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. History The Navy Ministry was created in April 1872, along with the Army Minis ...

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, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

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 is 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 colonization ...

- the

Meiji Emperor , also called or , was the 122nd emperor of Japan according to the traditional order of succession. Reigning from 13 February 1867 to his death, he was the first monarch of the Empire of Japan and presided over the Meiji era. He was the figure ...

'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 (410mm, 45

caliber In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel Gauge (firearms) , bore – regardless of how or where the bore is measured and whether the f ...

) * 20 cm/50 3rd Year Type naval gun (I) * 20 cm/50 3rd Year Type naval gun (II) * 6.1 in (155 mm) 15.5 cm/60 3rd Year Type naval gun * 14 cm/50 3rd Year Type naval gun * 5 in (127 mm) 12.7 cm/50 3rd Year Type naval gun * 4.7 in (120 mm) 12cm/45 3rd Year Type naval gun (Note: "3rd Year" refers to these weapons

Welin breech block The Welin breech block was a revolutionary stepped, interrupted thread design for locking artillery breeches, invented by Axel Welin in 1889 or 1890. Shortly after, Vickers acquired the British patents. Welin breech blocks provide obturation for ...

, 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, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...

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

: *

Ōtori class torpedo boat , also transliterated Ootori and Ohtori is a Japanese word meaning "large bird," "a key performer," or a Japanese name. Possible writings Ōtori can be written using different kanji characters and can mean: *大鳥, "large bird" or "big bird" ...

s *

Type B1 submarine The , also called was the first group of boats of the Type B cruiser submarines built for the Imperial Japanese Navy (IJN) during the 1940s. In total 20 were built, starting with , which gave the series their alternative name. Design and descri ...

sReport of the sinking of ''I-35''

Department of Defence (Australia) Defence Australia is a department of the Government of Australia charged with the responsibility to defend Australia and its national interests. Along with the Australian Defence Force (ADF), it forms part of the Australian Defence Organis ...

, undated

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

Kaidai class submarine The was a type of first-class submarine operated by the Imperial Japanese Navy (IJN) before and during World War II. The type name was shortened to Navy Large Type Submarine. All ''Kaidai''-class submarines originally had a two-digit boat na ...

s *

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

s *

Momi class destroyer The ''Momi''-class destroyers were a class of twenty-one second-class destroyers of the Imperial Japanese Navy. All were named for plants. Obsolete by the beginning of the Pacific War, the ''Momi''s were relegated to mostly secondary roles, with ...

s *

Wakatake class destroyer The were a class of eight second-class destroyers of the Imperial Japanese Navy. Background The medium-sized ''Wakatake''-class destroyers were a follow-on to the as part of the Imperial Japanese Navy's 8-6 Fleet Program from fiscal 1921 as a ...

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 destroyer The were a class of twelve destroyers of the Imperial Japanese Navy. All were given traditional poetic names of the months of the year by the Lunar calendar or phases of the moon. Some authors consider the and ''Mutsuki''-class destroyers to ...

9th Year Type Mine (1920)

The 9th Year Type

mine Mine, mines, miners or mining may refer to: Extraction or digging * Miner, a person engaged in mining or digging *Mining, extraction of mineral resources from the ground through a mine Grammar *Mine, a first-person English possessive pronoun ...

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 The 14 cm/40 11th Year Type naval gun was the standard surface battery for Japanese submarine cruisers of World War II. Most carried single guns, but Junsen type submarines carried two. Japanese submarines ''I-7'' and ''I-8'' carried an unu ...

, which was the standard Japanese submarine deck gun. 11th Year Type Guns were mounted on the following ships: *

s *

Type B submarine The was a class of submarine in the Imperial Japanese Navy (IJN) which served during World War II. The ''Type-B'' submarines were similar to the ''Type-A'' apart from not having the headquarters installation. Class variants The ''Type-B'' subma ...

s *

Type C submarine The was one of the first classes of submarine in the Imperial Japanese Navy (IJN) to serve during the Second World War. ''Type-C'' submarines were better armed than the ''Type-A'' and ''Type-B''. The ''Type-C''s were also utilized as '' Kō-h ...

References

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