mounted on vertical bearings. When a small sensor gyroscope on the bridge sensed a roll, a servomotor would rotate the gyros about a vertical axis in a direction so their precession would counteract the roll. In tests this system was able to reduce roll to 3 degrees in the roughest seas. For about 20 years the effectiveness of the stabilizers was unclear (in part due to improved gunfire directors), and in the US Navy the feature remained experimental (gyrostabilizer on the USS Osborne (DD-295), active-tank stabilizer on USS Hamilton (DMS-18)) until 1950s. One of the most famous ships to first use an anti-rolling gyro was the Italian passenger liner , which first sailed in November 1932. It had three flywheels which were 13 feet in diameter and weighed 108 tons. Gyroscope stabilization was replaced by fin stabilization due to its lower weight and bulk, but it has seen renewed interest since the 1990s (Seakeeper, etc.). The fin stabilizer had been patented by Motora Shintaro of Japan in 1922. The first use of fin stabilizers on a ship was by a Japanese cruise liner in 1933. From the late 1930s the British were actively installing the Denny-Brown fin stabilizers onto their warships (over 100 installations by 1950). US Navy continued unsuccessful experiments with roll tanks until the successful fin stabilizer installations onto USS Gyatt (1956) and USS Bronstein (DE-1037) (1958). In 1934 a Dutch liner introduced one of the world's most unusual ship stabilizer systems, in which two large tubes were mounted on each side of the ship's hull with the bottom of the tubes open to the sea. The top of the tubes had compressed air or steam pumped in. As the ship rolled, the side it was rolling to would fill with water and then compressed air or steam would be injected to push the water down, countering the roll. In 2018, rocket and space technology company Blue Origin purchased the Stena Freighter, a roll-on/roll-off cargo ship, for use as a landing platform ship for its New Glenn launch vehicle booster stages. the ship is undergoing refit to prepare for its role of landing rockets. The rocket boosters will be recovered downrange of the launch site in the Atlantic Ocean while the hydrodynamically-stabilized ship is underway. The ship stabilization technology is designed to increase the likelihood of successful rocket recovery in rough seas, as well as helping to carry