In the decades immediately following the Civil War, naval weaponry underwent a massive change as muzzle-loading smoothbores firing solid shot were replaced by breech-loading rifled weapons firing projectiles that could be fused to burst in the air, explode on contact, or penetrate a structure before detonation.
All this change was not occurring without difficulties. Steel metallurgy for guns and shells needed to be perfected. Explosives had to be made more stable and fuses more reliable. Propelling charges produced ear-shattering noise, were incredibly smoky, and interfered with observation of fall of shot. Interested members of the military and naval services, industry, and the general public sought answers to these problems.
Ohio schoolteacher D. M. Medford thought that a gun using compressed air to fire a projectile would solve a number of the problems. There would be no noise or smoke, and, because the shot was propelled by air, both the gun and the projectile could be of weaker construction and the weight saved invested in the exploding charge. On his own, Medford built several small-caliber versions of such a weapon and took out a patent on his creation.
A prototype was demonstrated to the Army at Fort Hamilton, New York, in 1883. The weapon inspired artillery Captain Edmund Zalinski to build and demonstrate several improved prototypes that impressed both Army and Navy leaders and resulted in government contracts to satisfy the desires of both services. Thus was born what is remembered, improperly, as the “dynamite gun.”
The Navy version of the pneumatic weapon consisted of a cast-iron 55-foot-long barrel with a smooth 15-inch bore. A 1,000–pounds-per-square-inch air blast was used to fire projectiles, and compressors recharged the guns’ air-storage tanks. Muzzle velocity was on the order of 800 feet per second. The weapon’s seven-foot shell consisted of a steel or brass casing containing the warhead, a shaft, and spiral vanes aft to cause a spin and provide stability in flight. It was fitted with an electrical point detonating fuse.
The warhead charge could be varied up to a maximum of 550 pounds and consisted of a “desensitized blasting gelatin” composed of nitrocellulose and nitroglycerine. The latter, which is the active ingredient in dynamite, was the source for the gun’s misnomer, although it was much more stable than its shoreside cousin.
To carry its dynamite guns, the Navy, on 3 August 1886, ordered what became the Vesuvius from the Pneumatic Dynamite Gun Company, which in turn hired the William Cramp and Sons Shipyard in Philadelphia to build the vessel. Her keel was laid in September 1887, and she was launched on 28 April 1888. The ship finally was commissioned on 2 June 1890 with Lieutenant Seaton Schroeder commanding her crew of 70.
The Vesuvius seems to have been designed solely with her main battery in mind. She was about 246 feet long, with a beam of just 26.5 feet, and displaced 945 tons. Because of the 10-to-1 length-to-beam ratio, the ship proved to be a roller. And because of her narrowness, insufficient space was available to permit her twin screws to operate without interfering with one another. Furthermore, space was lacking for a steering engine of adequate power, with the result that her turning circle was greater than the battleships then in service. (A second unit, authorized in 1889, never was laid down.)
As for her main weapons, she mounted three of the dynamite guns in parallel forward. They were in mountings fixed at an 18-degree angle penetrating through two decks to the magazine/loading room, their muzzles like stiff fingers above the forecastle. Shipboard ammunition allowance was set at ten rounds per gun, carried in ready-service magazines that could load directly into the tube. The entire installation occupied the forward third of the ship.
To aim the guns, the ship had to be maneuvered into position. Firing a projectile with the largest warhead charge, maximum range of the weapons was only 2,000 yards; reducing the warhead weight to just 200 pounds could double the distance. Range also could be varied by changing the pressure of the propelling air or duration of the air blast. Firing was accomplished by turning levers connected to cables running from the small pilothouse to controlling valves on the air reservoir. In an 1889 test, 15 shells were fired in just under 17 minutes. Brief, throaty coughs were the only immediate evidence of the gun going off.
The Vesuvius joined the North Atlantic Squadron upon commissioning, and for the next five years was occupied largely with port visits, participating in festivals, and occasional exercises. From 15 April 1895 until 12 January 1897, the ship received major repairs at the Philadelphia Navy Yard before returning to operations along the East Coast until May 1898, when she joined the fleet assembling at Key West, Florida, for combat operations against Spain in Cuban waters.
Beginning in mid-June, the Vesuvius conducted eight shore-bombardment missions against Santiago. On each occasion, she would close the coast under cover of darkness, loose a few rounds from the dynamite guns, and then scamper back out to sea. Bracketing fire was employed, with one gun adjusted to fire on target, the second a little short, and the third a little over, hopefully landing at least a part of the bombardment on target. No record has been found of material damage inflicted, but the bombardments had considerable psychological effect, coming as they did without warning and announced by explosions of considerable power, each leaving a crater “like the cellar of a country house.” When not engaged in these missions, the ship was used as a dispatch vessel on runs between Cuba and Key West, Florida.
At war’s end later that summer, the Vesuvius sailed north and called at Charleston, South Carolina; New York; and Newport, Rhode Island, before ending her voyage at Boston, where she was placed in ordinary. In 1904 the Boston Navy Yard converted her to a trials vessel for the Torpedo Station at Newport. The dynamite guns and their associated equipment were removed, and four torpedo tubes—three 18-inch and one 21-inch—installed.
At Newport, she conducted experiments until decommissioned again on 27 November 1907 for repairs. Commissioned yet again on 14 February 1911, she returned to duty at Newport, on occasion serving as station ship. Repaired after an inert torpedo rammed a hole in her, the Vesuvius remained active until 1921. The next year she was decommissioned, appraised for sale, and purchased for scrapping.
The dynamite gun failed because its limitations far outweighed its advantages. Fortunately, it was seen as an experiment and no further expenditure was made on this unproven idea. It is a lesson worth remembering.