If the primary function of a warship is to give and take hard knocks, it is not stretching the point too far to say that the greatest development in our navy during the past ten years has been in the matter of guns and armor. In 1897 our navy was in a parlous state in respect of its powder; and, although the guns were serviceable, they were sadly behind the long-range, flat-trajectory, pieces of some of the foreign powers. en war was declared, our ships, with few exceptions, were armed with guns of low velocity and energy, and their magazines were filled with the already out-of-date brown powder. At the battle of Santiago our ships were at times absolutely enveloped in dense billows of the smoke of their own guns; and, in spite of the comparatively close ranges at which the running fight was carried on, the number of hits, as determined by a careful subsequent investigation by our naval officers, was only two out of every hundred shots fired. Since the close of the war, our Xaval Bureau of Ordnance has done most creditable work as its share of the general improvement of our navy. It has developed a powder which is giving high velocities, with a relatively small amount of erosion. The bureau early became satisfied that, if erosion was to be kept within reasonable bounds, it was necessary to eliminate the powerful but erosive nitroglycerine, and develop, if possible, an all- nitrocellulose powder. This has been done; and as far as oui' information goes, there is less trouble with erosion in our naval guns than in those of the foreign powers. The only drawback, and it is one of some consequence. is that a powder chamber considerably larger than that necessary for high-nitroglycerine powder is necessary; and there is a consequent increase in the size of the charge, and a call for greater stowage space in the ammunition rooms. The greater velocity and power of the guns with which our latest ships are armed are due, mainly, to the use of smokeless, slow-burning powder. The advantage of this powder lies in the fact that its slow rate of burning enables it to give off fresh volumes of gas during the whole of the time that the projectile is traveling down the bore. The earliest black powders (and in a less degree the brown powders) were ignited almost instantaneously, and their whole mass converted into a volume of gas at high pressure, whose pressure fell rapidly during the travel of the shot, until, at the time the projectile left the muzzle, it amounted to not more than about a ton and a half to the square inch. In the new guns, the continual formation of gas during the travel of the projectile serves to prevent this rapid fall of pressure so effectually, that, if the projectile is started under a pressure of say 18 tons to the square inch, at the instant of leaving the muzzle it is still under a pressure of as high as 6 to 8 tons to the square inch. The result is seen in the fact that, whereas the velocity of the guns used in the Spanish war was only about 2,000 to 2,100 feet per second, the velocity in our present guns is from 2,700 to 2,800 feet per second. This increased velocity has a double advantage; for since t.he energy increases as the sqwarr of the velocity, there is necessarily a great increase in the striking energy at all ranges; and. secondly, the higher velocity means a lower trajectory or curve of flight, a wider danger space, and far greater likelihood of hitting the mark. The accompanying table embodies the latest types of guns, with which the majority of the ships of the Pacific fleet are armed; and a comparison of these with the corresponding pieces mounted during the war shows what a great advance has been made. That the remarkable increase in the fighting power of the ships of the Pacific fleet is due to the improved guns and powder, is well shown in the DEVELOPMENT OF 6-INCH GUN, 1883 TO 1901. Weight of gun, 12.7 tons. I.en:,rth, 2, feet. Weight of poivder charge, 59 pounds. Weight of projectile, 165 p°unds. II lizzie veloeIt)-, 2.700 feet per second. muzzle energy, 8,349 foot-tons. Perforation Krupp armor at 3,0011 yardK, f>> inches. SEVEN-INCH RAPID-FIRE GUN MOUNTED ON THE SIX BATTLESHIPS OF THE “ CONNECTICUT” TYPE. Weight of gun, 5:3 tons. Length, 46 feet. 'V eight of powder charge, 335 pounds, Muzzle velocity, 2,700 feet per second. Muzzle energy, -14.02.5 foot-tons. arnior at 3,000 yard*, W.a inches. THE NEW NAVY 12-INCH GUN ON TRANSFER CRANE AT PROVING GROUND, accompanying tabular comparison of the total energy of fire in five minutes of the battleship “Oregon” of Sampson's fleet at Santiago and the battleship “Rhode Island” of the Pacific fleet. The total energy of all guns firing at their maximum rate of speed, with carefully aimed shots, was for the “Oregon” 819,456 foot- tons; whereas the total energy of all guns during the same time on the “Rhode Island” would be 3,927,172. The increase in efficiency of the modern gun is largely due, moreover, to the greatly accelerated rate of fire; and this has been rendered possible by improvements in the mounting of the gun and in the breech mechanism and loading arrangements. One of the most important improvements conducing to rapid fire is the means adopted for enabling the gunner to hold the gun steadily upon the target. In early guns the sights were mounted upon the gun itself, and moved with the gun at every recoil. Now, the sights are mounted upon a sleeve which carries the trunnions, and in this sleeve the gun recoils. The man who traverses and elevates the gun stands on a platform, which is supported from this same sleeve; so that the gunner and his sights, which are of the telescopic kind, are not disturbed by the discharge of the gun, and he is enabled to keep the cross wires in the eye-piece of the telescopic sight upon the target with great accuracy. Other important improvements are found in the methods of bringing the ammunition up from the hold and loading and firing the guns. The 7- inch guns and all calibers below open the breech with a horizontal lever, one single sweep of which unlocks the threads of the breech plug, withdraws the plug, and swings it clear of the breech. The 8-inch rifle and all calibers above this open the breech with a crank, the plug being too heavy for manipulation by the swinging lever. Undoubtedly the most interesting gun carried in Admiral Evans's fleet is the new 45-caliber piece, which weighs 53 tons and is 46 feet in length. It flres a projectile weighing 870 pounds with a charge of smokeless powder weighing 335 pounds. The projectile leaves the muzzle with a velocity of 2,700 feet per second, and a corresponding muzzle energy of 44,025 foot-tons; or sufficient to lift the “Lusi- tania” bodily out of the water. A problem in connection with the designing of big guns which calls for very careful planning and workmanship is the control of the recoil. Newton's well- known law that action and reaction are equal and opposite comes into play when a shell is fired. At the instant that a 12-inh projectile is driven from the muzzle of the gun with an energy of over 44,000 foot-tons, the gun itself is driven in the opposite direction, backwardly, with exactly the same energy; and (Continued on page 424.) Weight of projectile, 870 pounds. Perforation Krupp
This article was originally published with the title "Guns and Armor"