- Stabilization while not under way
Stabilization while not under way or Stabilization at Rest or "'ZeroSpeed Stabilization'" or "'OnAnchor Stabilization'" refers to the process of augmenting roll reduction for a
vessel that is not under way. This process may be implemented through use of equipment systems which are also used for stability enhancement while underway.Vessels at
anchor , at moorings, adrift or keeping station are subjected to roll and pitch generating forces similar to those which affect vessels under way. Different strategies for mitigating the effects of these forces have been adopted.An important variable systems using "active fins” and which are designed for effectiveness with the vessel under way for system sizing calculations is the lifting force imparted by water movement past fins adjusted to maximum working angle at minimum vessel speed.
When these same systems are used for roll stabilization of stationary vessels, the lift force from vessel motion and water flow across inclined fins is not available. For stationary vessels, the ability to generate lifting force (i.e. roll resisting force) is constrained by powered fin movements, and by the water volume displaced while stroking the fins in one direction at a precise point in time.
Active fin systems can provide incremental add-on stability for vessels at rest, but these systems will usually have larger actuators and fins, and will likely have special power source requirements in comparison to systems designed for stability under way.
The worlds first retractable fin stabiliser with Stabilisation at Rest feature is supplied by Rolls-Royce. The product is the Aquarius 50. The fins can be automatically retracted when not in use.
Quantum Marine Engineering of Florida, Inc, has over 200 commissioned ZeroSpeed and OnAnchor systems; and produces MagLift rotary stabilizers, which utilize the
Magnus effect for retractable zero-speed stabilization. The Magnus Effect is what makes golf balls hook and slice, and baseballs curve- a rotating sphere or cylinder generates lift relative to rotation direction and velocity. Quantum's active fin zero-speed stabilizer systems create significant roll reduction at anchor or while drifting.External links
* [http://www.thrusters.com/products/stabilizers_tracstar.shtm Arcturus Marine - manufacturers of TRACSTar]
* [http://www.naiad.com Naiad Marine] - manufacturers of roll stabilizers, stabilization at anchor systems, interceptors, bow and stern thrusters, integrated hydraulic systems
* [http://www.quantumhydraulic.com Quantum Marine Engineering of Florida, Inc] Yacht stabilizer products including ZeroSpeed and OnAnchor systems, with over 200 commissioned ZeroSpeed active-fin systems.
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