1st electric stabilizer for yachts up to 30m
RAAMSDONKSVEER _ Boats give you more rock ‘n roll than your stomach can handle? Call Theo Koop, founder of RotorSwing Marine NV, maker of the first electrically powered roll damping system for yachts of up to 30 meters. “Generally speaking a reduction of up to 90% in boat’s roll motions is achievable,” says Koop (right).
He says his electric RotorSwing kills a boat’s rolling better at lower speeds than the conventional fin system. That’s because the latter needs substantial boat speed to be effective as the fins are kept small to reduce drag and damage. Also, in shallow waters, fins are vulnerable. RotorSwing’s retractable rotors swing out from the hull when the engine is in gear. When it goes into idle, they fold back.
Koop is also head of product development at Quantum Controls, a Dutch-American company that makes powerful hydraulic damping systems for super-yachts. Koop: “Because the roll of small boat is so short any correction must be applied quickly. It’s easier to stabilize the longer roll motion of a large boat.”
Koop thought up the RotorSwing, the first fully electric, non-hydraulic roll damping system for yachts up to 30 meters. It exploits the Magnus Effect named after 19th century German scientist Heinrich Gustav Magnus. He discovered that a spinning object moving through space (or water) creates lift as it builds up more pressure on one side than the other depending on the spin direction. You see that same lift in the top spin of tennis or golf balls. And in that arc of a soccer ball kicked by people who bend it like Beckham.
Koop uses the lift created by spinning cylinders in glass fiber tubes to steady a boat rocked by sea waves or the wake of passing vessels. The heart of the RotorSwing is sophisticated software “required much work,” says Patrick Noor of Dynamic Marine Systems, the European distributor of the RotorSwing which works at speeds of 3 – 14 knots. At the push of a button, the rotor cylinders emerge from the hull. In only 0.8 seconds, the rotors reach 1,000 RPMs. The RotorSwing uses a nominal 1,000 watts per rotor. The rotors themselves have no impact on steering and, unlike fin systems, can be mounted anywhere. No expensive, vulnerable hydraulic pumps. No cylinders. No high pressure lines. No oil leaks.
Koop: “Right now we are experimenting to see if we can place the rotors off the transoms of fast ships. From the point of view of speed you don’t want an object under the hull there.” He also pursues industrial applications for his RotorSwing, notably for stationary vessels. Large dredgers, for instance, that help build wind parks at sea and need to dump their loads with precision in very exact locations.
Koop’s brainchild can be used in existing steel, polyester and aluminum yachts provided the hull is reinforced in areas where the equipment is installed. As is the case with fin systems. “Because the rotors create no steering issues,” says Koop, “they can be placed in many locations, even near the stern.”
Copyright Jachtbouw Nederland / www.dutchyachtbuilding.com