13-inch/35-caliber gun

13"/35 caliber Mark 1 and Mark 2
Forward 13-inch gun turret of USS Indiana (BB-1), c. 1898.
Type	Naval gun
Place of origin	United States
Service history
In service	1895
Used by	United States Navy
Wars	Spanish–American War Philippine–American War Boxer Rebellion World War I Siberian Intervention
Production history
Designer	Bureau of Ordnance
Manufacturer	US Naval Gun Factory
Unit cost	$53,000[1]
No. built	Mark 1: 12 (Nos. 1–12) Mark 2: 22 (Nos. 13–34)
Variants	Mark 1 and Mark 2
Specifications
Mass	136,000 lb (62,000 kg) (without breech) 137,900 lb (62,600 kg) (with breech)
Barrel length	455 in (11,600 mm) bore (35 calibers)
Shell	1,130 lb (510 kg) armor-piercing
Caliber	13 in (330 mm)
Elevation	-5° to +15°
Traverse	−150° to +150°
Rate of fire	1 round per minute
Muzzle velocity	2,000 ft/s (610 m/s)
Effective firing range	12,000 yd (10,973 m) at 15° elevation

The 13"/35 caliber gun Mark 1 (spoken "thirteen-inch-thirty-five-caliber") was used for the primary batteries on eight of the first nine battleships in the United States Navy, Indiana-class, Kearsarge-class and Illinois-class; USS Iowa (BB-4) used the 12-inch (305 mm)/35 caliber gun.^[2]

The Navy's Policy Board called for a variety of large caliber weapons in 1890, with ranges all the way up to 16-inch (406 mm). A 16-inch caliber gun was beyond US manufacturing capabilities at this time though and the largest gun possible was the 13-inch (330 mm)/35 caliber. The Navy intended to use this gun in short-range action against heavily armored targets and was fitted to the first true battleship in the US Navy, Indiana. This turned out to be the only 13-inch gun developed for the US Navy.^[2]