Patent ID: 7661379

Claim:
A propulsion and steering arrangement for a ship ( 2 ), the arrangement comprising: a) a rotary propeller ( 3 ) having a hub ( 5 ) and at least two propeller blades, b) a turnable rudder ( 6 ) arranged downstream of a propeller ( 3 ), c) on the rudder ( 6 ), a streamlined bulb ( 10 ) integral with the rudder ( 6 ), the bulb being separated from a propeller ( 3 ) by a gap (e) and d) a cap ( 13 ) on a propeller hub ( 5 ), the hub cap ( 13 ) bridging a gap (e) between the propeller ( 3 ) and the bulb ( 10 ) characterised in that the rudder is twisted, in that a twist of the rudder is greatest in an area of the bulb ( 10 ) and decreases with a distance from the bulb ( 10 ) and in that a twist angle (β) at a certain distance from the bulb is smaller below the bulb than above the bulb.