Scale: HO scale (1/87)

Includes 1 mount (turret), trunnion and barrel.
 
This multi-part model kit represents the 5 inch 54 caliber Mark 42 Mount installed aboard many US Navy and allied warships.  To assemble the model, insert the cannon, barrel first, through the open bottom into the gun slot

Features:
overall dimensions from official US Navy drawings
separate cannon and trunnion to allow the modeler to set the barrel at any realistic elevation from +85 deg. to -15 deg. just like the real mount.
two detailed "frog-eye" local fire control domes (right for antiaircraft, left for surface firing)
properly scaled hatches with hinge details
access plates with hex-head bolt details
 
© Model Monkey LLC.  This 3D-printed item may not be copied or recast.
 
From Wikipedia: "The Mark 42 5"/54 caliber gun (127mm) is a naval gun (naval artillery) mount used by the United States Navy and other countries. It consisted of the Mark 18 gun and Mark 42 gun mount. United States naval gun terminology indicates the gun fires a projectile 5 inches (127.0 mm) in diameter, and the barrel is 54 calibers long (barrel length is 5" × 54 = 270" or 6.9 meters.) In the 1950s a gun with more range and a faster rate of fire than the 5"/38 caliber gun used in World War II was needed. Because of this reason, the gun was created concurrently with the 3"/70 Mark 26 gun for different usages. The 5"/54 Mk 42 is an automatic, dual-purpose (air / surface target) gun mount. It is usually controlled remotely from the Mk 68 Gun Fire Control System, or locally from the mount at the One Man Control (OMC) station.

"Users:
United States
United States Navy
First used on USS Northampton (CLC-1)
Forrestal-class aircraft carrier
Belknap-class cruiser and USS Truxtun (CGN-35)
Charles F. Adams-class destroyer
Farragut class destroyer
Forrest Sherman-class destroyer
Mitscher-class destroyer
Knox-class frigate

Australia
Royal Australian Navy
Perth-class destroyer (modified Charles F. Adams class) 

Egypt
Egyptian Navy
Damiyat class frigate (ex-USN Knox class frigates)

Germany
German Navy
Lütjens-class destroyer (modified Charles F. Adams class)

Greece
Hellenic Navy
Ipiros class frigate (ex-USN Knox class frigates)
Kimon class destroyer (ex-USN Charles F. Adams-class destroyer)

Japan
Japan Maritime Self-Defense Force
Tachikaze-class destroyer
Hatakaze-class destroyer
Haruna-class destroyer
Takatsuki-class destroyer
Shirane-class destroyer

Mexico
Mexican Navy
Ignacio Allende class frigate (ex-USN Knox class frigates)

Spain
Spanish Navy
Baleares-class frigate (modified Knox class)

Taiwan
Republic of China Navy
Chih Yang class frigate (modified ex-USN Knox class)

Thailand
Royal Thai Navy
Phutthayotfa Chulalok-class frigate (ex-USN Knox class frigates)

Turkey
Turkish Navy
Muavenet class frigate (ex-USN Knox class frigates)"