8-inch/30-caliber gun

The 8"/30 caliber gun (spoken "eight-inch-thirty-caliber") formed the main batteries of the United States Navy's "New Navy". They were a US naval gun that first entered service in 1886, and were designed for use with the first three protected cruisers, USS Atlanta (1884), USS Boston (1884) and USS Chicago (1885).

Mark 1
Mark 1, Nos. 1–4, Mod 0, consisted of a tube, jacket, 19 hoops and an elevating band with integral trunnions. The Mod 1 had no trunnions and were not hooped to the muzzle. They weighed 29100 lb, without the breech, with a barrel length of 240 in bore (30 calibers).

Mark 2
The Mark 2 Mod 1, Nos. 5–8, was similar, but had the hoops differently arranged, did not have integral trunnions and had its rear sights controlled by worm and miter gears. Mark 2 gun No. 7, from Chicago, was later modified into a pneumatic gun and mounted in USS Vesuvius (1888) to fire a 10 in aerial torpedo.

On display
Two guns from the cruiser USS Boston (1884) are currently (2010) on display at Hamlin Park in Shoreline, Washington. A plaque at the site states that one of these guns fired the first shot at the Battle of Manila Bay on 1 May 1898. Another plaque states 8-inch 30 Caliber Gun U.S.S. Boston Captain Frank Wildes, U.S. Navy Commanding This gun is credited at           THE BATTLE OF MANILA BAY with dismounting three guns in the Spanish fort at Cavite May 1, 1898 The two guns from Boston are marked "U. S. NAVY 8in MARK II 1899 CONVERTED".