sentences:  They were intended to reinforce Japan's "eight-eight fleet" of eight battleships and eight battlecruisers after the United States announced a major naval construction program in 1919.However, after the signing of the Washington Naval Treaty in 1922, work on the ships was suspended; one pair was cancelled in November 1923 and the other in April 1924.By 1918, the Navy had gained approval for an "eight-six" fleet of eight battleships and six battlecruisers, all ships under eight years old.