Toward modeling emergency unmooring of manned and autonomous ships – A combined FRAM+HFACS-MA approach

The development of Maritime Autonomous Surface Ships (MASS) comes with the necessity of preparing contingency plans for various emergencies. These need to account for the operational profile of prospective MASS significantly differing from the contemporary merchant vessels. Such potentially dangerous situations may vary in nature, but when encountered while a ship is moored in port, they might require her to leave it immediately. Due to the hazards involved, this operation must be performed harmlessly and smoothly to ensure the safety of the vessel, port infrastructure, and other assets. The study proposes models of emergency unmooring procedures for manned and crewless merchant ships using the Functional Resonance Analysis Method (FRAM) and compares them through an application of the Human Factors Analysis and Classification System for Maritime Accidents (HFACS-MA). Such a combination of two methods within the Safety-II concept allowed for a deeper insight into the potential variabilities of the process.