In a new ship building project the contractual design process is the most important design phase where all design calculations are carried out, final design and configuration decisions are made and a smooth building process with an end product delivery that would fulfill precisely the customer’s needs are guaranteed. Provided that it depends on the content of the project, within the outcome of the contractual design process there are following information, documents and calculations.
The introductory/brief specification which is prepared as a framework is detailed in this phase. The content of subjects under each main topic are expanded. The list of design documents, General Arrangement Plan and simplified diagrams of the important ship systems are included into the specification.
If the resistance and propulsion model tests are carried out, the results of these tests are used with optimum propeller design in order to make speed-power calculation. As an alternative to model tests along with ship resistance and propulsion calculations, speed and power calculations with optimum propeller are carried out by using Computational Fluid Dynamics (CFD) method. In case of the absence of model tests or CFD calculations, taking into consideration the form variables of the final hull form, speed and power calculations are updated with the help of empirical methods or data belonging to ships of similar geometrical characteristics.
Polar diagrams are prepared and additional wave resistance calculations are carried out according to characteristics of the sea where the ship will operate as well as required seakeeping criteria.
Hull form and appendages are updated to their final status. The lines are faired and a 3D hull model is prepared in order to be used during the production engineering process.
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.
Based on final General Arrangement Plan and Midship Section, the light ship weight and the coordinates of the center of gravity are re-calculated and updated.
General arrangement, engine room(s) arrangement, accommodation arrangement, arrangement of mooring and anchoring equipment, arrangement of live saving equipment and arrangement of other relevant spaces are prepared/updated based on the chosen equipment and the requirements of the customer.
This booklet in which global and local forces that the ship’s structure would stand are determined according to ship’s type, mission, particularities and her operational area, is prepared for consideration during structural design.
Midship Section Plan is updated according to findings in Structural Design Criteria Booklet.
Structural design documents such as longitudinal sections, deck sections, shell expansion, typical sections, fore ship, aft ship, superstructure, etc. are prepared.
Structural foundation drawings of main ship equipment such as main engine, generators, boiler, mooring equipment, crane(s) are prepared.
A booklet comprising of welding plans that shows types and dimensions of welding to be applied in different parts of the ship is prepared.
Depending on the selected propulsion system, an arrangement drawing describing the integration of the propulsion equipment (propeller, azipod, water jet, etc.), shaft, couplings, bearings, main engine, reduction gear, alternator etc. is prepared.
The design of the rudder blade is carried out. The capacity of the steering gear and thrusters are calculated. If a characteristic of the ship, the dynamic positioning calculations are done.
The preliminary electrical load calculation is updated and finalized based on the capacities and energy need of the selected equipment.
The preliminary heating load calculation is updated and finalized based on the capacities of the selected boilers and compressors for heating and refrigerating operations.
The design of the whole electric distribution diagrams together with the main switchboard and emergency switchboard is prepared.
Taking into consideration the type and functions of the ship, piping and instrumentation diagrams (P&ID) are prepared for various piping systems such as cargo, heating, vapor, inert gas, nitrogen, oxyacetylene, fuel oil, lubrication oil, cooling water, compressed air, exhaust, sanitary, ballast, fire, bilge and sludge, airvent, sounding, drainage, etc. that are located in different parts of the ship (engine room, accommodation, open deck, etc.) and need to be distributed.
The drawings describing the fire and noise insulation, arrangement of firefighting and safety equipment are prepared.
The drawings where the access and escape ways are shown are prepared in order to be framed and hanged on ship’s panels and to be used especially for emergency situation.
After determining the characteristics like dimension, power, capacity, amount for each and every system of the ship, a list of material and equipment for procurement operations is prepared.
Docking plan is drawn to describe the necessary form structure to dock the ship, to show the bottom structure for installation of keel blocks and to determine the additional appendages as well as dimensions or information (framing, location of the collision bulkhead, etc.) that would be a reference for docking operation.
A drawing that defines the division of the ship into blocks is prepared taking the building strategy, physical conditions of the builder shipyard and particulars of the selected material into consideration.
3D Model of the outer ship profile is updated based on latest General Arrangement Plan and other relevant arrangement plans. In case of request architecture of the internal parts are also modeled and presented.
In addition to above mentioned works, the scope of the contractual design phase can be extended towards “functional design” with many different and additional studies such as realization and coordination of model tests, advanced engineering analysis of the ship’s structure using Finite Element Method (FEM), vibration and noise analysis, functional simulations, preparation of technical specifications of material and equipment to be procured, detailed cost estimation, preparation of procedures for Harbor Acceptance Tests (HAT) and Sea Acceptance Tests (SAT).
The system diagrams of heating, ventilation and air conditioning (HVAC) in different locations of the ship are drawn.
Depending on the changes made on General Arrangement Plan, Midship Section and Light Ship Weight Calculation, the calculations of tank capacity, intact and damaged stability and longitudinal strength are updated.