- This article refers to the nautical term. For other uses, see stabilizer.
are fins mounted beneath the waterline and emerging laterally. In contemporary vessels, they may be gyroscopically
controlled active fins, which have the capacity to change their angle of attack
to counteract roll caused by wind or waves acting on the ship.
The bilge keel
is an early 20th century predecessor. Although not as effective at reducing roll
, bilge keels are cheaper, easier to install, and do not require dedicated internal space inside the hull
In November 1932 the ship Conte di Savoia
made its maiden voyage. It had three huge gyroscopes were fitted low down in a forward hold. These rotated at high revolutions and were designed to eliminate rolling - a persistent problem on the rough North Atlantic crossing that affected all shipping lines. Each of the three flywheels was 13 feet in diameter and weighed 108 tons.
The first mention of automatic stabilizers for ships, was is in 1932, by an engineer working for General Electric. Popular Mechanics, August 1932
The first use of fin stablizers on a ship was by a Japanese cruise liner in 1933. April 1933, Popular Mechanics