The dynamite guns
Vesuvius was laid down in September 1887 at Philadelphia by William Cramp & Sons Ships and Engine Building Company, subcontracted from the Pneumatic Dynamite Gun Company of New York City. She was launched on 28 April 1888 sponsored by Miss Eleanor Breckinridge and commissioned on 2 June 1890 at the Philadelphia Navy Yard with Lieutenant Seaton Schroeder in command.
Dynamite guns[edit]
Vesuvius carried three 15-inch (38 cm) cast-iron pneumatic guns, invented by D. M. Medford and developed by Edmund Zalinski, a retired officer of the United States Army.[3] They were mounted forward side by side at a fixed elevation of 16 degrees. Gun barrels were 55 feet (17 meters) long with the muzzles extending 15 feet (4.6 meters) through the deck 37 feet (11 meters) abaft the bow. In order to train these weapons, the ship had to be aimed, like a gun, at its target. Compressed air from a 1000 psi (70 atm) reservoir projected the shells from the dynamite guns. Two air compressors were available to recharge the reservoir.[2]
The shells fired from the guns were steel or brass casings 7 feet (2.1 meters) long with the explosive contained in the conical forward part of the casing and spiral vanes on the after part to rotate the projectile. The explosive used in the shells themselves was actually a “desensitized blasting gelatin” composed of nitrocellulose and nitroglycerin. It was less sensitive to shock than regular dynamite, but still sensitive enough that compressed air, rather than powder, had to be utilized as the propellant. Shells containing 550 pounds (250 kg) of explosive had a maximum range of 1 mile (1.6 km), but range could be extended to 4,000 yards (3.7 km) by reducing projectile weight to 200 pounds (91 kg). Maximum muzzle velocity was 800 feet (240 meters) per second. Range could be reduced by releasing less compressed air from the reservoir. Ten shells per gun were carried on board, and 15 shells were fired in 16 minutes 50 seconds during an 1889 test. The shells employed an electrical fuze which could be either set to explode on contact or delayed to explode underwater.