Boat with built in trailer

Discussion in 'Boat Design' started by HarryN, May 19, 2008.

  1. HarryN
    Joined: May 2008
    Posts: 13
    Likes: 1, Points: 3, Legacy Rep: 24
    Location: CA

    HarryN Junior Member

    Hi Ken

    Thanks for the ideas. I used to know more about boats when I was a kid, but I am not pretty unqualifed about choosing a hull design from a drawing. With that in mind, your design looks interesting, and the comment about amphibious vehicle vs boat with trailer is also an interesting.

    As far as "modify existing setup vs new", I am open minded on this, but I pretty much decided that it was unlikely that I would find a way to re-use the existing boat.

    I am trying hard to warm up to the idea of a solution that requires him to drive the boat / amphib up a ramp onto another trailer, then work his way off of it down to the ground safely. So far, I think this would be very difficult for him.

    I noticed in your link that you have some size range ideas (min 70 lbs). That will not be a problem. LOL. As far as carrying capacity, I am hoping that this setup could handle either him by himself, or him, me, and my son, so about 600 lbs of people, plus gear. If I asssume 4 Pb acid batteries plus motors - about another 400 lbs, plus light fishing gear, cooler of drinks, life jackets, etc - it gets up to a load of 1,200 - 1,400 lbs remarkably quickly. For some reason, I think his existing boat is more like 1,000 Lbs rated, and it handled more like 2 adults and gear, so maybe that is enough.

    I am not sure how that relates to a normal use row boat kind of setup or the speeds people expect from an electric motor powered boat. Maybe someone can comment on this. ( I also need to visit some boat shops )

    Before I found this site, I had been searching for an amphibious vehicle that could be towed at high way speed behind his dodge mini van. That would in theory allow for a tow to the lake, disconnect in the parking lot, then ride it right up the ramp and into the water - use like a boat - then back down to the van.

    The parts that I could not find, were a version of that which is
    - Electric only
    - Tires for highway speed
    - Able to be maneuvered easily into position to hook up the trailer hitch
    - Reasonable speed / efficiency. Speed is perhaps not so important for speed itself, but mostly so he can come back to the dock against a head wind, which is very common.

    Thank you everyone for all the ideas and suggestions. It will be 2 weeks before I can really do anything toward this project, but I am grateful for the ideas.
  2. snoman774
    Joined: May 2008
    Posts: 16
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: arkansas

    snoman774 Junior Member

    remember the max amphibious vehicles i did not know they still built these
    maybe skid steer with golf cart type power train.
    still thinkin on how he can climb up and down on the trailer safley though.
    wait a minute i think i have seen flat trailers for forklifts maybe
    where the bed lowers to the ground flat then raises for travel.

    sorry just thinkin out loud
  3. kengrome
    Joined: Jul 2006
    Posts: 718
    Likes: 25, Points: 0, Legacy Rep: 305
    Location: Gulf Coast USA

    kengrome Senior Member

    No problem HarryN. As long as I know that this is the biggest issue you're worried about, I can come up with a solution ...

    The first option that occurs to me here is that the amphib does not have to drive up and down the tilted flatbed trailer. Instead it can be winched up and allowed to roll down via gravity. Then your father can get into and out of it from ground level.

    The weights noted in the design I showed you were used because of the specifications the other guy wanted. Your requirements are dramatically different so I would adjust the hull to meet your needs. I think my design is too small to handle the loads you've described but I won't know for sure until I redesign it, and then run the numbers again.

    A more 'boaty' shape is easier to propel but if it's going to be an amphibian it needs to have overland features and capabilities too, even if the only place it has to move over land is in a parking lot.

    There's a huge problem and related expense with this approach. The boat needs to be super-strong to withstand highway stresses this way, and this boosts the cost and complicates it tremendously. It is usually much better to put the boat on a trailer designed for highway speeds and let the trailer handle the road stresses, then the boat can be lighter and less 'overbuilt for the water'.
  4. bargeboy
    Joined: Oct 2005
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: UK

    bargeboy New Member

  5. HarryN
    Joined: May 2008
    Posts: 13
    Likes: 1, Points: 3, Legacy Rep: 24
    Location: CA

    HarryN Junior Member

    Thanks everyone for the continuing flow of ideas. Also, Ken and everyone, please keep in mind that

    a) "IF" my Dad decides he is willing to try out something like this, and
    b) "IF"' I can swing the finances to buy such a boat, and
    c) My wife lets me, and
    d) It turns out that there is a viable solution

    Then, I still prefer to buy an existing solution, even if it is not optimal. Second choice is to buy a solution which is a modification of an existing solution. I am not sure I am able to really financiallly support a project that requires custom build up for a one off project.

    Ken, you asked if I had a particular concern - yes - is it really feasible for my father to pull off the entire process of handling the boat / trailer, etc ?

    Just a bit more background on him: He was in good shape, but slipped on some ice (that looked like a water puddle) and really destroyed his hip. After a rebuild and lots of therapy, he gets around wtih a walker - sort of 1/2 way between a wheel chair and a cane from a flexibility standpoint. Try watching some one who uses a cane for an hour - it is quite an education on what is possible / difficult / very difficult.

    We all know that if he falls and breaks his hip again, he is pretty much dead - this is reality, so he is quite cautious with slippery surfaces and climbing up on things.

    Any "solution" must deal with both the real and perceived limitations of someone in this condition to be viable. I honestly don't believe a "separate trailer" approach is viable, but I will try to be open minded. This just does not seem enough different than what he has now.
  6. Knut Sand
    Joined: Apr 2003
    Posts: 471
    Likes: 30, Points: 28, Legacy Rep: 451
    Location: Kristiansand, Norway

    Knut Sand Senior Member

    How much room is it (available) inside the van?

    I would consider a "light" version of the solution mentioned in with bicycle wheels ( as mentioned above)/ wheelbarrow wheels? It shall be used in fresh water - minimum corrosion problems, nylon bearings will anyway be sufficient. The wheels can be fixed, only sticking 5-10 cm below the keel line.
    These wheels fitted on a Light/ small inflatable equipped with an electric motor?
    A "ramp" plate on the back of the van, with an angle making it easy to pull the boat out, an electric winch installed inside the van, pulling the inflatable all the way inside the van?
  7. CTMD
    Joined: Dec 2007
    Posts: 198
    Likes: 9, Points: 0, Legacy Rep: 117
    Location: Melbourne, Aus

    CTMD Naval Architect

    The seales uses a generator with an hydraulic pump. If your dad is happy to cruise around slowly you could replace the genset, petrol and outboard with an equivalent weight of 12V hydraulic power pack and batteries. Then bolt a small electric outboard on the back.
  8. brysten
    Joined: May 2008
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: canada

    brysten New Member

    Float Trailer

    I think you really need to check out the Float Trailer by Admiral Drive Systems . This boat/trailer will let your dad explore with endless possibilities and he won't have to worry about slipping because the floor is all checker plate.
  9. kach22i
    Joined: Feb 2005
    Posts: 2,403
    Likes: 111, Points: 63, Legacy Rep: 1222
    Location: Michigan

    kach22i Architect

    1,500 lb payload.............if they made it just a little bigger an old VW Beetle could tow it and ride on it.

    I like it as-is though.:)
  10. brysten
    Joined: May 2008
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: canada

    brysten New Member

    Float Trailer

    1500lbs payload on our small boat which is 14'6" the 20' model is a tandem axle trailer and has a payload of over 2000lbs. The Float Trailer only draws 6" of water which means you can run it right into the shore, drop the front gate down and drive your Beetle right off of it.
  11. tos1
    Joined: Jun 2008
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: netherlands

    tos1 New Member

  12. Village_Idiot
    Joined: Oct 2007
    Posts: 382
    Likes: 14, Points: 18, Legacy Rep: 138
    Location: USA

    Village_Idiot Senior Member

    You might also take a look at
    Although they are a company from "Down Under", I would bet that you could get a good local aluminum custom boat builder to construct a much smaller version of the trailer barges they show on the website. Just another avenue to consider...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.