Page 106 - Practical Design Ships and Floating Structures

81

60
GM = 0.95 rn
(SHIPMO)
50
+Current
E 40 L ships
+tests
E
= 30 -
+with
ART
%
g 20 criterium
10
0
0 30 60 90 120 150 180
following waves Heading [deg] head waves
Figure 3: Downtime analysis for enlarged upper ART

5 CONCLUSIONS

Traditionally applicable only to propulsive performance, the hydrodynamic design based on clear
definitions of operability requirements and mission criteria have made seakeeping and manoeuvring
oriented design decisions easier through a quantitative description of performance throughout the
design process. By utilising available knowledge, dedicated computational tools and verification by
model tests, a balanced design that met all the numerous requirements was obtained.
Based on the desk studies, a single-screw single-rudder configuration with open shaft arrangement was
chosen for the propulsion and steering of the ship. During the model tests, it was found that this
steering arrangement could be used successfully to comply with the dynamic tracking requirements,
resulting in a cost-effective solution. For further improvement of the operability an anti roll tank was
installed.

References
Blok J.J. and Beukelman W. (1984). The High Speed Displacement Ship Systematic Series Hull Forms
- Seakeeping Characteristics, SNAME Transactions.
IMO Resolution A.75 1( 18). (1993). Interim Standards for Ship Manoeuvrability.
Kapsenberg G.K. and Brouwer R. (1998). Hydrodynamic Development for a Frigate for the 21"
Century, PRADS I998 Proceedings Practical Design of Ships and Mobile Units, Elsevier Science. NL.
Lloyd A.R.J.M. (1989). Seakeeping: Ship Behaviour in Rough Weather, Ellis Honvood Ltd., UK.
STANAG 4154 (1998, Edition 3), Common Procedures for Seakeeping in the Ship Design Process.
A TO Standardisation Agreement. unclassified.
Wolff P.A. (2000). Conceptual design ofwarships. ISBN 90365 14495.