Sea transportation is vital for the global economy, and the amount of seaborne trade is expected to increase in the future. In some areas, icebreakers are necessary for maintaining open shipping lanes all-year round and ensuring safe navigation. Vessels operating in ice are exposed to harsh environmental factors such as severe weather and heavy ice, and when external forces become too strong vessels will depend on icebreaker assistance. However, successful icebreaker operations require the icebreaker to operate in close vicinity to the assisted vessel to break the ice, which in turn increases the risk of collision.

There are many factors which make icebreaker operations complex. The aim of this thesis is to use work organization, operational safety, and interpersonal communication as three lenses to describe and analyse the complexity of icebreaker operations, and its implications for practice. To thoroughly investigate this complexity, data are drawn from numerous sources; semi-structured interviews, a questionnaire, and a substantial amount of recorded authentic communication all provide complementary insights.

The results show that the icebreaker performs a multitude of tasks directly concerned with icebreaking, e.g. directing and physically assisting other vessels, but that these tasks indirectly rely on interpersonal interaction and communication. A number of conflicting constraints add to the complexity. For example, harsh winter conditions impede vessels’ independent navigation in ice, while offering icebreaker crews opportunities to practice and maintain important skills. Furthermore, it was shown that language skills and communication play an important role in upholding the operational safety. However, closed-loop communication is not always used as intended, a deviation from intended communication protocol with potential to increase the risk of misunderstandings.

This thesis suggests that safety and efficiency of winter navigation can be enhanced by making better use of existing technology and data; by examining the past track of other vessels, e.g. via AIS, finding suitable ice tracks will be made easier. Another implication concerning communication is that training institutes should emphasize the logic behind standardized communication protocols rather than focusing on standard phrases, i.e. facilitating means for advanced English speakers to adapt their communication style. That way, novice and advanced speakers could find common ground.