The Type 3 120 mm 45 caliber naval gun was a Japanese naval artillery

Naval artillery

Naval artillery, or naval riflery, is artillery mounted on a warship for use in naval warfare. Naval artillery has historically been used to engage either other ships, or targets on land; in the latter role it is currently termed naval gunfire fire support...

 and coast defense gun used on destroyer

Destroyer

In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s and submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 and World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. It was an indigenous development of the British-designed QF 4.7 inch Gun Mk I - IV

QF 4.7 inch Gun Mk I - IV

The QF 4.7 inch Gun Mks I, II, III, and IV were a family of United-Kingdom 120-mm naval and coast defence guns of 1888 and 1890s which served with the navies of various countries. They were also mounted on various wheeled carriages to provide the British Army with a long range gun...

, which had been previously produced in Japanese as the “Type 41”, under license from Elswick Ordnance Company, part of Armstrong Whitworth

Armstrong Whitworth

Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. Headquartered in Elswick, Newcastle upon Tyne, Armstrong Whitworth engaged in the construction of armaments, ships, locomotives, automobiles, and aircraft.-History:In 1847,...

. It should not be confused with the later Type 3 12 cm AA Gun

Type 3 12 cm AA Gun

The was an anti-aircraft gun used in quantity by the Imperial Japanese Army during World War II. It replaced the earlier Type 88 75 mm AA Gun in Japanese service.-History and development:...

 developed by the Imperial Japanese Army

Imperial Japanese Army

-Foundation:During the Meiji Restoration, the military forces loyal to the Emperor were samurai drawn primarily from the loyalist feudal domains of Satsuma and Chōshū...

 in 1943.

Design and development

Designed in 1914, the Type 3 120mm gun was used as the main armament on Kawakaze, Momi

Momi class destroyer

The Momi class destroyers was a class of twenty one 2nd class destroyers of the Imperial Japanese Navy. All were named for plants. Obsolete by the beginning of the Pacific War, the Momi were relegated to mostly secondary roles, with some vessels serving throughout the war as patrol vessels...

, Minekaze

Minekaze class destroyer

The was a class of fifteen 1st-class destroyers of the Imperial Japanese Navy. Obsolete by the beginning of the Pacific War, the Minekaze class ships were relegated to mostly secondary roles, serving throughout the war as patrol vessels, high speed transports, target control vessels, and as kaiten...

, Wakatake

Wakatake class destroyer

The was a class of eight 2nd-class destroyers of the Imperial Japanese Navy.-Background:The medium-sized Wakatake-class destroyers were a follow-on to the Momi class destroyer as part of the Imperial Japanese Navy's 8-6 Fleet Program from fiscal 1921 as a lower cost accompaniment to the larger...

, Kamikaze and Mutsuki

Mutsuki class destroyer

The was 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...

 class destroyers in single mountings.

The type was re-designated in the metric system

Metric system

The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...

 from October 5, 1917.

A re-design in 1922 with a shorter gun barrel

Gun barrel

A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....

 and improved horizontal sliding breech-blocks

Breech-loading weapon

A breech-loading weapon is a firearm in which the cartridge or shell is inserted or loaded into a chamber integral to the rear portion of a barrel....

 was designated the Type 11, and was used on submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s and the Otori

Otori class torpedo boat

The were a class of eight 840 ton fast torpedo boats of the Imperial Japanese Navy.-Development:The eight ships were ordered in 1934 and were commissioned between 1936 and 1937...

 and Chidori

Chidori class torpedo boat

The was a Imperial Japanese Navy class of torpedo boats that served during the Second World War. They proved to have too much armament for the hull and capsized shortly after completion in heavy weather. The entire class had to be rebuilt before they became satisfactory sea-boats...

 class torpedo boat

Torpedo boat

A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

s.

The gun, which was manually loaded, normally fired a 20.3 kilograms (44.8 lb) High-explosive shell or an illumination shell. After 1943, anti-submarine shells also become available.