Original scientific paper
Ship Track and Speed Model in Case of Steering Gear Breakdown with Rudder Remaining Fix at non Zero Angle
Đani Mohovoć
; University of Rijeka, Faculty of Maritime Studies Rijeka, Studentska 2, 51000 Rijeka, Croatia
Robert Mohović
; University of Rijeka, Faculty of Maritime Studies Rijeka, Studentska 2, 51000 Rijeka, Croatia
Igor Rudan
; University of Rijeka, Faculty of Maritime Studies Rijeka, Studentska 2, 51000 Rijeka, Croatia
Abstract
Ship navigation is determined by the ship’s position on a certain part of the fairway from the place of departure to the place of arrival. During the voyage, in a given period of time ship changes the course and the speed. Navigation itself can be viewed from the aspect when during the voyage all onboard systems are functioning properly and the person managing the ship practices good seamanship, and from the aspect when an extraordinary event occurs, which affects the possibility
of maintaining the desired course and/or speed.
This paper analyzes the movement of the ship in case of an extraordinary event with the assumption that the malfunction occurred in the steering system. Depending on the navigation area and the sea traffi c, such an event generates two basic maritime navigation risks, the risk of ship grounding and the risk of collision. This paper explores ship movement that, depending on the scenario, may result in ship grounding.
For the purposes of conducting research on ship movement due to the assumed extraordinary event onboard, various scenarios were defi ned. To create a track model, an Euler spiral/clothoid was chosen. By modifying the parametric clothoid equation, a curve was obtained which very well approximated the curve of a turning ship. Furthermore, developed was the speed change model that can show the speed change at any point of the curve of a turning ship when the rudder defl ection was constant, and the engine was stopped. The designed models were tested in 60 scenarios in accordance to which the research on the navigation simulator was carried out.
Ship track model can be used in the fi eld of research for simulation model development, the result of which will enable determining the extent of grounding damage, and after determining the extent of grounding consequences, it will enable the defi ning of acceptable risk as well.
Keywords
extraordinary event; ship track model; speed change model; risk of grounding
Hrčak ID:
85032
URI
Publication date:
15.6.2012.
Visits: 1.603 *