The 4.5 inch Mark 8 is a British naval gun system which currently equips the Royal Navy's destroyers and frigates, and some British destroyers and frigates sold to other countries. Guns with a 4.5 inch calibre have been the standard medium-calibre gun of the Royal Navy for use against surface, aircraft and shore targets since 1938.

The 12"/50 caliber gun Mark 8 was a US naval gun mounted on the Alaska -class cruiser. The gun, like the "large cruiser" that mounted it, was intended to fill the gap between US "heavy cruisers" (6-8") and US battleships (14-16").

The latest 4.5" (11.4 cm) mounting, the "Electric Gun" Mark 8 Mod 1, is a boxier-looking mounting that is designed to reduce the radar cross section. RO Defence, a division of British Aerospace Systems (BAE), was awarded the contract in 1998 for the full development, production and support of this new weapon system.

Designed to fire the new "super-heavy" AP projectiles, their side belt armor penetration at 20,000 to 30,000 yards (18,290 to 27,430 m) was almost identical to and the deck plate penetration better than the larger 14"/50 (35.6 cm) guns used on U.S. pre-treaty battleships.

英国MK8型114mm舰炮（British mk8 114mm navel gun）是一种结构紧凑、自动化程度高的 中口径舰炮 武器。 英国MK8型114mm舰炮60年代中期，英国海军提出了应发展一种结构紧凑、自动化程度高的 中口径舰炮 武器，经过论证，英国维克斯军械部巴罗工程机造厂提出了在早期MK6型114毫米舰炮的基础上，借鉴105毫米自行火炮的一些技术，设计研制新型MK8型114毫米舰炮的方案 随后开始了研制工作，1970年首座MK8型114毫米舰炮研制成功并投入使用。 由于该炮体 …

The 4.5 inch Mark 8 is a British naval gun system which currently equips the Royal Navy's destroyers and frigates, and some British destroyers and frigates sold to other countries. The 4.5 inch gun has been the standard medium-gun calibre of the Royal Navy for use against surface, aircraft and shore targets since 1938.

Main characteristics of the Cockerill 90 mm Mk8 gun can be summarised as follows: (1) calibre length of 48.5. (2) maximum pressure of 310 MPa. (3) very efficient one-stage muzzle brake. (4) very rugged recoil mechanism with nitrogen counter recoil system. (5) bore evacuator for toxic gas evacuation. (6) progressive rifling from 6 to 9°.

Designed to fire the new "super-heavy" AP projectiles, their side belt armor penetration at 20,000 to 30,000 yards (18,290 to 27,430 m) was almost identical to and the deck plate penetration better than the larger 14"/50 (35.6 cm) guns used on U.S. pre-treaty battleships.

Integrated on to the UK Navy’s Type 23 frigates and Type 45 destroyers, the modern, semi-automatic Mk8 weapon variant can be used to rapidly fire high-explosive rounds against land and sea targets with exact accuracy.

The blunt-nose Mk8 Mod 0 measured 116″ long and 14.5″ in diameter 2.1. With the detonation of shot Baker of operation Crossroads, an underwater detonation weapon began to be considered. 1.1. May 15th 1947, Z Division was assigned to study the possibility of creating a gun-type penetrating bomb. 1.1