Kokura Army Arsenal
■ Its Roots
Originally, the Tokyo Army Arsenal in Koishikawa, Tokyo, suffered catastrophic damage during the Great Kanto Earthquake. In the search for a new site, Hiroshima and Kokura remained as the final candidates. Kokura City campaigned vigorously, even appealing to military elders from the region, and successfully attracted the facility. This move was driven by the city’s decline following the 1925 military disarmament, which saw the relocation of the 12th Division Headquarters and its main forces.
■ Establishment of the Kokura Arsenal
In 1927, it was decided that the new arsenal would be built in the former castle grounds on the left bank of the Murasaki River. The military consolidated the Kokura Weapon Factory (established in 1916) into the new facility and cleared the barracks and training grounds of the 14th Infantry Regiment, which had been stationed there since 1875. This secured a site of 68 hectares. Today, this area covers most of Jonai, all of Otemachi, and Kanda 1-chome. It officially opened in 1933 as the Kokura Arsenal of the Army Ordnance Department. In 1940, the name was changed to the Kokura Army Arsenal due to organizational restructuring.
■ Overview
The Kokura Army Arsenal consisted of three manufacturing plants. It produced a wide range of equipment, from leather goods and cast steel to rifles, machine guns, autocannons, artillery shells, vehicles, and even light tanks. Toward the end of WWII, it also manufactured “balloon bombs” designed to fly to the U.S. mainland. It was one of the largest comprehensive weapon manufacturing facilities in Western Japan. At its peak, the workforce—including military personnel and civilian employees—is said to have reached 40,000.
■ The Great War and the Arsenal
During WWII, the No. 2 Manufacturing Plant was hit during a U.S. air raid, claiming the lives of many members of the Women’s Volunteer Corps (Joshi Teishintai). In August 1945, near the end of the war, the city center of Kokura—with the arsenal at its heart—became the primary target for the second atomic bomb after Hiroshima. Following the end of the war on August 15, the arsenal ceased operations. Machine tools were removed as war reparations, and part of the U.S. 32nd Infantry Division was stationed there. In 1946, the U.S. 24th Infantry Division took over, establishing its headquarters in the former main building. When the Korean War broke out, this division was immediately deployed to the front lines. Even after WWII ended, peace did not immediately return to this land.
Target Information Sheet (From U.S. Military Records)
Excerpt from “Air Raids on Kitakyushu” by Yoshishige Okuzumi and Yoichi Kudo
Note: Do not carry this onto aircraft during sorties. This is a translation from Japanese translated material.
Do not bring it on board when flying out.
1. Summary
The Kokura Arsenal is one of the largest in Japan and is perhaps the most important regarding the manufacture of light automatic weapons, small anti-aircraft guns, and anti-tank guns. It is closely integrated with Japan Iron & Steel (Yawata), Watanabe Iron Works in Fukuoka, and several other plants in Northern Kyushu. It also manufactures combat vehicles.
2. Description of Facilities
The total target area is 4,140 feet by 2,040 feet, centered on a north-south axis. Thirty-six buildings, each covering over 20,000 square feet, occupy 33% of this area. Three overhead cranes connect the railroad sidings to the storage area in the southeast corner of the complex.
Information provided by POWs indicates that the plant consists of three separate departments arranged in parallel strips running north to south: (1) Ammunition Department: Located on the east side, closest to the river. (2) Artillery Department: Two rows of buildings extending through the center of the complex. (3) Combat Vehicle Manufacturing: Reported to be located in the western section of the site. Approximately 22 barrack-like buildings at the northern end of this area serve as military quarters.
Of the major buildings, 71% are steel-framed and 29% are concrete-framed. Secondary buildings are also generally steel-framed, with wooden-framed structures interspersed. Walls consist of corrugated iron, concrete, or asbestos. Most roofs are covered with corrugated iron or asbestos, with only a few flat roofs believed to be concrete. Numerous smaller buildings have combustible roofing. Virtually all floors are concrete. The majority of the buildings are single-story.
3. Importance
As an arsenal with such diverse activities, production rates are unknown, but it likely produces thousands of machine guns of all types per month. Its importance as one of the two or three largest arsenals in Japan is evident. While basic steel or copper production is not performed here, secondary metal processing is extensive.
The arsenal is known to produce 6.5mm and 7.7mm light machine guns, 7.7mm heavy machine guns, 20mm anti-aircraft and anti-tank guns, and ammunition. It has been reported that mixed poison gas shells are produced, filled, and stored in basements. The most critical processes are the machining and assembly of weapons. Forging and pressing are also significant.
Damaged machine tools are difficult to replace and could stall production for months. Damage to assembly and machining facilities would have an immediate effect.
XXI Bomber Command A-2, Target Section June 10, 1945
Kokura city area immediately after the war
