Number of benefits of gyro stabilisation have been appreciated by Ferrari chairman Luca Cordero di Montezemolo who chose to charter the Ocea 108 Commuter motor yacht Marhaba, for the past two seasons. Certainly a man that understands the importance of unhindered speed and beauty. Seakeeper gyros provides superior roll reduction in a range of sea conditions, without drag-producing appendages. Their quite operation and low power consumption make them the stabilisation choice over fins, including for underway use. Motor Yacht Marhaba has been recently fitted with two Seakeeper M21000 gyros.
A “Control Moment Gyro,” it employs the physics of gyro-dynamics to deliver powerful righting force that stabilizes a yacht. The gyro’s flywheel spins at high speed in a near vacuum, inside an aluminum spherical housing. This virtually eliminates air friction, which allows Seakeeper gyros to weigh much less, and consume very little power.
“The Seakeeper gyros’ performance has been really satisfying. The feeling onboard Marhaba charter yacht has changed dramatically, during navigation, due to an important reduction in roll. This allows everyone on board, even the more sensitive people, to fully enjoy the experience of Marhaba,” said Montezemolo. “We recommend Seakeeper gyros because the effective roll reduction has been very important, more than expected. And also, all the technical requirements that we have taken into consideration for our choice have been completely satisfied.”
Montezemolo experienced the power of Seakeeper gyros himself during a side-by-side comparison of a fin and gyro-type stabilizer on yachts off the coast of Viareggio, Italy. “We considered the Seakeeper gyros’ high rotational speed, which created a high value of angular momentum. Also, they produced limited noise and added limited weight,” said Montezemolo.
Seakeeper gyros also include an active control mechanism which optimizes the gyro’s performance over a wide range of sea states. A passively controlled gyro must be turned off in the roughest conditions to keep from damaging itself, whereas the Seakeeper Gyro can continue to operate when it is most needed.
The M21000 gyros were retrofitted in the lazarette, one port and one starboard. Superyacht Marhaba already had a hydraulic fin system in place. Subsequent sea trials 2 miles off the coast of Genoa, Italy, verified the performance of the Seakeeper gyros, both underway and at zero speed.
Though seas were relatively calm on day one for underway testing, with light winds and short, choppy waves with estimated maximum heights of 0.4m, when compared to the performance of the yacht’s stabilizing fins, Seakeeper proved its capabilities extremely well.
With Marhaba yacht travelling at 10 knots in beam seas, the gyro and fins were engaged separately, and then used together. The Seakeeper gyros, operating alone underway, reduced the standard deviation of the roll rate from more than 1.2 degrees to 0.8 degrees. The gyros also reduced the standard deviation of the roll angle from nearly 1.0 degrees to 0.6 degrees, producing results very similar to those achieved by the fins alone.
Zero speed trials performed aboard motor yacht Marhaba further prove the versatility of the Seakeeper gyro’s stabilization capabilities. On day one, even in such calm conditions, the combination of waves and the yacht’s natural roll at zero speed produced uncomfortable motion. The Seakeeper gyros achieved an impressive 76% resonant roll reduction.
On day two of the sea trials, a storm blew in, creating breaking waves with maximum heights of approximately 1.25m. Those onboard even witnessed a waterspout nearby. Again, with the Seakeeper gyros engaged, a powerful 77% zero speed resonant roll reduction was achieved aboard charter yacht Marhaba.