With the Naval Brigade in Natal (1899-1900) Part 7

CHAPTER IX

Gunnery Results: The 12-pounder Q.-F. Naval gun -- Its mounting, sighting, and methods of firing -- The Creusot 3" gun and its improvements -- Shrapnel fire and the poor results obtained by the Boers -- Use of the Clinometer and Mekometer -- How to emplace a Q.-F. gun, etc., etc.

A word or two now as to what we with the guns have learnt during the campaign, although I feel that this may be rather a dull, professional sort of chapter except to those interested in guns and gunnery, and that the subject as treated by myself may be open to criticism from others similarly engaged. I may certainly say that it was not for at least three months after our opening fire at the first battle of Colenso (December 15th, 1899) that I personally felt myself as "fairly well up" to the constantly varying conditions of gun positions, gun platforms, enemy's positions, and the ever-changing "light and shade"

of the South African climate, against all of which one had to fight to get correct shooting; the last-named of these, viz., "light and shade," being perhaps our greatest bugbear, often throwing one many thousand yards out in judging a range by eye, which gift is, I think, the best a gunner can possess!

Then, too, the Naval guns as they were sent up (owing to the work being pushed at the last moment), some on high wheels and some on low ones, some with drag-shoes opened out and others which wouldn't take the wheels, some with the wires from them to trail plate handles the right length and others much too long, caused (I am talking of the 12-pounders) these guns, instead of forming a level shooting battery, to be each one a study in itself as regarded its shooting powers; and we constantly found one gun shooting, say, three or four hundred yards harder or further than the one next to it although laid to the same range on the sights. This at first sight was rather mystifying, but all these small but important matters above mentioned were not long in being put to rights. On any future occasion such defects will, of course, be avoided from the start by the guns being altogether more strongly mounted on broad-tyred wheels and broad axles of similar height, size and pattern, and, above all, with a strong and uniform system for checking the recoil of the carriage, of which the drag-shoe, as it was fitted and sent up to us, was certainly not capable.

[Ill.u.s.tration: _Photo by Symonds, Portsmouth._

Captain Percy Scott, C.B., R.N.]

I am rather keen on this question of the best means of checking the recoil of a field carriage. A very strongly made drag-shoe fitted with chains to the centre of gun trail will do very well; and these were, later on in the campaign, fitted by the Ordnance authorities at Maritzburg to new "Percy Scott" carriages, which they sent up to us to replace the original "Percy Scott" carriages, which, as I remarked before, were not strongly enough built, particularly as regards the wheels, to stand any very bad country or a lengthened campaign, in both of which we found ourselves involved. In these remarks, please let no one think that I am running down the 12-pounder carriage for a purpose; not so. I simply wish to point out details that, if more time had been available, would certainly have been avoided in them by their very clever designer, Captain Percy Scott, R.N., to whom the service in general (and I personally) owe a debt of grat.i.tude; for a.s.suredly not a Q.-F. gun, or a single one of us with the batteries, would ever have been landed unless it had been for him and his brains and his determination to have the Royal Navy represented in the campaign, as was their due--being on the spot with what was most wanted, namely, heavy guns.

Here I wish to distinctly state my own opinion, and that also of the many officials and gunners, Naval and Military, with whom I have talked over the matter, _i.e._, that not only did the Naval guns save Ladysmith, but they also in a great measure helped to save the campaign outside for its relief, and with it Natal. And my opinion now, when the war is nearly over, is only strengthened and confirmed by what I have heard the Boers say of the guns, viz., that they are the only things when using shrapnel that have shaken them much during the fighting, and, considering the country, naturally so. That it was to the Navy and not to the garrison gunners that the original credit has gone, was simply because we were here and they were at home at the start. One is, as regards their gunnery powers, as good as the other, and the garrison gunners earned their laurels later on. Still, I have a great hankering after a gun's crew of "handy men" to beat any crew in this world for all-round service and quick shooting, and I am ready to back my opinion heavily.

Returning from this digression to the subject of recoil, we found that sandbags placed at a certain distance in rear of each wheel not only effectually checked the carriage, but also (a great consideration) ran it out again. This system was used both by the 4.7's and ourselves at the end of the war; and seeing that the guns had only half crews, it was a _most_ important saving to men who had perhaps marched ten miles, loaded and off-loaded ammunition, and then had perhaps to fight the guns under a hot sun for hours. To fill and carry the bags, however, is a nuisance, and some better system on the same principle is needed, such as the inclined wedges that I saw by photos the Boers were using in rear of wheels; and I should very much like to see some such system subst.i.tuted for our present one. I have not seen the hydraulic spade used, perhaps that is the _best_.

To put it briefly, the hastily improvised gun-carriage of the 12-pounders had, on account of this very haste, the following defects:--

(1.) Too weak generally in all parts, particularly wheels and axles, for any long campaign.

(2.) Wheels and axles being a scratch lot, none in any of the batteries were interchangeable, which caused many times later in the campaign when wheels began to give out, much anxiety. Several times we only had guns ready for action or trekking by the "skin of one's teeth," and it must be borne in mind that any new wheels wired-for sometimes took two months to arrive on the very overcrowded railway--a single line.

(3.) The system of checking the recoil of the field carriage was a bad one.

(4.) All the 12-pounders except two were in the first instance sent up without limbers, and therefore had to be limbered up to wagons. This for practical purposes in the country we had to trek over was absolutely useless and caused endless delays. Eventually we all got limbers built at Maritzburg, and equivalent gun-oxen to drag the guns separately from the wagons.

(5.) The trail of the gun consisted of a solid block of wood some 12 feet long; so that if one laid the gun to any long range (in most over 7,000 yards, I think) the oil cylinder under the gun, on trying to elevate it, would bring-up against this trail and prevent laying. This therefore necessitated digging pits for trails to shoot much over 7,000 yards, which in bad ground often took some considerable time. To obviate this defect would of course be very easy with a steel trail of two side plates, and s.p.a.ce for gun and the cylinder between the sides.

(6.) The general idea of all the mountings I saw was narrow axles and high wheels, whereas, for all trekking purposes, it should be broad s.p.a.ce between the wheels and low wheels. This was amply proved to us by the number of times the high-wheeled narrow mountings upset on rocky ground, whilst the broad low type went along steadily. The 12-pounder gun itself did its work beautifully, shooting hard and lasting well, and owing to the dry climate of Africa we had no trouble at all to keep the guns clean and all gear in good order.

(7.) Perhaps the most troublesome defect of all was that the gun-carriage had no brake fitted. The gunnery drill-book system of "lash gun wheels" may be at once erased from the book for all practical purposes over any rocky or bad country; it simply, as we soon found, tears the wheels to pieces, and chokes the whole mounting up. An ordinary military Scotch cart brake, or a brake fitted as the trek wagons here have, under the muzzle of the gun on the forepart of the wheels, acts very well, and my bluejackets, although not carpenters, fitted these for me. They are screw-up brakes.

The sighting of the gun (drum and bar system) cannot be beaten, I think. Perhaps a V-shaped notch to give one the centre of the H, or hind sight, might be an improvement, as here personal error often occurs. Lieutenant, now Commander, Ogilvy, R.N., always made his men correct their final sighting of the gun for elevation from about six paces in rear of the trail, and my experience is that this is a small but important matter, especially for fine shooting say at a trench at 5,000 yards, which merely appears to one as a line on the ground. One invariably finds that the gun, with the eye of a man laying close up to the hind sight, is laid slightly short of the object; so this should be noticed in the gunnery drill-book as regards field guns.

_Telescopic_ sights, the patent, I believe, of Lieutenant-Colonel L.

K. Scott, R.E., were sent out and used by us with the 12-pounders to fire on the trenches at Spion Kop and Brakfontein, when fine shooting was required. These sights had the cross wires much too thick, so we subst.i.tuted cobwebs picked off the bushes and stuck on with torpedo composition, and these did admirably. Still this sight was not altogether a success. The power of the telescope, especially in the rays of the sun, was poor, and it took a man a long time to lay his gun with it, thus further reducing the quick-firing power of the 12-pounder reduced already by the recoiling field carriage. As to the 4.7's, it was found that the ordinary Naval small telescope, fitted on a bar and with light cross wires, could not be beaten as a sight for ranges they had to fire at. It is a very good useful gla.s.s, and it was, I believe, used both in Natal and elsewhere right through the campaign, and I unhesitatingly give it the palm.

As to the system of firing and gear used, electric firing was very successful as long as one had the gear for refitting and repairing and an armourer attached to one's guns; this, of course, as the guns became split up into pairs was impossible, and I may say that carting electric batteries (which of necessity for quickness have to be kept charged) in wagons or limbers over rocks and bad roads, and with continual loading and off-loading, becomes a trouble and anxiety to one. So for active service I should certainly recommend that percussion firing should be regarded as the first and princ.i.p.al method to be used with guns on the move, carrying also the electric gear for use if guns are left for any time at fixed spots as guns of position.

I may here remark that when firing with electricity from a field carriage the battery has to be placed on the ground, clear of recoil, and therefore the wire leads must be adjusted in length accordingly. I am uncertain whether our other 12-pounders used mostly electric or percussion, but I think on the whole, percussion; and, speaking for myself, I certainly did so after experiencing the disappointments which miss-fires often gave one, when trying to get in a quick shot, say from the line of march, with the electric gear. These "miss-fires"

are, moreover, often unavoidable under active service conditions, such as we had with our semi-mobile guns. The guns and connections get sometimes an inch thick in mud or dust and require time to clean, when one has no time to spare: the use of percussion tubes avoids all this.

Before we leave the subject of guns the following description of the French 3" Creusot gun by the _Revue d'Artillerie_ will be of interest, viz.:--

_South Africa._--The Field Artillery of the Boers consists for the most part of Creusot 3" rapid-firing guns made after the 1895 model. These guns were purchased by the South African Republic during the year 1896.... The gun, which is constructed of forged and tempered steel, has a 3" bore. Its total length is 8 feet and its weight is 726 pounds. The body of the gun consists of three elements:--1. A tube in which the breech piece is fixed. 2. A sleeve covering the tube for a length of 3 feet 6 inches. 3. A chase hoop. The chamber is provided with twenty-four grooves of variable pitch which have a final inclination of 8.

The system of breech closing is that of the interrupted screw, which presents four sectors, two of them threaded and two plain, so that the breech is opened or closed by a quarter revolution of the screw. The mechanism is of the Schneider system, patented in 1895, and has the advantage of allowing the opening or closing of the breech to be effected by the simple motion of a lever from right to left, or _vice versa_.

The gun is fired by means of an automatically-c.o.c.ked percussion apparatus. A safety device prevents any shots from being fired until after the breech is closed.

The carriage is provided with a hydraulic recoil-cylinder fitted with a spring return. It is also furnished with a "spade," which is placed under the stock at an equal distance from the trail and the axle, and which is of the model that General Engelhardt has adopted for the Russian Artillery.

During a march this spade is turned back and fastened to the stock. The carriage is likewise provided with a road brake, which is to be employed in firing only when the nature of the ground is such that the spade cannot be used.

The gun is placed in a bronze sleeve that carries the brake cylinders and the various other connecting pieces for the return spring and the aiming apparatus.

The hydraulic recoil consists of two cylinders placed laterally and at the height of the axis of the piece.

The axle has the peculiarity that in its centre there is a wide opening in which are placed the cradle and the gun. It is provided with two screw trunnions, around which the pivoting necessary for lateral aiming is effected. This arrangement of the gun with respect to the axle has the effect of greatly diminis.h.i.+ng the shocks that firing tends to produce.

Elevation and depression are accomplished by rotating the axle in the wheels of the carriage. This is done by means of a crank which, through an endless screw and pinion, controls a toothed sector attached to the sleeve.

Pointing in direction is done by means of a lever known as a tail piece. Mounted upon the axle there are two small sights, forming a line of aim, that permit of bringing the carriage back in the direction of the target as soon as a shot has been fired. All that the gunner has to do is to give the piece a slight displacement laterally with respect to the carriage by means of a hand-wheel, which turns the gun 2 to one side or the other.

The line of aim is found by a back and front sight arranged upon the right side of the sleeve in which the gun is mounted. The back side permits of aiming while the gun is being loaded. It carries a small oscillating level that indicates the elevation of the gun during rapid firing.

The weight of the carriage, without wheels, is 1,146 lbs. and with wheels, 1,477 lbs.

The ammunition consists of cartridges containing charge and projectile and having a total weight of 19 lbs. The powder employed is of the smokeless kind, designated by the letters B.N.

The weight of the charge is 1-3/4 lbs. The projectiles are of three kinds--ordinary sh.e.l.ls, shrapnel sh.e.l.ls, and case shot. The weight of each is the same, say 14-1/4 lbs. The shrapnel sh.e.l.ls contain 234 b.a.l.l.s, weighing 155.8 grains each, and an explosive charge of 3.13 ozs.

As the gun can be pointed at a maximum angle of 20, and the initial velocity is 1,837 feet, the projectiles can be fired to a distance of 26,248 feet.

The crew necessary to serve the gun consists of six men--a gunner, a man to manoeuvre the breech-piece, a man to manoeuvre the pointing lever, two men to pa.s.s the ammunition, and a man to regulate the fuse. The rapidity of firing can easily be raised to ten shots a minute.

The accuracy of the gun is most remarkable. Upon the occasion of the trials made when the guns were received, the following firing was done: a regulating shot, a first volley of six shots in forty-two seconds, and a second volley of six shots in forty-six seconds.

The fore carriage of the gun and that of the caisson are identical. They carry a chest containing thirty-six cartridges, and are capable of accommodating four men.

The back carriage of the caisson carries two chests like that of the fore carriage.

The total weight of the gun and fore carriage loaded is 3,790 lbs., and that of the caisson 4,330 lbs.

On reading over this description of the French 3" Creusot gun, it seems to me that the kind of axle used with it is first cla.s.s and should be used in our field carriages for quick-firing guns; it must certainly take the strain of recoil off the centre of the axle, which recoil we found cracked our axles as we used them (once in my own guns) so badly that the whole thing had to be s.h.i.+fted and replaced.

Another advantage it has is to lower the whole gun and mounting, and the centre of gravity of the weight of it and carriage, and therefore the gun is much harder to upset on rocky ground or going up steep precipices, as we had to do in Natal. This detail of wheels and axle is, I think, the most important one almost in a field carriage. The axle I mention is one bent down in its centre for about two-thirds of its length.

In regard to the ammunition. The cordite charges in their bra.s.s cylinders and zinc-lined boxes did admirably, and the amount of knocking about which the cases and boxes out here stand is marvellous.

At one time early in the campaign before Colenso and Ladysmith, a decided variation in shooting of our guns was noticed, and was put down in many cases to the variation of the cordite itself, the bra.s.s cases sometimes lying out, in fact, in a powerful sun for hours, while the guns were waiting or in action, and often becoming then too hot to touch. Now, however, I personally don't think that this theory was right but am of opinion that the variation then noticed, and even after in the shooting, was simply due to the varying recoil of guns on different slopes of ground and with indifferent drag-shoes. Royal Artillery officers confirm one in this opinion.

As for the sh.e.l.ls, both common and shrapnel, they stood the knocking about well, and I never saw or heard of a single common sh.e.l.l used with 12-pounders not exploding on striking, which speaks well for the base fuse. The shrapnel I am not quite so sure about; one noticed often a great deal of damp collected in the threads of the fuse plug and nose of the sh.e.l.l; owing, I presume, to condensation in their sh.e.l.l boxes under the change of heat and cold. Still they did very well and I think seldom failed to burst when set the right distance. I say the right distance because this at first was a slight puzzle to us, the subject of height in feet above the sea-level of course never having before presented itself to us as altering very considerably the setting of the time fuse; and I don't think that a table of correction for this exists in the Naval Service; at any rate, I have never seen one.

To ill.u.s.trate this, we found at Spion Kop (about 3,500 feet above the sea-level) that it was necessary to set the time fuse for any given range some 500 yards short to get the sh.e.l.l to burst at all before striking; and on the top of Van Wyk, fronting Botha's Pa.s.s (some 6,500 feet above sea-level) I had to allow the fuse 800 to 900 yards short of the range, and similarly at Almond's Nek. This is, I take it, due to the projectile travelling further against a reduced air pressure at any height than it does for the same sighting of the gun at sea-level, for which of course all guns are sighted. I should like to talk to experts regarding this as we are not quite sure about it up here.[6]

[Footnote 6: I am since glad to hear from Lieutenant Henderson of H.M.S. _Excellent_, that he is engaged in working out a table of corrections, such as I mention, and is also interesting himself in the question of "range-finders,"