This research integrates a socio-technical perspective into the safety risk management of ammonia-powered ships, with a particular focus on the engine room. The objective is to develop strategies that enhance crew safety by examining the complex interactions between humans, organizations, and machines within this high-risk environment.

The international shipping industry, responsible for a significant portion of global greenhouse gas emissions, faces an urgent need to adopt more environmentally friendly technologies. Anhydrous ammonia (NH3) has emerged as a promising alternative fuel due to its carbon-free nature and higher volumetric energy density compared to other fuels. However, ammonia’s toxicity presents substantial challenges, especially in enclosed spaces like the engine room, where crew members are at increased risk of exposure.
Current research predominantly addresses the engineering aspects of ship design to minimize ammonia leakage risk but lacks a focus on safety risk management through a human-centered approach that enhances crew safety. This research addresses this gap by adopting a socio-technical system (STS) approach, emphasizing the intricate dynamics and implications of human interaction with new technology. The study demonstrates that incorporating a socio-technical perspective through the Functional Resonance Analysis Method (FRAM) provides a comprehensive understanding of human-machine interactions, enabling the development of human-oriented modifications.

Employing a multidisciplinary approach, this research combines qualitative and quantitative methods. FRAM is used for qualitative analysis, offering detailed insights into interactions and performance variability within the socio-technical system. This research developed the complex STS relationships through Work-as-Done FRAM, identifying actor roles, time spent, location, and procedures related to engine room activities. Complementing this, Fault Tree Analysis (FTA) and Quantitative Risk Assessment (QRA) provide a deeper understanding of risk factors and their implications.

The findings indicate that adopting a socio-technical approach to safety risk management can significantly enhance the safety of ammonia-powered ships. This research has developed modification frame works that integrate human-machine interaction activities derived from FRAM with necessary system modifications. The study identifies on-board maintenance activities as having the highest probability of crew presence in the engine room (PER). By modifying the engine room layout and work procedures with the on-board maintenance as considerations, the Individual Risk Per Annum (IRPA) can be substantially reduced from the current value of 1.33E − 05 to 2.00E − 06. Normatively, these modifications result in an IRPA level that is lower than that of the currently operating LNG (CH4) powered ship engine room, which has an IRPA value of 3.16E −06. Thus, these modifications meet the risk acceptance criteria as outlined by the IGF Code guidelines.

The research provides several recommendations for stakeholders within the maritime industry. These include modifications to engine room layout and task locations to minimize human exposure to ammonia leaks, advancements in on-board maintenance procedures specifically for ammonia, enhancement of gas sensor response times, and digitization of the engine room logbook. These strategies aim to ensure safe operations and support the adoption of ammonia as a sustainable maritime fuel.