Akatsuki-class destroyer (1931)

The Akatsuki-class destroyer (暁型駆逐艦) was a class of four destroyers of the Imperial Japanese Navy. Almost identical in appearance to the previous Fubuki class, they are regarded as a sub-class by many authors, partly because the Imperial Japanese Navy itself kept the improvements made a secret, and did not officially designate these four destroyers as a separate class. This class of destroyer should not be confused with the much earlier Akatsuki class of the Russo-Japanese War period.

Background
After a number of years of operational experience with the Fubuki-class, the Imperial Japanese Navy General Staff issued requirements for four additional Special Type destroyers (特型) destroyers, with a maximum speed of 39 knots, range of 4000 nmi at 14 kn, and armed with Type 8 torpedoes. These destroyers were intended to operate with the new series of fast and powerful new cruisers also under consideration as part of a program intended to give the Imperial Japanese Navy a qualitative edge with the world's most modern ships. The new vessels were built from 1931-1933.

Design
The Akatsuki vessels had larger boilers and a narrower fore funnel than the previous Fubuki, and internally the number of boilers was reduced from four to three due to improvements in boiler design and efficiency. Other improvements over the Fubuki-class included a splinter-proof torpedo launcher-turret, which allowed the torpedo launcher tubes to be reloaded in action (something which Western destroyers still did not have in the 1990s).

However, the Akatsuki-class shared a number of inherent design problems with the Fubuki-class. The large amount of armament combined with a smaller hull displacement than in the original design created issues with stability. After the Tomozuru Incident, in which the basic design of many Japanese warships was called into question, additional ballast had to be added. In the Fourth Fleet Incident, during which a typhoon damaged virtually every ship in the Fourth Fleet, issues with the longitudinal strength of the Akatsuki class hull was discovered. As a result, all vessels were reconstructed in 1935-1937. This increased the displacement to 2050 tons standard tons and over 2400 tons full load. The rebuild reduced the top speed slightly.

The main battery consisted of six Type 3 127 mm 50 caliber naval guns, mounted in pairs in three weather-proof, splinter-proof, gas-tight gun turrets. Ammunition was brought up on hoists from magazines located directly underneath each gun turret, which had a greater rate of fire than other contemporary destroyers, where ammunition was typically manually loaded. The mounts could elevate each gun separately to 75° elevation for AA use. Originally Type 8 torpedoes were carried, arranged in three triple mountings. These were later replaced with the famous Type 93 "Long Lance" oxygen-propelled torpedoes during World War II.