Stabilizer of ship rolling

Abstract

The roll-stabilizer consist of short wings, with aspect ratio r=0.5-0.75, fastened immovably to the ship hull in staggered rows or in lines along the bilges, at port and starboard sides. The height of the wings is such that they do not protrude the maximum breadth and base line of the ship. The transverse distance between two wing lines of the staggered row is 0.5-0.7 of the wing's chord, and the stagger between wings of the two lines is equal to the chord. The wing profiles are parallel to the longitudinal axis of the ship or form a small angle of 2-4° with this axis. At zero forward speed the roll damping moment of the staggered stabilizer is almost equal to that of continuous bilge keels having the same height and area. During motion of the ship ahead the lift forces of the wings produce a large damping moment, considerably reducing the ship rolling.

1 . Stabilizer of ship rolling, consisting of wings, immovably fastened to the ship hull in longitudinal lines or in staggered rows, on the port and starboard sides, characterized so, that for the purpose of considerable decreasing the roll amplitudes of the ship in sea-way conditions with a sufficient strength of the wings, the aspect ratio of the wings is 0.5-0.75, the height of these short wings is such that they do not protrude beyond the maximum breadth and base line of the ship, the intervals between the wings in each line equal to wing's chord, and in a staggered row the stagger between wings of two lines is equal to the chord, while the transverse distance between the lines is 0.5-0.7 of the chord. 
   
   
       2 . Stabilizer of ship rolling according to  claim 1 , characterized so, that for the purpose of reducing the injurious interaction of wings in the staggered row, the wings form an angle of 2-4° with the longitudinal axis of the ship, so that the angle in the one line of the staggered row is in opposite direction to the angle in the other line.