Studies to develop technologies for making a wider channel in ice

The Krylov State Research Centre has worked out a radically new icebreaker concept as a spin-off from the R&D efforts under the Federal Target Program “Development of civil marine engineering in 2009 – 2016”. This novel icebreaker would be capable to make a 50 m or wider channel in ice. A remarkable feature of this advanced design is that the icebreaker will have a 30 – 40% lower icebreaking resistance as compared with a conventional icebreaker in making a channel of the same width. Therefore, the advanced icebreaker will have a relatively low power requirement. The propulsion & steering system is designed to combine the traditional propellers with propulsion pods. The novel multi-hull icebreaker is a sophisticated engineering structure consisting of four displacement hulls and an integral superstructure (topside). The Krylov State Research Centre is currently performing comprehensive investigations of the novel icebreaker hydrodynamics, propulsion performance and maneuverability in ice as well as structural strength and fatigue life of the major ship structures and components. The structural design of the multi-hull icebreaker needs to take into account the specific stresses and strains arising from longitudinal and transverse bending under wave and ice-induced loads. Special care should be given to the structural detailing of the superstructure subject to the loads resulting from interactions between the four individual hulls under the global bending of the multi-hull icebreaker. A global finite-element model (FEM) of the multi-hull icebreaker was elaborated using the ANSYS software package to define the parameters of the topside structural details. The FEM model included the models of four icebreaker hulls integrated with the topside of different architectural detailing. A range of different wave and ice load combinations were modeled in the investigation of stressed-strained conditions. Based on the estimated stressed-strained conditions of the multi-hull icebreaker the optimum sizing of the topside structural details was done.