The was an anti-aircraft gun used in quantity 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...

 during 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 replaced the earlier Type 88 75 mm AA Gun

Type 88 75 mm AA Gun

The was an anti-aircraft gun used by the Imperial Japanese Army during the Second Sino-Japanese War and World War II. It replaced the earlier Type 11 75 mm AA Gun in front line combat service, and at the time was equal in performances to any of its contemporaries in western armies and was...

 in Japanese service.

History and development

In order to address the shortcomings of the Type 88 75 mm AA Gun, the Army Technical Bureau developed a larger version with superior range, designated the Type 3. It was one of the few weapons in the Japanese inventory capable of reaching the USAAF B-29 Superfortress

B-29 Superfortress

The B-29 Superfortress is a four-engine propeller-driven heavy bomber designed by Boeing that was flown primarily by the United States Air Forces in late-World War II and through the Korean War. The B-29 was one of the largest aircraft to see service during World War II...

 bombers that were attacking cities and other targets in the Japanese home islands. However, despite its superior range and firepower, the Type 3 gun could not be produced in sufficient quantities to be truly effective, due to costs, lack of raw materials and damage to Japan’s industrial infrastructure by Allied air raids

Air raids on Japan

During World War II the Allied forces conducted many air raids on Japan which caused extensive destruction to the country's cities and killed over 300,000 people. These attacks began with the Doolittle Raid in mid-April 1942, but did not resume until June 1944 when United States Army Air Forces ...

. Only 120 units were completed before production was discontinued, although the units produced continued to be used until the surrender of Japan

Surrender of Japan

The surrender of Japan in 1945 brought hostilities of World War II to a close. By the end of July 1945, the Imperial Japanese Navy was incapable of conducting operations and an Allied invasion of Japan was imminent...

.

Design

The Type 3 12 cm AA gun had a single piece 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....

 with sliding breech

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....

, mounted on a central pedestal. The firing platform was supported by five legs, each of which (along with the central pedestal) had adjustable screwed foot for leveling.

Combat record

Coming into service towards the end of the war, most the Type 3s were retained on the home islands as part of the bolstering of Japan's defenses against Allied air raids

Air raids on Japan

During World War II the Allied forces conducted many air raids on Japan which caused extensive destruction to the country's cities and killed over 300,000 people. These attacks began with the Doolittle Raid in mid-April 1942, but did not resume until June 1944 when United States Army Air Forces ...

 and against the perceived thread of Allied invasion

Operation Downfall

Operation Downfall was the Allied plan for the invasion of Japan near the end of World War II. The operation was cancelled when Japan surrendered after the atomic bombing of Hiroshima and Nagasaki and the Soviet Union's declaration of war against Japan. The operation had two parts: Operation...

. These guns were deployed to cover military targets around Tokyo

Tokyo

, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...

, Osaka

Osaka

is a city in the Kansai region of Japan's main island of Honshu, a designated city under the Local Autonomy Law, the capital city of Osaka Prefecture and also the biggest part of Keihanshin area, which is represented by three major cities of Japan, Kyoto, Osaka and Kobe...

, Kobe

Kobe

, pronounced , is the fifth-largest city in Japan and is the capital city of Hyōgo Prefecture on the southern side of the main island of Honshū, approximately west of Osaka...

 and the Yawata Steel Works in Kitakyushu. Overseas, they were deployed to guard the oil fields at Palembang

Palembang

Palembang is the capital city of the South Sumatra province in Indonesia. Palembang is one of the oldest cities in Indonesia, and has a history of being a capital of a maritime empire. Located on the Musi River banks on the east coast of southern Sumatra island, it has an area of 400.61 square...

 in the Netherlands East Indies Units in Tokyo were credited with downing at least ten B-29 bombers.