METHOD OF BREAKING ICE COVER AND SHIP ATTACHMENT FOR REALIZATION OF THIS METHOD Russian patent published in 2003 - IPC

FIELD: shipbuilding; methods of breaking ice cover; designing ice-breaking attachments. SUBSTANCE: ice-breaking procedure includes notching of ice by jets of water, water steam mixture or steam heated in heat generator. Said jets are directed at angle to water surface so that lumps of ice are formed in notching ice and end faces of these lumps lie at angle to water surface; jets are delivered in rotary motion. Compressed air is fed under ice for forming preliminary stress of ice cover before breaking it. After notching ice cover, electric current is conducted under water through notch in ice. Ice-breaking attachment includes wedge-shaped framework whose skin forms concave bilges in form of two-sided plough with upper ice- breaking ridge. Attachment is also provided with one collector connected with nozzles through heat generator. One nozzle is provided with swirler for imparting rotary motion to flow of working medium. Attachment is also provided with sliding contact connected to electric circuit and located under said collector for breaking ice cover by electric current. Attachment is provided with mechanical or hydraulic drive for raising and lowering it. EFFECT: reduced power requirements; low cost; enhanced efficiency. 6 cl, 5 dwg