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Bible Encyclopedias
Bombthrowers
1911 Encyclopedia Britannica
or "When, contrary to all expectation, and therefore to all ideas that had governed war preparations, the World War, instead of reaching its decision in the open field, came to the deadlock of trench warfare, there arose a demand for short-range engines which could throw bombs to a greater distance than was possible by hand, or, alternatively, could throw heavier bombs to the same distance.
Eventually this need was met by the development of trench mortars and trench guns, many types of which were loosely called bombthrowers, but all of which are differentiated from bombthrowers in the sense here meant by the fact that they used an explosive propellant. These are dealt with under Trench Ordnance. But in the first phases of trench warfare such ordnance either did not exist at all or existed only in such small numbers and in so imperfect a form, that for the needs of day-byday trench warfare along the front temporary substitutes were evolved. To these substitutes the name " Bombthrower " is - so far as army usage is concerned - restricted.
They relied for their propulsive effort, like ancient and mediaeval engines, on the energy of springs. In some cases the spring was a system of powerful rubber pieces put in tension when the weapon was cocked and suddenly released by the pulling of a trigger. In one case the source of power was an assemblage of coiled springs. In others, the rubber was replaced by a system of wire which, on being bent out of shape, stored up the power to reassert itself. In another, perhaps the last evolved during the war and certainly one of the most ingenious, centrifugal force was utilized, without previous storage of power.
Under the heading of bombthrowers as above defined should also come the class of pneumatic guns, certain representatives of which figured in the war on both sides, but owing to the general similarity of these to normal (i.e. explosive-propellant) trench ordnance they are treated along with the latter.
In naval usage, on the contrary, the term is applied to explosive-propellant derivatives of trench ordnance which were mounted on trawlers and other craft for the purpose of attacking submarines. The object was to throw for a certain distance very heavy charges of explosive that, equipped with a hydrostatic fuze, would act in the same way as depth charges. These bombthrowers are dealt with under Ordnance: Naval Gunnery. FIG. I.
The first form of catapult to become a regulation weapon in the British army in France was the " Leach," used in 1915-6. This was a strong forked wooden frame (fig. i) about 7 ft. in length from front to rear, the width at the splayed end or fork being about i ft. 10 in. Near the ends of the forked arms or " horns " were attached two sets of powerful rubbers, the rubbers of each set being firmly bound together at the extremities. The inner ends of these sets of rubbers were attached to the pouch or bomb receptacle of the catapult, which, when the rubbers were out of tension (and the pouch therefore in its forward position), was about i ft. 9 in. from the front of the fork. When, in order to fire, the rubbers were pulled back to extreme tension the pouch was less than a foot from the tail end of the frame. This pulling back was effected by a wire attached to the rear of the pocket, which passed round a pulley on the tail to a gear-box on the underside of the frame. This gear-box contained a winding-handle, gear, and a retaining-pawl; when the handle was turned, the wire was drawn into the gear-box (the pawl preventing its unwinding) and the rubbers extended. A bomb was then placed in the pouch, and on the word or signal to fire a trigger release broke the connexion between the pouch and the wire, and the rubbers, reasserting themselves violently, propelled the bomb.
With a heavy type of grenade weighing i 2 lb. the Leach catapult was capable with new rubbers of a range of 200 yd., and like other bombthrowers it possessed the important advantage, as against trench mortars, of invisibility and silence in action. The main disadvantage, the rapid wear of the rubbers, could be overcome by the frequent issue of replacements, the rubbers being regarded as " consumable " stores. There was, however, a limit to the practical usefulness of this cheap and efficient weapon. Its ranging powers were unnecessarily great for grenade work proper and not great enough for the tasks which came to be assigned to the trench mortar. Accordingly, a lighter and more portable weapon of the same t y pe was designed later b y Capt. G. H. Wicks of the British Trench Warfare Department. This was easily portable and manageable by one man, and ranged, with the i 2 lb. bomb, to about loo yards. It was, however, not used in the field, as the line had by that time (1916) been drawn clearly between trench-ordnance projectiles and grenades. The heavy i 2 lb.-2 lb. grenade having ceased to exist, the necessity for a weapon to propel it ceased also.
The catapult of the French army, known as the " Sauterelle," was smaller and more portable, but correspondingly less powerful, than the Leach. It was a magnified crossbow, acting by the reassertion of springs bent in cocking.
The " West " spring gun, used by the British army in 1915 and to some extent in 1916, was a heavier and more powerful weapon. It derived its energy from a group of strong coiled springs; for extreme range, no less than 28 of these springs were brought into action. The general principle of action is shown in fig. 2. The weapon having been well bedded in with sandbags for steadiness, the throwing-arm which carries the bomb-cup is forced back FIG. 2.
wards and downwards, against the resistance of the springs, by means of a long lever inserted in an appropriate position for leverage. When the " trigger bar " on this arm engages with a member called the trigger hook (visible in the drawing under the bomb-cup arm), the gun is cocked. The long lever is removed, a bomb placed in the bomb-cup, and the gun is then fired by pressing on the horizontal lever which actuates the trigger release. This disengages the trigger hook from the trigger bar, and under the force of the springs the throwing-arm, carrying the bomb, flies up. The range obtained with this weapon using a 2 lb. bomb was about 240 yd., 24 springs only being in action. Variation of range was obtained, as in the catapults, by varying the tension, but also, in this case, by adjustments of the position of the bomb in its cup. The West spring gun was an ingenious design, which probably comes near the limit of efficiency obtainable in applying the force of springs to an act of throwing. But it was heavy, and not very easily managed, and required as large an emplacement as a trench mortar.
The Minucciani bombthrower, though it appeared late in the war - after trench engines of the 1915 type had had their day--was probably the most efficient and ingenious weapon of its class. It was a large metal casing, circular, supported on a pedestal. Inside the casing was a revolving member, formed somewhat after the fashion of a centrifugal pump. Grenades of a special design (disc percussion) were fed into the " pump " through an opening in the casing, and when the pump was operated by turning a handle, they were expelled by centrifugal force through another opening in the casing. Extraordinarily high rates of fire combined with accuracy were obtained with this machine, which could throw the bombs practically as fast as they could be fed in, while, owing to their shape, the grenades themselves ranged well.
Other types of engine developed in the war for throwing grenades differed fundamentally from these in that an explosive propellant was employed. Setting aside certain throwers which are hardly distinguishable from light trench mortars (for which see Trench Ordnance) and throwing-devices attached to the service rifle (see Grenade), there remains a type in which the grenade is formed with a sleeve tail and the thrower consists essentially of a peg over which this sleeve fits, the propellant charge being loaded into the sleeve. The action is thus exactly the reverse of that of a gun or trench mortar. An engine of this type, known as the " Hay pocket howitzer," was experimented with in Great Britain but never adopted as a service store. The Belgian " Van Deuren " type and the German Granatwerfer, on the contrary, were both used in large numbers and the latter especially played a part not only in trench warfare but in the open warfare of 1918 in which it was carried by the infantry in their advance for the purpose of reducing machine-gun nests.
The Granatwerfer of the German army was issued on a large scale, 12 being allowed for each infantry regiment. There were two models, of which the later, that of 1916, is here described.
The equipment comprised the thrower and baseplate (weighing 53 lb.) and a metal platform (weighing 35 lb.). The " gun " (see fig. 3) consisted of a cylindrical firing-peg screwed into a body. This body (which was provided with a carrying handle) had at its rear end trunnions which rested in trunnion seatings fixed to a small baseplate, as in German trench mortars. Elevation was given by clamping the body at the desired angle to an arc on the left side which was rigidly attached to the baseplate. Laying for direction was done by moving the baseplate (and with it the whole system) round a pivot situated at the front end of the platform, and clamping it when on the desired line.
The grenade as such is dealt with under Grenade while this article is concerned onl y with its tail. This is a hollow tube, fitting over the firing-peg, and having at the inner end of the cavity a propellant charge contained in either a service rifle cartridge (with the bullet removed) or else a capsule with a percussion cap. The interior of the firing-peg is formed in somewhat the same way as the interior of a rifle-bolt, that is, it carries a striker, striker-rod and striker-spring which are controlled by a trigger. On the right side is a cocking-lever by which the striker-rod is forced back against its spring till the notch formed on it is engaged by the sear of the trigger. When the FIG. 3.
grenade, with its propellant cartridge or capsule, is placed on the peg and the safety pin of its fuze withdrawn, the trigger lanyard is pulled, the sear frees the striker rod, which is impelled forward by its spring and fires the cartridge cap, exactl y as in a rifle. Until 1918 this weapon used only simple H.E. bombs. In that year a second type was introduced in which a small repellant charge in the head of the bomb was fired on impact with the ground, causing it to rebound and so to burst in air instead of burying itself. The ordinary (1915 model) grenade weighed 1.85 kgm. (4 lb.) and had a range of about 330 yards. The bouncing bomb was heavier (2.5 kgm., 51lb.) and ranged only to 275 yards. (C. F. A.)
These files are public domain.
Chisholm, Hugh, General Editor. Entry for 'Bombthrowers'. 1911 Encyclopedia Britanica. https://www.studylight.org/encyclopedias/eng/bri/b/bombthrowers.html. 1910.
