A NEW STEEL GUN.

Globe, Volume XXI, Issue 1682, 11 July 1879, Page 4

A NEW STEEL GUN.

The British War Office has been invited by Herr Krupp to send representatives to be present at the trials of a new steel gun of extraordinary sire, to take place at Happen, in Westphalia. The invitation has been accepted by the War Office, which will be represented by two officers deputed for that purpose. The gun to be experimented with on this occasion is the largest specimen of steel ordnance yet made. It weighs 72 tons, with a calibre of 40 centimetres, or 155 inches. The length of the gun is 32ft. Sin., and that of the bore 28ft. 6in. The English 80 ton gun has a calibre of 16 inches, a total length of 27ft., and a bore of 24ft. long. The superior length of bore in the Krupp gun is thus apparent, being 21 $ calibres, as against 18 calibres in the English gun. The material of which the Krupp gun is composed is steel throughout. The core of the gun consists of a tube running its entire length, as in the Woolwich gun, but open nt the rear, the loading being at the breech instead of the muzzle. The tube of this large being of such great length it has been made in two portions, the joint being secured in a peculiar manner. We may observe that a sectional drawing of a Krupp gun is not to bo obtained; that the exact mode of building up is not discoverable, except by cutting the gun to pieces. Over the tube are four “jackets,” or cylinders, of various lengths, supplemented by a ring over the breech portion. The cylinders are much less massive than in the Eraser gun, and approximate more to the pattern of the Armstrong ordnance. The gun is chambered —that is to say, the powder chamber has a greater diameter than the bore. The form given to the powder prisms, and the adjustment of the cartridge in the bore, allow altogether an amount of space which gives 40 per cent of air to the powder actually composing the charge. The gun is rifled on the polygroove system, with a uniform twist, and the shot is rotated by means of a copper ring let into its circumference near the base. This rirg, by filling the grooves of the rifling, also acts as a gas check, and seals the bore from the moment it is rammed into its place, without waiting for any “ setting up” by the pressure of tbo powder gas on igniting the charge. The closing of the breech is effected by means of a sliding wedge, which passes across the bore, and is there fixed. The construction of this wedge is highly ingenious and simple, one feature being that of rendering it impossible to fire the gun until the breech is effectually closed. The wedge is rounded at the back into the form of the letter D, so as to prevent the splitting of the gun by sharp angles. This modification of the wedge has made the Krupp guns much more secure than they were some years ago, when the wedge was made square at the rear. The charge for this monster gun is to be 285 pounds of prismatic powder, the projectile being a chilled iron shell of 1660 pounds, with a bursting charge of 22 pounds of powder. It is estimated that the velocity of the projectile as it leaves the muzzle of the gun will be 500 metres, or 1610 feet per second, corresponding to an energy of very nearly 31,000 foot tons. Calculations have been made for certain distances—namely, at 547 yards a velocity of 1565 feet, at 1094 yards a velocity of 1502 feet, at 1611 yards a velocity of 1443 feet, at 2187 yards a velocity of 1391 feet, and at 2734 yards a velocity of 1345 feet per second. This last rargo, it will be seen, is equal to 2500 metres, the other distances given being respectively 500 metres, 1000, 1500, and 2000. The Meppen shooting ground is admirably adapted for the trial of this great gun, there being an available range of 17,000 metres, or nearly eleven miles, with a breadth of 4000 metres. It is not likely that the_ gun will be fired at any great angle of elevation, or even this noble range would be insufficient. It is estimated, rather ns a matter of curiosity than otherwise, that if the gun were fired with its axis raised to an angle of 43 deg. with the horizon, it would send a projectile to a distance of fifteen miles. Great accuracy is also claimed for this weapon, as for all the Krupp breech loading guns. At the forthcoming trials targets will be placed at such a distance that the gun will have to be directed by other means than the visibility of tbe object to be hit, As may bo supposed, the cost of this great steel gun will considerably exceed that of the Eraser gun of 80 tons. The largest steel guns previously made are Krupp’s two 56 ton breech loaders, one of which is at Constantinople and the other Gronstadt.