Warships and their story

by R. A. Fletcher

INTERIOR OF A BARBETTE, SHOWING 12-INCH GUN, H.M.S. “CÆSAR.”

Photograph by Gale & Polden, Aldershot.

Time brings strange revenges. At one period the French were the leading nation in the world in the matter of naval construction, and the English were content to copy the French designs. But in later years England has taken the lead, and not only France but the other maritime powers of the world have been glad to sit at the feet of Britannia and accept the instruction she has been able to impart. Some of these pupils, if pupils they be, have proved themselves exceedingly apt copyists and improvers, and are inclined to think that their own creations are every whit as good as anything this country can produce.

The superiority of the British methods alluded to by the famous French gun-maker were not lost upon French naval architects, and in some of the latest French battleships these methods have been copied. The rapidity of the fire of the big guns would thus, it was expected, be raised to two rounds a minute. Electricity, however, has been retained, as the French consider it to be better than hydraulic machinery for the loading of the guns and movement of the turrets, and more easy of repair in case of damage under hostile fire.

The size and weight of the pieces forming the breech mechanism of the modern guns of large calibre made compulsory the adoption of mechanical means for loading them. There was also the further advantage that machinery was less likely to make mistakes, or to suffer from the accidents which are bound to disable some of the crew in a naval engagement. In some of the earlier battleships, in which the large muzzle-loading guns were fitted, the charge was raised to the gun-mouth by machinery worked by hand-power, and after it had been rammed home by the crew the projectile was inserted and rammed home also, obviously an impossible arrangement when it was sought to introduce rifled explosive shells. When guns were made too large to be withdrawn into the turrets to be loaded, they were loaded by being depressed so that their muzzles just entered a specially cut orifice in the deck in front of the turret, and the loading crew were able to do their work in safety. The drawback to this system was that the gun had to be brought back to the same position for loading, then revolved with its turret once more to the direction in which it was to be discharged, and aimed afresh before its missile could be sent at its mark. The chief advantage of this system was that the gun required a smaller, and consequently less weighty, turret for the protection of its crew. The introduction of the breech-loader enabled the guns to be loaded in greater security, with greater speed, and without interfering with the aim or training of the gun, thereby rendering a more rapid fire possible. Ammunition hoists brought the charge and projectiles right into the turret or barbette more expeditiously and with greater precision than the best-drilled crew, and the men had simply to load the weapon and fire it. The human element came in here, however, in all its uncertainty, and, in spite of the greatest possible care, accidents occurred. A charge or a shell was dropped or caused to explode in some way, and disastrous were the results. Again the necessity for the mechanical appliances caused them to be forthcoming. The projectiles and charges for fighting purposes, which naval strategists declared to be necessary in ever-increasing size and weight, and the greater rapidity of fire which was demanded, made it impossible for dependence on hand power to be retained. After various experiments, both steam power and electricity being tried, hydraulic power was introduced, and has proved more suitable for the purpose than any other method. Now the heaviest projectiles, weighing half a ton or more, are lifted with the greatest ease and exactness to the required position by hydraulic power, are pushed into their places by the same power which does a like office for the charge of explosive, closes and fixes the breech, and does not desist until its task is finished. In the latest appliances, the machinery is made interlocking, so that, at least in the system introduced lately by Messrs. Vickers, no one operation connected with loading the gun can be performed until its immediate predecessor has been accomplished. With a view to securing more rapid and accurate fire this firm has introduced a modification of the breech mechanism by what is known as a “pure couple.” The hydraulic breech mechanisms just alluded to are used for the largest guns, such as the 12-inch weapons, and have also been installed on the Japanese ships for the 10-inch guns. The guns can be loaded at the required angle of elevation, the advantage claimed for this being that the sight can be kept on the target all the time.

The pressure to which guns are subjected when the charge explodes is enormous. One reason why they do not burst is that they have not time to do so. How rapidly the pressure arises against the sides of the gun and then against the projectile to expel it from the bore, was shown by experiments which Sir Andrew Noble conducted some time ago with a 6-inch gun of 100 calibres length of bore. Practically instantaneously with the ignition of the charge, that is to say in about the four-hundredth part of a second, a maximum pressure against the interior of the gun of 22 tons per square inch was reached, but this declined to about 13 tons per square inch in about the twelve-hundredth part of a second more. But by that time the projectile had left the gun, and was rushing, faster than the eye could follow it, towards its mark.

The English 12-inch (Mark IX.) gun consists of a steel tube, wound practically from end to end with layer after layer of steel ribbon or wire of very great tensile strength. This tube is known as the A tube, and may be called the hollow heart of the gun. As much as a hundred miles of wire will be used for one of these guns, and, of course, for the newest guns, the 13-inch weapons, such as have been placed in the latest super-Dreadnoughts, or the 15-inch guns which it is said will be placed in the Dreadnoughts of 1912 or the year after, the amount is a great deal more. The greatest thickness of layers is placed round the breech of the gun, where the strain is most severe, and each succeeding layer is wound on with increasing tension, though to the ordinary observer the first layer seems to fit so tightly that nothing could be tighter; but the gun makers know better. All along the chase or fore part of the tube another tube, called the B tube, is shrunk on to ensure that it shall be the tightest fit possible. Then, over a portion of the B tube, and also over a portion of the winding, that part of the gun known as the breech jacket is shrunk. Apparently everything is so strongly fixed together that nothing can cause the parts to separate, but the gun makers know this is not so, for into this jacket a bush is screwed to prevent any movement of the A tube, so far as the jacket is concerned. The A tube itself contains a thin steel inner tube inserted from the breech and fixed in position by the breech bush. It is this inmost tube which has to bear the wear and tear caused by the firing, and suffers from erosion, due to the gases generated by the explosion of the charges, and has to be replaced by a new tube when it is no longer fit for service.

THE 12-INCH GUNS OF H.M.S. “NEPTUNE.”