Stop, Drop the Roll
Gyroscopic stabilizers are not new—the technology has been around since the early part of the last century. They were effective at arresting the undesirable movement of boats back then, too, but their size and power draw made them unwieldy.
“To make it more practical for recreational yachts…we had to develop a gyro that was lighter and demanded less power,” says Andrew Semprevivo, international sales manager of Seakeeper. “Spinning the flywheel in a near-vacuum let us spin a wheel faster while using less power.” In layman’s terms, a gyroscopic stabilizer with a lighter flywheel will give good performance if you can spin it faster.
The lack of air drag in the vacuum-packed unit means faster speeds, but with another key. “On our model 7000 gyro, we are spinning a 432-pound flywheel close to 10,000 rpm while drawing a max of 3 kW of power during spool-up and 1.5 to 2 kW while in operation,” says Semprevivo. “The operating power draw is similar to that of a hair dryer.” Today’s gyroscopes are already speeding toward the future. Seakeeper just rolled out its M21000 model, which can stabilize a 90-ton boat.
“We put an active control on the gyro to monitor the roll of the boat and the sea conditions” says Semprevivo. “It controls that precession rate so it matches a swell or a chop.” Precession means the gyro is working on the hull. “When the boat rolls port to starboard, the gyro precesses fore and aft, and exerts its torque,” he says.
Can you add this technology to your boat? “The most important thing when sizing gyros to a vessel is to have the proper amount of angular momentum for the vessel,” says Semprevivo. “Our gyros typically weigh one to two percent of the vessel’s displacement and reduce resonant roll by 60 to 80 percent.”
The installation may be much simpler than you’d think. “On planing boats we want it from midship aft,” says Semprevivo. “It does not matter where it is in relation to centerline. It will perform on centerline just as well as it will if it’s all the way to one side. And on multiple gyro applications, they’re totally independent, they do not rely on each other for anything and they can be installed in any manner.”
Refit Considerations: Take a look at reducing roll and adding to the enjoyment of being on board.
Seakeeper, (410) 326-1590; www.seakeeper.com
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Stop, Drop the Roll