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With systems installed
on several high-end yachts in the 150-foot-and-up range, including Gallant
Lady, Princess Marla, and Aurora B, Quantum Controls arguably has the
most prestigious client list in the “stabilization-at-anchor”
market. It can also take credit for one of the more challenging installations,
in the Sparkman & Stephens-designed and Palmer Johnson-built Anson
Bell, a 156-footer, with two pairs of stabilizers that allow reduction
of pitch as well as roll.
Stabilization at
speed. The advent of solid-state sensors and digital controllers paved
the way for stabilization systems on yachts operating at speeds of 20
to 30 knots or more. Older analog systems simply cannot respond quickly
enough and pose the potential risk that control-system lags might actually
cause the fins to increase roll motion.
Ironically, because
fins produce more lift with higher speed, fast yachts will require smaller
fins and drive mechanisms than would slower yachts of similar size. Thus,
if the stabilizers on an 80-foot yacht designed for 15 knots cost $60,000,
the stabilizers on the same-size yacht designed for 25 knots might cost
only $40,000.
How good are today’s
stabilization systems compared to the flopper-stoppers of ten or 15 years
ago? According to Milo Halliberg of American Bow Thruster, for yachts
in the 40- to 80-foot range, “roll-damping” systems using analog
technology typically achieve about 40 percent roll reduction, whereas
yachts with digital control systems can expect a 90- to 98-percent roll
reduction in beam seas of three to four feet.
Ride control systems.
Going beyond roll stabilization, for yachts operating at semiplaning
and planing speeds, there are a variety of systems available that provide
pitch control in addition to roll reduction. KoopNautic Holland (an affiliate
of VT Naiad Marine) makes a system combining specially designed trim tabs
and electronic controls that automatically adjusts the tabs to counter
the pitch-and-roll forces that are produced by each wave.
Next page >
Part 3: Mitsubishi Heavy Industries has developed
a system that involves no components outside the hull. > Page 1,
2, 3, 4
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