SHIPBOARD SCREW-RUDDER Russian patent published in 1999 - IPC

FIELD: shipbuilding; propulsion complexes of ships running in ice. SUBSTANCE: screw-rudder includes upright and nacelle with members of drive mechanism and propeller shaft whose cantilever projecting portion holds propeller fitted in steering nozzle and ice-breaking members made in form of blades and vanes secured before propeller and intended for crushing ice; they are mounted at distance of 0.02 to 0.25 of propeller diameter from plane of inlet hole of nozzle and their diameter is equal to 0.6-0.8 of propeller diameter. Blades or vanes of ice-breaking members are smoothly distributed over circumference in plane which is transversal relative to propeller shaft. EFFECT: improved service properties of ships navigating in ice; enhanced efficiency of protection of inlet hole of screw-rudder against choking with ice fragments. 2 cl, 2 dwg