1. THE PASSAGE OF INFANTRY THROUGH ARTILLERY LINES.

The artillery of a mobilized German army corps with its twenty-four batteries takes up approximately 2500 m. of the front of about 4000 m. available for the corps. When the ground is unfavorable, the front available for the other arms may be still further reduced. All remedies suggested for reducing the frontage required by artillery offer no real solution of the difficulty; in fact, they have resulting drawbacks, such as the reduction to ten paces of the interval between guns, and the posting of artillery in two lines, one in rear of the other. On account of these drawbacks, a commander will avail himself of these remedies only in case of the most urgent necessity. The question as to how infantry can best pass through these long artillery lines is therefore of especial interest. While artillery will generally seek commanding positions and avoid covered terrain, infantry will make use of depressions and cover as the natural routes of advance for passing by batteries in action and for deploying subsequently in front of them. In this case the solution of the problem is simple. The difficulties are disproportionately greater when terrain impassable for artillery is lacking. Nothing could be more desirable for hostile artillery which has adjusted its fire upon our batteries, than for the intervals between our guns to become suddenly filled with infantry, whereupon our artillery, until now under fire, would have to cease firing so as not to endanger our infantry. This pause in the fire will be more noticeable, when our artillery has not yet succeeded in gaining a superiority of fire over the hostile guns; and its length will depend upon the depth of the infantry formation. In this case the infantry cannot avoid heavy losses as it must cross the fire-swept space in rear of the guns, and soon thereafter must enter the zone of the opponent’s actual “fire for effect,” besides losing for the time being the support of its own artillery fire. It is obvious that for infantry to advance in deployed lines through artillery in action, condemns the latter to long silence, and even exposes it to the danger of being placed altogether out of action. Infantry can pass through artillery lines at certain points only, its passage being subject to an agreement between the infantry and artillery commanders. It is advisable to have those batteries cease firing whose fire has the least influence on the course of the artillery combat. It is, however, of the utmost importance that the fire of all hostile batteries which possibly could fire on our infantry, be kept down by the increased fire of our artillery. In this manner, we may perhaps be able to draw the fire of the hostile artillery away from those points at which our infantry is to pass through our artillery line. This is especially important. It will also be advantageous to designate successively, different points in the artillery line for the passage of infantry. This should be done for two reasons: first, in order that a favorable target whose re-appearance the hostile batteries could await with loaded guns, may not be presented to the enemy at one point for a prolonged period; second, in order that movements by the flank on the part of the infantry may be obviated. The column of squads would be a suitable formation in which two battalions of infantry could simultaneously pass through the line of guns approximately within the space occupied by one battery. These battalions should then at once deploy, executing front into line toward their respective outer flanks. The guns can resume firing only when their infantry has reached a point 3-400 m. in front of them. The artillery will be able to resume its fire earlier when it is posted in rear of a crest, and for this reason such points should be selected for the passage of infantry.

2. THE ADVANCE UNDER ARTILLERY FIRE.[315]

In almost every attack, infantry will be obliged to advance for considerable distances under artillery fire without being able to take advantage of cover. It should guard against being surprised by artillery fire while in an unsuitable formation.

In the first place, everything that facilitates the enemy’s adjustment and observation of fire should be avoided. (See p. 119 supra). To this end, infantry should not remain unnecessarily long near objects that are clearly visible at a great distance. If it is noticed that the enemy is beginning to adjust his fire on some prominent feature of the terrain, that point should be passed as quickly as possible; the same is true of a plain in the enemy’s zone of fire. Narrow columns, separated by intervals of 50 m., their heads not on the same line, are advantageous. This formation prevents shrapnel from simultaneously striking two columns, and makes it difficult for the enemy to judge the relative position of the smoke from the burst of his shrapnel with respect to the target. This increases the difficulties of the enemy’s observation of fire, as it is not easy for him to determine whether his shots go over or fall short. A shallow echelon formation (about 50 m. deep, as used in Russia, for example) is valueless for reducing losses, owing to the depth of the beaten zone of modern projectiles.

The narrowest possible front should be presented to the enemy when within his zone of fire.

It is moreover desirable to make the further observation of fire difficult for the hostile artillery, and to diminish the effect of his projectiles at the target (see p. 120 supra) by taking up suitable formations. Broad, shallow formations were suitable against the shell fire of the past. However, they had the great drawback of considerably facilitating the observation of shots falling short or going over, as the smoke from the burst hid the target in the first case, and as the target appeared silhouetted against the smoke from the burst in the second. The cone of dispersion of the modern base charge shrapnel combines comparatively small lateral spread with great effect in depth. The effect of a well-placed shrapnel may be confined to one target, and that of projectiles bursting in the intervals reduced by taking up a formation in which narrow columns (columns of squads) are separated by wide intervals (up to 50 m.).

The range is determined or verified by bracketing; that is, by enclosing the target between shots which, fired at a known difference of range, strike respectively, short of and beyond the target. In France this is done either by battery salvo or by piece. In the former case, the French distribute the fire equally over the entire space which they wish to cover with fire; hence, they do not direct it upon the individual columns, especially when they employ indirect laying, their favorite mode of procedure. It is in this kind of fire especially that narrow columns, separated by wide intervals, are a great advantage, because it is pure accident if a projectile falls so that its burst can be observed. Moreover, when the columns are not abreast of each other, the observations of bursts may be contradictory. Thus, in one salvo, “over” and “short” bursts may be obtained, especially if several bursts could not be reliably observed, and the salvo will have to be repeated. When a projectile bursts “short,” immediately in front of the 1st company, for example, it may be assumed that the next projectile will be fired at a range increased by 100-200 m. The 1st company should therefore move to the front at double time, the 2nd and 3rd likewise, while the 4th executes platoons front into line and takes to cover in anticipation of an “over” shot. The “over” meant for the 1st company will then be the signal for the 4th company to rush forward. The following general rule may be given: A projectile bursting “over” or just “short” of the target requires that the force fired upon move quickly; a projectile bursting far “short” of the target requires that cover be taken. The platoon and squad leaders of the attacking force should not betray its presence by standing upright; the force should disappear absolutely without leaving a trace.

A force cannot, in the long run, prevent artillery from effecting an adjustment of fire upon it; all it can do is to postpone the beginning of the fire for effect.

Fire for effect is of three kinds:

1. “Progressive fire” (tir progressif).[316] In this fire, after establishing a bracket (as a rule, one of 200 m.), every piece fires two rounds at each of four ranges, viz., at a range 100 m. less than the short limit of the bracket, at both ranges of the bracket, and at a range 100 m. greater than the long limit of the bracket. For example, if a bracket has been established for the target at 3000 and 3200 m., the battery would fire at 2900, 3000, 3200, and 3300 m.

2. “Sweeping” (fauchage) is employed when it is desired to cover a broader zone. In this every gun fires three rounds at each of the ranges designated. The first round is fired with the line of sight directed on the right portion of the target (or on the aiming point). Before firing each of the succeeding rounds, the direction of the piece is changed to the left by three turns of the traversing handwheel. At the next range this process is reversed, the direction of the piece being changed to the right by three turns of the traversing handwheel after each round. At 2500 m., for example, a battery can cover, in this manner, a space twice the width of its own front.

3. “Fire at successive ranges” (searching fire). In this fire salvos or volleys are delivered at the target at a number of ranges to be designated by the battery commander.[317]

During the Russo-Japanese war, all close order formations proved unsuitable under artillery fire, except when the terrain afforded cover. The Japanese infantry recognized very soon that the best protection against artillery fire lay in constant motion (irregular rushes made by small units) and in wide extension. The following procedure, employed at Yoshirei on July 31st, 1904, seems worthy of imitation:[318] The several platoons of the companies followed each other in deployed lines at distances of 200-300 m. When they had to cross open ground in order to reach a designated line, the platoons sought to advance by squads, whose men were deployed at intervals of 5-10 paces and who moved at a rapid gait interrupted by breathing spells. The men invariably assembled when cover was reached. The losses were insignificant. The Russians also made use of a similar procedure after their first disastrous experiences. In many instances the platoons ran forward in single rank. “Change of gait and direction, as well as the use of loose irregular skirmish lines make it difficult for the artillery to hit anything.” (Par. 450 German I. D. R.).

Formations used by Infantry during the Russo-Japanese War when under Artillery Fire.

These formations made it possible to advance at a walk to within 3000 m. of a hostile position; beyond that an advance by rushes had to be resorted to, in which the attacking force avoided showing itself simultaneously in long lines. The simplest scheme might be to move forward in column of sections, each section in skirmish line. Formation “a” is well adapted for quickly crossing fire swept places, and when there is hope of re-forming the column subsequently. Formation “c” is suitable for quickly deploying from company column. However, the last-named formation no longer guarantees a proper leading of the company, and quite naturally does not absolutely prevent losses. After the Japanese 5th Brigade (Nambu) had taken possession of Yuhuntun[319] and the three houses during the night of March 6/7, 1905, the following dispositions for attack were made by the Russians about noon on the 7th: On the right, the 5th and 10th Rifle Regiments, in five lines, each consisting of one battalion (total depth of the formation 600 m.); in the center, the 123rd Infantry (Koslov) of which the companies of three battalions were deployed in single rank lines, each consisting of one company, with the men at intervals of from 3 to 5 paces, the companies in rear of each other at distances of 100 paces; the IVth Battalion, similarly formed, was posted in echelon to the left rear. The 124th Infantry advanced on the left flank. The Koslov Regiment, advancing without hesitation in quick time and at attention, was fired on by three Japanese batteries while it was moving from 4000 to 2000 m. The regiment lost about 600 men. This loss is insignificant when the size of the target (about 600 m. wide and 1000 m. deep) is considered. The Japanese did not care to become involved in a serious infantry action and therefore evacuated the place. It would have been better to advance by rushes with smaller units, as the terrain afforded no cover whatever. Whenever the Japanese had sufficient time, they crossed such plains singly, one by one, and then assembled under cover for the attack.

3. FIRING ON ARTILLERY IN POSITION

was in the past a pet fire problem. The effect of frontal fire on artillery whose guns are protected by shields is so small that the expenditure of ammunition is not justifiable.[320] The gap between the steel shields of the French field gun is not large enough to exert a noticeable influence. Steel shields, 3 mm. thick, afford protection against steel jacketed bullets fired at or beyond 300 m.; against “S” and “D” projectiles they afford protection, it is said, beyond 500 m. only. Machine guns directing continuous fire on a point may obtain better results. According to firing tests 3 mm. armor plate can be pierced up to 1000 m. only by special projectiles (solid steel projectiles and those having a steel core), the adoption of which is precluded on practical grounds (variations in sectional density, and difficulty of manufacture).[321] For this reason, it is better to leave the task of destroying shielded batteries, even when they are in the open, to one’s own artillery, than to attack them with infantry. The fire effect of the infantry is not noticeably increased when delivered obliquely against the front of the battery. (Par. 184 German I. D. R.). In Germany the gun commander and cannoneer No. 3, who is posted at the trail, are then especially endangered; but in order to flank the guns effectively and to reach in rear of the shields with its fire, the infantry must move to a flank a distance at least equal to ¹⁄₃ of the range, and even then the fire effect is very small. The effect may even be entirely nullified when the flanking fire is delivered from the side on which the caisson bodies are posted. In this case it suffices to push forward the caisson body to protect the personnel. It is a good plan for infantry to direct its fire on the limbers and the reserve. And again, infantry should not let any opportunity pass to fire on artillery in motion or in the act of limbering or unlimbering within effective range. Guns moved by hand into positions from which direct laying can be employed for the purpose of warding off the infantry attack, offer particularly favorable targets. Infantry that is to capture artillery must approach its objective by means of irregular rushes made by small groups, and increase its fire to the utmost intensity when the limbers are brought up to the guns. The effect of artillery fire is small under 200 m., in the absence of canister.[322]

The disaster which overtook Trautmann’s Battery at St. Hubert, during the battle of Gravelotte, demonstrates how difficult it is to unlimber on open ground when under effective infantry and artillery fire; but, if five limbers with their teams had not stampeded, perhaps it might have been possible after a while, for the battery to reopen fire. Hasse’s Battery, also at St. Hubert, was rendered incapable of moving in a short time, but, in spite of the greatest difficulties, managed to continue its fire for about two hours, though with only a part of the guns. Gnügge’s Battery managed to unlimber under cover of a garden wall at St. Hubert and to maintain itself there under enfilading infantry fire till the end of the battle. Trautmann’s Battery lost 17 men and 37 horses; Hasse’s Battery, 38 men and 77 horses; and Gnügge’s Battery, 15 men and 40 horses.[323]

Unlimbering under uninterrupted hostile fire at short range will always produce conditions similar to those in Trautmann’s Battery, and in the two British batteries of Colonel Long at Colenso.[324] These two batteries did not cease firing because they had suffered too heavily, but only because they had expended all their limber ammunition and the caissons were unable to come up. It was impossible for these batteries to limber up under the hostile fire. It was likewise impossible to destroy a battery, though without protecting shields, even when great quantities of ammunition were expended.

At the battle of Beaumont, the artillery of the 7th Infantry Division suffered heavy losses. “Although the first caisson sections were up and the men with them were detailed to assist in working the guns, the gun squads in both batteries had dwindled down to 2 or 3 men each by 1 P. M., i.e., within half an hour.” Immediately after the French attack had been repulsed, one of these batteries was able to accompany the advancing infantry, however, while the other (the 4th Light Battery) could not move its guns until an hour later, as it had lost 29 men and 34 horses.[325] This example proves again that when artillery has once managed to go into position and to open fire, it cannot be annihilated by infantry alone, and therefore need not fear to take up a more than temporary position in the first line.

The best way for artillery to protect itself against annoyance from hostile infantry fire is to push forward an infantry screen, even if only a weak one. In the days when batteries had no shields, this screen enabled artillery to devote its entire attention to the principal target without regard to hostile infantry. At the present time, especially in positions in rear of a crest and in long artillery lines, the principal object of such a screen is to prevent hostile patrols from molesting the artillery. Small detachments posted at wide intervals are sufficient for this purpose. The flanks and rear are now as in the past the vulnerable points and are most exposed to daring, sudden attacks, even if only made by weak hostile detachments. (Par. 448 German I. D. R.).