How to Design a Vessel in 5 steps

Discussion in 'Education' started by middlemarinedub, May 7, 2016.

  1. middlemarinedub
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    middlemarinedub Captain Vadimo

    Looking back at my design experience I would love to share some thoughts regarding how to design a vessel in 5 steps. By yourself. If you are a Naval Architect or a self-taught amateur.

    After some time spent in thinking I decided to describe following stages or steps:

    Step 1 - Imagination & Analyzing.

    At this step we are imagining what kind of vessel are we going to design, for which purpose, what kind of main dimensions we would like to have and what type of the hull we are planning to choose (classic, X-bow, mono hull, catamaran, etc). Number of crew on board. Once we decided it's time to analyze what kind of Rules or/and International Conventions we would take as the basement for our project.
    We can determine following sub-steps for this stage:
    • Is our vessel below "conventional dimensions"? So we are not applying for any Certificates and Rules.
    • Is our vessel above "conventional dimensions"? So we will apply for IMO, SOLAS, MARPOL, LL, COLREG, STCW, HSC, SPS and others.
    • Under what “Flag” are we going to sail? If we have already chosen the “Flag” we will have to immediately do research about the local Classification Authority, in a circle of interests of which we might to appear and Rules of which we will have to implement for our project.

    Step 2 – Concept Design and work with Rules.

    At this step we are working closely with “first entry” 3D design of the vessel’s hull to materialize our imagination and “make it done” in simple 3D model of the outside skin of the vessel.
    Golden Rule - It DOES NOT matter if we are not going to claim for certificates of any Classification Society or Conventions – we are always designing a vessel using any suitable Rules of Classification Societies and/or International Conventions in a value we able to implement them to maximize and risen the level of our quality and safety.

    There are following sub-steps we can highlight below:

    • Research and choosing of the Rules to implement.
    • Concept design: 3D model; General form of the ship; Volumes; Gross Tonnage; Proportions; Dimensions ratio; Etc.
    • General Arrangement (GA) drawing - preliminary.
    • Applying Rules and carrying out calculations of structural elements

    Step 3 – Principle Design and GA Drawing.

    At this stage we are taking the final decision about going ahead with whole project if all Rules and standards we have chosen before been implemented at the Step 2 and this implementation helped us to find a right balance between our desired concept design and strict requirements of the Classification Society/International Conventions.
    Once we took decision to go ahead, we will have to do following sub-steps:

    • General Arrangement drawing of the vessel.
    • Lines Plan.
    • Main principal plans and schematics.
    • Preliminary calculations of weights and Centers of Gravity (CG).
    • Correct calculations of the exact vessel’s displacement(-s).
    • Operation conditions of the future vessel (will be used for Stability Booklet).

    Step 4 – Solidworks.

    This is the most happy stage for a professional designer – set the vessel’s hull and materialize it into a 3D model including frames, bulkheads, carlines, beams, stringers, floors, keels, stiffening girders, tanks, holds, engine room, forepeak, afterpeak, living compartments, etc. At this stage we can highlight the following sub-steps:

    • Solid work and 3D designing of the vessel’s hull.
    • he final calculation of the weights and Centers of Gravity (CG) based on 3d data and calculations of CG in the software– will be used for Stability Booklet.
    • Designing of the Engine room arrangement.
    • Creation of the basic 2D sections and plans to be used for Class Project.

    Step 5 - Class Project.

    At this final stage we are preparing a Class Project (if we are under Class) or a “Technical Project” of the vessel (if we are not under any Class). At the same time this stage includes preparation of Stability Booklet and stability calculations. The advantage of this stage is that if there is more than one Naval Architect the Class Project and Stability calculations can be in progress parallel with stage Nr.4 which saves time. If you are a lonely hero – you will have to do it step by step. This stage includes following sub-steps:

    • Creating of Class Project which includes set of 2D drawings of Midship section; Middle Frame section; Cross frames sections; Deck(-s) plan(-s); Plan of Bulkheads; Side Planking; Tanks; Engine room plans; Cargo holds plans; Bottom plans; Living compartments and Superstructure; etc.
    • Stability Calculations and issuing of Stability Booklet.

    Here we go. Sounds scary but I’m sure it is one of the most organized methods of vessel’s design. I tried it many times before by myself being a single designer involved in a process and I had to follow the steps to come to the final stage – Class Project of the vessel.

    Of course it is not obligatory to have a 3D part if you got used to work only in 2D format. Even me belong to the old school of drafting. When I used to study in the College in Saint-Petersburg it was forbade for us to draw in CAD system before Diploma project. We had to draft a proper shipbuilding drawings (hundreds of them) using just a pencil, drafting set and paper of A1 format. It was a great experience. However it's a XXI century and working in a 3D environment has many advantages compare to 2D. For example it allows you to do quick and maximally exact adjustments based on the results of your progress in calculations and implementing of Rules, Standards and Conventions. At the same time I do not recommend to start the Solidworks stage until you 100% sure about your vessel's outline.

    I hope this publication was interesting for maritime professionals, naval architects including students. I appreciate attention of everyone who read this publication, however conversation is open for future comments, questions and suggestions.

    Link to publication on LinkedIn
    Last edited: May 12, 2016
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    I think a very interesting study that has required a thorough analysis and therefore has much merit.
    With the intention to improve it, based on my experience, I would propose the following ideas, which are not intended to be a thorough analysis of the process:
    • Include a final step 6 consisting in, with the information acquired so far, to re-start with the first step: the so called "the design spiral".
    • Do not start the analysis of the structure, as proposed in stage 2, without a GA, which is provided in step 3.
    • Not build a 3D virtual model of the ship if no GA studied.
    • In general, it does not seem possible to do anything of stage 2 without having a provisional GA (step 3).
    • All stage 4 should not be subject to the existence of a 3D model. The process of defining a project could not depend on the tool that every designer use to create his model. This can also be a 2D model.
    • Etc.
    Thank you for sharing your ideas. It can be a very interesting thread.
  3. middlemarinedub
    Joined: Jun 2015
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    middlemarinedub Captain Vadimo

    Good ideas, thank you! I will work on it.
    Only one thing is that yes, you are right regarding the point that not all designers are creating 3D models. I'm talking about mostly my experience in designing of the vessel and I do prefer to have a 3D model, always. It helps to do preliminary and quick adjustments and re-calculations much faster.
    And of course, all points you mentioned they are correct and they are already there, but hidden. However there is always room for improvements.
  4. TANSL
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    TANSL Senior Member

    I always make a 3D model of my projects, but not in the initial stages but as a result of several previous stages, and as necessary to develop naval architecture calculations or as a help in creating hull construction drawings.
    For example, the GA is always prior to the 3D model or the design of the structure is always prior to the 3D model.
    I can design, and so I always do, the whole structure of the boat (from the scantlings to the CNC files for cutting pieces), without having a 3D model. One of the reasons to work in this way because the software that allows you to create these models is too expensive for an independent designer.
    Perhaps your thread should be titled "My process to design a vessel in 5 steps".
  5. CDBarry
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    CDBarry Senior Member

    Any thoughts on getting that first very early stage weight estimate?
  6. TANSL
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    TANSL Senior Member

    Naturally but first, for example, it must be designed and calculated the structure. It all depends, of course, on the level of accuracy that one wants to achieve at each stage of the design and what each one means by "very early stage" of the design.

  7. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    No magic sadly. Just blood sweat and tears of experience. Plots/graphs of trends etc help...but no substitute for running the numbers from scratch to confirm the 'wetted finger in the air' first pass estimate.
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