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Lessons from maritime accidents are conventionally used to inform safety improvements in design and operation of ships. However, this process is only as good as the core understanding derived from accident analysis is. The current explanation of accidents is limited to direct and contributing causal factors, whereas the role of a wider socio-technical context that has given rise to causal mechanisms behind major maritime accidents in recent years is left unexplained. The paper describes analysis results of maritime incidents and accidents occurred over the last decade with passenger ships, with the purpose to illuminate the prevailing causal factors, not least the systemic ones. The results show where the weak links in maritime safety control are (e.g., interactions between ship operators and equipment manufacturers), what their role in accident causation is, and how they can be strengthened. The study seeks to provide valuable input for enhancements in overall maritime safety control and proactive safety management at the ship and shipping company levels.

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Diesel–Electric Propulsion (DEP) has been widely used for the propulsion of various ship types including cruise ships. Considering the potential consequences of blackouts, especially on cruise ships, it is essential to design and operate the ships’ power plants for avoiding and preventing such events. This study aims at implementing a comprehensive safety analysis for a cruise ship Diesel–Electric Propulsion (DEP) plant focusing on blackout events. The Combinatorial Approach to Safety Analysis (CASA) method is used to develop Fault Trees considering the blackout as the top event, and subsequently estimate the blackout frequency as well as implement importance analysis. The derived results demonstrate that the overall blackout frequency is close to corresponding values reported in the pertinent literature as well as estimations based on available accident investigations. This study deduces that the blackout frequency depends on the number of operating Diesel Generator (DG) sets, the DG set’s loading profile, the amount of electrical load that can be tripped during overload conditions and the plant operation phase. In addition, failures of the engine auxiliary systems and the fast-electrical load reduction functions, as well as the power generation control components, are identified as important. This study demonstrates the applicability of the CASA method to complex marine systems and reveals the parameters influencing the investigated system blackout frequency, thus providing better insights for these systems’ safety analysis and enhancement.

His research focuses on the development of scientific approaches to holistically capture the safety, energy and sustainability interplay of the complex marine systems including cyber-physical and autonomous systems by employing advanced model-based methods and tools for their design and optimisation pursuing life-cycle risk and energy management, efficiency improvement, and safety and sustainability enhancement. He is a member of the IMarEST Scottish branch committee responsible for the young members early career professionals.

The stringent regulatory framework for the emissions and safety from shipping operations as well as the market pressure to reduce the operational costs has led the cruise ship industry to pursue and investigate alternative solutions for both the new-built and the existing ships by using multi-objective optimisation methods. This study aims at investigating and comparatively analysing the optimal power plant solutions for different fuel types for an existing cruise ship by employing cost, emissions and safety objectives in a lifecycle basis. For this purpose, a bi-objective optimisation method is employed to identify optimal power plant configurations of a modern cruise ship considering the actual ship operational profile and several energy system design parameters. In subsequence, availability and the blackout event frequency were estimated using availability formulas and the Combinatorial Approach for Safety Assessment. The results demonstrate that the cruise ship power plant optimal configurations with dual fuel engines operating with natural gas exhibit lower lifecycle cost and lifetime emissions, whilst demonstrating a level of the systems safety comparable to the baseline power plant configuration. Furthermore, it is concluded that an increase in the generator sets redundancy does not necessary result in a considerable improvement of the power plant safety performance.

The lubricating oil systems are essential for ensuring the safe and reliable operation of the cruise ships power plants as demonstrated by recent incidents. The aim of this study is to investigate the safety enhancement of a cruise ship lubricating oil system by employing safety, reliability, availability and diagnosability analyses, which are based on the system functional modelling implemented in the MADe™ software. The safety analysis is implemented by combining a Failure Modes, Effects and Criticality Analysis and the systems functional Fault Tree Analysis. Subsequently, Reliability Block Diagrams are employed to estimate the system reliability and availability metrics. The MADe™ toolbox for determining sensors locations is employed for a more advanced diagnostic system development. A number of design modifications are proposed and the alternative configurations reliability metrics are estimated. The derived results demonstrate that the suction strainer and the lubricating oil pump are the most critical system components. Seven additional sensors are proposed to enhance the original system design. Compared with the original system design, the investigated alternative designs exhibit significantly lower probabilities of failure and higher values of availability.

Cyber-Physical Systems (CPSs) represent a systems category developed and promoted in the maritime industry to automate functions and system operations. In this study, a novel Combinatorial Approach for Safety Analysis is presented, which addresses the traditional safety methods’ limitations by integrating System Theoretic Process Analysis (STPA), Events Sequence Identification (ETI) and Fault Tree Analysis (FTA). The developed method results in the development of a detailed Fault Tree that captures the effects of both the physical components/subsystems and the software functions’ failures. The quantitative step of the method employs the components’ failure rates to calculate the top event failure rate along with importance metrics for identifying the most critical components/functions. This method is implemented for an exhaust gas open loop scrubber system safety analysis to estimate its failure rate and identify critical failures considering the baseline system configuration as well as various alternatives with advanced functions for monitoring and diagnostics. The results demonstrate that configurations with SOx sensor continuous monitoring or scrubber unit failure diagnosis/prognosis lead to significantly lower failure rate. Based on the analysis results, the advantages/disadvantages of the novel method are also discussed. This study also provides insights for better safety analysis of the CPSs.