fishing trawler to pleasure conversion

Discussion in 'Boat Design' started by James Wellington, Dec 27, 2022.

  1. James Wellington
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    James Wellington Senior Member

    [​IMG] [​IMG] Scenario: you like the design of a commercial fishing boat and would like to buy it, new, but configured as a pleasure boat. The blue longliner(Damen 2007) is designed to carry a massive load of fish, but the pleasure trawler(Seaton 60) isnt. Similar full discplacement hulls, size, weight, etc. What would the Damen navel architects have to change? All that fish storage not needed. This affects stability, etc, since the boat wont have that heavy load. The Damen is a diesel electric hybrid, so one change would be for massive battery capacity. And solar panels on the big roof. Close in watertight the main deck. What else would the builder say?
     

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  2. James Wellington
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    James Wellington Senior Member

    Here is the general arrangement. We already like the bridge, and accomodations for 5, and the propulsion. The main deck could be sealed, as waterproof lounge space.
     

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  3. fallguy
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    fallguy Senior Member

    Well, the bridge may be in the wrong place.

    I am not your expert, but one must assume the bridge was placed with some consideration of load which means the bridge is wrong for a no load boat. Determining typical operating conditions might help. That is, does she run with a certain amount of mass in the holds typ.

    The vessel, capable of great load, would also be costlier to operate than a vessel not designed for such massive loads.

    I will tune in for more expert discussion, but say a few words to get alerts on the thread.

    I don't think it ideal at all, I'm afraid it will be far more costly to run than needed. So, you also ought to mention intended use and consider fuel economy and range.
     
  4. James Wellington
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    James Wellington Senior Member

    Interesting point regarding the bridge, and I would like to hear what thecnaval architects would sayvabout it. They would have to take it into consideration of course. Ill try to find out more.
    About other loads, not fish, if it would be used for lenghtly trips, circumnavigation, there would be tremendous stores as well. Half a year food and booze weighs a lot too. The product sheet from Damen doesnt say what the discplacement is, in steel. If available in aluminum, it would be a lot lighter.
    Thanks for your input.
    Fuel economy....it would need a range of say 2000nm at 5kts, and Ive seen other boats of similar size capable of that already.
     
  5. fallguy
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    fallguy Senior Member

    I could be full of it. Most likely the bridge is far forward to let the skipper see the buoys faster than slower and then the cockpit has a shot at hooking..., but I would think it is considered against the other masses on onboard thus
     
  6. James Wellington
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    James Wellington Senior Member

    For sure better visability. But I like slow speed, like even 5kts is fine.
     
  7. bajansailor
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    bajansailor Marine Surveyor

    Here is a link to the Damen 2007 trawler -
    Sea Fisher 2007 - Long Liner - Damen https://www.damen.com/vessels/fishing-vessels/seafishers/seafisher-2007-longliner

    James, I tried to open your Product Sheet PDF attachment, but it refused, saying that the file is corrupted - does it work for you?
    I cannot see a mention of it on the webpage - did they email it to you?
    Re how you would like to buy one of these new, what is the basic cost of one 'off the shelf'? I think that Damen do build vessels on speculation and thus they can have them ready to be customised with a short lead time.
    Have they given you even a rough estimate as to what their additional design fees would be for converting a fishing vessel design into a motor yacht design?
    And what is your total budget for this project?
    You should compare this amount with the cost of building a new trawler yacht (like a Seaton or a Nordhavn perhaps?).
     
  8. James Wellington
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    James Wellington Senior Member

    Hi Bajansailor.....****, too bad,, opened here. I will try again. I requested and they sent it to me within one day, unlike some builders who dont even respond, like Moen Marin. So far nothing on prices, but would likely be at least 2_million..
     
    Last edited: Dec 28, 2022
  9. James Wellington
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    James Wellington Senior Member

    Banjan.......I kept trying but just doest pick it up. But maybe by email address if you have one. Its in pdf.
     
  10. kapnD
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    kapnD Senior Member

    Longliners generally depart with a full load of ice, which melts over time, and as warm fish are added , so they’re never really in a light condition. I delivered a longline boat once that was virtually empty, floating like a cork, dam near impossible to drive it in a straight line, and autopilot was totally unable to steer it.
    5 knots is an unacceptable speed for a commercial fishing boat carrying a perishable load, they more often shoot for 10 or more.
     
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  11. James Wellington
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    James Wellington Senior Member

    Yes, and Ive seen that some of them use sea water as ballast that they regulate. Regarding the slow speed that we like, I would also be interested to see what the Damen designers would sayabout that. So two boats, about the same size, hulls, etc.
    Also, As opposed to the Seaton 60, we like the long flat roof of the longliner, for lots of solar panels. So optimized for slow, long distance.
     
  12. kapnD
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    kapnD Senior Member

    I would suspect that draft and freeboard will be different (less) on the pleasure model, if indeed they do sit on the same hull.
     
  13. James Wellington
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    James Wellington Senior Member

    Thanks, but not sure of the diffetence in the hulls. Theyre bothfull displ and about the same size. So im wondering what would be in the space allocated for fish? So far the answer seems to be.....anything that gives some ballast, like battery banks, etc. Since its a solar/diesel/electric hybrid, there is need for lots of battery capacity. Perhaps also the fuel tanks would be reconfigured. Some boats have several fuel tanks , and they pump the stuff around for stability.
     
  14. fallguy
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    fallguy Senior Member

    The issue is you can add water ballast, but then you must realize you are paying fuel bills to move seawater...not a good plan with modern fuel expenses unless liveaboard or minimal ranging from anchorage to someplace relatively close..
     

  15. James Wellington
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    James Wellington Senior Member

    Point taken, but then again look how many boats are moving lead ballast around. Then too, there is fuel itself as ballast, and huge battery banks. I wonder what the Seaton 60 does.
     
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