of the weight added to meet such regulations, especially given that real streets have potholes, would reduce your economy as a cruiser. I should point out that pulling ashore at the boat ramp of some proverbial KOA would not involve public roads but their own facilities and would need only their approval, not need being street legal.

    Weight and loading on wheels/tracks/whatever also can affect where folks would tolerate you crawling ashore for various reasons. The less likely you are to damage the beach or tear up the grass the less likely they are to balk being the thought.

    For that reason a boat in many respects similar to one of Bolger's state designs (though likely more punt-like in the bow), but not Illinois which would be too heavy, which is very light seems to me like a good starting place.

    For example, I've envisioned even a Tennessee-sized boat supported by a pair of steerable tail-dragged style wheels lifted into the sponsons in the back and a set retracting gear like those used by Grumman seaplanes up front. These latter could be made of carbon fiber to keep weight down and, likewise, the wheel hub (use tires similar to old aircraft wheels: low pressure for uneven ground and some shock absorption, smaller hub for same reason)

    A Wyoming sized craft may take 8 such gear and might require all wheel steering to have any kind of turning radius that doesn't involve a proverbial 40 acre field.

    Power to the wheels is another issue. Though speed to my mind isn't important so much as just being able to get in and out of the water on your own in the first place. It would be more critical an issue for you, though.

    I should confess that one of my motivations has to do with just avoiding slip fees, you may give up space to have some (in the extreme) Wyoming-sized amphibian but you'll spend a lot less on a very long carport in your lakeside backyard than you would a boat slip.

    It might be good, particularly the longer the boat, to have independently adjustable ride heights so as to keep the boat as level as possible when transversing a beach or obstacles.

    Edit: one interesting idea I had involved a sidewheeler whose rims extended beyond the floats and had, essentially, knobby bicycle tires, and use that in conjunction with a fore and aft pair of weight bearing retracting gear. The same differential steering used on water would work on land and it would simplify the retracting gear considerably. An adjustable feathering mechanism for the floats might permit them when on land being feathered for greatest overall ground clearance.
     
  3. Petros
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    Petros Senior Member

    limit it to two seats (or two occupants) and use three wheels (rather than 4). than it can be legally licensed for street use as a motorcycle (trike actually). You will have a lot less regulations to comply with as a trike vs. a four wheel car or buggy. You do not need a glass wind shield, nor wipers, you don't need seat belts, bumpers or turn signals and a number of other requirements for a 4 wheeled car.
     
  4. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Don't exactly see a two person limit, except for no plural (passager(s)), and ditto for no "operators".

    Turn signals are required(probably not a bad idea in crowded waterways of weekenders used to driving cars Mon-Fri), as are helmets, no weight limit and "Lane Splitting" is allowed :)

    http://www.americanmotorcyclist.com/rights/state-laws.aspx?stateid=5

    Trike config with bow mounted wheel does seem to be the way to go, since bows tend to be wasted space, or house things which could be shoved aside in the design.

    Then again, with twin wheels at the bows would allow the wheels to be more or less added on.

    I might butcher/deface someone's Option One sketch shortly, with apologies. I guess it will be similar to a Sea Legs, just on different boat.
     
  5. Nnnnnnnn
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    Nnnnnnnn Junior Member

    some pictures as inspiration :)
     

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  6. Petros
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    Petros Senior Member

    you would only have to limit it to two passengers when driving on public highways to meet the motorcycle requirements. You can get away with that by only having two official "seats", the rest would be cargo area. Likely for short distances no one would care if you drive it on roadways with 3 or 4 people in it (to get to and from a boat launch for example), but there is the potential to get a ticket from local law enforcement if you made a habit of driving down the highway with a big boat party going on in the back when you are driving it down the interstate.
     
  7. whitepointer23

    whitepointer23 Previous Member

    Brilliant. Do you have any info about it.
     
  8. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Yep, those pics by Nnnnnnn are pretty much it, although I'm not in love with the way they included the required headlights. Looks like the tires would double as boat fenders.

    Looks like they swing down and at least the rears have motorcycle type chain drive?

    I'm also thinking of more liveaboard lower preformance larger craft, and BARELY roadable.
     
  9. waikikin
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    waikikin Senior Member

    A plural component "system" might be the cheaper/easier where 4wd tows a front loading barge & then a simple derrick or skip bin lifter style loader whacks the trailer onto racks...... or similar, an old school landrover had a pto to run propulsion from to sterndrive or similar....... like a "de-constructed" amphibious.. recovery winch on the front could be directed to derrick...
    or there's this bloke...
    J.
     
  10. waikikin
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    waikikin Senior Member

    Looks like it could be part of the thunderbirds range. Needs a number though.
    J.
     
  11. rwatson
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    rwatson Senior Member

    Terrific idea, and great example. I had always though your could register as an agricultural machine even if you had to have a little flashing light on top as you drove slowly to the garage for maintenance, or the local camping ground.

    http://www.wwf.org.uk/wwf_articles.cfm?unewsid=5178
     

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    Last edited: Jun 20, 2015
  12. rwatson
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    rwatson Senior Member

    This is still the most stylish amphib i have seen

     
  13. waikikin
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    waikikin Senior Member

    Very cool! The tracks seem pretty effective.
    J.
     
  14. Rurudyne
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    Rurudyne Senior Member

    ... I would have to name my Iguana "Don" ... I've a really strong silly streak you see....
     

  15. Jamie Kennedy
    Joined: Jun 2015
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    Jamie Kennedy Senior Member

    In the human powered expedition category I've seen some interesting designs where the boat carries a bike and the boat becomes a trailer, and of course you can still sleep in the boat even when on the road. I can't remember but I think you take it a step further and only need the front half of a bike, so the bike/boat becomes a three wheeler. I've seen a few variations on this them, for both single and double-handed expeditions. It could certainly be extended to solar powered, wind power, coal powered or whatever it is you motorboat folks are using these days, and more people. :)

    http://www.angusadventures.com/rowedtrip/boats.html

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