2.3 Learning of Steering Operation Using the ISSS
It has become possible for students to correctly and efficiently view on the display of the newly developed ISSS such post-steering phenomena as drift, turning, speed reduction, displacement of pivoting point, kick, drift angle, and heeling as they occur simultaneously in a brief time, while experiencing steering operations with the ship-handling simulator.
Here, explanatory notes are given on practical learning with the simulation using the ISSS under the procedural sequence of events.
(1) Steering simulation with a ship-handling simulator
Prepare a scenario simulating the scenery of sheet of graph paper as shown in Fig. 9. This attempts to allow a student to visually judge the motions of the own ship and the size of the occupied water area during steering operation on the basis of changes of scenery projected on the horizontal screen of the ship-handling simulator. Under the initial conditions of ship size, draft, depth of water, speed and rudder angle, the own ship proceeds straight on, and takes the specified rudder angle when the ship comes to the origin of the coordinate axes.
Fig. 9 Scenery of sheet of graph paper
(2) Experiencing steering operation
Experience the real feeling of the ship's motions from the changing scenery projected on the horizontal screen of the ship-handling simulator. At this moment, the students physically experience slow-moving ship motions and the size of occupied water area that is necessary for making a turn.
(3) Learning with the ISSS
The students learn a variety of post-steering phenomena of motions and their dynamic mechanism that are generated in a brief time after the rudder is taken such as drift, turning, speed reduction, displacement of pivoting point, kick, drift angle, heeling, by viewing numerical information and animated graphic information displayed on the screen of the ISSS.
(4) Real-time lessons and replayed lessons
The ISSS features the capability of offering students to acquire ship-handling experience and an opportunity to study the dynamic mechanism of steering operation through linkage with the ship-handling simulator. Accordingly, the students can replay lessons under a variety of preset conditions with the ship-handling simulator. On the other hand, if the results of a simulation are stored in a data file, replayed lessons are available if the ISSS is used alone with slow or fast reproduction.
3. EDUCATIONAL EFFECTS OF THE ISSS
3.1 Experimental Study
It is not easy for students to learn and understand the relationship among a variety of post-steering phenomena of motions and their dynamic mechanism in a systematic way that are generated in a brief time after the rudder is taken until a steady state of turning motion is reached
When a lecture on ship-handling theory including steering operation is given in a classroom, explanations refer to figures and sketches drawn on a blackboard. However, it is not easy to have students understand the dynamic mechanism of such ship motions as turning motions using fragmented and static figures drawn on a blackboard.
To provide solutions for these difficulties, this system aims at providing experience-oriented education and training by combining a steering operation using a ship-handling simulator and a visual-aid teaching material that is capable of displaying the dynamic mechanism of ship motions in a visually understandable form.
It is anticipated that the levels of the students' understanding of the dynamic mechanism concerning why and how a ship turns would be enhanced and the students ' understanding of the ship motions during making a turn would be deepened.
Under these circumstances, an attempt to verify the educational effects of this system was made to assess how this system helps improve the students' understanding of steering operation, using 24 subjects chosen from among students of the first year, second year, third year and fourth year of Kobe University of Mercantile Marine.
Note, however, that the students of the third year and the fourth year have completed the subject of ship-handling theory including steering operation. The students of the first year and the second year have not received the subject of ship-handling theory including steering operation, but they have steering experience onboard a training ship.
In the experimental study, the subjects were divided into two groups. One is Group A, representing those who receive ordinary, classroom lecture using a blackboard, and the other is Group B, representing those who receive lecture using the ISSS. The composition of each group is given in Table 1.
Paper tests were carried out in which examinees were requested to choose phenomena that simultaneously occur at the initial stage of turning motions of a ship from multiple alternatives. The results of the paper tests are given in Table 2.
Table 1 Groups detail
||Juniors & Seniors
||Sophomores & Freshmen
|Had learned steering before
||Had not learned steering before
As can be seen from Table 2, there were no distinct differences in the achievements of the students of the third year and the fourth year, and between those students who had lecture merely with a blackboard and those students who had lecture using the ISSS.
However, the students of the first year and second year showed different results; i.e., the members of the group that received lecture using the ISSS could understand more accurately than the members of the group that had lecture merely with a blackboard.
Table 2 Right answer rate of each group
||Right answer rate
|Had learned steering before
||Had not learned steering before
It may be deduced from the above discussion that the educational effects of the ISSS are particularly significant for beginning students of the first year and the second year.
3.2 Students' Comments on the ISSS
Comments on the ISSS were solicited in the form of free descriptions from those students who received lecture using the ISSS. Shown below are the comments received from the students.
(1) Points considered to be good
- It was readily understood what would occur simultaneously while a ship is engaged in turning motions.
- The changing conditions of heeling motions of a ship were readily understood.
- The relationship between the forces acting on the hull and the heeling motion could be understood well.
- The conditions of the entire process of turning motions of a ship were readily understood.
- Using the temporary stopping function of the simulator, simulation can be stopped to better confirm ship motions.
- Forces created in a ship can be understood time-historically.
(2) Problems or points to be improved
- The numerals and symbols on screens are too small and could not readily be read off.
- It would be much better if three-dimensional presentations were available.
- It would be better if the ISSS lecture were given together with a blackboard lecture.
- It would be better if the ISSS could be handled by the student without assistance.
On the basis of the above discussions, all of the students who used the ISSS gave positive support for lecture using the system, although there is room for improvements in the method of conducting lecture and the contents of display, so it may be concluded that the usefulness of the ISSS as a visual-aid teaching material has been verified.
4. CONCLUDING REMARKS
The general practice in traditional lectures using blackboards and textbooks on dynamic phenomena such as generation of kick, displacement of pivoting point, generation of drift angle, which are simultaneously occurring immediately after the rudder is taken was to explain them one by one in a sequential manner. However, it is extremely difficult for students, particularly those with little experience on board, to come to grips with these phenomena as simultaneously occurring events.
The Integrated Steering Simulation System (ISSS) has been developed to provide solutions just for these problems. By providing a lecture utilizing this system linked to the ship-handling simulator, it has become possible to enable students to learn more easily and empirically understand the fundamental phenomena for steering operation.
The educational advantages using this system are as follows :
(1) Conventionally, a ship-handling simulator has been used mainly as a training tool. Experience with a ship-handling simulator alone is not sufficient for effective education and training of students. More effective education and training can be realized if the Integrated Steering Simulation System (ISSS) linked with a ship-handling simulator is utilized as an empirical visual aid teaching material.
(2) By displaying animated graphic information on the multiple displays, the students can visually understand the dynamic phenomena occurring simultaneously at steering operations of a ship. By displaying the forces and moments acting on the hull with elastic arrow marks, in particular, the students can easily understand the mechanism of ship motions during steering operations.
The authors have, in addition to the Integrated Steering Simulation System (ISSS), developed an Integrated Anchoring Simulation System (IASS) dealing with the swinging motions of a ship at anchor through computer simulation techniques (1), and its educational effects have been verified.
The idea of developing such simulation techniques and innovative visual-aid teaching materials in linkage with ship-handling simulators is expected to contribute greatly to broadening the application areas of ship-handling simulators in the future.
[l] INOUE. K, USUI H. and MA R.: "Development of an Integrated Simulation System for Analyzing the Swinging Movement of a Ship at Anchor and Its Application for Educational Use", Proceedings of 3rd General Assembly of the International Association of Maritime Universities, pp.9.1-9.9, 2002
Name: Kinzo INOUE
Chronology of Education:
1964-1968: Kobe University of Mercantile Marine, (Bachelor of Maritime Science)
1976-1978: Graduate School of Kobe University of Mercantile Marine, (Master of Maritime Science)
1985: Doctor of Engineering. University of Kyoto
Chronology of Experience:
1968-1975: Deck officer of seagoing vessels, NYK Line
1975-1981: Associate Professor in Toyama National College of Maritime Technology
1981-1990: Associate Professor in Kobe University of Mercantile Marine
1990-present: Professor in Kobe University of Mercantile Marine
2000-2002: Vice president in Kobe University of Mercantile Marine
Major Research Field:
Marine Traffic Engineering
Theory of Ship Handling
Maritime Safety Management