Systematic review of battery electric ship safety: risk factors, assessment methods, and preventive measures

Abstract

With the advancement of global environmental protection policies and the transformation of energy structure, battery electric ships (BESs) are expected to enter a period of accelerated development. However, the associated risk factors are more complex than those of traditional ships, making it difficult for existing risk assessment approaches to fully capture emerging risks. This paper systematically identifies the key risk factors from four dimensions: seafarer, ship, environment and management, summarizes the risk assessment methods ranging from single-component failure analysis to overall ship safety evaluation, and examines corresponding assessment results and preventive measures. The findings show that seafarer and ship risks exert direct influences on ship safety and impose higher technical requirements, whereas environmental and management risks exert indirect effects. For single-component failures, differentiated assessment methods are recommended, such as processbased analyses for seafarer risks, component-focused approaches for batteries, motors, and electronic systems, and dynamic hazard identification for charging facilities and environmental factors. For overall ship safety, comprehensive risk assessment frameworks are suggested. Finally, targeted prevention measures are proposed for various risk categories, including optimization of battery design and enhancement of seafarer competencies. Current risk assessment for BESs faces challenges related to limited data, immature models, and insufficient regulations. Future efforts should focus on gradually accumulating accident cases and risk datasets, as well as developing quantitative assessment methods or models capable of capturing interdependencies among risks.