No. 30, is that you?
At the turn of the 20th Century, the U.S. Army fielded an impressive array of “disappearing” guns along the American seacoast and few remain. In all, the Army would order some 75 “super heavy” 12-inch disappearing guns, 128 slightly smaller 10-inch guns on similar mounts, 64 8-inch disappearing guns, and the most common type: 152 assorted 6-inch models.
Of the Army’s mixed bag of 419 disappearing guns in various sizes, just four survive in the U.S. today still mounted on disappearing carriages. Two 10-inch guns are currently located at Battery Worth at Fort Casey on Whidbey Island, Washington, and a pair of remaining 6-inch “sister” guns are installed at two locations 2,200 miles apart– one at Battery Chamberlin on the Presidio in San Francisco and the other at Battery Cooper on Fort Pickens near Pensacola, Florida.
I recently visited with the latter and delved into its strange history.

I present to you, a 6-inch rapid-fire rifled gun, Model of 1905, Serial No. 30, on Disappearing Carriage, Model of 1903, located at Battery Cooper near Fort Pickens on Santa Rosa Island in West Florida, just a few miles off Pensacola Beach. Once common, it is one of just two still in existence in the country in its original format.
More in my column at Guns.com.
Pretty cool. and congrats on the move.