Aker Finnyards has built the three latest Baltic escort icebreakers for the Finnish Maritime Administration. The shipyard has thus taken responsibility for setting a new performance standard and operational mission roles for the Baltic icebreakers. Icebreakers Fennica and Nordica use two Aquamaster azimuth thrusters, with nozzles, at 7.5 MW a unit. The Botnica uses two open propeller Azipods, at 5 MW a unit. These vessels are also designed to be efficient support vessels for the Offshore Oil industry, both in ice and in ice free conditions. Current paper shows the efficiency and operability of these vessels in their various roles. The paper demonstrates how the application of the new technology offers a quantum step in efficiency and operability of ieebreaking vessels, in their many operational roles. Furthermore, the surprisingly big differences between the two generations of vessels are shown. The full scale trials data from ice and open water of these vessels is the basis of all these evaluations. Based on the Beaufort Sea and Sakhalin offshore operations m ice, use of azimuth propelled multipurpose icebreaker concepts is discussed.
Aker Finnyards has built the three latest Baltic escort icebreakers for the Finnish Maritime Administration. The shipyard has thus taken responsibility for setting a totally new performance standard and operational mission roles for the Baltic icebreakers. First two of these vessels were sisterships, MSV Fennica, delivered 1993 and MSV Nordica delivered 1994. The latest multipurpose icebreaker, which was delivered 1998, MSV Bomica is a significant departure from the designs of the first two. The main characteristics of these vessels are presented in Figures 1 and 2. Specifically those parameters are highlighted here which differ between these two vessel classes.