Alignment deviations remain one of the main causes of excessive vibration amplitudes among all rotating equipment. Their influence is particularly noticeable in ship shaft lines since their length is often much greater than their diameter. Dial gauges and laser measuring instruments are the most commonly used methods for measuring the alignment deviations of ship shaft lines. Due to the increasingly common use of vibration diagnostics in shipbuilding, it is necessary to develop methods to identify shaft misalignment using vibration methods. The authors of this study identified the spectra components corresponding to the misalignment of a working test station of a ship’s shaft line. Identification was carried out in two stages: based on an analysis of the FEM model using the Abaqus program and based on measurements on a unique laboratory stand. The obtained results confirm the possibility of using FEM simulations in the operational diagnosis of shaft line alignment deviations.

Prevention of air pollution from ships, according to MARPOL Annex VI, regulates the emission of specific pollutants contained in the exhaust gases into the atmosphere. In this paper, the Port of Kotor is analysed as a case study because of its distinct geographical features, permanent attraction for tourists, and the title of the third busiest port in the Adriatic in 2017. Ships arriving to the Port of Kotor represent one of the major sources of air pollution not only in the Port area, but also in Boka Kotorska Bay as an approach route towards the Port. For calculation of air pollution inventory in this case study, ship engines’ power method was used. The focus of the research analysis is on the cruise ships visiting the Port of Kotor in 2018. For that reason, all ships under 500 GT were excluded from the analysis. The pollution shows clear seasonal pattern characteristic for ports in the Mediterranean. This behaviour is emphasised as an increasing problem that needs to be addressed. The seasonal pattern causes 82.6% of all air pollution from cruise vessels concentrated in the period from May to November.

In today’s environment of increasing pressure to reduce fuel consumption and emissions of carbon dioxide (CO2) and nitrogen oxides (NOx), the LNG (Liquefied Natural Gas) transportation industry is growing in size and influence. In this context, furth...

The implementation of a system for the acquisition, transferring and processing of data essential for marine engine diagnostics is the basis of condition maintenance. Determining the most influential operating parameters, and conducting monitoring, analysis and taking action based on expert knowledge prevents downtime due to possible malfunctions. Timely corrections and replacements of worn parts based on condition diagnostics enable maintenance planning, which reduces the frequency of maintenance and the accumulation of unnecessary spare parts in warehouses. For research purposes, a system for remote data collection from electronically controlled marine engines was developed and applied. The system was installed on a four-stroke high-speed propulsion engine from a ferry, and the operating parameters of the engine were monitored during regular sailing in order to detect irregularities and possible failures at an early stage. The measurement system monitored the parameters obtained through the electronic engine control module via the J1939 protocol, and in this paper, the following relevant engine parameters were analyzed: engine speed, boost pressure, fuel consumption and engine load at the current speed. The analysis included the creation of trend diagrams to present the distribution of the minimum, median and maximum values of each parameter of all the measurements performed. This study also examined the simulation of the faults of the high-speed four-stroke marine engine model. By utilizing sensor data from critical system components, this research investigated different scenarios. The analysis aimed to elucidate the impact of these faults on engine performance. Based on the analyses of the relevant operating parameters of the engine, diagnostics were carried out.

Marine propulsion shafting systems are exposed to torsional vibrations originating from excitations in their prime movers and propellers. It is essential to analyse their steady state response in the earliest stage of ship design. The paper describes the implementation of SimulationX software based upon simulation modelling for these calculations. This software can be used either by the design office of the shipyard or by the classification society for verification within the plan approval phase. Some specifics of the input data preparation are briefly discussed. In addition, the simulation results depend on the modelling approach chosen. For these reasons, the real two-stroke Diesel engine ship propulsion system was chosen and several different models were implemented for system modelling. SimulationX calculation results are compared with those of two well-known and field-proven programs that use an analytical approach. Finally, the results are compared with the measurements performed on the actual newly built ship. Discussion reviews the selected SimulationX model, and its verification and validation in the case of engine cylinders with normal ignition.

The implementation of a system for acquisition, transferring and processing data essential for ma-rine engine diagnostics is the basis of condition maintenance. Determining the most influential operating parameters, their monitoring, analysis and action based on expert knowledge prevents downtime due to possible malfunctions. Timely corrections and replacement of worn parts based on condition diagnostics enable maintenance planning, which reduces the frequency of maintenance and the accumulation of unnecessary spare parts in warehouses. For research purposes, a system for remote data collection from electronically controlled marine engines was developed and applied. The system was installed on a four-stroke high-speed propulsion engine from a ferry and the operating parameters of the engine were monitored during regular sailing, in order to detect irregularities and possible failures at an early stage. The measurement system monitors the parameters obtained through the electronic engine control module via the J1939 protocol, and in this paper, the following relevant engine parameters are analyzed: engine speed, boost pressure, fuel consumption and engine load at the current speed. The analysis included the creation of trend diagrams to pre-sent the distribution of minimum, median and maximum values of each parameter of all measurements performed. This study also examines the simulation of faults of the high-speed four-stroke marine engine model. By utilizing sensor data from critical system components, the research investigates different scenarios. The analysis aims to elucidate the impact of these faults on engine performance. Based on the analyses of the relevant operating parameters of the engine, diagnostics were carried out.