ICE BREAKER, AND OPERATION METHOD THEREOF

PROBLEM TO BE SOLVED: To provide an ice breaker, and an operation method thereof capable of conducting safe navigation and effective ice breaking of the ice breaker in a sea zone where accumulation of snow exists on an ice plate. SOLUTION: A water storage tank 12 at a higher position than a draft line 17 at a bow part, a drain mechanism connected to its bottom part, a brine lifting pump 11, a water injecting passage 23 to inject brine into a water storage tank 11, a drain passage 22 for introduction to the drain mechanism 21, and a change-over valve 14 for introduction to one passage are provided. The drain mechanism 21 is provided at a height of a specified distance from the draft line 17 at a bottom part of the bow part, it is composed of the switching valve 14 and a drain port 13, a movable current plate 19 is provided in the drain port 13, and in discharging water from the drain port 13, regulation of a discharging direction and current regulation are conducted. The drain port 13 is formed as a slit, and one or a plurality are disposed along a flat surface form of the bow part at a height of a specified distance from the draft line 17. In operating this vessel, continuous discharge of water and discontinuous discharge of water in large flow are changeably conducted from the drain port 13 in accordance with ice sea situations.