How to make your superyacht more stable?
Watch how the other sea life moves and follow suit!
The superyacht industry has come a long way since the dawn on stabilisation technology, opening up the market to many potential owners and guests who were previously not able to travel on boats without feeling dramatically sick. But it is still by no means perfect. The typical fixed fin stabilisers used by much of the industry are limited in size by the ship’s “beam-keel” envelope (hull envelope), meaning superyachts – which would ideally use very large fins to stead themselves against the sea – are not able to achieve optimum stabilisation.
However, for those willing to pay slightly more, there are now more effective options. Indeed, stabilisation expert Quantum has recently launched its DYNA-FOIL™ fully retractable dual-purpose fin stabiliser system, marking a completely new approach to fin stabilisation.
The key difference is that the Dyna-Foil system moves. The fin movement, not far off that of a large sea mammal, essentially creates a dynamic lift for the vessel resulting in great stability in every movement.
Putting its efficiency to the test, the active fin system underwent extensive third-party model testing by the MARIN (Marine Research Institute Netherlands) to assess its performance at anchor/zero speed and underway compared to a traditional stabiliser. Dyna-Foil was found to have a more efficient down angle than possible with fixed fin. Its stabiliser moments were also found to be up to 150% greater than those generated by a standard fixed fin of the same size at anchor or zero speed.
Dyna-Foil stabilisers retract completely, which eliminates the usual size restrictions meaning that larger vessels can enjoy a smooth ride whether at zero speed and underway. Depending on a vessel’s type of hull form, they can either fold into a full pocket or in parallel position to the hull when not in use. The two versions are designed to accommodate multiple types of hull forms.
How does it work?
At Anchor or Zero Speed: Traditional fixed fin system using a “paddling” action.
Quantum’s Dyna-Foil uses the hydrodynamic lift generated by water flow over the foil from a swing action of the unit. This action creates water flow over the surface of the foil thus generating lift. The direction of swing determines the direction of lift force generated. Both the angle of attack and the swing speed are controlled variables that are adjusted to provide the optimal ship stability.
Underway Stabilisation: The foil is deployed at 90 degrees to the hull centreline, lift is generated by articulating the foil.
Its profile allows high lift force to be generated at low angles of attack with minimal resistance; maximum lift with minimal drag. This coupled with the mechanical properties of the stabiliser actuation mechanism (dynamic foil positioning) provide for an almost instantaneous positioning of the foil, thus improving lift force timing, which in itself is critical to maximizing roll reduction for minimal effort.
CHPU (Compact Hydraulic Power Unit): The Dyna-Foil uses a newly designed and engineered dedicated CHPU (Compact Hydraulic Power Unit) system to power the stabiliser system, bringing together time-tested hardware with a new approach to hydraulic power management and power shaving.
Through the stored energy accumulators and variable motor control, the CHPU provides power to Quantum’s product with extremely low power cycling on the ship’s net. By using an in-tank submerged pump, airborne noise is reduced without the use of sound shields. Structural born noise is handled with both mechanical absorption and hydraulic suppression hardware.
This new fully-retractable approach to stabilisation provides exceptional roll reduction for superyachts, many of which could not achieve this beforehand. Coupled with Quantum’s SMC4000 series hydraulic control system and a dedicated CHPU compact HPU, the Dyna-Foil provides the most technologically active fin stabiliser system in the world. Therefore, although listed at a higher price point than traditional stabilisers, it is definitely worth it for those with the budget. With the superyacht industry limited to only the fixed fin model for so long, this moving model seems to represent the future of stabilisation.
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