This 6-inch Rapid Fire Armstrong Rifle was purchased from England in 1898, because the United States did not yet have the capability to produce a small, rapid fire weapon for the defense of its principal harbors. The advent of the Spanish-American War brought about the need for such weapons in this area due to the close proximity of Cuba to Florida.
Funding for these guns was included in the appropriation for the "National Defense Act" of March 9, 1898. The installation was completed as a part of the armament of Fort Dade, on Egmont Key, on December 10, 1898. (Approximately 2 miles southwest of where you are now.) The guns were placed under the command of an artillery detachment sent from St. Francis Barracks in St. Augustine. Only a limited number of these particular weapons were purchased by our government and these two rifles, are believed to be the only remaining models still in existence.
These weapons, weighing 17 tons each, were breech-loaded, utilizing shell cases that were refillable with 13 1/4 pounds of powder. The projectiles weighed 100 pounds and had a maximum range of 10,000 yards (5.68 miles) reaching such a target in 28.12 seconds.
Caliber of Gun: 6" (152 mm)
Length of Bore: 20 feet
Rifling - Number of Grooves: 24
Muzzle Velocity: 2,154 feet per second
Wrought Iron Plate: 10" at 2,000 meters
Firing: Electrical - (Batteries) or Mechanical
Fort Dade was deactivated in 1921 and these guns, which were intended to defend the southwest pass into Tampa Bay, were left to the mercy of the elements.
On April 12, 1980, Pinellas County recovered these cannons from Egmont Key. After two years of refurbishing, they were installed here on March 19, 1982.