Victory at Sea: Yamato[countdown]2020 08 29 0: 0: 00[ countdown] Yamato (, "Great Harmony") and her sister ship, Musashi, were constructed shortly before the outbreak of World War II. They were the heaviest and most powerfully armed battleships ever constructed; armed with nine 18. 1 Type 94 main guns the largest guns ever mounted on a warship. The battleships design was an answer to the numerically dominant US Navy Imperial Japans primary threat in the Pacific. Though