VARTILLERY FIRE
Object of study of artillery
Except in small engagements in detachment warfare the infantry will have the assistance of friendly artillery and will be opposed not only by infantry but by artillery fire. Some knowledge of artillery, its use, the effects it can produce and how best to utilize the aid afforded by our own and to meet the opposition of the enemy’s, is therefore necessary for the infantry officer and also for the men in ranks. While familiarity with the artillery will be far from breeding contempt, it will enable the infantry to escape much unnecessary loss and, by correcting the false conception so many have of its power, it will improve the morale of our men.
This chapter is not intended to teach infantry officers what they should know about artillery and its use. It is offered merely as a suggestion as to what our men should be taught and how to train them to meet certain phases of this fire. The officer should know much more about the subject and must goto more extended works by more competent men for the instruction.
Artillery is effective against infantry both physically and morally. The moral effect is the greater, the less instructed and trained is the man. Most untrained men have very exaggerated ideas as to the effectiveness of artillery, they know nothing but guess much. It is the terror of the unknown.
Classes of artillery
There are two general classes of artillery that accompany an army: light and heavy. The light artillery may be rifles or light howitzers; the first have a flat trajectory, the others, of greater caliber, have the advantage of being able to use high angle fire. Mountain and horse artillery are merely subdivisions of the light artillery and, except that the mountain artillery is less effective at long ranges than the others, “all look alike” to the infantry advancing under their fire.
The heavy field artillery in our service comprises 4.7” and 5” rifles and 6” and 7” howitzers. Their range is much greater than that of the pieces of the light field artillery. In a general way we may say that these heavy pieces will be used only against hostile batteries, earth works and material objects or against troops caught in some mass formation.They will generally not be used against an advancing skirmish line or troops in proper formation to meet light artillery fire. There is no training to be given infantry except discipline to hold them to their duty in an earth work under fire by heavy field artillery, hence in this chapter we may ignore it.
Light artillery
With light field artillery it is very different. The light field artillery is what concerns us most in our training. The extreme range for which these guns are sighted is 6500 yards, and at all ranges under 5000 yards they can produce serious losses on infantry exposed to their fire. They use two classes of projectiles, shell and shrapnel. The high explosive shell has a much smaller radius of action than the shrapnel, but is very effective within this area. It is generally used to batter material objects and with high angle fire to get at men in trenches or behind cover.
Shrapnel
The shrapnel of the 3” rifle contains 252 bullets and on burst these bullets are scattered over an area, roughly speaking, elliptical in form, 200 yards in depth by 25 yards in width. The flatter the trajectory, the deeper becomes the pattern made; the width practically does not vary. In other words the 252 bullets are scattered on burst over an area of 5000 square yards.
If these bullets were uniformly distributed there would beonefor every 20 square yards or an area of 15 x 12 feet. They are, however, not evenly distributed, being thicker in a small area near the front end. This bullet will not penetrate the infantry soldier’s pack at any range, so that when lying on the ground his pack affords complete protection to his spine and considerable protection to all vital parts except his head. The chance then of a man being wounded by a single shrapnel, even when inside the cone of dispersion, would only be about 1 in 80 if in the open and very much less with partial cover, as a trench, log, etc. The shrapnel bullet will not pass through one man and wound a second as will the infantry bullet.
Rate of fire
While artillery can fire very rapidly once the range data is accurately determined it requires considerable time to get into position and determine this data. Until then it is harmless.
Moving target
An erratically shifting target is hard for artillery to keep on. The fuze must be so set that the burst is at the proper height and distance to the front of the target to be effective, both not easy especially in case of a moving target, and the more erratic the movementthe harder is the task of the artillery-man.
On the defensive
On the defense the man’s protection is much better for he will generally have cover of some kind, but he has also a serious disadvantage, the line remains fixed, the hostile artillery soon locates it, gets its exact range and can place its own fire where it will do the most good. This is a decided offset to the defenders’ diminished vulnerability. The use of high explosive shells by their moral as well as physical effect weakens any advantage the defense might have as concerns artillery fire.
Artillery targets
To determine the relative vulnerability of different infantry formations let us apply to them the target made by a bursting shrapnel. A line of skirmishers at the normal interval extending across this beaten zone would have 19 or 20 men inside its extreme limits; if in squad columns there would be 2 squads at least and generally 3 squads or 24 men and the target, being much deeper, would give the artillery a better chance as it is easier to get direction correctly than the point of burst.
In platoon columns there can be but one platoon in the same burst if fire comes fromthe front, and platoons are 4 squads strong, but the whole platoon may be within it. If, however, the direction of the artillery fire be very oblique, and the platoons are on a line, more than one platoon may be caught by a single burst but not all of any one column.
In successive thin lines, if the advance be made by one man from a squad, and the fuze and direction be just right, there may be 2 men in the cone of dispersion, which is to say that, in that formation, the artillery has about one chance in forty of wounding a man. If the advance be by one man from each platoon the artillery’s chance, provided range and fuze are correct, is one in two that one man will be within the cone of dispersion of a given shrapnel and, if in there, there is one chance in 80 of his being hit; in other words, the artillery has one chance in 160 of getting one man and no possibility of getting two. Such a target will hardly draw artillery fire.
An infantry battalion in column of squads well closed up can nearly all be covered by the burst of a shrapnel. Such a target would likely draw many shots as would a company in this formation.
The advance under artillery fire
We can only win in the attack if our infantry can advance to the hostile position.We must get there, and as soon as practicable and with the least loss of life. We can not afford to lose too many in the advance or we shall be too weak at the end to drive the enemy from his position.
The infantry can not open fire until within rifle range of the enemy and should try to get much closer before doing so. In open country, however, infantry may be subjected to artillery fire while crossing the ground from 5000 yards to, say 1200 yards from the hostile position, with no chance to reply. The problem to be solved by the infantry commander is how to cross this zone without losing too many men and too much time.
In skirmish line
In skirmish line. The long advance in this formation is tedious work, and the target offered is sufficiently vulnerable to draw artillery fire. If no cover is afforded in the terrain the line is apt to suffer heavy loss and become more or less disorganized before reaching the point where it will take up the fire fight. Where the line of advance is crossed by ridges, sunken roads and other features of that kind affording cover, where the line can rest and to a certain extent reform, this formation can be used to advantage, especially if the terrain permits us to approach undercover from artillery fire to within two or three thousand yards. If this formation be used in a force of some size, as a war strength battalion or more, the platoons should not keep on a line but in an irregular echelon formation.
skirmish lines
This makes a much more difficult target for the artillery. The distance from front to rear between any two adjoining platoons should not be less than 150 yards. The advance in skirmish line has the advantage of being in the formation that it will be necessary to have when you open fire and no changes are necessary and, if the enemy is encountered much sooner than expected, you are prepared.
The squad column
The squad column. This formation was devised by our soldiers at maneuvers at Sparta and in California, where the ground in part was covered with thick brush. It was found an excellent formation to take when the skirmish line encountered these patches ofthick brush. Since it was placed in the I. D. R. it has been understood by some as a good formation for advancing in theopenagainst artillery fire. This is a mistake. It should never be so used. In this formation there will always be two squads, and generally three, in the burst of a single shrapnel, exposing more men to danger than if they were in skirmish line.
Marching in column of files is not as easy as in line on open ground. Remember good artillery is pretty accurate in getting direction. Most shots will be at the head of a column and if at the head of one, another on each side is included in the burst. Direction is much easier to get in artillery fire than exact fuze setting in the case of a moving target; this is another reason against the squad column, the target is deeper and thus slightly improves the chances of the artillery. This formation not only has no advantage on open ground, in an advance under artillery fire, but does have disadvantages.
Platoon columns
Platoon columns. In average terrain this formation will be more used than any other. The distance between these columns is great enough so that a shrapnel bursting between two may entirely miss both; it also permits amore or less erratic or zig zag course to be followed. Each column is lead presumably by a more intelligent and better instructed man than in the case of the squad.
These columns should never be on the same line but echeloned as explained for the skirmish line.
In most terrains there are little hills, clumps of trees, buildings and other cover of the same general kind. Platoon leaders must while keeping generally within their own zones of advance, rush from one cover to another where it is offered and, where cover is wanting, vary the pace and avoid advancing in a straight line.
Properly done this formation is one of the best. No time is lost, the columns are far enough apart to allow of advantage being taken of all the cover afforded, and the target is not, on average terrain, too vulnerable. It is not so good on flat open plains and it should not be used on such ground if the artillery fire is very oblique to the line of advance.
This form of advance requires that platoon leaders understand the theory and also requires much practice on different sites to give platoon commanders facility in leadingand skill in taking advantage of the cover offered. This is one of the things in which captains should give instruction during the indoor season with the aid of the sand table. In addition outdoor practice is most necessary. When this formation is adopted platoon commanders should know, if possible, before starting where line of skirmishers is to be formed.
Successive thin lines
Successive thin lines. This is by all means the safest formation on open ground in plain view of the hostile artillery observing station. The successive lines must be so far apart that no one shrapnel can reach two; this distance depends on the range but may be taken as 200 yards. With one man from each squad there will be two in the cone of a single shrapnel that bursts right; if the enemy is so situated that he can afford to fire at such a target and you do not want to pay the cost for such an advance, then send one man from each platoon in each line. Hostile artillery cannot afford to fire at such a target and if it does it will use up ammunition that will be much needed later and get small results for the expenditure.
The chief objection to this formation is the time it takes. In advancing in skirmish lineor in platoon columns your firing line is established as soon as you get your first line up, while, with successive lines formed from squads, it takes the longer time required for a line to advance 1400 yards, and if formed from platoons it takes the time required for a line to advance 6200 yards.
This formation is also safe against oblique fire.
The training of the men for it is simple. Before the line starts the point where it is to be rebuilt must be carefully designated. That the line may be rebuilt without confusion or mixing, each man must be taught to keep his eyes on the next preceding man of his own squad or platoon to ensure his finding his right place in the new line.
After a few of the successive lines have reached the new position, they form a dense enough target to draw artillery fire. For this reason the position of the new line should be one affording cover from artillery fire if possible; if not, men must get cover by digging to protect at least their heads from shrapnel. Head cover and the pack will give them protection from being killed if not from being wounded.
If the advance in this manner must be forthree or four thousand yards and the enemy has advanced posts or is likely to make an infantry counter attack, the advance over this whole distance can not be made at once but must be made by steps, growing shorter as you approach the enemy’s position.
Artillery sweeping fire
The artillery will often sweep with fire an area being crossed by infantry. This is done by increasing or decreasing the range after each shot until the entire area is beaten. If this process be repeated often enough the artillery will get anything within this area not under cover. But this does not change the average number of shrapnel required to get a man nor does it render advisable a great expenditure of ammunition for meager results.
Infantry encountering this kind of fire should, as it approaches, lie down and get what cover is available and, after the storm has passed, move on.
The artillery may determine the exact range to some zone which the advancing infantry has to cross and, as the infantry reaches it, open a heavy and accurate fire. The infantry must cross this zone in a formation which decreases its vulnerability as much as practicable, consistent with other conditions, such as the hostile infantry fire.
The enemy’s guns can get you if they expend enough ammunition at the task; but can they afford the ammunition? Your own artillery may interfere with such an expenditure even if the enemy were willing to make it.
A division deployed with 2500 men on the firing line, crossing correctly in thin lines a fire-swept zone from 4000 to 1200 yards, might lose 10% of this number from artillery fire and not have its advance even checked. With this open formation the loss is so small that the moral effect of it will be negligible with trained men. But a loss of 250 men at an expenditure of 160 shrapnel for each means 40,000 shrapnel. Even half that much would be more than could generally be afforded.
Forming skirmish line
After the skirmish line is formed at the position for opening the infantry attack, the further advance from there is conducted as already explained. In skirmish line the hostile infantry is now by far your most dangerous foe, but the artillery will still be punishing you: your line must advance under both fires.
Artillery fire will seldom be uniformly distributed along the entire skirmish line or continuous in its action. There will be blasts of intense fire, then a lull. The troops mustbe trained to take advantage of these lulls to advance and to lie quiet during the periods of hottest fire. Of course, if for any cause the artillery fire is not very effective, the advance continues as against the infantry.
Our infantry must be taught to keep their fire superiority over the hostile infantry and to this object to devote all their skill and energy, but to avoid unnecessary heavy loss from artillery whenever possible. The hostile infantry is their real opponent, their real danger. As the opposing lines get close the losses from artillery fire become relatively slight, compared with the losses from infantry fire.
How to practice advance under artillery fire
How are we to get this training in most of our posts where there is no artillery to afford us the practice?
A man with a red flag indicates the position of a hostile battery, or, if the battery is concealed, a position that can be seen and is in the general direction of the battery. When the flag is waved rapidly it indicates a rafale or violent burst of fire; waved very slowly, it indicates slow fire by battery. In most exercises no flag is necessary; the instructor can give verbally the direction from which the artillery fire is coming in stating theproblem; but in practicing the attack formation, under combined artillery and infantry fire, the flags should be used to practice platoon leaders in the rushes under such conditions.
Infantry as an artillery support
Infantry is sometimes detailed to support batteries that are somewhat separated from the rest of the troops and liable to attack by a rush of infantry or cavalry. Officers on this duty must thoroughly understand their mission. They must protect the artillery. Artillery can generally take ample care of itself if the attack comes directly from the front. The infantry commander must never mask the fire of the guns. Where he will place his men and what his general dispositions will be is a problem in tactics and the solution will vary with each case. These general propositions may be stated: his position must be such that from it he can effectively meet the attack; it should not be where he will get too much of the fire directed on the batteries; the command must be well in hand and the reconnaissance and observation groups so employed that he will have timely warning of the hostile approach and be prepared to meet it. His position will generally be to a flank and probably somewhat to the rear, never in front of the guns.
An occasional exercise in this work should be carried out as a maneuver. Something should be placed to represent the guns and a battalion or company assigned as their protection while another force is given the mission to capture them. This exercise should always be carefully umpired to see that the guns get credit for what they could do if fire is not masked. A problem of this kind is a small part of the work of infantry in war and when it comes it is a tactical problem like any other attack or defense. The reason for recommending it is that it affords excellent practice in security and information service and in combat when one position must be avoided. Combat exercises should be as varied as possible, here is another variety.
Fire superiority
The importance of fire superiority has already been dwelt upon as well as how much the effectiveness of hostile fire falls off as the effectiveness of our own increases. Infantry alone does not gain this fire superiority but it gains it by the help of our powerful ally and sister arm, the artillery.
Artillery fire over infantry
Battle fronts are too short for the artillery to occupy space in the line, even if this were a good place for it which it is not; it must fire over the infantry. All our men mustbe made to understand the effect of this artillery fire on the effectiveness of the hostile infantry, how much more effective this latter would be without the fire of our artillery, and the importance of having this artillery fire kept up to the last possible moment. Prove to them how much less we shall lose by an occasional premature burst than we should lose by the increased effectiveness of the hostile infantry if our artillery ceased to fire. The men must be taught that it is the infantry that does most of the killing and that, especially at the very short ranges, we want all the help we can get to keep down this killing by the enemy’s infantry.
It has already been shown why the attacker’s artillery has an advantage—the target is fixed. If the men are properly taught this there will be no trouble in getting them to want the artillery to fire over their heads as long as possible.
Tactical connection
The connection that must be kept between the infantry commander and the commander of the batteries told off to his support is of the greatest importance, but that will be the function of a higher ranking man than this book is written for.
How to instruct
How part of this instruction is to be givenhas already been told. It is believed that the best way to give the theoretical part is in small doses between exercises in the field—the little talks referred to before. Care must be taken not to give too much at once and to continue explaining until the men really grasp it. The theory should go along with the practical work; some of it can be best given in the non-commissioned officers’ school and, as before stated, on the sand table.
How and when you do it is of less importance thanthatyou do it.