Abstract Icebreaking trimaran is a new, promising vessel concept, which is under development at Aker Arctic. Goal of the development project is to create a product family of icebreaking trimarans suitable for icebreaking in light ice conditions in ports, escorting large merchant vessels in Baltic Sea traffic during winter and a heavy duty version for arctic seas. During the development project various aspects affecting the icebreaking capability of the trimaran have been studied, such as the optimal distance of the side hulls considering the icebreaking performance, proper cross-deck dimensioning for ice loads and various oil spill recovery functions. Also the open water characteristics of the trimaran hull have been studied in model tests. The trimaran concepts for light icebreaking in harbours and Baltic escort icecbreaker duties have been developed as separate conceptual cases. These cases are presented considering the operational benefits the trimaran concept can offer for these vessel types.