Fig.11 |
Mean values of subjective rating scales displayed on IMO's standard diagram (the 1st overshoot angle of 10 deg Z-test) |
Fig.12 |
Mean value of subjective rating scales displayed on IMO's standard diagram (the 2nd overshoot angle of 10 deg Z-test) |
Fig.13 |
Mean value of subjective rating scales displayed on IMO's standard diagram (the 1st overshoot angle of 20 deg Z-test) |
4. CONCLUSIONS
Through the simulator study using three models of series-ships with the different spiral loop width, the authors have reviewed IMO'S ship manoeuvrability standards particularly focusing the criterion for yaw-checking and course-keeping ability. As far as the present simulator study is concerned, the major concluding remarks are pointed out as follows.
(1) Overshoot angle of Z-test can be well used not only as index of yaw-checking, but also as index of course-keeping ability.
(2) Applied rudder angle during simulation has strong correlation with her instability on course and with subjective evaluation rating scale as well.
(3) Revised criteria on yaw-checking and course-keeping ability are proposed in view of degree of manoeuvring difficulty.
(4) Even though spiral loop widths are the same among three models of series-ships, fairway passing of ships with large L/V, on the whole, is more difficult than that of ships with small L/V
ACKNOWLEDGEMENTS
This work was supported by grant No. R01-2000-000-00320-0(2002) from the Basic Research Program of the Korea Science & Engeering Foundation.
REFERENCES
[1] Kang, Changgu "IMO's Ship Manoeuvrability Standards", Bulletin of the Society of Naval Architects of Korea, Vol. 30, No. 2, pp.79-85, 1993
[2] Yoshimura, Yasuo, et al. "Prediction of Full-scale Manoeuvrability in Early Design Stage", Chapter 3 of Research on ship Manoeuvrability and its Application to Ship Design, The 12th Marine Dynamic Symposium, The Society of Naval Architects of Japan, pp.111-112, 1995
[3] Sohn, Kyoungho "Hydrodynamic Forces and Manoeuvring Characteristics of Ships at Low Advance Speed", Journal of the Society of Naval Architects of Korea, Vol. 29, No. 3, pp.90-101, 1992
[4] Takashina, Junshi "Ship Manoeuvring Motion due to Tugboats and Its Mathematical Model", Journal of the Society of Naval Architects of Japan, Vol. 160, pp. 93-102, 1986
[5] Inoue, Shosuke, et al. "Hydrodynamic Derivatives on Ship Manoeuvring", International Shipbuilding Progress, Vol. 28, No. 320, pp.112-125, 1981
[6] Hirano, Masayoshi "Some Notes on Prediction of Ship Manoeuvring Motion", Workshop on Prediction of Ship Manoeuvrability. Fukuoka, Japan, pp. 17-26, 1992
[7] Sohn, Kyoungho, et al. "A Study on Real Time Simulation of Harbour Manoeuvre and Its Application to Pusan Harbour", Journal of the Korean Society of Marine Environment and Safety, Vol. 7, No. 3, pp.33-49, 1997
[8] Yoshimura, Yasuo, et al. "Modeling of Manoeuvring Behaviour of Ships with a Propeller Idling, Boosting and Reversing", Journal of the Society of Naval Architects of Japan, Vol. 144, pp. 59-71, 1978
[9] van Lammeren, W. P. A., et al. "The Wageningen B-Screw Series", Transactions of SNAME, Vol. 77, pp. 269-317, 1969
[10] Fujino, Masataka, et al. "On the Manoeuvrability of Ships while Stopping by Adverse Rotation of Propeller (1st Report)", Journal of the Kansai Society of Naval Architects, Japan, No. 168. pp. 57-70, 1978
[11] Isherwood, R. M. "Wind Resistance of Merchant Ships", Transaction of the Royal Institution of Naval Architects, Vol. 115, pp. 327-338, 1973
[12] Yoshimura, Yasuo "Revised Proposal of Yaw-checking and Course-keeping Ability", RR 74 Project Working Group of Manoeuvrability, The Society of Naval Architects of Japan, 2000
AUTHOR'S BIOGRAPHY
Dr. Kyoungho Sohn is now a professor at Korea Maritime University. He is concerned with manoeuvring and real time simulation. He received Bachelor's degree from Korea Maritime University in 1974, Master's degree from Inha University in 1976 and Doctoral degree from Osaka University in 1983. The title of thesis is "The Unstable Behavior of Ships Due to Coupling of Manoeuvring and Rolling", In 1983 he became a lecturer at the Department of Naval Architecture and Ocean Engineering at Korea Maritime University. Since 1992 Dr. Sohn has been a professor.
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