Breaking the ice: a work domain analysis of icebreaker operations

Abstract

Icebreakers are special-purpose ships designed to operate in different ice-covered waters, either independently or during assistance of weaker ships. In the Baltic Sea, as well as elsewhere, they are essential for maintaining continuous sea transport services during wintertime. Icebreaker operations are complex, and every situation in which a vessel requires assistance is unique, due to, e.g. changing ice and weather conditions, geographical location or language proficiency of the crew on board the icebreaker or assisted vessel. The icebreaker crew has considerable freedom to adapt to each situation, yet, for safe operations, there are constraints to which the crew has to conform. The study presented in this paper aims at identifying the constraints on nautical officers on board icebreakers during operations, as well as special situations that increase cognitive load. A work domain analysis based on a group interview with nautical icebreaker officers shows the multitude of tasks performed on board icebreakers. Furthermore, it identifies constraints specific to icebreaker operations such as ice assessment and direct icebreaking, but also generic constraints such as language and communication skills. At times, safety and efficiency come into conflict, resulting in a trade-off between the two. When that happens, safety gets priority, and the operation stops until the situation has been evaluated. In addition, several situations that increase cognitive load are identified, with the common denominator that they add elements of uncertainty, e.g. severe weather and technical malfunctions. Finally, further research within the area of icebreaker operations is recommended, with a continued focus on the system constraints, and their potential for system improvement.

A multi-ship following model for icebreaker convoy operations in ice-covered waters

“…This reaction time both includes the technical constraints of the vessels (inertia effects), and the delays due to operator response times. The former is affected by the vessel design, whereas the latter has a relation to observation and decision making of the navigating officer on the following vessel, which in turn is affected by the communication between the following vessel and the icebreaker (Boström, 2018). Previous work by Zhang et al, (2018) has determined the mean value of the reaction time as  = 84.45 seconds, which is used in this study.…”