Mud and the Tender

Discussion in 'Boat Design' started by rwatson, Aug 25, 2012.

  1. SamSam
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    SamSam Senior Member

  2. Petros
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    Petros Senior Member

    ha! I love it! but it means you have to have one for each crew member handy on you at all times. Could double as emergency floatation if you have to abandon ship, might be a long "walk" to shore however.
     
  3. hoytedow
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    hoytedow Carbon Based Life Form

    Pure genius!
     
  4. KJL38
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    KJL38 Senior Member

  5. CutOnce

    CutOnce Previous Member

    It is. I read about it in Woodenboat and was stunned at it's efficiency, adaptation to very shallow water and mud flats. Many of the posts in this thread are questionably serious, but this is one real contender.

    [​IMG]

    I was surprised at the hull's prop tunnel (mostly above the waterline) - and the completely protected drive that works forward or in reverse. The small inboard 15 HP motor is well suited to pushing through mud/sand and moving when just about anything else is fouled.

    Oh well, bring on more catapult photos, redneck snowshoes and gerbil balls.

    --
    CutOnce
     
  6. Village_Idiot
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    Village_Idiot Senior Member

    Yes, the Rescue Minor is a great little boat, but it can't cross over mud AFAIK, which makes it somewhat irrelevant to this thread. Even jet boats can't cross over mud. The only outboard-powered boat I know that comes close is a Majek RFL, but it requires an outboard upwards of 100hp and still needs an inch or two of water on top of the mud - hence my suggestion of airboat.

    Actually, with a large enough craft, you could draft 2-3 inches loaded with 3 people and still scoot along with a 13hp Honda and fan, but it still won't go thru pure mud.

    The old paddlewheelers used to have some sort of "grasshopper apparatus" that allowed the boats to push-pole through the shallow spots, but they would be slow to utilize.

    I have also seen four-wheel ATVs with floatation attachments outboard of their wheels, allowed them to float on water and drive through mud, but propulsion through water was still very slow.

    One solution might be an extendable drive with a pivot attachment connected to the transom that would push/pull the boat - drive wheels would be floatation-type tractor tires, but heavy enough to sink to the bottom to continue "driving" the boat along, thus giving back most of the traction/speed/efficiency of a terrestrial vehicle. Again, this would depend on water depth - anything over ten feet or so may be impractical.
     
  7. SamSam
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    SamSam Senior Member

    I'd like to watch you drive that through mud. I mean, it's a wonderful boat, but how can it be a "real contender" when everything about it says "In as little as 6" of water"? It's really no more relevant than the catapult or the human cannon. Or even the gerbil ball.

    I wonder if you can stop in 6" of water and get going again, or if you have to go at wide open throttle to be able to go through 6" of water..? Anybody know?

    If my ridiculous "solutions" are annoying, I'll try and quit posting them. I probably won't try too hard though.

    The SOR of this thread is 1. Be able to cross mud 2. be able to cross deep water 3. be able to be loaded on deck 4. do it all in reverse

    A loaded boat through mud seems iffy to me. I'm not sure all mud is the same as far as slidability. If you had a small canoe, poling it with a duckbilled push pole sounds doable. It opens when you push and closes when you pull it back.
    [​IMG]

    I had a small 12' sternwheeler with a 5 speed garden tracter transmission that in low gear would "caterpiller" over exposed sandbars, but I don't think it would work in mud and would be too bulky to load on a boat.

    I've been thinking of a "boat" that would float by itself and have an endless belt on the bottom, vaguely like a snowmobile track or a conveyor belt, that you would somehow push or row, rolling over the mud and then floating through the water.
     
  8. portacruise
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    portacruise Senior Member

    Good points, SamSam:


    Hope above comments help.

    The aqua trike I suggested would have good direction control on land/mud but issues with windage/traction in deep water, no sails. http://www.aqua-cycle.com/

    Also, the auto canoe was posted in response to sails/ motor consideration early in the thread. The paddlewheels would have to be altered as I noted, because they are too narrow and are not retractable to reduce drag. http://www.autocanoe.com/

    The kinetic sculpture race guys have some good ideas on this amphibian thing. Some of the KS designs are compact and also efficient in deep water, but it will take some searching to find the closest one for this application. Basically it will take powered, high floatation wheels which are retractable to meet the defined parameters, seems to me... http://en.wikipedia.org/wiki/Kinetic_sculpture_race

    Porta
     
  9. CutOnce

    CutOnce Previous Member

    SamSam:

    I'm pretty careful about avoiding ad hominem discussion of specific people on discussion forums. I did not use the word ridiculous.

    Rereading rwatson's starting post for this thread, I somehow missed your interpretation of his statement of requirements. Perhaps launching people by catapult is more relevant in some cultures.

    I'm not certain about how an existing, proven American design addressing the needs of the original poster generated such disdain.

    Atkin's original serious design was targeted for the US Government and military as a shallow water rescue workboat. The small, slow revolution (under 2000 RPM) diesel motor was well suited to slogging through soupy bottom conditions spinning a 10" prop, much above the waterline. No, it wasn't designed to run across dried out mud flats, but I've often found ankle-deep meadering channels.

    In answer to your pointed doubt regarding slow speed and starting from dead stop in six inches of water, please review Robb White's report discussing pictures available on his web site.


    According to the article in Woodenboat, the boat's draft doesn't change from dead stop to full speed, nor does the pitch attitude change significantly enough to affect draft.

    Just for clarity, Tim Schlieff quotes draft as 8" in his website.

    A little googling led me to a whole interesting subculture of mudflat adapted water-borne "four wheel drive" mud boats adapted for shallow water / bayou / mud in the US south. I'd seen these products on "Swamp People" an American documentary television series on alligator hunters. I'm not sure how suitable these boats would look hung from davits on an Australian yacht, but you never know.

    There are many different approaches to solving problems.


    --
    CutOnce
     
  10. SamSam
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    SamSam Senior Member

    No, I used the word ridiculous to describe my own ridiculous contributions.

    I've only heard of catapulting dead, diseased bodies into castles under siege, in hopes of killing all the inhabitants with an early form of germ warfare. Nothing lately though and certainly not living people.

    I think there is a misinterpretation of the objective here. This
    along with the pictures in the article

    [​IMG]

    clearly showing exposed mud, with no water on them, led me to believe the problem was mud, pure mud, with no water over it. If that's the case, the Rescue Minor is no more relevant than the catapult, and the gerbil ball, ridiculous as it is, would actually work.

    And no, I don't disdain the Rescue Minor, I think it's a wonderful boat and would work very well in shallow water.
     
  11. rwatson
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    rwatson Senior Member

    Some really deep thought going on gentlemen, and I personally dont mind the 'ridiculous' entries - as the Edward de Bono "Parallel thinking" concept suggests, no contribution sparked by the initial concept is rejected, but used for consideration in the solution.

    Samsams "endless belt on the bottom, vaguely like a snowmobile track or a conveyor belt" is a shining gem of potential. Even if it wasnt actually driven, it might be a mechanism for overcoming the problem of "A loaded boat through mud seems iffy to me. I'm not sure all mud is the same as far as slidability."

    That joking inflated ball also has potential problem solving implications. I still remember the " Rolligon" from the http://www.boatdesign.net/forums/boat-design/sea-worthy-amphibious-craft-19519.html, , http://blog.modernmechanix.com/cross-country-cruise-ship/#more-2971 with low pressure rolling inflated balloon tyres.

    Likewise, the catapult idea has precedents in moving across mud. The French developed a heavy vehicle"mudder" that used rotating weights to force the flat bottomed vehicle across mud surfaces. This might be a good reason for having the occupant of this vessel to face backwards and "row" - much like "pumping" in a sailboat in light wind.

    If we gave him a sliding seat (brown) like a rowing shell, could we make it drive a small roller ( green ) that rotated the low pressure "balloon tyres" ( orange ) ?

    Current concept illustration has been altered accordingly.
     

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  12. pdwiley
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    pdwiley Senior Member

    Rocket assist via 2 G cylinders of compressed air would do *something*. It'd be entertaining to try.

    Or a long hose from your giant compressor to an onboard turbine.

    If one eliminates the need for loading on board (which I don't actually require for my place) then a small hovercraft would be really cool. Maybe one could make the skirt out of round tube rather than flexible stuff and use it for flotation as well.....

    Personally I was thinking of a punt made out of ply, simple box form, good form stability & load carrying capacity, capable of being built by a wood butcher armed with a nail gun.

    PDW
     
  13. SamSam
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    SamSam Senior Member

    I think the Rescue Minor is a tremendously fine boat and the majority of mud flats would just have to sit there and take it from that boat, it's a classic and I am glad CutOnce put it in here. It is much more inspiring to see Rob White gliding by in clear shallow water than to see that other poor guy sitting in that contraption manhandling his way through the mud. I apologize for being rude, CutOnce. I have been a little crusty lately and will try and mend my ways.

    I see complications with the endless belt thing, but I wonder if spraying a mist of water ahead of a mud boat would help grease the ways. 5 or 10 gallons would go a long way.
     
  14. rwatson
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    rwatson Senior Member

    Oh sure, that is what you will probably end up with, but wheres the fun in that ? :)

    The world really needs a supper mudder though, so the quest continues. I was thinkinjg today, that there are lots of amazing nature reserves on the other side of mudflats, so its not just being able to get to the big boat, but maybe other types of local exploration .......

    If I get scientific, I need to allow say

    ~ 300 kilos payload
    ~ 150 kilos of boat and gear

    say ~450 kilos. if we allow a surface area of hull on the mud of say ... 1.5 x 2.5 metres, thats about 120 kilos per sq metre.

    those 'splatchers' are probably only half of that area, so it looks like the weight to surface ratio is quite favourable.

    I need to get some cheap ply, fit it with some of the gear we have been discussing, and see if I can drag and/or drive it across the muddy mire that is my spare block after a day of rain.

    I can probably source some wide plastic wheels, and see if they make progress easier. The 'endless belt' can be something cheap intially, until I can source a robust form of material. I would run some of that white, tough plastic stuff turned into rollers on a lathe, running on stainless steel axles.

    so - right after I finish the kayaks, build the bathroom in the sheds mezanine floor, the new mezzanine storage floor, the cnc router table ......
     

  15. bntii
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    bntii Senior Member

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