During ship's navigation on waves some relative motions occcur resulting in propeller emergence, which in consequence reduces the propeller thrust. The article presents an algorithm for calculating the propeller thrust reduction as a result of ship motions on waves. The algorithm has preset parameters: significant wave height HS, period T1 and geographical direction.

The article presents a preliminary estimation of the possibility of using Stirling engines in power and waste heat utilization systems of LNG carriers. Flexibility of applying heat sources, very silent operation and very low exhaust gas emission are to the advantage of applying Stirling engines in marine power plants. Unquestionably, one strong point of Stirling engines is the fact that various heat sources can be used to feed them, including waste heat generated by the main and auxiliary engines and burning boil-off gas (evaporated cargo), which is especially important in the LNG carrier power systems. The discussed issues include gas demand by the main propulsion of LNG carriers together with the amount of boil-off, main propulsion power and electric power demand of LNG carriers of various sizes. Finally, an example system for waste heat utilization and reduction of toxic exhaust gases emission of the employing a Stirling engine is describe

During ship’s navigation on waves some relative motions occur resulting in propeller emergence, which in consequence reduces the propeller thrust. The article presents an algorithm for calculating the propeller thrust reduction as a result of ship motions on waves. The algorithm has preset parameters: significant wave height HS, period T1 and geographical direction

One of the most common problems in the process of traffic management is the determination of the proper traffic volume. On the one hand there is a tendency of increasing traffic volume – it brings profits to all subjects involved in the transportation process. On the other hand there is a tendency to decrease traffic volume – it assures better safety. It is necessary to solve the problem of finding a compromise between those tendencies. Solving this problem is possible, based on developed methods of safety dimensioning that use the concept of traffic smoothness for quantitative evaluation of traffic safety level. In the paper the concept of those methods is explained. Besides, presented are results of simulation research on the relation between traffic smoothness and the safety level in a restricted control sector. Although the paper presents the implementation (examples) of the problem in the air traffic management, similar procedures and methods may be applied to the marine traffic

This author presents the results of an analysis of the effect of directly measured quantities and their measurement (standard) deviations on the value of the total measurement uncertainty of roundness deviation. The methods described refer to the determination of roundness deviation based on the mean square element and basic mathematical transformations and relationships that provided a basis for the analysis. Its results are given in the form of diagrams followed by final conclusions

The authors describe methods of presenting seasonal information on the occurrence of cyclones (typical tracks shown on Routing Charts, climatic routes and areas of cyclone formation according to NOAA). Besides, a spatial presentation of weather situations including cyclone tracks and the stages of their development understood as intensities are proposed. The relevant zones have been determined on the basis of cyclone data from 1998–2007. The zones indicate areas of potential tropical disturbances on the ocean, thus depicting the areas of the most probable cyclone threats

These authors present operational and safety aspects of research problems relating to waterway intersections and their safety and operational aspects. Attention is drawn to delay times that occur in the process of vessel traffic and the probability of close quarter situations. The results of simulations are compared with analytical research. Examples are given of real values of both system and traffic process measures

The method for automatic compensation of deviation on any heading is proposed for a Fluxgate compass. The mathematic description of the method is given along with a block diagram of the method implementation. Following an analysis of the accuracy, recommendations for achieving proper accuracy are presente

This article states theoretical assumptions for the method of identifying disadvantageous evacuation times from ships relating to diversified populations of passengers. The influence of age, sex and physical fitness of people is examined. The presented optimization uses the genetic algorithms method as well as Genetic Algorithm and Direct Search Toolbox included in Matlab software. Examples of calculations of the time of passenger evacuation from a passenger ship are given to verify the operation of the developed metho

The paper presents methods and models used for analysis of ships traffic in north of Bornholm Traffic Separation Scheme. Ships’ traffic has been analyzed by means of statistical methods with use of data possessed from AIS data obtained from HELCOM. The paper presents probabilistic models of ships’ traffic spatial distribution and its parameters. The results could be used for safety and risk analysis models in given area and for creation of general models of ships’ traffic flows

In this paper, an attempt has been made to present National Maritime Safety and Security Systems. Such systems have been established as a result of close cooperation of national maritime services and ships themselves. Such systems operate in national maritime areas of particular states, regardless of EU membership. The history of the development of above mentioned systems is much longer than the history of the International Maritime Safety and Security System. However, the organizational and functional structure of these systems has been scarcely presented in the shipping literature . Therefore, the main objective of this paper is to bring these issues closer to the public attention

The statistical analysis of existing data of similar ships is an effective tool for an initial estimation of principal parameters of a ship to be designed. High values of the correlation coefficient could signify that a high level of geometric and weight similarity occurs. If this statement is proved and supported by other premises, it means that there is a possibility to create statistical relations allowing to estimate the parameters of ship being designed with a high level of accuracy. This paper presents such case concerning membrane LNG tankers. The resulting parametric relations could be used for the creation of coherent design variants useful for the process of multicriterial optimization of these ships

In connection with the current investment project of building an liquefied natural gas (LNG) terminal in Świnoujście, an analysis of design solutions and operational features of the potential variant of an LNG carrier supplying gas from the Persian Gulf areas has been conducted. As a result of studying the waterway restrictions on the assumed route, the article presents the concept of the optimum LNG carrier size – its overall dimensions – along with an analysis of design parameters. A hull shape model was used to examine the hull resistance and propulsion system. Besides, the size of the ship engine room was estimated and the power demand of the main propulsion system was determined. The cost patterns of LNG carrier construction and operation was included as well as the estimated mean value of its construction unit cost

This article is an overview aimed at a synthetic description of computational mathematics applications in marine navigation. The presented classification of algorithms is based on their application in specific fields of marine navigation. The literature referring to each group of algorithms is then discusse

The paper defines the meaning of local and average heat transfer coefficient. The most frequently applied experimental methods for its estimation, particularly between the fluidized bed and the surface immersed in it, are presented. The method for the estimation of the influence of position and movement of fluidizing column on heat transfer coefficient is propose

The paper presents some selected results of research on applications of artificial intelligence to the optimization of main ship design parameters and hull shape coefficients with the ship transport efficiency as an objective function. Basics of ship transport formulation are concisely discussed, together with examples for different approaches to optimization. An example of neural network use for the determination of ship transport efficiency is given with an assessment of its ability for data generalization. Moreover, two optimization procedures are presented: one using genetic algorithms and the other with simulated annealing approach. Both procedures lead to the improvement of ship transport efficiency

During ship navigation on waves its relative motions occur which result in propeller emergence. This, in consequence, causes the propeller thrust drop. The article presents the results of calculations of the propeller thrust drop and ship service speed reduction on a preset ocean route where specific mean statistic weather parameters occur