Mark 42 5"/54 Naval Gun (No AA Fire-Control)

 military, research, United States Navy, gun emplacement

Easily identifiable by its lack of its right-hand side "frog-eye" Anti-Aircraft fire control dome, this variant of the Mark 42 is a operational representative of all still-operational Mark 42 mounts in service with aboard several ships in the Japan Maritime Self Defense Force and several remaining Knox Class Frigates in international service.

Developed as a replacement for the venerable 5"/38cal gun mount of WWII fame and 1934 vintage, the Mark 42 became the standard USA 5" single gun mount of the post World War II-era. The gun system was placed aboard the ships of the US Navy's Forrestal Class Aircraft Carriers, Northampton, Belknap and Truxtun Class Cruisers, Mitscher, Forrest Sherman, Farragut and Charles F. Adams Class Destroyers and Knox Class Frigates. The weapons system also saw heavy use in the Japan Maritime-Self Defense Force, where is was installed and presently is in use on the Destroyers of the Tachikaze, Hatakaze, Haruna, Takatsuki and Shirane Classes.

The Mark 42 system was phased out of service beginning in 1971 as a result of a reputation for jamming during protracted firing due to the complex nature of the loading mechanism during the Vietnam War. Remedied only by slowing the rate of fire, the mounts were eventually obsoleted and replaced in frontline US Navy service by the newer Mark 45 5"/54cal Naval Gun.

www.navweaps.com/Weapons/WNUS_5-54_mk42.htm