CONFIDENTIAL! FOR OFFICIAL USE ONLY NOTES ON THE METHODS OF ATTACK AND DEFENSE TO MEET THE CONDITIONS OF MODERN WARFARE COMPILED AT THE ARMY WAR COLLEGE FROM THE LATEST AVAILABLE INFORMATION WASHINGTON GOVERNMENT PRINTING OFFICE 1917 CONFIDENTIAL! FOR OFFICIAL USE ONLY NOTES ON THE METHODS OF ATTACK AND DEFENSE TO MEET THE CONDITIONS OF MODERN WARFARE COMPILED AT THE ARMY WAR COLLEGE FROM THE LATEST AVAILABLE INFORMATION APRIL; 1917 WASHINGTON GOVERNMENT PRINTING OFFICE 1917 WAR DEPABTMENT. Document No. 585. Office of The Adjutant General. (2* WAR DEPARTMENT, WASHINGTON, May 9, 1917. The following notes on the methods of attack and defense to meet the conditions of modern warfare are published for the information and guidance of all concerned. [2595445, A. G. O.] BY OKDEB OF THE SECRETARY OF WAR: H. L. SCOTT, Major General, Chief of Staff. OFFICIAL : H. P. McCAIN, The Adjutant General. (3) THE METHODS OF ATTACK AND DEFENSE TO MEET THE CONDITIONS OF MODERN WARFARE. INTRODUCTION. MANEUVER WARFARE. Early in the European war there were operations of ma- neuver on both the east and west fronts, but as the contest developed and the first drives on wide fronts were finally brought to a halt, due to the near equality of the opposing forces, making it impossible for the offensive to make a further move to the front, each side began to " dig in " in order to strengthen the defensive and prevent loss. This operation was kept up on both sides, and as the opposing forces tried to turn each other's flanks and brought forward other forces to pre- vent their own flanks being turned, the lines were extended and joined with other parts of the line similarly developed until the entire forces on either side formed one almost con- tinuous line of entrenched positions extending across the whole front, with flanks resting on impassable obstacles or on neu- tral territory. Owing to the fact that there has been comparatively little maneuver warfare, which has been confined mainly to the east- ern front, its principles of attack and defense have undergone very little change. There are a few things, however, that deserve mention. Artillery. The use of Artillery, especially heavy Artillery, has been greatly increased in maneuver (as well as trench) warfare, thus requiring deployment at greater distances and greatly, reducing the value of existing permanent fortifica- tions, and consequently compelling the construction of deep trenches and underground shelters in fieldworks for protec- tion against the destructive fire of the heayy guns. Aircraft. The extensive use of aeroplanes and dirigible and captive balloons has also been an important development of the present war, and they have been very valuable, especially (5) 6 in strategical reconnaissance, but also in tactical reconnais- sance in conjunction with the Cavalry and in directing the fire of Artillery. Every movement of troops is seen and re- ported by aeroplane observers, so that the element of surprise due to the rapid movement of troops in the theater of opera- tions has been eliminated, except in the case of movements at night or in rainy or foggy weather. Motor transport. One of the most interesting and important , innovations has been the use of motor transport for the move- ment of large bodies of Infantry from one theater to another to be thrown in at critical points. Undoubtedly the resort to such means contributed largely, even vitally, to the success of the French in the battle of the Marne. TRENCH WARFARE. 4 When, after indecisive maneuvers, both belligerents settled down in entrenched positions facing each other there was initiated a system of trench warfare different from anything heretofore known. It has since been continued and developed to a remarkable extent, until at present the position of each belligerent consists of two or three and even four entrenched zones, the trenches of each being very complicated in design and constructed with great care and at an enormous cost of labor and material. The methods of attack and defense (of these entrenched po- sitions) as adopted at different times have changed with the progress of operations and the development of various new kinds of offensive and defensive weapons ; new methods of attack and defense have been adopted only to be abandoned upon the appearance of some new weapon or some change in the method of use of an old weapon. Frontal attacks. Owing to the fact that the lines rest their flanks on impassible obstacles or on neutral territory wide turn- ing movements are not possible, and enveloping movements HI im- possible only in local attacks against small portions of the hostile line after it has been pierced, so that all main attacks are confined to purely frontal attacks. Obstacles. The use of obstacles, both natural and artificial, has greatly increased, one of the most important being wire entanglements, which are used extensively on all fronts. Liaison. One of the most important improvements developed in the present war has been that in communication between, and cooperation and coordination of, the different elements of a command ; this is covered by the French term " liaison." This feature is referred to in all reports from the various fronts. The aeroplane cooperates with the Artillery, not only in locat- ing the enemy but in directing the fire upon him, and also with the Infantry, giving constant information of the dispositions and movements of the enemy. Cavalry. Cavalry is no longer used in large bodies for mounted action ; the increased number of lines of trenches, the great increase in the use of artillery and machine guns, together with the use of barbed wire in almost unlimited quantity, ren- ders the opportunities for the use of Cavalry comparatively few. It was used in Belgium in earlier stages of the war, but since trench warfare began it has generally been dismounted and horses held in rear while the men are equipped as Infantry and put into the trenches. Artillery. In trench warfare the Artillery cooperates more closely than ever with the Infantry, Artillery reconnaissance officers and scouts accompanying the most advanced Infantry lines in order to obtain information about targets for the Artil- lery, even going forward with the assaulting lines so as to keep their batteries informed of the exact location of the Infantry and of any new targets presenting themselves. There is a cer- tain number of these Artillery observers or scouts attached to each battalion of Infantry. They carry back the information obtained to protected Artil- lery observing stations, from which it is telephoned (usually by a buried wire) to the observing station of the Artillery com- mander. This system of information, of course, causes considerable losses in the Artillery, but, on the other hand, it is of very great assistance to the Infantry, and prevents enormous losses from their ranks. Other developments which have greatly affected the methods of attack and defense are : The great increase and importance of machine guns and automatic rifles, the introduction of aerial torpedoes, trench cannon, armored tanks, rifle grenades, the reversion to the ancient system of bombs and hand grenades, and the use of gas. 8 THE ATTACK. Artillery. The general method of attack used almost exclu- sivi-ly at present in Europe is to smother the defense with u torrent of explosive shells, kept up incessantly for from one to three or more days, so shattering the defense that they will be able to offer but slight resistance to the advance of the Infantry; then to rush forward with the Infantry and seize the enemy's positions while his forces are still demoralized and consolidate them before reenforcements can be brought up through the Artillery barrage for a counterattack. This Artillery bombardment is absolutely necessary to pre- pare the way for the Infantry advance, as otherwise the Infantry could not advance in the face of the hostile artillery, rifle, and machine-gun fire. This bombardment has for its object: (a) To destroy or silence the hostile artillery. (&) To destroy or cut passages through the wire entangle- ments in front of the enemy's position. (c) To destroy the hostile Infantry trenches, especially the supporting points, or cause their defenders to abandon them. (d) To seek out and destroy the hostile machine guns. (e) To produce curtains of fire or barrage covering the ad- vance of the Infantry. (/) To prevent the bringing up of hostile reenforcements. Notwithstanding the close cooperation mentioned above be- tween the Artillery and Infantry, once the Infantry has moved out of their front trenches the connection is to a certain extent impaired, and, in fact, the wire communication may often be broken, so that there might be too much delay in getting word back to the Artillery commander to enable him to open effec- tive fire on suddenly discovered objectives, such as machine- gun emplacements, concrete dugouts, or hostile detachments exposing themselves for a brief period. To provide against such a condition light guns 37 millimeters are assigned to the Infantry regiments, one to each battalion, subject only to the orders of the regimental and battalion commanders con- cerned. They are light enough to be moved by hand and can follow by fire or change of position any advance of the Infantry. This gun is easily adjusted, very accurate and effective up to 1,500 yards. Its shell can penetrate two or three thicknesses of sand bags or a plate of steel and then explode, its explosive effect being about the same as a grenade. Save under exceptional cases it is always attached to the machine-gun company for the attack. It is primarily a weapon for the offensive, and its essential r61e is to destroy with direct fire the visible machine guns, but it is also very effective against troops taken under enfilade fire. They are employed separately and not grouped in batteries. Since they make good targets, they wait till the last few minutes preceding the assault to destroy the machine guns which the Artillery may not have reached. This use of a small-caliber gun with the Infantry is not favored by the British. They, however, use a gun of about equal caliber in their tanks, which is very effective against machine guns. Infantry. The Infantry, in trench warfare, is divided into two classes holding troops and attacking or shock troops. The mental and physical strain on troops in the trenches under conditions of modern warfare is so terrible that after being subjected to it for any length of time they are not con- sidered fit for an energetic assault, and this duty is assigned to other troops called shock troops, which consist of picked organizations recruited from the youngest and most vigorous men in regions which have produced the best fighting stock. Shock troops are rarely sent into the trenches for routine duty, but when not actively engaged in conducting or resisting an attack are kept in camps or cantonments well behind the battle front, where they can have good rest at night while training hard every day. In this way mobility, cohesion, and enthu- siasm are preserved in this most important class of troops. The holding troops are those kept in the trenches, and being under almost constant fire and subject to attack in their trenches, it becomes necessary to change them frequently and give them a period of rest behind the lines for recuperation. Two weeks in the trenches and two weeks in rear is the usual division of time. Auxiliaries. The auxiliaries of the Infantry are so im- portant and so intimately associated with it in the attack that mention of some of them will be made before going into the details of the attack. 98451 17 2 10 (a) The use of machine guns has greatly increased since (he European war began. The Lewis and other guns of that type ai'e classed usually as automatic weapons and consti- tute part of the equipment of each Infantry company, while the heavier guns, such as the Maxim, the Colt, and Vickers, into the details of the attack. The French have a machine-gun company of eight guns be- longing to each battalion of Infantry. The British have 16 guns to a machine-gun company and three or four of these companies form a battalion which consti- tutes the machine guns of a division, and the guns are assigned wherever needed. The Germans have probably a larger proportion of machine guns than either the British or French, and they make very extensive use of them in all phases of the attack and defense. The use of machine guns forms the subject of a separate paper and the details of their use are omitted. GRENADES. The extensive use of grenades has been revived in the present war after having been abandoned for 100 years or more. With the adoption of trench warfare it was discovered that while the fire of the modern high-powered rifle is of little value in as- saulting strong trenches, the fire of grenades is very effective, so much so that the grenade is now considered a necessary auxiliary of the rifle, and forms part of the equipment of every Infantry regiment. Indeed the grenade now plays almost as important a part in trench warfare as the rifle. All Infantry units are instructed in grenade throwing or bombing and the specialists of this class are generally in the advance wave of the attack. The trench mortar, another resurrection of an ancient weapon, has come into general use in trench warfare to supplement the work of the Artillery. It fires a shell up to a foot in diameter or a cylinder of shells with a range of more than 400 yards. It is fairly accurate and very effective against both personnel and mate'riel. THE ORGANIZATION OF FRENCH INFANTRY. A French regiment is composed of three battalions, each con- sisting of three companies of Infantry and a machine-gun com- pany of eight guns, with one 37-mm. gun attached. Each com- 11 pany has eight automatic rifles in addition to its other equip- ment. The battalion has thus come to be a very strong unit, capable of progressing by its own means, and of breaking most of the resistance it encounters. The company is divided into four identical sections, and each section into two half sections of two squads each, as follows : First half section, under command of a bomber-sergeant, or automatic rifleman (fusilier) sergeant. First squad (bombers) : 1 corporal. 7 bombers. Second squad (fusiliers) : 1 corporal. 6 fusiliers (2 automatics, with teams of three). Second half section, under command of a rifleman sergeant. Third squad (riflemen) : 1 corporal. 8 riflemen. 2 rifle-grenade men. 1 grenade carrier. Fourth squad (riflemen) : 1 corporal. 9 riflemen. 2 rifle-grenade men. 1 grenade carrier. This would make, in the four sections : 4 sergeants, automatic riflemen or bombers. 4 corporals, automatic riflemen or bombe*s. 24 automatic riflemen. 4 sergeants, riflemen. 8 corporals, riflemen. 68 riflemen. 4 corporals, bombers. 28 bombers. 16 rifle-grenade men. 8 grenade carriers. Total 168 A company has altogether 194 men. The other soldiers of the section not fighting in the ranks, such as the drummer or bugler, pioneer, cyclist, signaler, orderly, 12 hospital-corps man, etc., are divided among the squads to equal- ize their strength. This organization gives the advantage of permitting the intro- duction of the new arms into the Infantry without upsetting the organic channels of command as they are now established. The c-iptnin commands the sections. An important point to note is that all specialist groups are officered, allowing a company or battalion commander to con- centrate them if the particular tactical situation requires it. They play the normal part in combat if they do not receive special instructions. Every man must know how to throw a grenade, and every rifleman is taught a particular specialty so as to be able to re- place, in case of an emergency, any specialist who happens to be put out of action. From a tactical point of view, the char- acteristics of the new armament bring about a thinning of the firing line, thereby increasing the depth of the formations. Both in offense and defense the machine guns and the 37- mm. guns are a necessary complement to the other armament of the Infantry. These in conjunction with the automatic rifles and rifle grenades compel the enemy to remain hidden in liis holes and trenches, while the bayonet men, trench cleaners, and bombers are rushing forward to engage in hand-to-hand fighting. The machine guns, automatic rifles, and 37-mm. guns, having a flat trajectory, sweep down any objective emerging from the ground. The hand and rifle grenades, having a high trajectory, can reach the trenches and any objective under- ground, then the work of all these is completed by the bayonet men and trench cleaners. ATTACK OF A DEFENSIVE POSITION. In an attack it should be emphasized that the unity of com- mand in depth must be preserved everywhere unless there is an imperative reason for doing otherwise. The principle must govern in the regiment and if possible in the battalion, thus: If two or three regiments are to be as- signed to as many waves, each regiment must receive its proper proportion of the front, and the front of each regiment should also be divided between the two or three battalions. Thus each battalion commander, having to look after a front of about 500 to 600 yards, can exercise efficient control of his 13 command, and the colonel, by placing himself in the center of a zone 800 or 1,000 yards wide, can be kept well informed of the progress of his battalions and will be able to direct their movements. If deployed over much greater fronts and the reenforcements come from different organizations, the homogeneity in depth would be entirely lost and field officers would lose control over such an extended front. Moreover, as the attack progresses, the mixing of different units would be very objectionable, owing to the difficulty of assigning new and different targets to the many heterogeneous groups thus formed from the various organizations. In any case success is impossible unless the ground has been thoroughly prepared, and this takes a long time. In preparing for an assault, seniors must take steps to organ- ize it and make all necessary preparations themselves and not leave all responsibility with the juniors, as this would prob- ably mean isolated advances by small bodies and resultant con- fusion and disaster. The hostile terrain must be studied with the utmost care by direct observation, by patrols, and by the aid of aerial photo- graphs. In the assault each unit must know its special task before- hand, and if possible the entire movement should be rehearsed in rear of the lines in trenches laid out to correspond to those of the enemy. Each commander must know the exact time he is to start and must not fail to start on time. To insure all starting at same time, all watches are carefully synchronized beforehand. The hosile defensive works generally consist of two or more intrenched zones, each composed of two or more lines of trenches with supporting points or strong points constructed at villages, woods, and other suitable places, so arranged as to furnish flank fire on the ground in front and in the intervals. At the present time the more and more extended use of the counter battery has permitted sending of men forward in much thinner lines than formerly, which are of course much less vulnerable, consequently the almost general rule of forming the first waves of men placed at 4 or 5 paces interval. A chief of section can command only a front of 80 to 100 paces, and the section consisting of about 40 men, it is necessary to form the section in two lines or waves, the first wave con- 14 sisting usually of the grenadiers and the automatic riflemen, the latter in the center, and the second wave of the riflemen and the rifle grenadiers, the latter in the center. The section is thus capable of becoming completely i-ngagt-d in case it should come in contact immediately with the enemy, since the rifle grenadiers are placed at sufficient working dis- tance to the rear of the first wave, and the automatic riflemen can instantly reach any enemy in movement oa the open ground. If the terrain is cut up by woods, villages, etc., the proportion of grenadiers may be increased by taking them from the sections in support and the automatic riflemen sent back to the second wave. Or if the distance to cross between departure trench and the enemy exceeds 300 or 400 yards, the number of automatic riflemen would be increased. Two or three sections are usually placed abreast on the com- pany front, which thus covers 200 or 300 yards. The support sections follow the leading sections of their company at about 50 yards, marching in two lines, or, where possible, in two lines of squad columns at 20 yard interval, with a few yards distance between the lines (practically a line of half sections in column of files). In the latter formation they may be maneuvered to a certain extent toward important points, such as the intervals where the first wave has already broken through and advanced toward the support of the trenches of the enemy. The first wave or line of the support is usually formed of the half section of specialists, for the reason that in case of en- countering a difficulty which calls for reenfcrcements it is usually the specialists who will be needed and called upon first. The echeloning of the specialists in front is also the most favorable formation to progress by rushes in a terrain cut up by shell holes ; the half section of specialists is sufficiently armed to clear out the shell holes or resist temporarily a hostile counter attack. The chief of section is ordinarily between the two waves of his section. The captain is usually in front of the support sections. The support sections are closely followed by a powerful line of machine guns, which are thrown into the fight where needed to reenforce the leading units and organize new assaults or to 15 open fire on any new targets offered by advancing hostile troops. The machine guns are directed on selected points which are offering obstinate resistance to the attacking lines, especially the hostile machine guns. If an attack is made in the form of an assault certain frac- tions detailed to clean up the enemy trenches, called " trench cleaners," usually march immediately behind the leading sec- tions and may be taken from the support sections. They are armed with pistols, knives, and hand grenades. If the attack takes the form of a gradual progression the echeloning of the sections is made according to the same prin- ciple, but the special details of trench cleaners is unnecessary, as the trenches are cleaned up by the same troops that took possession of them. The captain can use his sections complete, or, since the specialists have been specially trained, he can take them out of their sections and use them for a particular purpose and some- times with much greater results. The soldier specialists, such as the grenadiers, automatic riflemen, ammunition carriers, rifle grenadiers, and trench cleaners, carry only tl.c weapons or munitions of their specialty, and otherwise have their loads lightened. The ordinary riflemen carry the usual pack and equipment. The officers no longer lead the assault, but direct it. They wear no distinguishing insignia and are equipped with the rifle and bayonet, the same as the enlisted men. Each unit of the first wave of attack is given a definite objective. At the sig- nal for the assault the waves rush forward at short distances from each other so as to cross in a very brief space of time the zone of barrier fire of the enemy, but the different waves must not break upon the first wave, for that would only increase the density of the skirmish line and increase the losses. Fire is opened by the assaulting troops only at short ranges, the advance being protected by a curtain of Artillery fire. As the leading wave approaches the enemy's first line of trenches to within throwing distance, grenade fighting begins and is kept up until the trenches and approaches are cleared of the enemy. The advancing lines make use of shell holes or any depres- sion or other place offering any concealment or protection in the advance to the assault or from trench to trench. 16 This must be done step by step and with great caution, in order to minimize losses caused by enemy's grenades and by traps, fougasses, etc. Genades are thrown ahead so as to gradually clear the ap- proaches, and when a lateral trench is reached several grenades are thrown in each direction right and left. The grenadiers are assisted by the automatic riflemen, who fire on any of the enemy attempting to advance along the ap- proaches, and when the enemy is overwhelmed they move for- ward and clear the way for the further advance of the grena- diers, who in turn bombard the next section of the approaches with grenades. When the first wave reaches the objective it is joined by the half section of riflemen, who immediately organize the cap- tured ground and prepare to defend it stubbornly against counterattack. Wneri no further advance is possible, sandbag barricades are built at the point of furthest advance and preparation made for another assault. The main efforts are directed against the intervals between the supporting or strong points. No attempt is made to storm these points for to do so would entail t->> great losses, but cer- tain units are given the task of encircling them by occupying their flanks or borders to prevent their bringing an enfilade fire on the troops assaulting along the intervals. If the attack on the intervals succeed, the supporting or strong points will fall of themselves. THE BRITISH DIVISION ATTACKING FROM TRENCHES. BECONNAISSANt K. The division commander is assigned his frontage, objective, and assembly area, and is informed of the Artillery support he may expect and of the action of the divisions on his flanks. Before he can formulate his plans for attack there must be a thorough reconnaissance of the enemy's trenches and the ground over which the attack is to be made. The aeroplane reconnaissance and photographs must be supplemented by per- sonal observation and patroling. When brigade and battalion commanders are assigned their tasks they must also reconnoiter their fronts. 17 ARTILLERY. The Artillery preparation lies to a certain extent outside the province of the division commander, as the Artillery plan, except for minor operations, is coordinated by the Artillery commander under the orders of the corps commander, after consultation with the division commanders concerned. The division commanders study the plan so far as it affects their tasks and make such recommendations as they think necessary. The commanders of brigades and battalions, with the com- mander of the Artillery detailed to support them, study on the ground the Artillery plan so far as it affects them. In regard to the use of the Artillery for barrage purposes two batteries of a battalion are assigned to a front of about 250 yards, this front being divided about equally between them. The third battery is assigned to cover the whole front of the other two batteries. The advantage of this arrangement is that the third battery may be switched to some special objective off the main front without stopping entirely the fire on any part of the front. A jumping rather than a creeping barrage is generally used in order to jump from one hostile trench to the next, unless it becomes necessary to search thoroughly all shell holes and other hiding places in between the principal lines of the enemy trenches. Immediately after the advance of the Infantry begins the light Artillery supporting it commences an intense bombard- ment with the object of forcing the enemy to take cover, and thereby prevent him manning his defenses before the In- fantry reach the trench. At the moment laid down in the time table of Artillery fire the barrage lifts clear of the trench and the Infantry rush in and capture it. The Infantry must therefore be taught that success depends on their getting within about 75 yards (depending on the range) of the barrage before it lifts, in order that they may reach the trenches before the enemy can man them, and this requires only a few seconds. The secret of a successful assault rests upon the assumption that the Infantry conform their movements exactly to the timing of the barrage. Therefore the importance of th : s timing can not be overestimated. 98451 17 3 18 The pace of a barrage depends, to a certain extent, on the pace of the Infantry, which varies with the conditions of the ground, the length of the advance, the number of enemy trenches to be crossed, etc. It may be from 75 to 15 yards per minute. The pace of the barrage should be quicker at first and grad- ually slow down as the men become exhausted, in order to give them time to get close up to the barrage, and pull themselves together for the final rush. SIGNALS FROM THE INFANTRY TO THE ARTILLERY. For the first hour or so after the assault, until the communi- cations can be well established, touch between the Infantry and the supporting Artillery will generally be restricted to calls for barrage fire by means of light signal rockets, and leading troops should have an ample supply of these. Colored flags, carried by one or two men in each platoon, are waved to indicate line gained by the leading Infantry. They must not be stuck in the ground. Signals from the aeroplanes will be referred to later. INFANTRY ORGANIZATION. The British have abandoned the regimental organization, and a brigade now consists of 4 battalions, and a division of 3 brigades, or 12 battalions. An administrative staff and transport are assigned to bat- talions. The machine guns of a division are organized into 3 companies of 16 guns each. They are being increased to 4 com- panies of 16 guns each to a division. The Infantry company of 250 men is divided into 4 platoons, each of 4 sections. They count on an effective strength of about 160 men to the company, or 40 to the platoon. The organization of the sec- tions is different and each has its particular task. The first section is composed of bombers and rifle grenade men. The second and third sections are composed of riflemen with bayonets. The fourth section is composed of seven Lewis gunners, with one Lewis gun. 19 The Lewis guns form part of the regular equipment of the In- fantry companies and are not a part of the machine-gun com- pany. FORMATION AND FRONTAGES. In an attack each unit must have sufficient driving power in itself to carry it through to its objective and maintain itself when it gets there. When a number of trenches have to be carried, considerable depth will be required to the formation in order to give the necessary driving power, and the frontage must be reduced. If in later attacks there should be only one or two lines of trenches as the objective, the frontage may be increased. A brigade usually has a front of attack of about 500 to 700 yards, but this may be increased to 1,000 or 1,200 where the resistance is much less. A battalion should have a frontage of from 250 to 350 yards. The battalion must be organized in depth in a series of waves. Two companies are usually put abreast in the first line, and the others in the second line. Each company in both lines attacks in column of platoons at about 50 yards distance with intervals of 3 to 5 paces between men, so there would be eight lines or waves, of two platoons each. The eighth and sixteenth platoons, the two in rear forming the eighth wave, are usually not employed in the attack, but are left behind as a nucleus to form on in case of heavy casualties. ORGANIZATION OF THE TRENCHES FOR THE ATTACK. FRONT TRENCHES. The front line or parallel of departure must be not less than 200 yards from the enemy's front line, and as nearly as possible parallel to that line, so as to insure the leading waves jumping off squarely toward their objective. ASSEMBLY TRENCHES. The leading two or three waves are more likely to meet machine-gun fire, and generally move in extended order, as they should present as unfavorable a target as possible. For 20 this reason continuous trenches parallel to the parallel of de- parture are necessary. Not more than two waves can be accommodated in one trench. The subsequent waves will move in line or in line of section columns in single file, and for these small tees or sidings off the approach trenches most easily provide cover. Reserves can usually be accommodated in the trenches of the reserve or intermediate lines without much additional labor. APPROACH TRENCHES. There should be separate trenches for moving forward or to the rear, and these are called " in " and " out " trenches, which are plainly marked as such. There should be one of each on each battalion front of attack to within 800 yards of the front line, and a separate one of each on each brigade front of attack up to the same point. In addition there should be one of each on each company front of attack for the depth of the company zone of assembly. " Out " trenches must have corners rounded so as to allow passage of stretchers. A map showing " in " and " out " trenches must be made and issued down to company commanders. Where time does not permit digging necessary trenches, some will have to be used as both " in " and " out " trenches, and provision made for pass- ing by widening trench or digging sidings every 25 yards long enough to admit stretchers. Detailed police are placed on duty to regulate the traffic. SAPS. Russian saps must be run out as far as possible across " No man's land " to be opened up immediately after the assault, as approach trenches, or for use previous to the assault for in- stalling boring machines, trench mortars, machine guns, etc. EXITS FROM TRENCHES. For the leading waves which move in line, and must there- fore leave the trenches simultaneously, ladders or steps are necessary. If ladders are used, all those in one bay should be fastened together at top and bottom to prevent falling, and none should project above the parapet. 21 For the subsequent waves, when moving in column, short zigzag saps run out from the trench and terminating in a ramp, form the most convenient exit. Provision must be made for bridges over the first line trenches for the rear waves. FOBMATION OF THE WAVES. In the original assault where machine-gun fire is likely to be more trouble than the enemy barrage, lines will be more suit- able for both leading and rear waves, but in the later stages of the attack when the enemy's barrage is the dominating fac- tor, it is better for the rear waves to move in small handy columns, which are easier to maneuver and can pick their way through the enemy barrage with fewer casualties. In the original assault the distance between waves may be 75 to 100 yards, in order to minimize the casualties from machine- gun fire. In later stages as many waves as possible must be started before the hostile barrage comes down, and they may follow each other at 50 yards or even less. It is not possible to lay down for use on all occasions a definite signal for the Infantry to leave their trenches and to commence the assault. In the original attack where the enemy's barrage is not likely to be heavy, zero, or the initial time for the assault to begin, may be fixed for the moment at which our barrage lifts from the enemy front trench, the Infantry timing their advance so as to be close under our barrage before it lifts. In the later stages, when the enemy, being on the alert, may be expected to put down a heavy barrage very quickly, it is essential that the Infantry all start together. Zero then must be the moment at which our barrage commences, and this com- mencement will be the signal for the Infantry to leave their trenches. THE ASSAULT. Each wave is assigned its own objective. Great care is given to the synchronization of all watches in order that all units may start off at its exact appointed time. The first wave is composed of bombers and rifle grenade men, and attack the enemy's first-line trenches. It must go straight through to its objective, following the Artillery barrage as 22 closely as possible. Intervening hostile trenches must be crossed as quickly as possible, the line reformed oil the other side, and the advance resumed. The second and third waves, composed of riflemen with bayonets and Lewis guns, reenforce the first wave after the latter have occupied the enemy's first-line trench and attack the enemy's second-line trench. The fourth wave takes up tools, ammunition, and sandbags and assists in consolidating the lines. The fifth wave is a mopping-up party to clear the enemy's dugouts. The sixth wave comprises battalion headquarters, and has two Lewis guns, kept for a special purpose. The seventh and eighth waves, if used, seize and consolidate the enemy's third-line trench. Bombing squads (one N. C. O. and 8 men) are on the flank of each attacking wave. The battalion bombers are assigned a special task. All movement must be over the top of the ground. The pace throughout should be a steady walk, except for the last 30 or 40 yards before reaching each trench, when the line should break into a steady double time, finishing up the last 10 yards with a rush. The men of the mopping-up parties must be trained with great care under selected officers, as it is very important that every man should know exactly what to do. They should always wear a distinguishing mark. Sometimes each wave has its own mopping party, or separate parties may be assigned to each of several waves. On arrival at their allotted trench they must at once dispose of any occupants who may have emerged from their dugouts, and picket the dugout entrances to prevent any more coming out, then clean them out with grenades, while other parties are sent to clear the approach trenches forward as far as the next line trench. The ultimate unit in the assault is the platoon. The platoon must be organized and trained as a self-contained unit, capable of producing the required proportion of riflemen, bombers, rifle bombers, Lewis gunners, carriers, and runners trained to work in combination. On the skill of the platoon leader and the teamwork of the different small parties trained to their particular tasks under their own leaders, the success of the assault will largely depend. 23 When conditions are favorable that is, when there is plenty of dugout accommodations available assaulting troops should take over their parallel of departure in sufficient time to give them 12 hours of daylight in the trenches before the assault. This gives time to get acquainted with the ground over which they have to assault and enables the men to get some rest before the assault. Arrangements must be made to give all ranks a hot meal, including hot tea or coffee, before the assault. Every precaution must be taken to prevent the enemy realiz- ing that the assault is about to take place. Bayonets must not be allowed to show over the parapet or in communication trenches. There must be no increase in the rate of the artil- lery fire, and no unusual or sudden movement in the trenches. The enemy must be kept in the dark until the barrage com- mences ; otherwise he will put down his own barrage and possibly prevent our attack from leaving our own trenches. CONSOLIDATION. When a trench has been carried it becomes necessary to con- solidate it, to provide against a counter attack. OUTPOST. In order to protect this consolidation the first thing is to throw out a covering force or outpost line formed of small self-contained posts of about one noncommissioned officer and six riflemen with a Lewis gun, about 150 or 200 yards apart and 100 or 200 yards beyond the line. These posts establish themselves in some convenient shell hole, which is converted as rapidly as possible into a short length of fire trench, and wire entanglements constructed as soon as possible. Approach trenches running toward the enemy must be blocked and hand and rifle grenadiers posted to guard them. MAIN LINE. The main captured treich must be converted at once into a fire trench facing the enemy. If the trench is badly knocked to pieces, it may be better to consolidate an entirely new trench 40 or 50 yards in front of the captured line. 24 Existing dugouts are cleared out, entrances opened up, and traverses built to protect them. Old approach trenches to front and rear are cleared out or new ones dug. In the latter case small bombproof s for two men each should be constructed where material is not available for larger ones. REORGANIZATION. If too many men are left in the captured trench they can not all get cover from hostile shelling, and the commander must reorganize his unit in depth to provide supports and reserves for counter attacks. STRONG POINTS. To give additional depth to the defense the engineers construct small posts or strong points, designed for garrisons of about 20 rifles and one or two machine guns, located 200 or 300 yards in rear of the consolidated line, and as soon as they are ready they are occupied by garrisons detailed beforehand. SIGNAL COMMUNICATIONS. (a) Cooperation with contact aeroplanes. Contact patrol work by aeroplane is designed to keep all headquarters informed as to the progress of the troops during the attack, to report the movements of the enemy, and to transmit mes- sages from the troops to the headquarters of their organ- izations. Aeroplanes for this work should have special markings which are known to all ranks of the Infantry. They will carry Klaxon horns and Very's lights for the purpose of making themselves known and answering signals from the ground. Infantry may expect to see their contact patrol vertically over our own and the enemy trenches. Attacking Infantry signal to aeroplanes by means of flares lit by previous arrangement, either at specified places or, pref- erably, at specified times. At the hour fixed the Infantry on the most advanced line keep on the lookout for signals and light their flares when their aeroplanes call for them by Klaxon. Flares can be seen if lit in bottom of trenches or in shell holes if care be taken that there are no obstructions. Battalion and brigade headquarters indicate positions and identity by ground-signal sheets and strips, and send messages by ground-signal panels and by lamp. Headquarters will indicate that they have a message for an aeroplane by displaying the white side of panel or shine their lights on the aeroplane. When the aeroplane is ready to receive a message, it will send the call letters of the headquarters concerned, either by Klaxon or by lamp. Wireless will be used by contact patrol aeroplanes ordinarily only for the purpose of sending down targets for the Artillery. Contact patrol aeroplanes may be employed on special recon- naissance before and during an attack to report the enemy's dispositions and his defenses, and the result of our Artillery bombardment. Commanders giving orders for such reconnaissance should fully consider the risks run by pilots in carrying them out. At 1,500 feet elevation or less an aeroplane is almost certain to be hit by rifle or machine-gun fire from the ground, unless the enemy is fully occupied in fighting. At a height of 3,000 feet an attack can be followed by an aeroplane, damage to trenches by bombardment can be reported upon, and railroad tracks can be seen. At 2,500 feet men massed in trenches can be seen. At 2,000 feet wire (in good light) and overhead traverses can be seen. At 1,500 feet dugout entrances can be seen, and men making signals, such as waving helmets. At 1,000 feet our troops can be distinguished from those of the enemy. (&) Cable. The rapid establishment of good signal communi- cations after the assault is most important and very dif- ficult, and no possible means should be neglected. The most valuable form is via cable lines for telegraph and telephone, and these should be laid as soon as possible. To make them secure requires burying to a depth of 6 feet or more. Approach trenches not required for consolidation may pre- viously be selected as cable trenches and the cables buried in these, as that would take less time than digging new ones, and there will usually be dugouts that can be used for test points. 2G C.-ihles are run out immediately behind the last wave of the assaulting column and carried through to the trench that " heavy shell tire and while the curtain fire is used to prevent reserves being brought up. Not too many should be placed in the front line, but they should be echeloned in depth to confuse the enemy as to their position and in order to obtain flank fire on any hostile parties breaking through any part of the line. The value of machine guns depends on the ability to use them suddenly for brief periods when the enemy presents a suitable target and in fighting them as long as they can be effective, even if this results in their capture. Every machine gun disposed for flanking fire must be well covered by grenadiers, otherwise the gunners will be tempted to think more of their own defense and fire upon enemy groups approaching them, rather than upon their designated objectives. This is true to an even greater extent with the automatic rifles. Those automatic rifles not used for flanking fire, the rifle grenades, and the hand grenades are used to constitute bar- rages to keep back the enemy. The entire front ought to be defended by a. barrage of hand grenades, while the barrages of the automatic rifles and the rifle grenades are superposed further to the front, up to about -4i><> yards, beyond which it is better to form the two with a short distance between them. All the riflemen and those grenadiers not employed in forming the barrage are reserved to make a counter attack on the enemy. The companies of the second line operate on similar prin- ciples; the machine guns, automatic rifles, and rifle grenades are arranged so as to cover with fire every portion of the first line which might be invaded by the enemy. After a short preparation by fire from these the grenadiers and riflemen make the counter attack. The captains in charge of the two lines are responsible for the arrangement of the machine guns, automatic rifles, and rifle grenades, the distribution of the barrages, and the distri- bution of the groups for the counterattack, the art of which to obtain the best results while interfering as little as possible with the channels of command in the different sections. 35 The defensive capacity of Infantry, as well as their offensive power, have been greatly increased by the introduction of the new high-powered armament, but these weapons are valuable only if they are in the hands of courageous, well-instructed, and dis- ciplined soldiers directed by chiefs having definite notions as to the use that may be made of them. " In this war the methods of combat are being modified con- tinually ; it is the duty of everyone to follow these modifications and to take advantage as early as possible of the progress accomplished. Courage being equal, the victory is to the most skillful." The real strength of the defense consists, not in holding the firing and cover trenches, or even the support trenches, but in holding the supporting and strong points until the counter- attack can be launched. All arrangements for the counter- attack are made beforehand down to the last detail. When the enemy's Artillery preparation begins, the troops leave the firing trenches and go back to the bombproof covers, leaving only a few men in the observation positions. These bombproofs are placed along the cover trenches and are pro- vided with at least two entrances so as to allow a prompt exit and to provide against one entrance being closed by an ex- plosion. When occupied for an extended period the bomb- proofs are connected with each other by underground passages. When the fire of the hostile Artillery is raised to make way for the Infantry attack or to resort to curtain fire, the troops return to their firing trenches, put their machine guns in posi- tion, and break up the attack, pouring a flanking fire into any exposed groups from concealed positions. The Artillery, while keeping up a heavy fire on hostile Artil- lery, opens a heavy fire on the Infantry line as soon as the attack begins. The Artillery attached to the Infantry en- deavors especially to bring a fire to bear on the hostile machine guns. If the enemy succeeds in gaining the firing trenches the counterattack is launched before the ground gained can be consolidated. o