MARINE REQUIREMENTS ELUCIDATION AND THE NATURE OF PRELIMINARY SHIP DESIGN

My thanks to the author for a fine paper. It is also an important one, at least in the area of naval whole ship procurement where the idea of ‘Requirements Engineering’ has been taken up by those ignorant of the process of successful ship design. It is notable that such mistakes do not appear to be made in commercial ship procurement, where the pressures of finance, time and more direct accountability seem to concentrate the mind against ill-thought-out fads.

Investigating the Performance of a Ship by Matching the Stern Hull Form to Propeller and Engine Power

Designing the form of the ship stern hull could have some impacts on the efficiency of ship propeller and the requirement of the ship speed. Therefore, stern hull form of a ship matched to its propeller and engine power is important consideration in preliminary ship design stage. The main objective of this study is to investigate ship performance by matching the stern hull shape to the propeller diameter and engine power toward high speed. This study was conducted by free running model test and Maxsurf Resistance application. The stern forms were employed U-shape and V-shape. In addition, the fixed pitch propeller (FPP) with three blades was used and the diameter is varied into three sizes 0.032 m, 0.040 m, and 0.048 m. The results show the increase of propeller diameter increases model’s speed for both U-shape and V-shape stern and the effect of the propeller diameter on the speed could be described by using the equations of second-order polynomial. The optimum propeller diameter could be determined taking into account stern hull form, stern shape, tip clearance, and proper speed where then propeller diameter related to draft is given by 0.79T with tip clearance 10%Dp for both U-shape and V-shape. The ship resistances of U-shape stern at Fr 0.221 and V-shape at 0.208 are obtained approximately 89.797 KN and 77.10 KN respectively. Furthermore, the powers of ship for both U-shape and V-shape at those Fr are obtained 904,374 KW and 726,807 KW respectively. Finally, the best stern hull form matched to propeller diameter and engine power is selected and given by U-shape stern.

An Analysis of Basic Parameters of Ro-Pax Ferries in the Baltic Sea as Guidelines for its Preliminary Design

This paper presents results of an analysis of the operating and maneuvering parameters (length, width, draft, main propulsion power and maneuvering equipment, and windage area) of the Ro-Pax ferries over 150m in length. The analysis takes into accounts all ferries operating in the Baltic Sea in 2017. The work also includes route analysis of the collected Ro-Pax units. The influence of port infrastructure is also discussed. The mean optimal Baltic Sea Ro-Pax ferry and its parameters for short term and long term forecasts are presented. This paper may be used as a primary guideline for the determining the optimal Ro-Pax ferry dimensions size for the Baltic lines in terms of preliminary ship design.

Variants method approach to the preliminary ship design

Typical ship designing is an iterative method based on the accumulated experience of already built ships. In the case of a completely new type of ship, without the „dowry of previous experience”, the design consists in developing a series of parallel variant solutions using the optimization. The paper identifies selected designing methods applying the optimizations used in the preliminary ship design. The optimization methods used in the ship design are discussed.

Parametrical Method for Determining Optimal Ship Carrying Capacity and Performance of Handling Equipment

The paper presents a method of evaluating the optimal value of the cargo ships deadweight and the coupled optimal value of cargo handling capacity. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper second hand ship for a given transportation task. The deadweight and the capacity are determined on the basis of a selected economic measure of the transport effectiveness of ship – the Required Freight Rate. The mathematical model of the problem is of a deterministic character and the simplifying assumptions are justified for ships operating in the liner trade. The assumptions are so selected that solution of the problem is obtained in analytical closed form. The presented method can be useful for application in the preliminary ship design or in the simulation of pre-investment transportation task studies.