All good sportsmen know what is a cartridge, whether for gun or rifle; they know too that the nice brightly-polished little disc on the end of it contains the percussion cap by means of which the shot or bullet, as the case may be, is fired. Beyond this they do not worry. They load their gun or rifle; if the former, they are naturally pleased supposing forthwith they wing their bird, a "right and left" raises themselves in their own estimation no end of a great deal; if the latter, and they succeed in laying low the quadruped object of their strenuous quest, a haunch of venison, maybe, is their reward, their trophy a particularly fine head, a "Royal" displaying no fewer than a dozen "points." In either event, the little cartridge once having served its purpose is in due course extracted from the breech and flung unceremoniously away to be trodden with scant courtesy underfoot, carelessly consigned to oblivion. So too in war, or at any rate during the Distorted and not infrequently cracked or split, of what further use could they be? An occasional enthusiast would pick one up. At home, at least, it would be regarded as an authentic relic of the battle-field. Besides, any one with a spark of inventive genius could see quite a number of uses to which a cartridge case could be put; articles of domestic ornament and convenience could be evolved—anything, for instance, from a flower-vase to a lady's powder-pot. Those were early days however, and few there were, whether at home or at the front, who realised the extent to which "the war could be protracted" or "if its fortunes should be varied or adverse" were able to grasp the import of the warning that "exertions and sacrifices beyond any which had been demanded would be required from the whole nation and empire" (Lord Kitchener, House of Lords, August 25th, 1914). When, however, it became increasingly apparent that "the operations not only of our Cartridge cases varied, of course, in depth and diameter according to the type of shell, whether shrapnel or H.E., to which they were destined to be fitted, and to the type of gun, whether field gun or howitzer, within the breech of which they were to be fired. Thus the field gun with its long range and well-nigh flat trajectory (i.e. the curve described by the shell on its flight) required a heavier propellant charge with a high velocity than did the howitzer or high-angle gun, which throws a shell at a shorter range and with a high trajectory. The "marks" of cartridge cases treated in Crewe Works were those appertaining to the 18-pounder gun and the 4·5 howitzer, and it so happened that just at the time of the formation of the Coalition Government in May, 1915, when, Actually during the winter 1914-1915 the number of rounds per 18-pounder gun fell to less than five! Shrapnel (which it is interesting to remember was first used in the Peninsular War of 1808-14, and of which the older form of shell was filled merely with gunpowder as To pick a cartridge case up and look at it, one would say that there was literally nothing in it; yet on second thoughts it is surprising what a number of features are embodied in its hollow and simple form. It is solid drawn, of a substance the colour of brass called yellow metal, which is composed of 60 per cent. electrolytic copper and 40 per cent. zinc, and which costs actually £25 per ton less than brass. The base is integral and thick, with an external rim, behind which a clip automatically engages as the breech of the gun closes, for the purpose of extracting the case after the gun is fired. Into a hole in the centre of the base is screwed the percussion cap, which acts virtually in the capacity of a "sparking plug" to the gun, differing only from the familiar petrol-engine sparking plug, in that the spark which fires the propellant charge inside the cartridge case is created, not by the break of an electric current, but by the sudden shock or percussion of a striker against a cap in which is contained a thin, albeit highly explosive layer of fulminic acid and gunpowder. The walls of the case are thin, thereby expanding against the walls of the breech of the gun, and preventing any escape of the propellent gases; and for the purpose of easy extraction Upon receiving a returned, or fired, cartridge case in the Works, the primer is first of all removed, then the case is boiled in a solution of caustic soda for the purpose of removing grease and dirt. What is known as a "hardness" test follows next in order of sequence, this to determine whether the metal of the case is still good for further service, and is performed by a little instrument known as a sclerometer (derived, as our classical contemporaries will tell us, from the Greek word (s??????, hard), consisting of a tube marked with a graduated scale down which a tiny metal ball is dropped on to the side of the case; the ball should rebound to a point on the scale approximating a height of two inches, anything below this proving that the metal has become too soft for further use, when the case is accordingly scrapped. The cases which show a requisite degree of hardness are then annealed or suitably tempered round the mouth, this process ensuring a subsequent loose fit round the end of the shell. Rolling the mouth to internal limit gauges is effected by means of a specially improvised apparatus rigged up on the bed of an engine lathe, consisting of two fixed housings inside which runs a belt-driven sleeve bored to the correct taper of the cartridge case, and in which the latter is carried. A duplex ball-bearing roller running on a central spindle secured in a It should be borne in mind that the entire process of repairing these cartridge cases (with the exception of brazing by coppersmiths with an acetylene flame any cracks or splits which already existed or became apparent in the repairing operations) was carried out by female labour working three eight-hour shifts, and one of the neatest of the diverse mechanical requisites which the girls were called upon to operate and which was the immediate outcome of managerial forethought and ingenuity was an adaptation of an hydraulic press for the purpose of correctly reforming the taper walls of the cartridge case to the true form of the gun chamber or breech. A cast-iron block with recesses cored in (in which are fitted a rocking lever pivoted in the centre, and two hardened cast-steel dies, one on either side) repose on rolling bearings arranged on the bed of the press. At each end of the rocking lever is attached an adjustable ejector ram acting centrally inside the cast-steel dies, which latter are bored taper to the required shape of the cartridge case. Upon inserting a cartridge case in each die, the cast-iron block is pushed transversely by hand across the bed of the press, bringing one of the cases central with the ram, which, when applied, forces the case home into the die, thereby The cast-steel dies naturally become affected by constant use, more especially on the protruding shoulder against which the thickest part of the case (viz. where the walls rounded into the base) is pressed, this necessitating the shoulder being re-radiused perhaps every fortnight, and a slight readjustment of the die in the block. To allow for expansion of the walls of the case when being ejected after compression, the dies are turned slightly smaller (say 3/1000 parts of an inch) than the required finished size. After being pressed, the primer holes of the cartridge case (known as the plain and platform holes respectively) are rectified by a double-reamer, the case revolving in a sleeve bored to correct taper of the outside diameter of the case, this assuring concentricity of the two holes, and ensuring that the primer face and percussion cap lie flush with the base of the case. A forming tool, having a non-cutting face which acts as a depth guide against the base, corrects the outer rim and shoulder. A hand-tapping machine clamped centrally to A similar apparatus fitted with a sliding screw-driver removes the primers; the cartridge case in either event being securely held and easily fixed or released in a central clamp. Finally, after being immersed for a couple of minutes in a solution of sulphuric acid, the cartridge case is polished with sand and sawdust on a wooden pad covered with tapestry and revolving in a lathe at 300 or 400 revolutions per minute. The result of garnering in and renovating these cartridge cases instead of turning them adrift in the battle area, reckoned in figures of pounds, shillings, and pence, was undoubtedly very considerable; for apart altogether from the saving effected in the cost of labour when repairing old cartridge cases as compared with the manufacture of new ones, the weight of metal alone contained in a couple of million cases may be taken at approximately 1500 tons; and with yellow metal costing £82 12s. 0d. per ton, the saving in metal alone amounts to no less than £123,900. |