1/1800 IJN No.13 BB

The Number 13-class battleship was a planned class of four fast battleships to be built for the Imperial Japanese Navy (IJN) during the 1920s. The ships never received any names, being known only as Numbers 13–16. They were designed by Captain Yuzuru Hiraga, the naval architect responsible for most of the previous Japanese capital ships. The ships were based on his previous Kii-class battleship and Amagi-class battlecruiser designs, enlarged to take 457-millimeter (18.0 in) guns. 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. The Number 13 Class was designed to be superior to all other existing battleships, planned or in production. After the signing of the Washington Naval Treaty in 1922, they were cancelled in November 1923 before construction could begin. The Japanese followed the doctrine that they had used since the First Sino-Japanese War of 1894–95 of compensating for quantitative inferiority with qualitative superiority. In the words of naval historian Siegfried Breyer, "Had [the ships] been completed, they would have been the world's largest and most powerful battleships. Their gun caliber alone would have caused a new and more intensive naval arms race. From an engineering aspect they were more than ten years ahead of their time because they anticipated the characteristics of the fully developed, fast battleship."