OPERATION
MANUAL
Product:
Document #:
Rev:
Page:
SEAKEEPER 26 / 20HD
90266
7
2 of 8
Section 1: SYSTEM OVERVIEW
The gimbal angle and the rate of rotation about the gimbal axis (termed precession rate) play an
important role in its operation. These parameters are illustrated in Figure 2. At zero degree
gimbal angle, the sphere is vertical; it can precess a maximum of +/- 60 degrees about this
position. The amount of torque that the Seakeeper
exerts on a boat’s hull to counter the wave
induced roll is directly proportional to the precession rate. The further the Seakeeper is from
vertical (zero degrees) the lower the anti-roll torque. The vertical arrows in Figure 2 illustrate the
direction of the forces that the Seakeeper
exerts on the boat’s hull to damp roll motion.
FIGURE 2
– SEAKEEPER PRECESSION
Seakeeper precession is actively controlled by an electronic controller and a hydraulic brake
throughout each roll cycle so the Seakeeper supplies the maximum anti-roll torque and does not
make mechanical contact with hard stops that limit the maximum gimbal angle travel to +/- 60
o
.
