Abstract: Apparatus for roll-stabilizing a vehicle broadly includes a compound physical pendulum operatively arranged to sense the lateral and angular acceleration of the vehicle attributable to an applied disturbance torque, and an inertia wheel arranged to be accelerated in the appropriate angular direction to exert a reaction torque on the vehicle to oppose the disturbance torque. The compound physical pendulum has a rigid dumbbell-shaped member mounted for frictionless pivotal movement between opposing discharge nozzles of a hydraulic amplifier. The hydraulic amplifier produces a differential control pressure in response to the acceleration forces acting on the pendulum, and this control pressure is used to operate a servovalve. The servovalve produces a drive pressure which is supplied to a hydraulic motor to accelerate the inertia wheel in the appropriate angular direction.

Abstract: A floating semi-submersible platform is heave stabilized by velocity damping of platform motion. Vertical velocity of the platform is sensed and a force is applied to the platform as a function of and in opposition to the sensed heave velocity. The system may be passive, as by provision of velocity damping in tethering cables. It may be actively hydrostatic by employing variable ballast tanks and water pumps or air pressure for displacement of water, or it may be actively hydrodynamic by employing propellers or rotor blades for thrust generation. By applying a heave opposing force that is proportional to heave velocity, the platform response to waves at the platform resonant period is greatly reduced with exertion of relatively small magnitude opposing forces, whereby the platform may be designed with a considerably smaller resonant period for a given set of expected conditions.

Abstract: A stabilizing device for a ship comprising two rotors housed one within the ther for rotation in opposite directions and positioned on each side of the ship. The rotors are axially movable relative one to the other to permit the outer rotors to be alternately put into and out of action. Guide elements disposed downstream of the rotors and covering parts may be provided to reduce resistance to water flow.

Abstract: An angular accelerometer incorporates two tilt sensors both connected to a differential amplifier arranged to provide a difference signal which is fed to a first integrator the output of which is fed to a second integrator. The tilt sensors are of the torque balance type. The tilt sensors are spaced from one another in a direction transverse to the direction along which the angular acceleration movement takes place.

Abstract: A stabilizer device for minimizing the roll of a boat including two plates connected by a hinge and a plurality of bridles attached to the plates so that when the stabilizer is pulled up through the water by the bridles the plates open about the hinge to resist upward motion and when the stabilizer is released the plates close together about the hinge to permit the stabilizer to fall rapidly.

Abstract: An apparatus for damping vertical movement of a semi-submersible vessel having a small waterplane area, whose buoyancy is provided substantially completely by submerged pontoon means and which includes at least one submerged damper plate having valves or similar flow controllers therein for providing substantially greater resistance to upward movement of the plate than downward movement. The damper plate is supported deep beneath the semi-submersible vessel by flexible, tensioned support elements such as chains or cables, at a depth beneath the water surface in the semi-submerged condition of the vessel, at which depth the amplitude of subsurface wave motion is less than the maximum heave amplitude which would be experienced by the semi-submersible vessel alone under identical sea conditions. The area of the damper plate is several times larger than the waterplane area of the vessel.

Abstract: A stabilizer for reducing the amount of roll motion induced by ocean swells in a vessel drifting or at anchor. A stabilizer arm is pivotally mounted about a horizontal axis on the deck of the vessel and supports a stabilizer disc at its outer end. The disc has sufficient buoyancy so that it is self positioning at the surface of the water, but at the same time is sufficiently submerged to be fully effective. The disc constantly adjusts its relative angular position to the vessel through the pivotal interconnection. As the vessel is exposed to the force of a swell that would tend to cause the vessel to roll, the disc is pushed or pulled through the water. The drag force on the disc is in opposition to the force tending to cause the vessel to roll.

Abstract: Anti-roll apparatus for a marine vessel. A plurality of fins are carried by the vessel. Each fin is operatively moved by motor mechanism which is connected thereto by means of clutch mechanism. The motor mechanism is in continuous operation. A roll sensor unit is mounted in a position to detect roll motion of the vessel. The roll sensor unit transmits signals to the clutch mechanism in response to roll motion of the vessel. The clutch mechanism joins the motor mechanism to the fins for movement thereof in accordance with operation of the roll sensor unit. The fins are thus operatively moved to reduce and/or eliminate the roll action of the vessel.