Among naval historians, the USNavy 5"/38 caliber cannon is considered the best intermediate-caliber, dual purpose naval gun of World War II. These three models represent the 5"/38 cal. Mk.30 Mod.60 single-gun mount fit to several classes of warships and Coast Guard cutters.
These "Lightweight" versions were known as "Single Knuckle" mounts during World War II, so named because of the single "bump" on the turret roof, called a "knuckle". Compared to the "early version", the late version, reproduced here, appeared sometime after 1942, had a different arrangement of stiffeners on the front of the gunhouse and additional fasteners on access hatches. Three of these mounts are often seen on "square bridge" Fletchers such as USS Kidd DD-661, now preserved as a museum ship.
Of the five 5-inch/38 Mk.30 single mounts normally fitted to a Fletcher class destroyer, for example, three "Single Knuckle" lightweight mounts were carried, all fit on top of deckhouses in superfiring positions, known there as "Mount 52", "Mount 53" and "Mount 54". The other two mounts were "Double Knuckle" heavyweight Mod.41 mounts, available separately (click here). The two "double knuckle" mounts were fit to the main deck.