1945. Four license-built Type 93 machine guns were also fitted to Hatsushimo, but these were also of limited utility against modern aircraft. The 61 cm Type 90 torpedo was mounted in quadruple tube Type 92 launchers, derived from the twin tube Type 89 launcher used in the heavy cruisers. Shields were fitted to both the torpedo mounts and lockers to protect them from the weather and from strafing aircraft. Initially the shields were made from Duralumin to save weight, but these quickly corroded and had to be replaced. "NiCrMo" steel, taken from the air chambers of obsolete torpedoes, in thickness, was chosen for the new shields to save weight. It was traversed by an electro-hydraulic system and could traverse 360° in twenty-five seconds. If the backup manual system was used the time required increased to two minutes. Eight reloads were carried, and each tube could be reloaded in twenty-three seconds using the endless wire and winch provided. Because of the weight of the extra guns added, one set of reloads for the torpedo tubes was removed, together with the minelaying and minesweeping gear. By the start of the Pacific War, all ships of the class were using Type 93 torpedoes. Only eighteen depth charges were initially carried in a rack at the stern, but this increased to thirty-six after the autumn of 1942, with four depth charge throwers. Apparently no sonar or hydrophones were fitted until after the outbreak of the war when the Type 93 sonar and Type 93 hydrophones were mounted. Radar Radar was not installed on the surviving ships of this class until late in the war, possibly as late as 1944. Surviving ships were given a Type 22 radar on the foremast, a Type 13 on the mainmast and a Type E-27 radar countermeasures device was carried high on the foremast. Operational history None of the Shiratsuyu-class ships survived the Pacific War. The lead ship of the class, was sunk northeast of Mindanao in a collision with the oiler Seiyo Maru. Most of the class were lost to US submarines, with Kawakaze, Yudachi, and Murasame being lost in surface actions. Only Harusame fell victim to aircraft. All ships in the class took part in either the Battle of Midway or the Invasion of the Aleutians. was employed in several campaigns, beginning with the invasion of the Philippines. In 1942 she participated in the Battle of the