About landing crafts

Discussion in 'Boat Design' started by karayelhb, Sep 15, 2011.

  1. SaugatuckWB
    Joined: Jan 2014
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    SaugatuckWB Junior Member

    Just picking this up

    Maybe this has been covered, I couldn't read through the whole thread. Take a look at Munson Alum boats. Lots of landing craft but mostly based on the same idea. I'm involved with building a very similar boat for UCC right now. It was originally going to be a landing craft but for unloading equipment and gear at a dock or other boat, not onto a beach but then the client decided that the articulated ramp would just get ruined in use so it won't have that feature. Still, the same hull and construction are being followed.

    http://saugatuckwoodenboatcruises.com/wp-content/uploads/2015/02/IMG_0425.jpg

    http://saugatuckwoodenboatcruises.com/wp-content/uploads/2015/02/IMG_0426-e1423607452596.jpg

    http://saugatuckwoodenboatcruises.com/wp-content/uploads/2015/02/IMG_0565.jpg
     
  2. TANSL
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    TANSL Senior Member

    I can not know what the customer will have thought to not want your landing craft but I see in it some serious design error.
    But, following the philosophy that you have shown in any of your answers, in another thread, what relationship does your post with the OP?
     
  3. Kailani
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    Kailani Senior Member

    What's the serious error?
     
  4. TANSL
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    TANSL Senior Member

    Of course, this is just my opinion. I see the following:
    - Dead reise high in the bow area.
    - Little dead raise at transom
    - The wheelhouse extends from side to side preventing quick and easy access to the lateral zones.
    - Insufficient reinforced in transom for outboard (although here, I admit, may be missing information)
    - Very narrow bow ramp. Much of the width of the boat is not used, which greatly limits the possibility of loading.
    - The deck plate should have some anti slide.
    - Very rigid structure in the stern, where there is no weight to bear, above (deck cargo) or below (bottom of the boat).
    - Very large lightening holes in the girders (have to study it).
    - No double bottom tanks.
     
  5. SaugatuckWB
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    SaugatuckWB Junior Member

    The original post was asking about hull form of landing craft and asking for sources of info. I mentioned Munson who builds lots of these. Cats and mono. Other posts were about small landing craft for carrying a motorcycle or atv, nothing too big.

    To be clear, the boat pictured is not my design, I'm just working on it. The dead rise at the bow is not that great and quickly decreases, maybe easier to see in these pics. The deadrise at the transom is minimal to provide a stable work platform and shallow water capability. The customer is an underwater construction company that works on water intakes, nuke plants, dams, etc. They decided to drop the articulated ramp at the bow after talking with others who owned similar boats and were constantly damaging the ramps, eventually just welding them shut. The boat will see hard use.

    The pilot house is as wide as it is because the beam at the deck is only 9', adding usable side decks would reduce the pilot house to less than 6' and there wouldn't be room for the required equipment inside. Furthermore, the deck at the stern is less than four feet long and will be used for equipment boxes and fuel tanks (portable, stowed on deck) as the customer specified. Therefore there is very little reason to make numerous trips from the foredeck. The pilot house is located this far back to leave the maximum deck space forward for a generator, compressors, dive heater, welding equipment, materials, and the dive crew.

    The transom is reinforced with a 3/4" motor bracket, supported by gussets to the three longitudinal girders shown which are deck to hull (similar to the transverse frames), the two other londitudinals (deck to hull as well) and the deck plating, plus gussets to the tunnel. The deck is welded on so no good way to show a pic of this. More than enough.

    The bow ramp would have been just over 4' wide, allowing the equipment needed by the customer to be loaded easily. This is a small boat designed for a very specific use as a dive boat, its not like trucks are going to be loaded on it.

    The deck will get anti-skid, but its way to early for that.

    The stern structure is rigid, just like the rest of the boat. I don't see a problem.

    Lightening holes in the transverse frames don't seem large at all. I've seem much larger, and with the transverse and longitudinal frames on 22" centers there is more than adequate material.

    There are no tanks at all, so I'm sure what you are referring too. Fuel will be portable tanks on deck, and there is no water.
     

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  6. jmahoney266
    Joined: Dec 2014
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    jmahoney266 New Member

    I have LCM-3 conversion

    I currently live aboard a converted LCM-3. I have not heard of another but would like to network with anybody that could provide resources to help me understand more about the vessel and it's history. Hull# 50WB8413 Marinette Marine Corp built. Now a trawler of sorts but she still has a lot of character.... 100_5409.jpg
     
  7. ProfromDover
    Joined: Apr 2016
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    ProfromDover New Member

    Lcvp

    COR,

    I'd love to see some more pictures. Doesn't look too bad. Its not a WWII Higgins but probably a 1950's clone.

    Any idea as to owner, status, or availability? You can post or send to email below.

    Thanks!

    Bill Goebel
    vasprofromdover at gmail dot com
     
  8. cor
    Joined: May 2008
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    cor Senior Member

    The Higgins boat that I took the photos of (back in 2001) is in a very remote place, Teller Alaska. It is way out in northwestern Alaska close to the Bering Straits. I used to live near there but moved a few years back. I do not have any idea about the boats ownership or condition, but if I had to bet I would say it is still sitting in the same spot.

    If you could track down an owner it would be a real challenge to get the boat back to civilization. Might be able to truck it the 75 miles to Nome and then put it on a barge going south. Would be complicated and expensive.

    C.O.
     
  9. myark
    Joined: Oct 2012
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    myark Senior Member

    I designed many landing barges with removable heavy duty torsions suspension that float in 2" of water with no dramas and can be retrieved or launched of a surf beach or remote regions with no boat ramps .

    Really easy to make, low cost and they go fast with low HP and the hull is the trailer structure meaning light to tow.

    Some time later I will start to manufacture again, but next time in China
     

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  10. myark
    Joined: Oct 2012
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    myark Senior Member

    I designed and built this Myark self trailer barge so it could at any time be brought ashore to be maintained, such as weed taken off from bottom hull with no drama, or to be sheltered from a storm also the fact it does not need to be moored like landing craft this size.
     

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  11. Wavewacker
    Joined: Aug 2010
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    Wavewacker Senior Member

    Just saw this, talk about late to the party!

    That reminds of of the "Big Daddy" turned out by Jack's Plastic Welding, they make inflatable tubes.

    At one time, I was considering inflatable tubes and a frame, the frame was actually the trailer that would be pulled by my motorcycle. That meant I could take off, float down the river and take out, pack it up and return myself, no driver needed. I have a 650 Transalp v twin that could do that job, but the real problem was the hitch set up for that bike.

    As to the LC, I was side tracked with health issues, so progress was set aside. I'm fine now but not as able to attack a large build. I'm not sure there is any "Great Loop" in me and my expeditionary adventures appear to be more overland on 4 wheels. My 1600 2 wheel cruiser goes in a trailer, the canoe goes on top. So, I can still do travels, enjoy cruising on the bike and mess around on the water.

    Things don't always go as planned and everything is a compromise! But, I would still like to try a small build, like CO's LC, might just cut up an old aluminium boat and add a float collar to the thing. :D

    That Myark is a great looking rig with a dolly built on it. Good idea!
     
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