23' car roof jon boat

Discussion in 'Boat Design' started by montero, May 16, 2025.

  1. fallguy
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    fallguy Boat Builder

    Each bridge section weighs 12,000 pounds.
     
  2. montero
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    montero Senior Member


    Current armies do not use gasoline. But as you can see, not entirely. I have not seen diesel chainsaws either.
    And those exposed red gas tanks for better aiming. Polish army bought this.
     
  3. montero
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    montero Senior Member

    I understood weight and strenght problems with my an exaggerated state of requirement.
    But there are modern materials. I assume the use of pvc foam, cfc.
    Solid and fast connection of 2 hull parts is not easy. I would be happy to hear some advice.
    Hull structure 20mm PVC core 70kg , 400g carbon bottom , 200g carbon inside the hull .
     
  4. skaraborgcraft
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    skaraborgcraft Senior Member

    High speed? In Europe you are restricted in speed when towing, and rightly so.

    A light towing vehicle then has to work harder to pull another axle. The differences in towing in the EU and and the US is chalk and cheese, as are what is considered to be a suitable towing vehicles. Different regulations apply to the same model being sold on both continents.
     
  5. montero
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    montero Senior Member

    yeah 50mph on the highway . 1500km .Speed limits overall they are interesting, 40 ton truck speed limit is the same for hayabusa. Great, but it doesn't make sense to me.
     
  6. montero
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    montero Senior Member

    80km/h (50mph) speed limits for trailers is kind of s.f. because trucks have 90km/h (56mph) which means , that according to the regulations a 40 ton truck must overtake e.g. a caravan .
     
  7. montero
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    montero Senior Member

  8. skaraborgcraft
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    skaraborgcraft Senior Member

    Lots of those cheap crap trailers from Poland in Sweden. Better stuff from Germany and once upon a time, the UK, at a price. Not everyone hauls for 1000s km every year.
    All my trailers have had Knott couplings, not the pressed steel type.
     
  9. montero
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    montero Senior Member

    Zugkugelkupplungen - Knott GmbH https://www.knott-anhaenger-shop.de/zugkugelkupplungen-1.html
    I know Knott makes good stuff but it's stuff for road use. In my previous post there's a link about trailer connections. They're not EU homologated. All those Knott hitches are not suitable for off-road use.

    The speed limits for trailers in the EU are exaggerated and unjustified. I gave an example distance to Cro.

    How to connect 2 parts of the hull 3m stern + 4m bow?
     
  10. skaraborgcraft
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    skaraborgcraft Senior Member

    End each hull section with a bulkhead, and use thru-bolts.
     
  11. baeckmo
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    baeckmo Hydrodynamics

    Take a look at "pistnbroke's" thread "Stacking boat in production"!
     
  12. montero
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    montero Senior Member

    It is possible to do this way but I would prefer to get continuity of the composite surface , connect the bottom and freeboards. Continuity for stretching forces not for hydro drag. In this case bulkheads will not be very necessary in the connection. Question is how to get it.
     
  13. montero
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    montero Senior Member

    I read of course but I have an appetite for more hp outboards. Strongly strained and light structure.
     
  14. baeckmo
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    baeckmo Hydrodynamics

    I referred to your question about "how to connect....". Bolting through bulkheads works for higher hp:s as well, just a matter of normal strength calculation.
     

  15. montero
    Joined: Nov 2024
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    montero Senior Member

    Yours Scaraborgcraft and Beackmo advice is tension bolts. I'm thinking more about shear bolts.
    Tension bolts eliminate any play, which is an advantage.
     
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