Navigation in restricted basins is connected with evaluation of vessel’s safety level, especially during anticollision manoeuvres. The paper presents the factors, which have influence on anticollision manoeuvres in restricted area. The results of the researches concerning overtaking manoeuvres carried out on reduction models for a VLCC ship are presented as well

Ship collision is a hazardous event within the chain of maritime transport. Collisions may result in human losses, adverse economic consequences, and environmental damages causing significant impact to local societies and related activities. A major factor in any risk analysis concerning ship collisions is the probability of these collisions occurring. The purpose of this study is to assess the probability of ship-to-ship collision in the Aegean Sea. The basic concept of the developed model is to (statistically) simulate traffic flow in the area of interest and determine the collision candidates; this will be implemented in a pilot study in a segment of the Aegean Sea. The input of this effort is based on values that are extracted from statistical analysis of the international fleet in combination with the study of maps depicting traffic flow in the studied area. Hence, it does not employ detailed AIS data. The obtained results are presented and their agreement with actual incidents is discussed in depth. The paper concludes with interesting insights of the aforementioned tasks.

During winter in arctic seas, navigation of ships near ports occurs within ice channels created and maintained by icebreakers. Small ice floes fill the relatively narrow navigable channel, and ships are forced to produce the overtaking or opposing separation over short distances and under the action of ice floes. This paper presents an analytical model of the interaction of ships under the conditions just described as well as the results of a simulation. The simulation showed side force and yawing moments were dependent on ice conditions and the ship’s dimensions and motion characteristics.

Oil spills from maritime activities can lead to very extensive damage to the marine environment and disrupt maritime ecosystem services. Shipping is an important activity in the Northern Baltic Sea, and with the complex and dynamic ice conditions present in this sea area, navigational accidents occur rather frequently. Recent risk analysis results indicate those oil spills are particularly likely in the event of collisions. In Finnish sea areas, the current wintertime response preparedness is designed to a level of 5000 tonnes of oil, whereas a state-of-the-art risk analysis conservatively estimates that spills up to 15000 tonnes are possible. Hence, there is a need to more accurately estimate oil spill scenarios in the Northern Baltic Sea, to assist the relevant authorities in planning the response fleet organization and its operations. An issue that has not received prior consideration in maritime waterway oil spill analysis is the dynamics of the oil outflow, i.e. how the oil outflow extent depends on time. Hence, this paper focuses on time-dependent oil spill scenarios from collision accidents possibly occurring to tankers operating in the Northern Baltic Sea. To estimate these, a Bayesian Network model is developed, integrating information about designs of typical tankers operating in this area, information about possible damage scenarios in collision accidents, and a state-of-the-art time-domain oil outflow model. The resulting model efficiently provides information about the possible amounts of oil spilled in the sea in different periods of time, thus contributing to enhanced oil spill risk assessment and response preparedness planning.

Various methods of trajectory determination are used for finding solutions to collision situations involving ships. This applies to avoiding collisions with other ships or stationary objects. In addition to the methods generally used, new or modified versions of methods derived from other modes of transport are proposed. One of the algorithms for route determination serving to avoid obstructions is the method of artificial potential fields, used for determining routes of mobile robots. The method is used in maritime transport, for instance for detecting anomalies in ship movement. The article presents the method of potential fields used for solving the problem of route selection avoiding navigational dangers and obstacles. This article presents an algorithm of route determination based on the said method, its implementation in the MATLAB program and examples of application for the ship’s safe trajectory determination in some navigational situations.