Conceptual design phase includes a group of works and processes where all documentation that describes and guarantees the ship according to customer’s needs is generated. As a result of conceptual design phase it becomes possible to extract a preliminary material list, to calculate the cost of workmanship and therefore to form a preliminary approach about building cost estimation. Provided that it depends on the content of the project, within the outcome of the conceptual design process there are following information, documents and calculations.
A specification document in which the ship’s main particulars, her functions, main equipment and systems are described. This specification provides a brief insight about the ship that will be built.
General Arrangement Plan is a drawing where main compartments, systems and equipment of the ship are shown. This drawing which is accepted as the ship’s identity card is prepared based on customer’s need while also considering the latest applicable rules and regulations of national and international bodies.
It’s a preliminary drawing of the ship’s lines which is used for calculations of speed-power, stability, carriage capacity and sea-keeping that will take place at later stages of the design project. Previously designed similar hull form designs which have proven their success by full scale performance measurements are one the key elements to make such a drawing. Depending on the type of the ship draft designs of some underwater appendages such as rudder blade, A-bracket, bilge keel, sonar dome are also prepared.
This drawing shows the main equipment in engine room(s) and their arrangement in relevant spaces. Based on the dimension of the ship this drawing is either prepared separately or the details are shown in the General Arrangement Plan.
A draft midship section drawing that would include a design standing against the global and local forces and appropriate for ship’s type and functions. By using this design document, it is possible to calculate ship’s lightweight and the amount of steel material and therefore a more precise approach can be developed regarding the building cost of the ship.
In order to determine the capacity, strength and weight of the mooring and anchoring equipment of the ship, Equipment Number Calculation is carried out. As a result of this calculation an information pool is formed for selection of mooring and anchoring equipment.
By using the information on General Arrangement Plan, Midship Section Plan, weight of main equipment and statistical data, the light ship weight and the coordinates of the center of gravity are calculated.
According to International LoadLine Convention the maximum draft value that limits the submersion of the ship is determined by Freeboard Calculation.
Gross and Net Tonnage calculations are carried out based on relevant national and international rules and regulations. This calculation is of critical importance since it affects the fees which will be paid to ports during ship’s entire operational life.
Using the designed hull’s parameters, the speed-power curve is drawn based on still water resistance values and propulsion variables. Still water resistance values and propulsion variables are calculated on the basis of well-known empirical methods as well as similar hull forms that have been designed and/or have been tested within a scaled model test. In the meantime the wave resistance values is checked by using in-house developed potential flow solving software, DeltaFlow which uses Dawson algorithm and is integrated with B-Surf, also in-house developed hull form design software. While calculating the power values, optimum propeller values which are determined according to open water propeller efficiency curves.
In order to define the capacity of the generators providing necessary electricity the power need of main equipment of the ship and previous calculation experiences are used and therefore a preliminary electrical load analysis is carried out. The number and output power of the generators are determined based on the calculation of energy level that would be needed during voyage, harbor and loading-unloading operations.
Especially for ships carrying heated or refrigerated cargoes a preliminary heating load calculation is carried out to determine the capacities of boilers and compressors.
Based on the pre-determined cruising range the fuel consumption calculation is done to define the capacities of the bunker tanks and the Energy Efficiency Design Index (EEDI) value.
Depending on the operational courses of the ship a risk analysis comprising of possible dangers that the ship may face is carried out. The evaluation of the risks and their effects on the ship’s operational procedures within the scope of ISM regulation include the risk evaluation tables as well as the cost-benefit analysis.
Considering the technical, administrative and financial dimensions of the shipbuilding project all items that could be included into the cost are defined and the estimated costs are gathered within a report.
3D model of the ship’s outer profile is prepared for design coordination and presentations.
A preliminary drawing showing the arrangement of tanks and watertight compartments is prepared. Based on this work, calculations of tanks’ capacity, typical loading cases, intact and damaged stability and finally longitudinal strength are carried out.