|
4. MANEUVER PLANNING SYSTEM BASED ON THE MODELS OF STANDARD MANEUVERS
Planning maneuvers should be based on the standard maneuvers by expert and skillful mariners. In order to find the standard maneuvers by expert and skillful mariners, questionnaire surveys and simulator studies on deceleration, course alteration and stopping maneuvers were executed. Through these surveys and experiments, standard maneuvers of GT499 inland vessels on deceleration, course alteration and stopping were found. A photo and a principal particulars of the typical GT499 inland vessel, which is the target ship on this study, are shown in Photo 1 and Table 1.
Table 1 Principal particulars of GT499 inland vessel
| Gross Tonnage |
498 T |
| Length p.p. |
70.00m |
| Breadth |
11.80m |
| Depth |
7.20m |
| draft |
3.78 m |
| MCR |
2400 ps x 260 RPM |
| NOR |
2050 Ps x 240 RPM |
| Bow Thruster |
203 ps x 2.03 t |
| Stern Thruster |
162 ps x 1.52 t |
| RATING |
RPM |
SPEED(kt) |
| Navigation Full |
240 |
12.4 |
| Full Ahead |
240 |
12.4 |
| Half Ahead |
180 |
9.3 |
| Slow Ahead |
120 |
6.2 |
| Dead Slow Ahead |
60 |
3.1 |
|
4.1 Standard deceleration maneuvers
The result of a questionnaire to experts on deceleration maneuvers is shown in Fig. 6. On basis of this result, a model of standard deceleration maneuvers was developed. It is well known that the speed response of the ship motion to a telegraph order, such as the half down and the slow down orders, is approximated to a first order differential equation (1) and (2) as shown by the following.
v(t):Ship Speed [m/s], n(t):RPS of Engine,
Constants of the above equations, which are m: mass, c: resistance factor and k: thrust factor, can be estimated from the principal particulars of the ship.
| Fig. 6 |
Results of a questionnaire to the experts on deceleration maneuvers |
Fig. 7 Model of deceleration maneuvers by the experts
|
