Carbon dioxide emissions have become a growing problem worldwide. Global institutions are addressing this problem and developing solutions. Countries that are aware of this problem are implementing regulations that affect global industry and, in particular, maritime transport. Considering that the combustion process, namely, diesel, remains the main energy conversion process on board ships, the question arises: what is the best solution to reduce pollutant emissions? Coastal countries have taken various measures to reduce the emission of harmful gases into the marine environment. The problem with these measures is that it is difficult to accurately predict their impact. This paper looks at one of these measures (slow-steaming) to determine how it affects carbon dioxide emissions from different types of ships and their modes of operation. Engine room simulators were used to study two marine power plants under different operating conditions. Fuel consumption was measured, i.e., flows from heavy fuel oil and diesel oil service tanks to all consumers, and carbon emissions were calculated accordingly. The study showed a large reduction in carbon dioxide emissions in the case of a modern power plant ship, and large deviations when all operating modes were compared.

This review describes the current liquefaction systems on ships for natural gas transportation in liquid form (Liquefied Natural Gas – LNG). Since in the construction of a gas carrier an essential requirement is the selection of a liquefaction system, this paper describes the principles of operation, thermal and technological processes, as well as the advantages of each system.

Maintenance intervals and approaches for marine equipment have been the subject of numerous studies, focusing on previous failure patterns and associated risks. However, in vessels like drillships, operating under high reliability requirements and possessing significant redundancy, maintenance strategies have a critical impact on overall performance. This study investigates the influence of operational configurations on maintenance intervals and approaches for generator engine subcomponents onboard a drillship. Using data on injector failures onboard drillships, we employ the maintenance concept adjustment and design (MA-CAD) method to analyse and determine maintenance intervals across various operational configurations. Initially, we analyse the failure pattern of fuel injectors and propose a reduction in maintenance intervals through Weibull probability distribution fitting. Additionally, a risk analysis is conducted to assess the impact of operational configurations on risk indices related to fuel injector reliability and safety consequences. Our findings reveal that different operational configurations of the power generation plant can lead to changes in risk indices, shifting injector reliability status from unacceptable to undesirable limits. Consequently, maintenance intervals need to be adjusted as well to ensure optimal performance and safety. Furthermore, considering various engine subcomponents and their reliability under different operational configurations suggests the need for tailored maintenance approaches. This research provides insights into optimising maintenance strategies for drillship, ensuring reliability and safety across diverse operational scenarios.

Combined heat and power (CHP) is a facility which uses one energy source to produce both electricity and thermal energy at the same time. CHP has an advantage when compared to conventional power plants which produce only electricity or thermal energy because it is much more efficient – it minimizes the usage of its primary energy source, grid losses and greenhouse gas emissions. CHP’s big advantage lies in its applicability: it is highly compatible with existing technologies already in use in different power systems across the industry, agriculture, business and residential sector. This paper describes the cogeneration in general, its application, classification and characteristics. It also describes various cogeneration plants on board, their principle and the advantages and disadvantages of individual processes. This paper contains analysis of cogeneration systems and their comparison, especially on board ships. The paper uses results of other authors to analyze on board systems and to suggest optimal solutions for various ship types. The papers aim to became one of the tools for project engineers and operation engineers.

The introductory part of this paper offers an overview of approaches on general marine maintenance and clarifies the significance of modern maintenance techniques, as well as their application in shipping practice. Unplanned down times and accidents, which result from inappropriate maintenance, create additional expenses. In today’s shipping practice the widely shared concept of planned maintenance is not the most effective of the approaches. The appropriate maintenance system needs to prevent or reduce down times. Modern condition-based and reliability-centered maintenance systems recognize the market demand for a better ratio of the invested funds and complex tasks that the maintenance systems need to fulfill. The paper further analyses the possibilities of adjusting the maintenance intervals, which are shown on the example of a modern system for cargo liquefaction on a liquefied petroleum gas tanker.