Assessing the Unreliability of Systems during the Early Operation Period of a Ship—A Case Study

Abstract

Sea-going ships are unique systems, and each ship—even those which are mass-produced—are different. Once in service, they are subjected to unique environmental exposure due to a variety of factors, including, but not limited to, their mode of operation, sailing area, cargo, hydrometeorological conditions, crew training, etc. This makes it very difficult, if not impossible, to compare individual units. The aim of this study is to present the damage data and analysis of a selected vessel—a complex technical system—during its first year of operation. To that end, the paper analyses the unreliability of a bulk cargo ship’s technical and energetic system components during its first year of operation. The paper also introduces the failure susceptibility of its technical systems, defines concepts of wear and failure and describes the object of analysis. Observed failures in subsystem components of the marine power plant, in the general systems and in the technological system of the ship, were presented in tabular form. Each failure was described by considering the time of operation until the first failure, type of failure, type of wear, nature of an event and methods used to regain efficiency. Selected failures were described in great detail, and the statistics of the ship’s components’ susceptibility to failure were presented by considering the wear type that caused a failure, the component type and the time to the first failure. Additionally the severity of each failure is discussed. Finally, conclusions regarding the susceptibility to failure of particular ship components were presented.