SHIP DESIGN SYNTHESIS
Every ship that is sailing around on our world’s oceans had to start somewhere. This starting point can be defined by looking at the Ship’s Design Synthesis which includes all the considerations that must be considered when designing a ship.
A good definition of the Design Objective is essential for the success of the Ship Design. The objective should not be “lost” along the way! Therefore, it is important to prevent scope creep. Scope creep can be defined as follows:
Scope Creep is caused by “…uncontrolled changes or continuous growth in a project’s scope. This can occur when the scope of a project is not properly defined, documented, or controlled. It is generally considered harmful.”
It is important to remember that the engineering solution needs to always be:
You may be asking yourself what the main considerations needs to be, or which is required, to define a ship design project from the onset of a project. These main considerations ties in perfectly with the main project objectives that needs to be developed. It is important to note that the project objective must focus on three critical aspects:
- Ship/Vessel performance
- Budget & Time
These three project objectives provide you as the ship designer with the major end goals that must be achieved. It is thus extremely important that the ship role and design requirements are properly defined from the onset of the project. It is also important that any additional client requirements for project success be determined as part of the early stages of the ship design process. You should always ask the client at least the following questions:
- Does the client require any special equipment or deem certain vessel characteristics important?
- What would the operating environment of the ship be?
- Where is the client’s preferred fabrication/build location?
- What is the client’s delivery location and the available transport options?
Regardless of the client’s requirements, during the design process it is also extremely important to consider the various rules, regulations, standards and legislation that specifies the various requirements that ship’s must conform to ensure a safe and reliable ship will be built to high quality standards. These guiding principles are mostly contained in:
- International Regulations and Conventions (e.g. IMO, IAAO)
- Regional Regulations (EU)
- National Regulations –Flag State & Ports of Operations (MCA, UKHSE, USCG)
- Local Regulations (SAMSA)
- International Standards (EU, ISO, British…)
- Industry Standards (OCIMF, API, MOD Standards)
- Ship Classification Societies (GL, LR, BV, DNV-GL…)
The Initial Steps of Ship Design
The initial steps of ship design combined forms the backbone of the ship concept design phase. This concept design phase process can usually be broken down into the following general steps:
1. Client Design Goals: What does the client want in terms of ship performance, aesthetics, the ship’s operating environment and usage profile etc.
2. Assist the Client in Design Objective Formulation: Remember, the client is always right, but they are not always able to formulate their objectives for the vessel in to achievable designs that can be implemented due to not having all the correct knowledge. It is your task to ensure that your clients objectives can be met, but in a way, that is viable and cost effective.
3. Work Out Main Characteristics: This includes the general proportions and powering, hull form, floodable length and freeboard, arrangements of the hull and machinery and the structure of the ship.
4. Review Similar Existing Designs: A lot of effort and research has gone into complete ship designs in the past, and the general focus lies on the acquisition of proven designs. Instead of developing a completely new ship from scratch (especially the hull form and shape), it is better to look at existing ship designs available that can be suitably tailored to meet the client’s requirements.
5. Consult Rules and Regulations: Rules and regulations govern the various characteristics that a ship must conform to ensure that it is safe and to a high-quality standard. See Legislation, Rules and Standards of Ship Design.
6. Form a Ship Layout and Basic Technical Specification: Determine the layout and arrangement of on-board equipment, compartments, machinery rooms, wheelhouses etc. and create the ship specification in terms of a breakdown structure. ESWBS or SFI can be used in the drafting of the specification.
7. Lastly, Discuss and Confirm with The Client. Buy-in must be obtained from the client prior to the commencement of the build of a vessel. If certain aspects have been kept from the client to “speed up” the project schedule, the shipbuilder may be held liable by the client for not meeting the client’s original brief and/or requirements.
Below shows the way ship design starts at a single point, and spirals inwards until the point where actual detail design can be carried out during the award of a contract. Consider the amount of time spent during the preliminary design phase which follows the concept design phase. The ship design spiral allows for the constant refinement of key design considerations as designers following this spiral continuously check, alter and re-check their calculations and design up to the point of the detail design phase.
Output from a Ship Design Process. GA of 25,000 DWT Bulk Carrier: