32 cm/45 Type 3 naval gun

32 cm/45 Type 3 naval gun. The 32 cm/45 Type 3 naval gun was a large-caliber naval artillery piece designed and manufactured by the Imperial Japanese Navy for its capital ships. Developed during World War I, it was intended to arm a new generation of Japanese battleships and battlecruisers. It saw service aboard several famous warships during the Interwar period and World War II, though it was ultimately considered inferior to contemporary foreign designs.

Design and development

The gun's development was initiated by the Kure Naval Arsenal in 1914, as part of the Imperial Japanese Navy's response to the global naval arms race preceding World War I. The design was heavily influenced by British naval artillery technology, a common practice for the Imperial Japanese Navy following the Anglo-Japanese Alliance. The "Type 3" designation indicated its development in the third year of the Taishō period (1914). The weapon was engineered to provide the planned ''Nagato''-class battleships and the never-completed ''Amagi''-class battlecruisers with superior firepower to potential rivals like the United States Navy's Colorado-class battleship or the Royal Navy's Queen Elizabeth-class battleship. Initial testing revealed challenges with barrel wear and dispersion, leading to modifications before final acceptance.

Description

The gun featured a built-up construction with a central A tube, multiple reinforcing hoops, and a Welin breech block mechanism. It fired separate-loading ammunition, with the 625 kg (1,378 lb) armor-piercing projectile and four bagged Cordite charges being loaded in sequence. The mountings, primarily twin-gun turrets, allowed for an elevation range of -5 to +43 degrees, providing a maximum range of approximately 32,400 meters. The turrets on the ''Nagato''-class were electrically powered and heavily armored, with faceplates over 300 mm thick. The guns had a relatively modest rate of fire, around 1.5 to 2 rounds per minute, due to the heavy weight of the shells and the cumbersome loading process at high angles.

Service history

The guns entered service in 1921, arming the ''Nagato'' and her sister ship, the ''Mutsu''. They were also installed on the battlecruiser ''Akagi'' before her conversion into an aircraft carrier under the terms of the Washington Naval Treaty. During the Second Sino-Japanese War, the guns of Nagato and Mutsu provided distant fire support for Imperial Japanese Army operations. In World War II, they participated in major engagements including the Battle of Midway, the Battle of the Philippine Sea, and the Battle of Leyte Gulf. At Leyte Gulf, Nagato engaged United States Navy vessels including USS ''California'' and USS ''Mississippi''. Both battleships were sunk late in the war: Mutsu by an internal explosion in 1943, and Nagato as a target during Operation Crossroads at Bikini Atoll in 1946.

Naval artillery comparison

Compared to its international contemporaries, the Type 3 gun was moderately powerful but generally outclassed. Its 625 kg shell was lighter than the 1,016 kg projectile of the 16"/45 caliber guns on the American ''South Dakota''-class, and its muzzle velocity was lower than that of the British BL 15 inch Mk I naval gun on the HMS Hood. The Japanese weapon's maximum range was also less than that of the later American 16-inch/50 caliber Mark 7 gun used on the Iowa-class battleship. Its performance in terms of accuracy and barrel life was reported to be inferior to both British and American naval artillery of similar vintage, a factor noted during gunnery exercises in the 1930s.

Surviving examples

No complete 32 cm/45 Type 3 naval gun is known to survive today. The most significant relic is a single gun barrel, removed from the ''Mutsu'' prior to her loss, which is preserved at the Yamato Museum in Kure, near the site of the Kure Naval Arsenal where it was manufactured. Fragments of the guns from the ''Nagato'' likely rest with the wreck of the battleship, which lies capsized in the lagoon of Bikini Atoll following Operation Crossroads. Various smaller artifacts, such as shell casings and training models, are held in collections in Japan and the United States.

Category:Naval guns of Japan Category:320 mm artillery Category:World War II naval weapons