THE APPLICATION OF SHIP-HANDLER'S MANEUVERING CHARACTERISTICS FOR FAIRWAY DESIGN
Hiroyuki MIZUNO (M.O. Marine Consulting, Ltd., JAPAN)
It is possible for the basic design of fairway which is attached a harbor that is designed based on the element of fairway design. There are the factors in the element of fairway design which is getting from the shape of fairway and the ship's maneuverability. We should be considering the characteristics of ship-handler when passing the fairway at the time of it's design. So, this paper proposes how to design the fairway within the harbor in consideration of the characteristics of ship-handler under the fairway which including the reducing speed and altering course change.
It is various standards for design to be helpful in case of fairway design. But, this standard isn't being taken into consideration such as the situation of each harbor and special characteristics, the difference of maneuvering characteristics of examination ship for the purpose of to make it have a generality.
So, in this research, it paid attention to the ship maneuvering characteristics and the shape of fairway, and decided to research on the fairway design which made the ship's maneuverability as a base.
Firstly, It is collected the element of fairway design by researching relations with the constituent element of the fairway and the ship's maneuverability under the fairway as the basic way of thinking for the planning of fairway.
Secondly, the ship maneuvering characteristics is obtained from the numerical simulation. The purpose of this stage is to investigate the basic performance of the vessel contained in the element of fairway design. The fairway design should be consider the human operator behavior when passing fairway. Accordingly, the numerical simulation by the human control model which contains the characteristics of ship-handler was carried out. A result of numerical simulation based on ship's maneuverability is compared with the result of human control model, and verified the fairway design.
2. THE ELEMENTS OF FAIRWAY DESIGN
How to way of approaching about the elements of fairway design to use for the fairway planning is explained in this section.
2.1 The factors of the fairway shape
The Fig. 1 is shown the basic factors of fairway shape which must be taken into consideration when the design of its shape. A fairway shape is decided by these basic factors.
Fig. 1 The basic factors of fairway shape
2.2 The elements of fairway design
The fairway shape is decided by relation between the basic factors of fairway shape. Therefore, the investigation of the necessary element was done to decide a fairway shape. That result is shown in the Fig.2 as the elements of fairway design. There are two patterns from combinations of the element of fairway design. The elements are given as an initial condition at the time of the fairway.
Fig.2 The elements of fairway design
PO: The position of intersection of the perpendicular taken down from the final position of ship-handling to the initial course
Ph: The starting position of ship handling
PS: The starting position of alter course change operation
PF: The final position of ship handling
PA: The position of altering course point
Pv: The final position of course change operation (set course position)
VS: The ship's speed at starting course change operation
VV: The ship's speed at finish course change operation (when set course)
Vf: The ship's speed at final position of ship-handling (below steerageway)
ΨS: The initial course of ship handling
ΨF: The approaching course to final position
ΨA: Bending angle of altering course point
l1: Distance between starting position and altering course point
l2: Distance between altering course point and final position
lS: Distance between starting position of ship-handling and course change operation
lf: The distance of slowdown operation from set course position
D1: Distance between initial course and final position of ship-handling
D2: Distance between altering course point and final position on initial course
a. The element decided automatically
b. The element decided in consideration of the ship maneuvering characteristics
For example, when the final position of ship handling and the position of altering course points are given, the approaching course to final position of ship handling decided automatically. This case is shown as the element decided automatically
On the other hand, when the elements of fairway design are given as initial condition, the ship's speed at the starting point of ship-handling is getting from the slowdown performance and distance. This case is shown as the element decided in consideration of the ship maneuvering characteristics.
The width of fairway becomes the ship breadth, if it navigates without deviate from the center line of fairway. But, the fairway width should be necessary more ships breadth because ships cause the lateral deviation at the time of passing fairway as shown in the Fig.3.
a. The lateral deviation of the new course distance when alter course change
b. The lateral deviation from course line when course keeping and alter course changing operation from the influence of external force.
Therefore, when a fairway shape and its width are decided, it is necessary to combine the ship's maneuverability with the elements of fairway design and to examine.
2.3 The elements of fairway design and ship maneuvering characteristics
It is consider about a ship-handling in the fairway from relations of the controller of a ship and ship's manipulability. It is shown as Table 1.The way of ship-handling at this time is ship-handling method which ship's maneuverability shown in the Table 1 and it was combined with.
Therefore, at the time of fairway design, it can be designed by combining each ship's maneuverability.
Table 1 The relation between controllers and ship's maneuverability
||Course keeping performance
Fig.3 is shown the ship's maneuverability at the passing fairway and combined with the elements of fairway design based on this idea and illustrated. The deceleration performance when going straight is used for the slowdown operation before starting and after finished course change operation. Turn performance is used for the course change operation at the passing bending part. The element which a fairway shape is decided and the relations of the ship's maneuverability are as follows.
a. The distance of fairway: Deceleration performance. Stopping performance
b. The width of fairway: Course keeping performance. Turning performance
The fairway design is held by using the element of fairway design by the combination of this ship's maneuverability.