Design a pleasure canal barge in aluminum alloy with diesel-electric propulsion

Discussion in 'Projects & Proposals' started by Rob Hellier, Jul 8, 2019.

  1. Ad Hoc
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    Ad Hoc Naval Architect

    It is not a concern, it is just a request/requirement.

    Every ite on the list is important as it is part of the SOR. The challenge is - which many seem to ignore/overlook, or do not understand - is once each item has been assessed on it's own merits, does it still satisfy the SOR. If it does, it matters little what may or may not be sourced elsewhere. There is no such thing as a 'perfect' design. Only the SOR and hence deign, for YOU.

    And this is the point of the SOR - if at some stage it is established that the keel coolers require significant work to integrate into the vessel, what drives the decision - cost!
    Thus it is not a design decision per se. But until it is investigated via the SOR - one is just guessing and making unfounded assumptions. Which is why it is very important to write up an SOR and then check can design be made to satisfy the SOR.
    An SOR by definition is personal.

    A successful vessel is greater than the sum of its individual parts - and as such the vessel is a series of compromises.
     
  2. M&M Ovenden
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    M&M Ovenden Senior Member

    Hi Rob,

    I suggest you order these two books by Dave Gerr:
    "Boat mechanical systems handbook"
    "The elements of boat strength"
    Worth every penny.
    Cheers,
    Mark
     
  3. Rob Hellier
    Joined: Jul 2017
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    Rob Hellier Junior Member

    I appreciate you keeping me on the straight and narrow when it comes to the SOR. I agree. Having a vessel that is "not sensitive to silty, trashy water" is the requirement. I just didn't think there were solutions other than eliminating water intakes by going than a keel cooler and dry exhaust. So my thought process was: since there's only one solution to a requirement then just short circuit the design spiral by stating the solution as the requirement. I believe this is done all the time. For example instead of stating a requirement: "vessel must have a reliable means of propulsion suitable for the harsh marine environment and an energy source that has very high energy density and low flammability", we instead state that the vessel must be "powered by a marine diesel engine". Solution, posed as Requirement

    I'm ready to be enlightened as to the other possibilities to achieve a vessel that can navigate silty, trashy waters with low risk.

    My concern with keel coolers is partly related to the fact that I'm just not familiar with them and my curiosity is peaked as a result. I do see a connection, however, between the keel cooler design/placement and what I might do to the turn of the bilge, which will impact overall design, interior volume and structure. The connection (at least in my mind) is as follows:
    • I've been reading that integrated keel coolers work best in a more vertical orientation, where the difference in density between hot and cooler water will create a natural stratification and therefore more effective cooling. In my current design there is no significantly large enough vertical, wetted surface area, since I've created the turn of the bilge with two chines.
    • If the above comment about vertical keel coolers is true, this suggests that I might have to consider a different turn of the bilge arrangement. For example if I had only one chine for the bilge, I'll have a much greater wetted surface area at roughly 45 degrees (not vertical but possibly good enough). If I was told and convinced that it is possible to have an effective, integrated keel cooler in the flat bottom of the vessel, however, then the keel cooler would no longer be a factor in my decision-making about the turn of the bilge.
    I hope this helps you understand my thought process, which I hope is not as silty and trash laden as the waters that this proposed vessel will navigate through :>)
     
  4. Rob Hellier
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    Location: Ontario, Canada

    Rob Hellier Junior Member

    I was going to get "The Elements of Boat Strength" as soon as I get my shore leave (my employer's shipboard firewall does not allow crew to access websites for on-line shopping!). I wasn't aware of this other book, which I'll consider too. Thanks for the suggestion.
     
  5. Rob Hellier
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    Rob Hellier Junior Member

    Your comments are so true, especially your last one. I've done a lot of design work over the decades - not boats per se but all kinds of other "products". In design parlance we have "design briefs" which is the equivalent of an SOR. I know how important "The Brief" is in shaping the design process, which is why I'm taking this process - and the collective comments of those following this project - seriously. I'm very familiar with the sometimes maddening "design spiral" as well as the many tools and techniques we employ (drawing, sketching and other means of conceptualizing, technical and mechanical problem solving and specifications, CAD modelling, scale modelling, prototyping, BOMs, costing, sourcing, and so on) to better understand the often intermingled relationships of the components within a design. Change one little item within a design and watch it topple - domino like - a bunch of other elements to the point where the whole "concept" comes into question. You've all been there and so have I. A holistic design is one where each element stands on its own merits but also is harmonious with the overall concept. Very hard to do, and it's certainly not going to come about by purely linear thinking. Sometimes, lateral trains of thought are beneficial, especially when it leads to insights or new creative paths. This is why I don't mind the occasional lateral foray into something like a "keel cooler", even if I'm still in a fairly preliminary stage of product development. I don't mind being reminded that it is a foray. But I'm also (usually) aware that it is :>)
     
  6. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    Indeed, leave no stone un-turned as such.
    But not forgetting there will always be opposing and positive views of anything you select, for whatever reason. Bottom line is, it is your boat, so the last issue to satisfy and tick that box - is you!
    Then live with that decision and not keep looking back or second guessing yourself, because of negative views. A design, is a very personal thing to undertake.

    Good luck.
     
  7. M&M Ovenden
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    M&M Ovenden Senior Member

    Hi Rob... don't just consider it... lol.. I wish it was published when we started.
    Cheers,
    Mark
     
  8. M&M Ovenden
    Joined: Jan 2006
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    M&M Ovenden Senior Member

    Hi Rob,

    I would also suggest Tom Colvin's steel boatbuilding. It's a bit dated now, but some good little bits of information tucked away.

    Cheers,
    Mark
     
  9. Rob Hellier
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    Rob Hellier Junior Member

    OK, consider them purchased!
     
  10. M&M Ovenden
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    M&M Ovenden Senior Member

    Hi Rob,

    Wouldn't steel be a better material for a canal boat ? They are usually pretty heavy boats so I would think the weight difference doesn't matter all that much ? Maybe a steel hull, alloy cabin top ?

    Cheers,
    Mark
     
  11. Rob Hellier
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    Rob Hellier Junior Member

    See earlier discussion and SOR. I prefer aluminum alloy for its lower maintenance requirements and bigger resale value. Costs may make me change my mind but for now my intention is all aluminum aloy
     
  12. Rob Hellier
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    Location: Ontario, Canada

    Rob Hellier Junior Member

    Hey Mark, are you available in late August to meet up? We'll be sailing to bay of Quinte.
     
  13. M&M Ovenden
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    M&M Ovenden Senior Member

    Hi Rob,
    We are about 2 hour drive from Belleville if you want to come over. My suggestion of steel was more based on abrasion resistance while scraping up against canal walls.
    Cheers,
    Mark
     

  14. Rob Hellier
    Joined: Jul 2017
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    Location: Ontario, Canada

    Rob Hellier Junior Member

    We'll see about renting a car or something. Really interested to meet someone who's done this already. Everyone says I'm crazy including my wife, though she's warming to the idea of a canal boat because to her its practically a house. She likes houses!
     
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