THE LATEST DYNAMITE GUN.

Star (Christchurch), Issue 5861, 1 May 1897, Page 1

THE LATEST DYNAMITE GUN.

A TERRIBLE WEAPON* I An American paper gives the following | account of the Sims-Dudley dynamite gun, ! the weapon which has done such deadly ! work in the hands of the Cuban insurgents : — This epochal invention, which seems fraught with greater possibilities for the ' future than any single invention since that of gunpowder itself, is American . from beginning to end. It is known as the Sims-Dudley pneumatic dynamite gun, and was first officially tested in this country before General Miles and the Ordnance Board at Glen Cove on Long Island last spring. After a wholly successful test of the capacity for throwing dynamite, the gun was blown up in firing a dummy shell of oak, which carried a defective type of fuse. This gun was 4-inch calibre and delivered a charge of fourteen pounds of explosive gelatine, the highest explosive known, projecting it the distance of a I mile. This was equivalent to a charge of 280 pounds of black powder. The 85-ton gun, with which the fortifications of the United States a,re chiefly equipped, shoots a shell which carries but abdut sixty-five pounds of black powder, so that the charge thrown by this slender field piece, weighing but one eighty-fifth of the bombarding guns, was equal in explosive force to four times that of the ordinary heavy type of shell. This charge was thrown with a small blank cartridge loaded with smokeless powder, and was shot from a gun so light that it can be carted around in an express waggpn. ' The mechanism which does this marvellous work is simplicity itself. It is made up of three slender steel barrels, laid Bidewise like three fingers and forming a lengthened coil almost exactly like that of a trombone, minus the flare. The middle barrel is a little longer than the other two and carries the dynamite shell. The two outer barrels are air chambers joined at their forward ends, with the rear of the left-hand chamber opening into the middle barrel, just back of the shell. At what would answer for the mouthpiece of a trombone is a breech mechanism in which is inserted the blank cartridge of powder which throws out the shell. The rear of the middle barrel is fitted with a BimUar breech mechanism, for the insertion of the shell. - When the shell and cartridge are in place and the breech is closed, a jerk of the lanyard fires the powder charge, which is delivered into the air chambers, compressing the air which these contain from one, thousand to one thousand five hundred pounds to the. square inch. The force of i the explosion, cushioned by the column of air intervening between the powder car- 1 fridge and the projectile in the central tube, is the propelling force, which expels the latter.. The action is almost simultaneous ; the compressed air making a circuit of . the coil almost instantly and throwing out the shell which lies in its path, bursts from the muzzle with a pop a little louder than that of a good-sized air gun. There is a not a particle of smoke or flame, and with no more announcement than this the dynamite-laden projeotile is sent flying along its trajectory. Practically the same, effect is here obtained as in the famous Zalinski pneumatic dynamite gun, with the difference that the extensive air compressing plant of the latter is in the case of the SimsDudley gun represented by a simple blank cartridge. In other words, the latter does not require a huge plant like unto that employed for running a street railway, and the gun is so light and so thoroughly takes up its own recoil that it may be mounted on an ordinary waggon truck and fired from the waggon, or set up on an ordinary cannon carriage and be rapidly hauled by a single horse. Indeed, in the smaller 2\ inch gun, such as the Cubans have, which shoots a projectile weighing 111b and containing a v 4-pound charge of explosive gelatine, the gun itself weighs but 2501b, and its carriage as much more, so that the two parts can be transported on the back of a pair of mules. The 4-inch gun showed at Glen jOove weighed just a ton, the mount taking up one-third of this. Fifteen ounces of Dupont smokeless powder formed the charge, and the gun had been fired over 160 times up to the day of the accident. The projectiles are somewhat similar to the familiar type used in the Zalinski gun, the body of the shell being a brass cylinder with pointed ends. In its front is a Merriam fuse, and from its rear a tailpiece extends which' carries vanes set at an angle, so as to insure rotation. The entire shell is fiftytwo inches long, and the charge weighs thirty-two pounds. The shells are exploded either by direct impact or by time fuses. The period of explosion is determined by the slow burning powder, and by altering this the time element can be regulated with the greatest accuracy.. For attack upon armour instant detonation is required, but for attack upon a ship more destructive effect is secured by an explosion under the water, arid this ina)| be regulated down to a fraction of a second. The fuse is hardly less ingenious than the gun itself. The lightness of the gun and the slight recoil places* this pneumatic dynamite thrower on a par with field artillery, so thatftt is plain it will supersede the light field pieces now in use. Careful experiments have shown that a much heavier charge may be thrown a much greater distance with entire safety, and an 8-in gun will shortly be constructed, built to throw 1001b of explosive a distance of three and a half miles. The Zalinkski gun has thrown fifty pounds of dynamite three and three-eighths miles, and a 500 pound charge a mile and a half. There seems nothing to prevent the Sims-Dudley gun frbm duplicating these feats, so that we shall very soon have an ordinary fieldpiece, which a pair of horses can drag over good roads at a headlong gallop, that will throw a charge for more than three miles equal in destructive effect bo a ton — 2000 pounds — of black powder. At the present time a 600-pound shell, ;hrown not more than twice the distance, nrins the finest battery gun in the .course )f a hundred shots or so. In other vords, save for long distance firing, where ihe force' of impact required to throw ihe shell would explode dynamite in the fun, it is apparent that the dynamite hrower]will retire the heavy powder guns low in use.