METHOD OF SHIP NAVIGATION IN ICE CONDITIONS AND ICE BREAKER TO THIS END Russian patent published in 2011 - IPC B63B35/08 B63B35/12 

FIELD: transport.

SUBSTANCE: invention relates to ship building, particularly, to ice breakers. Proposed method consists in that ballast tanks are unwatered to residual buoyancy of 0.001…0.002 of pontoon displacement. With ship approaching compact thin ice, platform is automatically lifted to move it above the ice with pontoon below the ice and struts with wedges on ice level, for ice to be broken by continuous run of wedges. On approaching compact thick ice, upper and lower skids are pressed to ice to repeat its surface. Slot cutters are used to cut pairs of grooves on top and bottom surfaces of ice ahead of each strut over width exceeding that of strut to generate strains in cuts. Nozzles are used to force water jets under cut ice strips to chop off ice for it to be ejected onto ice field surface in two broken strips. Ice breaker comprises above-ice part made up of the platform and under-ice part made up of pontoon coupled by vertical struts with their width smaller than that of above-ice part and under-ice part, and ballast tanks. Strut cross section represents double-sided wedge, struts being arranged along ice breaker. Pair of skids with slot-cutters and four hydraulic cylinders are arranged ahead of each strut. Skids are arranged to be pressed against ice top and bottom surfaces by hydraulic cylinders pressure chambers of which are communicated with hydraulic accumulators. Distance between said pair of skids makes, at least, width of the strut. Slot-cutters are secured to lateral surface of skids and made up of planning tools to cut boundaries of ice strip being removed. Water jet nozzles and four propulsors are arranged on pontoon between skids of each pair, each propulsor being provided with transducer articulated with servo drive with negative feedback.

EFFECT: higher ice breaker stability in operation.

2 cl, 5 dwg