Gun Cotton Shell after Impact.
It is apparent that the range of even the most highly perfected torpedo is comparatively short, while their accuracy of travel is low. Besides, their propelling, controlling, and discharging mechanisms are complicated, delicate, and easily deranged, they are very expensive, and not only the explosive chamber but the entire system is destroyed in use. The superiority of gunpowder guns as a means of throwing projectiles to great distances with accuracy is well known, and their capacity for safely and efficiently projecting shells filled with gunpowder has long been demonstrated. It was obvious that as the superior destructive power of dynamite, gun cotton, and other high explosives became known and their commercial manufacture was assured, attempts would be made to employ them as bursting charges for shells. Experiments to demonstrate how this might be done and what effects could be expected were begun more than forty years ago, and have been continued in many different places from time to time ever since; but while it has proved that small charges might be fired with low velocities and pressures in ordinary shell, and large charges in specially constructed shell or in specially prepared forms of charge, with comparative safety so far as the premature explosion of the explosive charge itself is concerned, yet these bodies are so sensitive to the shock resulting from the discharge of the propellant, the heat generated by its combustion, and that arising from friction in the “set-back” of the shell charge and the rotation imparted by the rifling, that they can not be safely fired from modern high-power guns under service conditions, particularly as these explosives all require that the shell shall be fitted with a detonator in order that the charge may be fully exploded. The most promising results with explosives of this class have been obtained with compressed wet gun cotton, which has been packed directly in the shell in rigid blocks completely filling the shell cavity, or cut in cubes and cemented in the cavity with carnauba wax, for shell filled in the former manner, but unfused, were repeatedly fired, in 1887 and 1888, at Newport, R. I., from 24-pounder Dahlgren howitzers and 20-pounder muzzle-loading rifles with service charges of powder, and though they were fired point blank into the masonry escarpment of the old fort on Rose Island, but fifty yards distant from the muzzle, so that the shells were broken up or distorted and the gun cotton in them subjected to a powerful compression, yet not only was there no premature explosion, but none of the shell exploded by impact. About the same time fused shell containing cemented gun cotton were fired in Germany, with an initial velocity of fourteen hundred feet per second, and they passed completely through four inches and three quarters of compound armor, backed with twenty-four inches of oak, and burst inside the bombproof, while in 1897 fused armor-piercing shells containing wet gun cotton were fired from the six-inch quick-firing gun, with a muzzle velocity of nearly nineteen hundred feet per second, which completely perforated three inches of steel and burst behind the plate. Encouraged by these results, this system was adopted by our army officials, but, on trial in larger calibers at Sandy Hook, it gave rise to premature explosions, and the tale of disaster reached its climax on April 29, 1899, when Captain Stuart, of the Ordnance Corps, was superintending the loading of a twelve-inch torpedo shell with wet gun cotton by compressing it into the shell, for an explosion resulted which killed four men instantly and fatally wounded two others, Captain Stuart being one of them.
Sims-Dudley Pneumatic Gun, limbered up.
(Courtesy of the Scientific American.)
Sims-Dudley Pneumatic Gun, in Battery.
(Courtesy of the Scientific American.)
Tyndall’s Bronze Bell-mouthed Gun.
The history of the attempts made to use nitroglycerin, dynamite, explosive gelatin, and explosives of this class as bursting charges for shell fired from service guns is even less satisfactory than that given for gun cotton. It is not surprising, therefore, that inventors should have proposed catapults, slings, rotary wheels, and other means for projecting these powerful agents into the enemy’s midst, but the Mefford air gun, as mounted on the United States steamship Vesuvius, and the Sims-Dudley gun, in which a reduced charge of powder is fired in a chamber exterior to the gun proper, were deemed to possess sufficient merit to warrant their trial in the field. These devices were employed in the recent war with Spain, the pneumatic guns on the Vesuvius being used to throw shells containing three hundred pounds of gun cotton, while the Sims-Dudley guns were used on land to throw small charges of dynamite or explosive gelatin; but, beyond frightening the enemy by the startling character of their reports, these superficial charges produced no serious effect.
