Advice on Raft/barge/ferry from lumberyard material for occasional 6 mile trip

Discussion in 'Boat Design' started by Randall Brower, Apr 27, 2020.

  1. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    Gentlemen, excuse me for asking, but why are we talking about Lowe's lumber and even plywood when this is an area where trees are landed on the beach every spring free of charge? Building with green lumber is normal practice after all. Just take any landing barge design and build it double planked with galvanized nails and screws. Use a chainsaw mill if a horizontal bandsaw (woodmizer) is not available and cut the trees to the needed sizes.
    LCVP (United States) - Wikipedia https://en.m.wikipedia.org/wiki/LCVP_(United_States)
    Ramped cargo lighter - Wikipedia https://en.m.wikipedia.org/wiki/Ramped_cargo_lighter
     
    Last edited: May 3, 2020
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  2. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    No, they don't steal from each other. If they need a raft then they gather the logs and make it. Then when done they take apart and cut it up for firewood.
     
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  3. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    I love the idea of building something more elaborate, and probably will some day, but at this point I need something that I can build in a day or so. Attached is the pic from http://www.scottcomarine.com/kits/instructions.pdf and this seems to fit the bill. I was shocked to find that Home Depot in Fairbanks AK sells everything required, including the floats. I love this because when not in use I have a dock in front of my house. They even sell floats with wheels integrated into the design so all you have to do is pull it onto shore. So my final task is design, dimensions and float sizes to carry a 8x18 vehicle. I mentioned big waves but for a load like that I'd wait until calm "seas". So how wide, long and how big of timbers and decking?
     

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  4. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Senior Member

    Actually, that's a really good point. I'm a little chagrined to admit that I built my first 2 boats that way. Logging and then running the logs through a Silva sawmill.
     
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  5. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    Bulldozer
    One day build
    Chainsaw
    Cable or chain
    Fasteners
    And a bazillion free logs, delivered, shore side.

    We're talking the Yukon River here: how many times has this been done...?

    Randall, how many hands do you have to help you for a day?
    Will the Natives help you, or just laugh?
    You can pay your help with the Lowe's money.

    I consider the bulldozer to be key in arranging, wrapping and securing the logs.
    Easy peasey, lemon squeezie!
    All your hardware can be reused for the next raft.

    What kind of wood stove do you have?
    I have a Jotul.
     
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  6. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Senior Member

    14' wide, and 24' long. Decking is light, except where tires roll. Then a built up assembly. They were 2" thick on bailey bridges when I was building those, but the bailey transoms were fairly closely spaced. I'd say 2" true thickness, wide enough you can easily stay on them, then convenient plywood elsewhere. Make sure the manufacturer lists that as an acceptable application. I'm still concerned about the flotation around the edges supporting heavy point loads in the middle. Don't want it to break in half and dump your truck.
     
  7. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Senior Member

    Picture a water bed. It can support my weight. A flat deck on my water bed when I'm sprawled out might be made of ³/¹⁶ plywood if I'm laying down moving slow. If I stand up on 1 foot, I'm going right through that plywood. Although theoretically that water bed can easily support me.
     
  8. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    I like the idea of using logs rather than styrofoam floats but my concerns are numerous. (1) The amount of time Ill spend in my boat out there trying to pick the right logs, lasso them and get them to shore. (2) The amount of time building it. (3) The cost of cables, cable rope clips... (4) Skills, design... How do I lash all of these together with cables so they are strong enough to withstand the pressures of transporting heavy cargo and being able to drag it onshore each year. (5) Hydrodynamics of 15 logs. (Same concern with styro floats though.) If I'm going to spend the time and money then I want it to last at least 5 years. (6) How long can these stay in the water before they waterlog? Ive not found a single How To online no matter the search engine or search terms.

    I've strongly considered doing the same thing as a log barge but with dimensional lumber. I just deleted the next 12 sentences explaining how I'd build it because I dismissed this option as it would be a lot of work to build, days perhaps, and be very heavy. Would take a bulldozer to move if it got beached which means it cant be in front of my house because a bulldozer cant get to that location. The same is true with the log raft. I would have to go down to the water every day to adjust the bowline to keep it from beaching. But with the styrofoam floats the wheels are integrated into the design so it will simply roll back into the water if the water recedes quickly and I don't let out the bowline in time. So I just wasted the last two paragraphs explaining something that doesn't appear to be a good solution. I left them to show Ive thoroughly thought through (say that three times fast) these options and why I dismissed them. So now I'm back to the dock floats as the best solution.

    I need help with how wide, how long and how deep should the 4'x8' floats be (12" 16" 24"). How many floats? If the concern is stability loading, offloading and while on the water, should I go with 12" floats under the entire structure or deeper ones in catamaran style or all the way around? Which design is easier to push the 6 miles up the Yukon against 5 to 8 mph current? It will pretty much always be unloaded going upstream, loaded floating back to the village. How much resistance will there be with the square floats? Would it be worth the considerable cost and time to build a false hull just to make it slip through the water more easily or could I just do a curved bow upfront to break the water?
     
    Last edited: May 5, 2020
  9. Dejay
    Joined: Mar 2018
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    Location: Europe

    Dejay Senior Newbie

    I thought the problem with logs was that they get waterlogged and don't survive the winter?

    Did you check if you can get cheap 55 gallon drums? I'd think using a chainsaw mill to make some big boards to make a barge with those drums as a lattice and decking would be best. There are many examples on youtube.

    About those floats, I've seen a video from those rollingbarge.com guys bashing them with a hammer that showed how much more sturdy the drums are. Adding some wheels might be nice though.
     
  10. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    What about a variation of this design? I assume it would be a lot more complicated to make this big enough to carry a vehicle.
     

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  11. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    These plywood boats are in two museums in Fairbanks and there's a great example here in the village. I'd love to build one and these could carry heavy loads, but not vehicles. I keep hearing about fiberglass and epoxy but these don't have that.
     

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  12. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    Here's more.
     

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  13. Randall Brower
    Joined: Apr 2020
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    Location: Tanana AK

    Randall Brower Junior Member

    Waterlogging of logs depends on several things. Ive heard natives say certain logs don't make good firewood, without telling me how they can tell. This area is classified as desert so logs/cordwood dry out during the winter due to sublimation. I didn't know until I got here that frozen logs continue to evaporate all winter long.
    We have the portable lumber mill here so I could cut logs down to uniform size but again, I cant find any data on how big to make it or how to lash it together. So many of the concerns listed in previous post that I had with just a log raft apply here. It would be a lot cheaper than buying floats. To be clear, I know how to lash logs together, but I don't know which method is best for stability and longevity.
     

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  14. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    I don't understand the problem. Every year a successful log raft gets built and used without a hitch. Why do you need hydrodynamic or stability calculations? The rafts work.
     

  15. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Senior Member

    The rafts aren't adequate to current needs. It's a lot of work to round up suitable trees, limb and buck them, cable them together with SWR. Then, it's a fast moving river and a random bunch of logs ain't exactly low drag.

    Then, the flotation necessary to carry a pickup means a big raft, but if you connect that many logs, it's a really flexible mess, unless you build in substantial cross beams, which either increase drag substantially, or make obstacles you can't drive over. And few non military trucks could even drive up onto such a mass of random.

    And after all that, days or weeks of work, you get one season out it, if you got anything at all.
     
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