Uni Ship Design Project Help Needed

Discussion in 'Boat Design' started by Rian199, Sep 29, 2015.

  1. Ad Hoc
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    Ad Hoc Naval Architect

    In terms of the "GA", yes, similar. BUT..in terms of the hull and the hydrostatics...no idea. Since as noted, whatever your GAS and then your weights are, you shall need a hull to match it, whether a copied from this 30m or from another.

    But that 30m I doubt will pas the HSC stability requirements, since I cannot see a double bottom tank on the vessel. Look at the rules in 2.6.7 and you'll see what I mean.

    As for speed/power, worry about that after you've done your first design spiral. No point looking at speed if the boat doesn't float float up right and on the waterline you want/need. Use the same engine as the 30m for your first loop and then you'll see if you have too much weight too!
     
  2. NavalSArtichoke
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    NavalSArtichoke Senior Member

    IIRC, SOLAS specifies that a double bottom be fitted to an extent as far as practicable.

    While having a full DB is preferred, I have done stability work on SOLAS certificated small passenger vessels where only a partial DB was fitted and accepted by the Administration.

    Typically, a DB fitted under the machinery space or in way of an underdeck passageway was acceptable. It usually depends on the depth of the hull as to whether fitting a DB is practicable in the machinery space or passageway.

    A DB under a fuel tank was usually fitted to prevent pollution in the event of minor damage to the bottom shell. Ballast tanks were typically single skin.
     
  3. Ad Hoc
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    Ad Hoc Naval Architect

    N.S.A

    Im not referring to SOLAS (big ship rules), im referring to the HSC 2000 Code. The only way to pass, especially for a monohull, is with a double bottom. Since the raking damage is 55%L from the fore end, and then up to 35%L anywhere. Thus only way to pass is with a double bottom tank, outside the limits prescribed in section 2.6.8.1.3 fig 2.6.8.1.
     
  4. Rian199
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    Rian199 Junior Member

    As a student I really like this back-and-forth arguments; very insightful to see pro's and con's for different situations and applications :)
     
  5. Rian199
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    Rian199 Junior Member

    Thanks again Ad Hoc. Will go through the spiral and comeback if I am stuck or have a first model :)
     
  6. Rian199
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    Rian199 Junior Member

    Hey Guys, so I have found a (rather large) textbook in my uni library, "Ship Design and construction Vol. 1" and Vol. 2 by Lamb and The Society of Naval Architects and Marine Engineers. It has a chapter (chapter 11) in which it describes Parametric Design. In this chapter it talks about using linear regression to find a relationship between an independent variable and some dependent variables in similar vessels to find estimated optimal dimensions. It uses an example of TEU container capacity vs L,B,D & V(k) to find a relationship between the capacity and vessel size and speed. Is this something that could benefit me. In class we had 6 similar ferry examples. Is this a big enough data set to perform this sort of approximation, or is it not worth it?
     
  7. Ad Hoc
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    Ad Hoc Naval Architect

    In a word, no :)

    Just keep plugging away as described above, and you'll be ok
     
  8. Rian199
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    Rian199 Junior Member

    Progress Report

    Hey guys, So I have gone back and did my initial GA(Not including the wheelhouse, which is not required for our project, though I know how it would look/~weight/centers), initial weight estimates, hull modeling, initial stability & resistance tests and initial engine options and selection. The GA is still a little rough, but for the sake of the project, it's not meant to be very detailed. And looking at the stability checks, my estimated VCG is a little low, and I think I might need to increase my depth. Though I will be working on that today and doing my more detailed structural weight estimates, since I only did my initial estimates on comparison of similar vessel, and common % weight distribution given to us by our lecturer. I've attached 2 spreadsheets with all the estimates as well as a maxsurf modeling file for anyone with software to open and have a look at it, and my GA done up in PDF form. I know I still need to do a profile view as well and draw in the hatches and a few other bits and pieces. Could any of you maybe have a look and see if this seems ok? Keep in mind this is my first attempt at a ship design, and that's how the project is set up as well. I still need to comply with SOLAS and HSC code, so any comments about that and my tank placement etc would be very much welcome :)
    Thanks again to everyone who's commented so far
     
  9. Ad Hoc
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    Ad Hoc Naval Architect

    Ok..the GA is well..it is slowly getting there :p

    I would focus on the GA and as noted previously ignore the rest, fro now. Since until you have a GA in plan and profile...what do you have?..just a series of numbers and liens with no reference. Thus you need to complete the GA.

    Once that is completed, then you can do the weight estimate. Can't do any other design work, until you complete this stage.. If you do..then the work is based upon guesses and assumptions of 'something' which may or may not be valid. Most likely not valid since how do you verify it?

    Thus keep plugging away at the GA :)
     

  10. Rian199
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    Rian199 Junior Member

    Hi again Ad Hoc, I had a look at very simmilar vessel and did the approximation just for the first run through based on those, but I will draw up the profile view now and post it. Does the rest of the work look alright though?
     
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