20.3 cm/45 Type 41 naval gun

The  20.3 cm/45 Type 41 naval gun was a Japanese naval artillery and coast defense gun used on cruisers of the Imperial Japanese Navy from the end of the Russo-Japanese War through the end of World War II.

Design and development
The 20.3 cm/45 Type 41 naval gun was an indigenous development of the British-designed Elswick Patterns “S”, “U” and “W” QF 4.7 inch Gun Mk I - IV, which had been previously produced by Ansaldo in Italy to equip Italian-built armored cruisers, and which had been received by the Japanese as part of the equipment supplied with the Italian-built JAPANESE CRUISER Nisshin. The weapon was officially re-designated as Type 41 on 25 December 1908, and re-designated again on 5 October 1917 in centimeters.

The weapon was used on the armored cruisers JAPANESE CRUISER Azuma, JAPANESE CRUISER Asama, JAPANESE CRUISER Iwate, JAPANESE CRUISER Izumo, JAPANESE CRUISER Kasuga, JAPANESE CRUISER Nisshin, JAPANESE CRUISER Tokiwa and JAPANESE CRUISER Yakumo, and the Chikuma-class cruiser, as well as some of the later protected cruisers, including JAPANESE CRUISER Takasago. Many of these ships were disarmed under the conditions of the Washington Naval Treaty or subsequent London Naval Treaty and their guns converted into coastal artillery batteries, including installations at Tokyo Bay, Tarawa and later at Wake Island during World War II.