The reliability of marine propulsion systems depends on the reliability of several sub-systems of a diesel engine. The scavenge air system is one of the crucial sub-systems of the marine engine with a turbocharger as an essential component. In this paper, the failures of a turbocharger are analyzed through the fault tree analysis (FTA) method to estimate the reliability of the system and to predict the cause of failures. The quantitative method is used for assessing the probability of faults occurring in the turbocharger system. The main failures of a scavenge air sub-system, such as air filter blockage, compressor fouling, turbine fouling (exhaust side), cooler tube blockage and cooler air side blockage, are simulated on a Wärtsilä-Transas engine simulator for a marine two-stroke diesel engine. The results obtained through the simulation can provide improvement in the maintenance plan, reliability of the propulsion system and optimization of turbocharger operation during exploitation time.
This paper is part of larger research on the impact of present and future air emissions from the shipping industry and especially the environmental impact of the rapid spreading of the LNG as a fuel in the industry. Therefore, it was important to gather data related to the LNG market and perform an analysis to gain realistic insight into the market behaviour. This paper analyses the situation and trends of the LNG shipping market over a longer period to predict future developments. Data analysis of the several aspects and patterns of the trade has been performed; the results obtained can enable prediction of the market situation for the future. From the data analysis and predictions of the LNG market, continuous growth in the following years is expected, which linked to an increase of the LNG fleet and number of importing countries. Research has shown that new propulsion alternatives such as MEGI and XDF are appearing on the market as the first choice for new builds, while steam turbines are slowly disappearing. Although market growth is projected from all research parameters, the situation has changed due to the COVID-19 pandemic and its impact on the market. Consequently, growth forecasts will not be realized in 2020.
This paper analyzes the shipowner's role in the development process of ship's computerized planned maintenance system database, paying specific attention to his/her impact on database quality grades resemblance equalization. The paper describes the database development process from the realization that the database is needed to the installation on board vessel, and all shipowner's and developer's actions in the process.The computerized databases of five shipping companies were tested using questionnaire developed for this purpose. of office user's workload with regard to the administration and correction of data besides database quality grades: that data serves to portrait the relation between data quality in the databases and importance given to the process of development and maintenance of the databases. The analysis of the results yields numerical values as indicators of shipowner's input on the resemblance of grades of both scenarios and on the database quality grades resemblance equalization.The conclusion shows how the shipowner affects the ship's computerized planned maintenance system database and what actions should be performed to obtain the final product (database, i.e. data in the database) as good as possible and, thus, maintenance of the ship and the whole system.The expected results of the paper are: -To analyze in detail the database ordering and development process, -To pinpoint controlling areas for the database quality, -To analyze the shipowner's impact on the database quality grades resemblance equalization.
This paper presents the extent of the currently achieved progress in autonomous and remotely controlled ships in the maritime sector. Major researches, statements from relevant sources and various anticipations on this subject are presented to outline a comprehensive scope of such progress. The engine room on conventional merchant ships is used as a viewpoint because it comprises numerous and complex systems. The main purpose of this paper is to establish a link between the levels of autonomy and the engine room with its associated systems on a conventional ship. At each level, the link should describe the relations between autonomy and the systems which are commonly found in the engine room on conventional ships. To create this link, comparison analysis uses the latest statements from the International Maritime Organization (IMO) and Classification Societies. Technical standards for autonomous and offshore vessels are derived from the guidelines provided by Classification Societies. Technical standards and requirements, related to the engine room of such ships, are individually described and compared to provide accurate and comprehensive scope of their current progress.
The paper describes an evaluation methodology for ship’s Planned Maintenance System database based on the application of a newly created questionnaire and the analysis of the evaluation results received by the questionnaire. The evaluation results of several databases and the analysis of evaluation results are also shown in the paper. The main purpose of the paper is to provide a simple and useful tool for the evaluation of all ships’ Planned Maintenance System databases, which will enable users to examine the data in the database and discover the areas where the database and maintenance can and must be improved. The expected outcome of the described methodology for the evaluation of ship’s Planned Maintenance System database can be described as: - Evaluating ship’s Planned Maintenance System database- Performing ship’s Planned Maintenance System database diagnostics to indicate insufficiencies- Determining the area and mode for ship’s Planned Maintenance System database quality improvement and, consequently, overall improvement of the maintenance and reliability of ships’ systems,- Setting up a standard for the development and evaluation of computerized database for ship’s planned maintenance,- Determining problems which occur during database development and describing complexity of the development process.
The paper presents the initial case of a research of analysing maintenance interval adjustment in the shipping industry. This case is an example of the adjustment of the maintenance interval carried out by ship's crew on starting air compressor system. The example is found and followed through the records in the computerized Planned Maintenance System. Maintenance interval adjustment proposal and actual adjustment were carried out based on user's experience, after rechecking maintenance data and actual machinery condition, without theoretical approach or analysis. That process created new maintenance plan which is in use on the system for past ten years. Missing actions in the process, i.e. theoretical analysis of the initial and modifi ed maintenance, are performed using the MA-CAD method with a modifi ed reliability testing and are described in the paper. Results obtained by the theoretical analysis are compared with the requested and performed modifi cation of the Maintenance Plan and a conclusion about performed action has been derived. Sažetak U radu je predstavljen inicijalni slučaj istraživanja analize podešavanja intervala održavanja u brodskoj industriji. Ovaj slučaj je primjer podešavanja intervala održavanja koji obavlja brodska posada pri pokretanju sustava kompresora. Primjer smo pronašli i pratili kroz evidenciju u računalnom sustavu planiranog održavanja. Prijedlog podešavanja intervala održavanja i stvarno podešavanje provedeni su na temelju iskustva korisnika nakon ponovne provjere podataka o održavanju i stvarnog stanja stroja bez teorijskog pristupa ili analize. Taj je postupak rezultirao novim planom održavanja koji se u sustavu koristi posljednjih deset godina. Radnje koje nedostaju u tom postupku, tj. teorijska analiza inicijalnog i modifi ciranog održavanja, provedene su primjenom MA-CAD metode s modifi ciranim ispitivanjem pouzdanosti i opisane su u ovom radu. Rezultati dobiveni teorijskom analizom uspoređuju se s traženom i izvedenom modifi kacijom Plana održavanja i donesen je zaključak o izvršenim radnjama.
The Port of Split is one of the busiest marine traffic regions in the Adriatic Sea and the third largest passenger port in the Mediterranean. A significant number of the ships is going in and out of the Port, creating a major impact to the environment in the area. That impact is created mostly by emissions from ships, which can be divided into greenhouse gases (predominantly Carbon dioxide – CO2) and the pollutants (Nitrogen oxides – NOX, Sulphur oxides – SOX, Particulate matter – PM and Volatile organic compounds – VOC). This paper is presenting emission inventory of international marine traffic in the Port of Split for the year 2017, which amounts to 19065.8 tons of CO2, 12 tons of SOX, 11.7 tons of PM, 14.6 tons of VOC and 338.7 tons of NOX. Emissions are presented in groups according to type of ships, thus enabling comparison of emissions coming from cargo and passenger traffic. Cruise ships activity in the Port of Split during 2018 is added to the paper to highlight the increase of the traffic and consequently emissions.
This paper presents a method of adjusting and designing the maintenance scheme for the high-pressure fuel pumps of a slow-speed two-stroke marine engine, MAN 6S70MC-C. The maintenance database for the marine fuel system was obtained from the planned maintenance software, and covered a period of 11 years. During this period, 29 failures occurred that required corrective actions. Our methodology includes failure mode analysis, risk analysis, reliability calculation and maintenance interval adjustment. Each failure is described using a failure mode analysis, based on a combination of the mode and cause of failure. The objective of this study is to recommend a new preventive maintenance interval based on the exponential reliability results and the analysed maintenance data. The initial maintenance plan for each fuel pump was set to 8,000 running hours, whereas in the modified plan, it is recommended to set this to 4,000 hours. Our results show an increase in the system reliability from 60% to 95% when the new modified maintenance plan is applied. In addition, the results and the recommended initial maintenance schedule are validated based on three similar types of engine with the same fuel pump system. The new maintenance approach can reduce the risk of component failure, which will lead to increased reliability of the fuel pump system and the optimisation of maintenance costs.
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