The was the externally operating division of the

Ministry of the Navy of Japan The was a cabinet-level ministry in the Empire of Japan charged with the administrative affairs of the Imperial Japanese Navy (IJN). It existed from 1872 to 1945. In the IJN and the Imperial Japanese Army (IJA), the ministries were in charge ...

responsible for the administration of naval vessel construction. From 1923 onward, it took on the role of a research institution for the research and development of naval technologies and engineering. This included studying and investigating existing western naval technology, developing and overseeing Japan's domestic shipbuilding and arms industries, and training officers to become naval engineers and inspectors. The bureau was dismantled along with the naval ministry in November 1945 after Japan surrendered to the Allies at the end of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

Taishō period weapons

The Department developed various weapons during the Taishō period. These were known a "Xth Year Type" weapons, with the year being the year of the Taishō Emperor's reign (dating from 30 July 1912 - 25 December 1926).Guns
, Mechanisms of Imperial Japanese Navy Warships in 3D, (based on information from "Naval Weapons of World War Two", John Campbell,

Naval Institute Press The United States Naval Institute (USNI) is a private non-profit military association that offers independent, nonpartisan forums for debate of national security issues. In addition to publishing magazines and books, the Naval Institute holds se ...

, 1985), accessed 26 April 2010 This nomenclature followed on from

Meiji period The was an era of Japanese history that extended from October 23, 1868, to July 30, 1912. The Meiji era was the first half of the Empire of Japan, when the Japanese people moved from being an isolated feudal society at risk of colonizatio ...

- the Meiji Emperor's reign (13 February 1867 - 30 July 1912). Records exist of a "8.0 inch 45 caliber, 41st Year Type" (1908).

3rd Year Type Guns (1914)

* 41 cm/45 3rd Year Type naval gun * 20 cm/50 3rd Year Type naval gun (I) * 20 cm/50 3rd Year Type naval gun (II) * 15.5 cm/60 3rd Year Type naval gun * 14 cm/50 3rd Year Type naval gun * 12.7 cm/50 3rd Year Type naval gun * 12cm/45 3rd Year Type naval gun (Note: "3rd Year" refers to these weapons Welin breech block, which was introduced in 1914; the weapons themselves often came later)

5th Year Type Gun (1916)

48 cm/45 5th Year Type naval gun

6th Year Type Torpedo (1917)

The 6th Year Type

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

* Diameter : * Length : * Weight : * Explosive charge: * Range : ** at ** at ** at . It was widely used in surface ships and submarines into

: * Ōtori class torpedo boats * Type B1 submarinesReport of the sinking of ''I-35''

Department of Defence (Australia) The Department of Defence, also known simply as Defence, is a Government department, department of the Government of Australia, Australian Government that is responsible for administering the Australian Defence Force (ADF) and its related enti ...

, undated

, accessed 24 April 2010 * Type L3 and L4 submarines * Kaidai class submarines *

Kaichū type submarine The submarines were double-hulled medium-sized submarines of the Imperial Japanese Navy during World War II. The name was derived from the . Several variants existed. From 1934 to 1944, the K6 type (''Ro-33'' Class) and the K7 type (Senchū, '' ...

s * Momi class destroyers * Wakatake class destroyers

8th Year Type Torpedo (1919)

The 8th Year Type torpedo: * Diameter: * Length: * Weight: * Explosive charge: * Range: ** at ** at ** at . An advance on its predecessor, it was used in: * Mutsuki class destroyers

9th Year Type Mine (1920)

The 9th Year Type mine was deployed from various ships. It was used as a test explosive on the hulk of ''Tosa''.

11th Year Type Guns (1922)

The 11th Year Type breech was a horizontal-sliding block breech type, adopted in 1922. It was used in the 4.7in Type 3 120 mm 45 caliber naval gun and the 5.5in 14 cm/40 11th Year Type naval gun, which was the standard Japanese submarine deck gun. 11th Year Type Guns were mounted on the following ships: * Ōtori class torpedo boats * Kaidai-type submarines * Type B submarines * Type C submarines

References

{{reflist Imperial Japanese Navy Naval history of Japan Science and technology in Japan