“…A ship's internal combustion engine is usually equipped with diagnostic subsystems that are used to assess the performance of the engine during operation, as well as to detect engine malfunctions and to locate any faults as per the adopted operating strategy (Piasecki et al, 2017;Chybowski, 2018;Chybowski, Gawdzińska and Souchkov, 2018;Chybowski, Gawdzińska and Laskowski, 2019;Kazienko, 2019;Bejger and Piasecki, 2020). Depending on the purpose and design of the machine, different diagnostic methods can be used (Kluj, 2000;Quan, W., Wei, J., Zhao, YW., Sun, LH., Bianl, 2011;Borkowski, T. Kowalak, P. Myśków, 2012;Ulewicz and Mazur, 2013;Bonisławski et al, 2019;Dunaj, Dolata and Berczyński, 2019;Dunaj, Marchelek and Chodźko, 2019;Ulewicz et al, 2019). For diesel engines that are equipped with indicator cocks, the graphs of the combustion pressure can be analyzed to provide this data (Bueno, Velásquez and Milanez, 2009;Chybowski, 2019).…”