Henderson "was the first large ship to be gyro-stabilized. The stabilizing unit was installed while the ship was being built at the Philadelphia Navy Yard. This view of the whole ship, taken on 13 April 1917, shows the size of the stabilizer compared to the ship. The gyros being installed through the side of the ship, weigh four-fifths of one per cent of the displacement of the ship, approximately 80 tons. The gyros are capable of holding the ship down to three degrees of roll in the roughest weather. On numerous trans-Atlantic crossings experiments have been conducted, rolling the ship with the stabilizers for experimental director gun fire as well as stabilizing the ship for economy in effort in operation and comfort of personnel on board. Henderson was well fitted for these experiments, being equipped with eight five-inch guns and a complete fire control director." (quoted from the original 1917-vintage photo caption)
