NOTES ON 
 FIELD FORTIFICATION 
 
 BY THE 
 
 ARMY FIELD ENGINEER SCHOOL 
 
 THE ARMY SERVICE SCHOOLS 
 
 FORT LEAVENWORTH, KANSAS 
 
 1914 
 
NOTES ON 
 FIELD FORTIFICATION 
 
 BY THE 
 
 ARMY FIELD ENGINEER SCHOOL 
 
 THE ARMY SERVICE SCHOOLS 
 
 FORT LEAVENWORTH, KANSAS 
 
 1914 
 
Press of the Army Service Schools 
 Fort Leavenworth, Kansas 
 
Preface 
 
 "Field Fortifications are a means to an end. In conjunction with 
 maneuver and fire, they constitute an instrument of tactics, and should be 
 employed only when and where required by the tactical situation." (Quo- 
 tation from French Manual.) 
 
 "Field Fortifications are always of use, never hurtful, when they are well 
 understood." (Napoleon's 103d War Maxim.) 
 
 / *~P H E above quotations set forth very clearly the 
 -^ legitimate role of Field Fortifications in military 
 operations, and their appreciation, when properly em- 
 ployed, by the greatest soldier the. world has yet pro- 
 duced. 
 
 The ' 'Notes on Field Fortification" was first is- 
 sued in 1912, having been prepared by the Director 
 and Instructors of The Army Field Engineer School 
 for use in the course given the student officers of The 
 Army School of the Line. The object is the inculca- 
 tion of correct views regarding the employment of 
 Field Fortifications by combat branches. It is in no 
 sense a manual of military engineering or a treatise 
 on fortification; but merely enunciates certain prin- 
 ciples which are to be amplified in the class confer- 
 ences and their application taught by terrain exer- 
 cises. 
 
 No solutions of map problems are issued with the 
 ' 'Notes, " as it is not believed that the subject of 
 Field Fortification can be satisfactorily handled ex- 
 cept with the ground actually before the student. 
 
 The original edition having been exhausted, ad- 
 vantage is taken of the necessity for reprint to make 
 changes which the use of the book in the instruction 
 of the three classes and the progress of the past two 
 years have indicated to be desirable. 
 
 M. L. WALKER. 
 Major of Engineers, 
 
Chapter I 
 
 GENERAL PRINCIPLES. FIELD FORTIFICATIONS IN RELATION 
 
 TO STRATEGY AND TACTICS. SIMPLE RIFLE 
 
 TRENCHES. LOCATION OF 
 
 TRENCHES. 
 
 T N all contests for the mastery, whether between 
 -- individuals or between aggregations of individ- 
 uals, there is an inevitable combination of offensive 
 and defensive action. Neither contestant, however 
 great be his superiority, can afford to neglect all de- 
 fensive precautions. This applies with particular 
 force to the game of war, in which the contestants 
 are represented by armies, often of huge size, oper- 
 ating over vast areas. 
 
 In military operations the advantages sought by 
 each side are, in the first instance, strategical; in the 
 second, tactical. The attainment of either, or both, 
 necessarily implies possession of the power of maneu- 
 ver. The advantages attained by strategical maneu- 
 vers are generally realized only by winning the bat- 
 tle, which is their culmination, and for which ability 
 to maneuver tactically must be maintained. 
 
 The power to maneuver, whether strategically or 
 tactically, is essential to success. The side which, 
 from any cause, loses the power of maneuver in 
 strategical combinations will be at a disadvantage in 
 the decisive battle. If it further loses the power of 
 tactical maneuver, final defeat is inevitable. 
 
 As maneuver is necessary to success, troops should 
 welcome orders to advance from the trenches. Chang- 
 ing conditions of the conflict have in the past fre- 
 quently led to the construction of trenches without 
 their being used, and officers must expect this as a 
 5 
 
feature of campaigning, and accept cheerfully what 
 at times may appear as unnecessary labor. 
 
 That offensive action alone can produce decisive 
 results is clearly established by military history, and 
 all military teachings are in complete accord on this 
 point. "Troops dig because they are forced to halt, 
 they do not halt to dig. " (Normand.) But while act- 
 ing generally offensively oneself, it is none the less 
 necessary to guard against the enemy's offensive 
 movements, and this can be most effectively accom- 
 plished by limiting his power to maneuver. The 
 means most commonly employed to this end are 
 fortifications, which have for their object the 
 strengthening of the terrain at predetermined points 
 in such manner as to permit relatively small forces to 
 check the movements of the adversary while at the 
 same time facilitating and increasing your own ma- 
 neuver power. Only those -fortifications, conceived 
 and applied in this spirit are really useful in the con- 
 duct of military operations. 
 
 According to whether they respond to strategical 
 or tactical needs, fortifications may be classified as 
 strategical fortifications and tactical fortifications. 
 Strategical fortifications are most frequently con- 
 structed, in whole or in part, during time of peace, 
 with all the resources of the technical arts, to 
 strengthen points whose strategical importance in 
 the event of war is clearly seen. Occasionally, how- 
 ever, the necessity for strategical fortifications arises 
 only at the outbreak, or during the progress, of a war 
 to strengthen points, the strategic value of which could 
 not be foreseen. Their construction, more limited as 
 to time, involves expedients less comprehensive than 
 in the case of works built during time of peace, but 
 still far in excess of those applicable in ordinary field 
 works. Strategical fortifications are also called Per- 
 manent and Semi-Permanent or Provisional, accord- 
 
ing to the time of their construction and the materials 
 employed. The various existing* land fortifications in 
 Europe are examples of permanent fortifications, 
 while the defenses of Washington, D. C., in 1861-65 
 form a good example of provisional fortifications. 
 Both permanent and provisional fortifications are 
 constructed by military engineers, mainly with civi- 
 lian labor and will not be further considered in these 
 ' 'Notes. " 
 
 Tactical fortifications are such as are generally 
 constructed by the troops themselves to satisfy pass- 
 ing tactical needs. The time and materials available 
 for their construction vary between wide limits, from 
 the hasty intrenchment built with the portable tools 
 of the troops, not infrequently under fire, to elabor- 
 ately fortified lines of defense requiring days, weeks, 
 or even months for their preparation, in which work 
 the civilian population may sometimes be employed, 
 as was done by the Russians in Manchuria and the 
 Boers in South Africa. 
 
 Tactical fortifications being constructed in the 
 field to satisfy temporary tactical needs are also prop- 
 erly called field fortifications. It is well to observe, 
 however, that the various classifications of fortifica- 
 tions attempted by different authors are not always 
 clearly defined. Strategy and tactics frequently blend 
 into each other and so do the fortifications constructed 
 to meet their needs. Similarly, classifications based 
 on the time and materials of construction employed, 
 imperceptibly merge into one another. Sometimes 
 hasty works commenced on the field of battle are 
 gradually developed into stronger ones in response to 
 the tactical situation as occurred with both the Rus- 
 sian and Japanese lines on the Shaho and with the 
 Turkish lines at Plevna. 
 
 *Refers to those existing before the outbreak of the Euro- 
 pean War of 1914. 
 
8 
 
 These notes will deal mainly with tactical, or 
 field fortifications, this being the type which most 
 directly concerns combat officers of all branches of 
 the service. 
 
 As previously stated the object of all fortifica- 
 tions should be to check the adversary's power of 
 maneuver with relatively small forces, while at the 
 same time facilitating our own maneuver. To sur- 
 render our own power of maneuver is either an ad- 
 mission of weakness justified only in the presence of 
 superior forces and resorted to for the purpose of 
 gaining time; or else, the result of the failure of the 
 commander to appreciate the part played by fortifi- 
 cations in tactical opperations. Unless, therefore, 
 the adversary is overwhelmingly superior, field forti- 
 fications must be employed in a manner not to kill the 
 offensive spirit. 
 
 The conception that field fortifications can, and 
 should, play a part in offensive operations, although 
 long recognized, was brought into great prominence 
 in the recent campaign in Manchuria, especially on 
 the part of the Japanese, who, while making free 
 use of field fortifications of all kinds, never relaxed 
 their aggressive spirit; on the one hand clinging des- 
 perately with the spade to what they had won with 
 the rifle; and on the other hand checking with their 
 rifle the Russian attempts to drive them from their 
 works. Troops acting offensively cannot continue to 
 advance constantly at all points of an extended bat- 
 tlefield where fighting is carried on for days. Halts 
 will be inevitable from time to time at various points 
 to permit assembling forces for further efforts, to 
 cover the mass of the attack, to choose the point of 
 the attack, or to hold the enemy. At all these halts 
 the offensive will wish to hold his ground, for which 
 purpose the strengthening of the terrain is desirable 
 and necessary. 
 
To derive the maximum benefit of field fortifica- 
 tions, especially in offensive operations, requires a 
 thorough understanding of their application in ac- 
 cordance with correct and definite principles. Too 
 early, too extensive, and too frequent use of field 
 fortifications are certain to injure the offensive spirit 
 of leaders and troops, sacrifice the maneuver power 
 and surrender tactical advantages to the adversary. 
 On the other hand, a total neglect of the benefit to 
 be derived from the employment of field fortifications 
 will involve needless and heavy losses and, against a 
 skillful adversary, will lead to disaster. Just where 
 and to what extent to use field fortifications in tacti- 
 cal operations without impairing the offensive spirit 
 is often a delicate and difficult matter to decide; for 
 this reason the art of applying hasty field works is one 
 of the most important and difficult branches of the en- 
 tire subject of fortification. This is all the more so 
 for the reason that, although all troops are now lib- 
 erally supplied with tools for the construction of field 
 works, it is a fact that little attention is devoted to 
 this important subject in peace training. Duties illy 
 learned in peace training will surely not be well per- 
 formed under the stress of war. 
 
 The most recent wars have left no doubt as to 
 the extensive part played by fortifications in field 
 operations, fortifications which must be constructed 
 by the troops themselves at all times and under a 
 variety of circumstances, requiring, therefore, good 
 understanding on the part of all officers and training 
 on the part of the enlisted men. 
 
 Since the object of field fortifications is to check 
 the enemy's maneuver power with relatively small 
 forces, it is pertinent to inquire just how this result 
 may be accomplished. In any combat the primary 
 object is to gain superiority of fire by means of 
 which the enemy will be compelled to yield ground, 
 
10 
 
 either by the fire itself or by the bayonet in the 
 hands of the troops whose advance has been rendered 
 possible by this fire. 
 
 Superiority of fire depends upon many factors, 
 such as the character of the fire arm, training of the 
 troops, size, vulnerability and visibility of targets; 
 but mainly on the relative number of weapons em- 
 ployed. It is obvious that advantage in numbers 
 may be offset by some of the other factors mentioned. 
 Thus, troops firing from behind cover are decidedly 
 less visible and less vulnerable than troops in the 
 open. A man standing and facing to the front pre- 
 sents about nine square feet of vulnerable surface, 
 while in the prone firing position he presents but 
 little more than two square feet in the open. Firing 
 from behind cover the vulnerable target of a rifleman 
 becomes less than one square foot; so that, other 
 things being equal, one rifle behind cover would 
 roughly be able to cope with two rifles firing from 
 the open. Other factors affecting the fire superiority 
 of troops behind cover as compared with those in the 
 open are the larger advantage of the former in the 
 matter of ammunition supply, preparation of fore- 
 ground, knowledge of ranges, better communications, 
 measures for concealment, and possibility of reinforc- 
 ing the firing line under cover. By a scientific and 
 skillful manipulation of all available means of fortifi- 
 cation, troops behind cover can check the advance of 
 an adversary many times their number. 
 
 It is therefore evident that superiority of fire is 
 not only a question of the relative number of weapons 
 brought into action but also of their relative fire 
 effect, and that fortifications afford the means for 
 bringing about equality of fire effect between forces 
 numerically unequal. Any device or artifice which 
 lends itself to diminishing hostile fire effect therefore 
 
11 
 
 constitutes an element of fortification and may be 
 employed either by the attack or the defense. 
 
 However, the advantages of fortification will 
 accrue in a much greater degree to the troops on the 
 defense since they can select and prepare their field 
 of fire so as to give the fullest effect to their weapons 
 and prepare better cover for their fire lines and sup- 
 ports while the troops of the attack, being necessarily 
 on the move must content themselves with such nat- 
 ural cover as the terrain affords or with the very 
 hasty and limited works that cannot be constructed 
 with their portable tools. 
 
 Unless fire superiority has been attained the 
 attacking troops cannot advance and their intended 
 tactical movement is checked. This is the time for 
 the commander of the defensive troops to reap the 
 advantages which his field fortifications have con- 
 ferred and, if he correctly understands the game, he 
 will pass to the offensive with his reserves, which he 
 has been able to spare for this purpose, attacking 
 vigorously, while the enemy is more or less exhausted 
 and used up by his previous efforts. It is only by 
 putting into execution such an aggressive action that 
 he can avail himself of the benefits to be derived 
 from the employment of field fortifications on the 
 battlefield of today. To continue a passive defense 
 must certainly lead to defeat by an energetic enemy, 
 who, failing in his efforts to dislodge the adversary 
 from his fortifications, will maneuver him out of 
 them, or avoid them in the first instance, if they ap- 
 pear too strong to attack. The latter consideration 
 leads to the conclusion that it would be a mistake to 
 prepare too strongly a battlefield position whereon a 
 decisive action is sought, for the enemy will then 
 simply maneuver and all preparation will have been 
 in vain. 
 
 From the foregoing observations we may rightly 
 
-12- 
 
 deduce the following general principles regarding 
 the employment of fortifications in connection with 
 tactical maneuvers: 
 
 1. The employment of field fortifications implies 
 a defensive attitude, but only a temporary one; they 
 must never be permitted to impair aggressive action. 
 
 2. Field fortifications constitute a means, coor- 
 dinate with maneuver power and fire effect, for the 
 attainment of tactical ends; their correct employment 
 therefore constitutes an essential part of the subject 
 of tactics. 
 
 The mere construction of field fortifications is a 
 comparatively simple matter, the knowledge of which 
 is easily acquired. Their correct tactical application 
 is an exceedingly difficult subject and calls for the 
 exercise of the highest judgment on the part of troop 
 leaders. In the modern battle, with its extended 
 front and long duration, the ever-shifting phases of 
 the combat will afford frequent opportunities for their 
 application upon the part of all leaders, from the com- 
 mander-in-chief down to the company officers. Ordi- 
 narily, technical advice and technical assistance will 
 be impracticable under the condition of the rapidly 
 shifting events of the battlefield, and this fact re- 
 quires that combat troops themselves be able to or- 
 ganize field works to suit the exigencies of the occa- 
 sion. All combat officers should, therefore, possess a 
 good understanding of the part played by field forti- 
 fications in military operations, know where and when 
 to use them; and the troops themselves should be 
 trained in their construction. 
 
 Simple Rifle Trenches 
 
 Superior fire effect being the primary object of 
 all tactical operations, the fullest possible scope must 
 be given to the weapons employed, which are the gun, 
 
13 
 
 machine gun, and rifle. Although of the greatest 
 importance in diminishing hostile fire effect, cover 
 must never be permitted to interefere with the fire 
 effect of our own weapons. Perfect cover, while ob- 
 tainable in practice, is therefore inadmissable since 
 no fire can be delivered from it. The use of the 
 weapon requires either that it should be capable of fir- 
 ing over the cover or through an opening made in it, 
 either of which involves a certain area of vulnera- 
 bility, which area should of course be made as small as 
 practicable. 
 
 In the use of existing and specially constructed 
 cover, the consideration of the free and unrestricted 
 use of the weapon must always be kept in view, as 
 this determines the organization of the cover. In 
 field fortifications, natural topographical, or existing 
 artificial features will be used, ordinarily, to secure 
 cover, provided their location is suitable for good fire 
 effect. They not infrequently offer better cover with 
 less preparation than is possible with specially con- 
 structed cover and include such features as ridges of 
 ground, banks of water courses, road embankments 
 and cuts, walls, property inclosures of all kinds, quar- 
 ries, etc. In thickly populated countries such features 
 occur in great abundance and their employment 
 largely reduces the necessity for specially constructed 
 cover. In sparsely settled country the necessity for 
 constructing cover is more frequent and the method 
 of providing it will now be considered. 
 
 The requirements to be filled by any cover are 
 readily deduced from a consideration of the objects 
 to be attained. As already pointed out it must permit 
 the most effiective use of the weapons employed. In 
 addition, it should afford the maximum material pro- 
 tection against the enemy's projectiles of every kind, 
 should be as inconspicuous as possible, and, finally, 
 
14 
 
 should be capable of easy and rapid construction with 
 the available means. Guns, machine guns and rifles 
 require different forms of cover to suit their special 
 dimensions and methods of use. We will consider, for 
 the present, cover for riflemen only, the rifle being 
 the main weapon of the offense and defense. 
 
 The form of cover best adapted for the riflemen 
 and best fulfilling the requirements above specified 
 is the result of experience and reasoning. This form 
 will naturally be subject to variations, both in the 
 manner of its execution and in its final dimensions, 
 depending upon available time, tools, and material. 
 Hasty cover prepared on the field of battle, in the 
 immediate presence of the enemy and frequently un- 
 der fire, will necessarily be more limited as to dimen- 
 sions than cover constructed with more deliberation. 
 
 In order to permit the most effective use of the 
 weapon the soldier should be able to adopt a com- 
 fortable firing position behind the cover. This require- 
 ment is fulfilled by a standing position with a firm 
 support for the rifle and calls for about 4' 6" relief, 
 between the top of the cover and the surface upon 
 which the soldier stands. This relief may be secured 
 by raising the top of the cover to a height of 4' 6" 
 above the natural surface of the ground, or by lower- 
 ing the surface upon which the soldier stands an equal 
 distance below the surf ace of the ground, or by a par- 
 tial combination of the foregoing methods. The con- 
 sideration of being able to overlook the foreground 
 dictates that the top of the cover should rise some 
 distance above the surface of the ground, whereas the 
 consideration of inconspicuousness dictates that the 
 heighth of the cover above the natural surface of 
 the ground shall be as small as possible. Considera- 
 tions of speed and ease of construction dictate that 
 the necessary difference of elevation between the top 
 
15 
 
 of the cover and the surface upon which the soldier 
 stands shall be secured by a partial elevation of the 
 former and a partial depression of the latter. These 
 considerations conflict more or less, with the result 
 that the adopted forms are compromises. 
 
 The thickness of cover desirable is such as to 
 secure protection against all projectiles of the enemy, 
 and it therefore becomes a factor of the penetration 
 of the projectiles in use. Experiment has shown that 
 3' thickness of ordinary earth is proof against all rifle 
 and shrapnel bullets, but that to stop light field gun 
 projectiles a thickness of from 9' to 12' is necessary 
 and still greater thickness for the projectiles of 
 heavy field guns. 
 
 The following table gives the penetration of the 
 modern small arm rifle bullet, caliber 30, at 400 yards: 
 
 Penetration 
 Material in inches 
 
 Dry pine 34" 
 
 Dry oak 25" 
 
 Dry loam 30" 
 
 Gravel or broken stone 9" 
 
 Snow, lightly compacted 90" 
 
 Brick work 15" 
 
 It is manifest that it will generally be beyond 
 the power of the troops to provide specially con- 
 structed cover of sufficient thickness to resist the 
 penetration of artillery projectiles and this condition 
 must be accepted. The danger from this source is, 
 however, trifling, for cover constructed with due re- 
 gard for inconspicuousness affords so poor a target 
 that few hits will be secured. A well placed projec- 
 tile will not destroy more than a yard of cover and 
 will reach but a single man. According to French 
 artillery officers, it is estimated that but one shot in 
 ten, even in well regulated artillery fire, will produce 
 a hit; and that 1,000' rounds would be required to de- 
 stroy a simple infantry parapet 100 yards long. This 
 would practically exhaust the entire ammunition sup- 
 
16-- 
 
 ply of a field battery, and as there will be miles of cover 
 on an extended battlefield no such expenditure of artil- 
 lery ammunition can be entertained. As aptly ex- 
 pressed by General Langlois, "firing against rifle 
 trenches with artillery shell would be like trying to 
 kill flies with a war club" and with all the chances of 
 failure. Furthermore, the greater portion of the am- 
 munition of a light battery consists of shrapnel, and 
 the practicability of effective fire against trenches 
 is thus largely reduced. 
 
 If, therefore, the cover provides protection against 
 rifle and shrapnel bullets, little need be feared from 
 artillery projectiles. The protection of rifle trenches 
 depends far less upon their strength than on their 
 slight command, good concealment, and dispersion of 
 the targets. The parapets should, however, keep out 
 rifle and machine gun bullets which are responsible 
 for 85 to 90 per cent of all casualties. Parapets that 
 do not keep out rifle bullets only serve to deform them, 
 making them capable of more serious wounds. 
 
 The simplest and most usual form of cover for the 
 rifleman is the simple standing trench shown in Fig. 
 1, Plate I. It will be noted that the elevation of the 
 cover, commonly designated as the parapet, is L' above 
 the natural ground surface and that the bottom of the 
 excavation, called the trench, is 3' 6" below the ground 
 surface, thus affording the requisite difference of ele- 
 vation, or relief, for the convenient use of the rifle in a 
 standing position. The area of the excavation is ap- 
 proximately equal to the area of the parapet, thus 
 satisfying the requirement of the maximum rapidity 
 of construction. The top of the parapet is practically 
 horizontal for a distance of three feet, insuring pro- 
 tection against the penetration of rifle and shrapnel 
 bullets, while its outer slope is quite flat, facilitating 
 the harmless richochet of artillery projectiles. The 
 side slopes of the trench and the interior slope of the 
 
17 
 
 parapet are held as steep as the nature of the soil will 
 permit, while a small berm, 1' wide and 1' high, is 
 left between the parapet and trench to serve as an 
 elbow rest for the rifleman and as a place to store 
 ammunition. The trench is furthermore made as 
 narrow as possible, reducing the amount of excava- 
 tion and diminishing the exposure. 
 
 This trench (Fig. 1) best fulfills all the require- 
 ments sought for in hasty cover for the rifleman and 
 is the form generally adopted by all armies. It can 
 be constructed in practically the same time as the 
 kneeling trench, and, as it affords better facility for 
 the use of the rifle and better cover for the man, 
 should be followed in all normal cases. Slight modi- 
 fications may at times be desirable or necessary; to 
 secure a somewhat higher parapet, to better enable 
 the foreground to be overlooked, to suppress the par- 
 apet for better concealment, or to provide for the con- 
 tingency of difficult soils preventing a depth of trench 
 as great as 3' 6". Modified forms of the simple rifle 
 trench are shown in Figs. 2, 3 and 4, Plate I, and 
 their construction is obvious from the figured dimen- 
 sions. 
 
 The cross-sections of trenches as shown are called 
 profiles. Although accurate dimensions are given, 
 these need be adhered to only approximately in prac- 
 tice, especially in hasty work. It is important that 
 the relief of the trench be suited to the stature of the 
 individual rifleman, who should look out for this him- 
 self. 
 
 These simple trenches constitute the main ele- 
 ments of the defensive organization for infantry in 
 situations calling for the execution of hasty cover. 
 By resting his rifle on the parapet and his elbow on 
 the elbow rest, the man need expose but little more 
 than his head while in the act of firing, and by 
 crouching down or sitting on the bottom of the 
 
18 
 
 trench he will be practically safe from ordinary 
 shrapnel fire and shell fragments. 
 
 In average soil the trench can be constructed in 
 one and one-half hours with the portable entrenching 
 tools. Slight as such trenches may appear, they 
 afford a material increase of resisting power against 
 troops in open terrain and are practically indestructi- 
 ble by artillery fire. Their very slightness is an ele- 
 ment of strength, affording the smallest possible tar- 
 get, the inconspicuousness of which may be further 
 increased by the use of artificial means as will be later 
 considered. 
 
 The forms of simple rifle trenches shown may be 
 regarded as normal types of hasty trenches applica- 
 ble to passing tactical needs, and capable of being 
 constructed by the infantry with their portable tools 
 in a comparatively short time. 
 
 The main defect of the simple rifle trench is its 
 total lack of lateral communication, rendering diffi- 
 cult the reinforcing of the fire line and the removal of 
 the wounded. If it be likely that such a trench may 
 be held for some length of time, it will pay to improve 
 its profile in the manner shown in Fig. 5, Plate I. 
 This profile affords a covered lateral communication 
 without interfering with the delivery of fire, and also 
 a more convenient cover against shrapnel for men 
 sitting on the step with their backs against the par- 
 apet. 
 
 The types of profiles shown in the Figs. 1-5 rep- 
 resent the practical limit of trenches applicable to 
 hasty works for use on the ' battlefield. In ordinary 
 soils their construction can be effected in four hours 
 or less. Still stronger profiles may be constructed by 
 widening and deepening the excavation and by in- 
 increasing the thickness of the parapet, giving bet- 
 ter cover to the riflemen when not actually manning 
 
19 
 
 the parapet, as well as resistance to the penetration 
 of the projectiles of field and heavier guns. 
 
 A type of profile secure against the penetration 
 of light field artillery projectiles is shown in Fig. 6, 
 Plate I. Profiles of this type are too monumental 
 and require too much work to be applicable to hasty 
 field entrenchments. They belong rather to the type 
 of provisional fortications and would be employed 
 for strategic rather than tactical purposes. Their 
 construction is the business of technical, rather than 
 non-technical troops, although situations may arise in 
 which hasty field works way be developed until they 
 reach the dimensions of the stronger types. The for- 
 tified lines of position on the Shahoand at Mukden on 
 both the Russian and Japanese sides afford examples 
 of such strengthening of hasty field works. Figs. 7 
 and 8, Plate P, show some of the profiles of strength- 
 ened trenches employed by the Russians and Japanese 
 in the Manchurian campaign. 
 
 With regard to the location of rifle trenches with 
 respect to the foreground, it is to be observed that in 
 order to realize the full effect of the modern firearms 
 a clear field of fire to the effective range of the wea- 
 pons is extremely desirable. The experinces of the 
 recent campaign in Manchuria have shown that sen- 
 sible losses from infantry fire were incurred at dis- 
 tances as great as 2,000 yards and that at 1,000 yards 
 this fire attained a tremendous power. But in order 
 to fire effectively at the longer ranges the rifleman 
 must have a clear view of the foreground. In per- 
 fectly flat terrain, whether level or sloping, the com- 
 mand afforded by the usual type of fire trenches is 
 insufficient to afford a good distant view of targets so 
 insignificant as those afforded by a skirmish line. 
 
 If it were merely a question of obtaining a good 
 distant view the best location for fire trenches would 
 unquestionably be on the military crests of heights 
 
20 
 
 with rather steep slopes, but such a location involves 
 two disadvantages, first, the sacrifice of grazing fire 
 which is so much more effective than plunging fire, 
 and, secondly, exposure of the trenches to the ene- 
 my's view. If the slopes of the heights are too abrupt, 
 there is the further danger of dead space at the shorter 
 ranges. 
 
 . Fire trenches located on prominent crests are 
 on the whole disadvantageous, affording good targets 
 to' hostile artillery which will thereby be able to sup- 
 port the advance of the hostile infantry with good 
 effect. Examples of the bad effects of locating rifle 
 trenches on prominent crests are furnished by the 
 Russian works in Manchuria as well as by the earlier 
 trenches of the Boers in South Africa. 
 
 To secure the advantages of a good view and at 
 the same time to minimize the exposure of the 
 trenches, a location on gently rising ground having 
 a concave slope is unquestionably the best. Unfortu- 
 nately the terrain must be taken as we find it, and 
 ideal positions, such as that of the French at St. 
 Privat with its gently sloping glacis-like foreground, 
 are not generally afforded. 
 
 The location of the fire trenches then resolves 
 itself into a choice between the military crest of ris- 
 ing ground or some position further forward. The 
 disadvantages of a conspicuous location on the crest 
 have already been pointed out, and such locations are 
 inadvisable unless the trenches be so strongly con- 
 structed that they can withstand ordinary artillery 
 fire, such as the Russian trenches on 203 Meter hill. 
 Positions forward of the crest sacrifice command and 
 limit distant view, but are less exposed to hostile fire. 
 The chief disadvantage of a position forward of the 
 crest is the difficulty of communicating with the fire 
 trenches, either for reinforcing the same or for with- 
 
drawing. Such being the conflicting considerations, 
 it is manifest that the location of rifle trenches with 
 respect to the foreground must be a matter of com- 
 promise, to be determined by sound judgment on the 
 part of officers responsible for the location. 
 
 In order to avoid the neutralizing effect of hostile 
 shrapnel fire, some French authorities have advocated 
 the abandonment of positions on or in advance of 
 crests altogether and placing them on the counter- 
 slopes of elevated ground on or near the rear edges of 
 plateaus. If the field of fire be not too restricted 
 such locations may occasionally afford marked advan- 
 tages. The Boer position on Spion-kop was of this 
 character. Ordinarily, positions on the counter- 
 slope afford a relatively short field of fire, permit the 
 enemy to approach the covering crest with little loss, 
 and to take up a covered position, at short ranges, for 
 a further advance. In general, counterslope positions 
 have little to recommend them, and the location of 
 fire trenches will be on or in front of the military 
 crest, so as to secure the best view of the foreground 
 consistent with a reasonable amount of security from 
 hostile artillery fire. 
 
 In rolling country, affording a succession of 
 crests within rifle range of each other, it will often 
 be difficult for the hostile artillery to bring a well 
 regulated fire to bear upon the trenches. If a posi- 
 tion for direct fire be taken upon the nearest crest in 
 front, the hostile artillery will itself be exposed to in- 
 fantry fire from the trenches. If it seeks a defiladed 
 position behind the crest, it may not be able to fire 
 at angles of elevation sufficiently low to reach the 
 trenches. 
 
 Besides the advantage of a better field of view and 
 of fire afforded by occupation of high ground the ad- 
 ditional advantages follow: 
 
22 
 
 (a) The crests will conceal our dispositions in 
 depth from the enemy's view. 
 
 (b) The enemy's assault will be made more ex- 
 hausting by compelling him to ascend the slopes. 
 
 (c) Good facilities will be afforded for launch- 
 ing a counter attack. 
 
 (d) The possibility of providing several tiers of 
 fire, will sometimes be offered. 
 
 In locating a trench upon a crest care must be 
 taken that the trench be not outlined against a sky- 
 line. To avoid this it will be necessary at times to 
 push the trench some distance down the forward 
 slope. If the forward slope is convex in profile or 
 consists of a succesion of crests, it will sometimes be 
 necessary to advance the trenches well forward in 
 order to secure the best field of fire. 
 
 Fig. 9, Plate l a , shows the usual location of a 
 trench on or near the crest of gently rising ground. 
 Fig. 10, Plate l a , shows a location on the forward 
 slope. The best location must be decided in each case 
 on the ground itself by placing the eye at the eleva- 
 tion of the parapet and sighting over the foreground. 
 
 When trenches have to be located upon steep 
 slopes some modifications of the profile are neces- 
 sarily involved. To enable the rifleman to fire down 
 hill conveniently the relief of the parapet should be 
 less than in the normal case, as shown in Fig. 11, 
 Plate l a . The diminished relief does not neces- 
 sarily imply a decrease of cover, for if the enemy 
 must look up the hill, the plane of defilade will rise 
 towards the trench and a less height of cover will 
 serve to protect men in the trench. 
 
 It has also been recommended to make the inter- 
 ior slopes less steep when firing down hill in order 
 to avoid a weak angle at the interior crest. This is 
 of doubtful utility for it involves more exposure to 
 shrapnel fire. 
 
23 
 
 Since trenches on crests and commanding slopes 
 are more exposed to the enemy's view and fire, 
 especial pains should be taken to secure concealment. 
 This may be partly accomplished by locating the 
 trench so as to take advantage of any existing natur- 
 al screen or by artificial means such as covering the 
 excavated earth with grass, sods, weeds or placing 
 branches and twigs in its front. The short lengths 
 of rifle trenches and their dispersion along the slopes, 
 both in depth and laterally, contribute to conceal the 
 works and to minimize the effect of hostile artillery 
 fire. 
 
I. 
 
 Simple S "handing Trench 
 
 Fig. I 
 
 
 
 Simple Standing Trencfi,l'5 Command 
 
 Simple Standing Trench , Parapet Suppressed 
 
 V^^W/=4vV^|l^ , wxm^'tf^'^!^^ 
 
 - ^\\ ii.l-1'n 
 
 Simple Standing Trench, Rockj Ground 
 Fi_g. ^ 
 
 Completed Standinq Trench 
 
 r~3.'~ r -3.'~r--3'-i " 
 
 w^K^^^^^2^4wA - ' "-?- - ^A\\4w/-J 
 _J;Foothoia 
 
 -3'5>^- tt ? -&~To be wasted 
 -5'1 
 
 Trianquiar Profile To Resis~r Pield Guns 
 
la. 
 
 Strengthened Russian TVench,Liaouanq 
 
 Sod Revet-men 
 
 Strengthened Japanese Trench, Chinchiatun 
 
 Location of Trench on Military Crest 
 
 Military Crest 
 
 Location of Trench forward of Military Crest 
 
 Military Crest 
 
 19 10 
 
 Modified Relief On Steep Slopes 
 
Chapter II 
 
 PRINCIPLES OF THE DEFENSIVE ORGANIZATION. SUPPORT- 
 ING POINTS. ARTILLERY POSITIONS. USE OF 
 ENGINEER TROOPS. 
 
 TN taking up a position the intentions of the com- 
 mander and the nature of the terrain govern. 
 The location, choice and organization of the position 
 are especially influenced by the object of the combat, 
 that is, whether it is planned to make a purely pas- 
 sive defense for the purpose of gaining time or to 
 seek a decisive action implying offensive conduct. 
 
 The general location of a position is influenced 
 mainly by the strategical situation. It must lie fav- 
 orably, not only to the direction of the enemy's line 
 of march but also to ones own. In general it must 
 be the natural result of the forward march without 
 requiring extensive displacements of the troops. 
 
 The choice of the actual position results from the 
 tactical situation in connection with the utilization of 
 the advantages of the terrain, therefore tactical 
 strength and security are sought. A position has 
 value only when it compels the enemy to attack or 
 when it permits the defense to gain the desired time, 
 or favorable opportunities for his own offensive 
 action in case the enemy undertakes a turning move- 
 ment. 
 
 As the opposing forces become smaller the value 
 of organized defensive lines diminishes, since the at- 
 tack can readily maneuver the defense out of its po- 
 sition without great loss of time. In considering the 
 defensive organization of lines, therefore, only fronts 
 of some extent are in question at least that of a 
 brigade which cannot be turned without the sacri- 
 
 26 
 
27 
 
 fice of considerable time, or without the incurrence of 
 certain risks. Defense of a defile might involve a 
 very limited length of line, but this is a special case. 
 
 In choosing a position the principal require- 
 ments to be satisfied are: a wide and clear field of 
 fire; concealment; freedom of maneuver along, and 
 in rear of the position; and security for the flanks. 
 The extent of the position in frontage and depth must 
 also be suited to the strength of the forces available 
 for its occupation. Too extended a front may lead 
 to a position being easily pierced but may be justified; 
 in order to gain secure points of support for the 
 flanks; to deceive the enemy regarding the strength 
 of the forces; and when there is an abundant am- 
 munition supply. Too limited a depth increases the 
 difficulty of covering the supports and reserves and 
 their lateral movement. It may therefore lead to the 
 disadvantageous occupation of advanced positions. 
 Too restricted a front, implying excessive depth, will 
 facilitate turning movements by the enemy and de- 
 lay reenforcing the front line. 
 
 The increase in size of armies as well as the 
 marked increase in fire effect of modern weapons 
 and the more liberal equipment of intrenching tools, 
 have all conduced to an extension of fronts since 
 1870. The French position at Gravelotte was occu- 
 pied at the rate of about ten men per yard of front 
 and similar densities obtained at Worth, Mars la 
 Tour and Sedan. The German lines of investment 
 around Paris and Metz were, however, much less 
 strongly occupied, counting but three to four men 
 per yard of front. At Plevna, the Turkish position 
 had a front of about 25 miles and was held with only 
 one and one half men per yard. In the South Afri- 
 can war the Boers held their positions on the Tugela, 
 11 miles long, with some 7,000 men. 
 
28- 
 
 At Mukden the Russian position was something 
 like 55 miles front and was occupied by a little more 
 than three men to a yard. 
 
 It must be evident that no definite rules can be 
 formulated for the necessary strength of occupation 
 of a position, based either on experience or reasoning. 
 So much depends upon the special circumstances, 
 such as the terrain, strength of works, armament, 
 and quality of troops that any figures are apt to be 
 misleading. 
 
 It may, however, be safely assumed that, given 
 good troops, a good field of fire, and cover, a strength 
 of one and one half men per yard can hold a position 
 for a reasonable length of time against greatly super- 
 ior forces, but the defense will be purely passive. 
 
 As regards the organization of the position in its 
 details, it is to be noted that there must be an inti- 
 mate cooperation between the working of the infantry 
 and the artillery. Before the perfection of indirect fire 
 methods the number of artillery positions was very 
 limited and the entire organization was based upon 
 these as a framework. At the present time no such 
 limitation as to artillery positions exists, and the or- 
 ganization is based upon the best disposition of the 
 infantry trenches, to which the artillery conforms. 
 
 The positions for the field artillery should be so 
 selected as to enable it: to combine its fire with that 
 of the infantry upon the probable directions of attack 
 up to the decisive moment; to combat the hostile 
 artillery up to the nearest positions; and to meet 
 possible flank attacks. The heavy artillery will be 
 posted in support of the field artillery at points 
 where it can bring its fire to bear upon presumed 
 lines of march and artillery positions of the enemy. 
 This applies especially to heavy guns, like the 4.7- 
 inch rifle whose great range and terrific shrapnel 
 effect are useful against the enemy's reserves and 
 
29 
 
 combat trains. Heavy howitzers, like the 6-inch, 
 are best held in a position of readiness near good 
 roads until the direction of the enemy's main attack 
 is developed. 
 
 Owing to the uncertainty as to the direction of 
 the enemy's main attack, the artillery positions will 
 necessarily call for a certain amount of dispersion, 
 but as a rule the guns will be grouped by battalions 
 or regiments in partial or completely defiladed gun 
 epaulments. The infantry positions should ordinar- 
 ily be so far to the front of the artillery positions as 
 to protect the latter from hostile infantry fire as well 
 as from attacks in flank or rear, while at the same 
 time not exposing the infantry to loss from prema- 
 ture bursts. A distance of at least 600 yards is de- 
 sirable. In addition, the infantry position must af- 
 ford a good fire on the near foreground, and where 
 the terrain does not permit of a frontal fire it must 
 be replaced or supplemented by flanking fire. In 
 broken terrain or on slopes with convex profiles, 
 flanking fire will frequently afford the only means of 
 covering the near foreground of a position. 
 
 Machine guns will be employed in carefully 
 covered emplacements at points where a special re- 
 e'n force ment! f the infantry fire is necessary, such 
 as upon small portions of the terrain useful to the 
 eneny, on the flanks of infantry units, and on the 
 wings of the position. 
 
 The area of terrain within which the posi- 
 tion may be chosen are fixed, to a large extent, by 
 the tactical situation. The nearer the enemy, the 
 less the field for selection; and when contact has 
 once been established and the fight has begun, the 
 side electing to hold its ground must generally halt 
 where it finds itself and strengthen the. terrain as 
 best it can. In prepared battlefield positions where 
 as much as a day's march separates the combatants, 
 
- 30- 
 
 the side electing to hold its ground for the time 
 being will have more latitude in the choice of a posi- 
 tion. It may advance or retire some distance to hold 
 a stream, valley, ridge of heights, edge of plateau; 
 or to take advantage of any other favorable topo- 
 graphical features. 
 
 The details of the "defensive organizations de- 
 pend upon the intentions of the commander, to which 
 this organization must respond. Does he intend to 
 seek a decisive action by an immediate and vigorous 
 attack? If so, it is evident that there is no use, a 
 priori, for defensive works on the particular portions 
 of the front covered by the attacking troops. In 
 such case, defensive organizations will be under- 
 taken only on such parts of the line as are not for 
 the time being involved in the attack. During the 
 progress of the attack, many occasions will arise, 
 especially in the long drawn-out battles of today, 
 calling for the employment of defensive works for 
 temporary purposes with a view to facilitating fur- 
 ther progress, holding captured points, etc. ; but the 
 need for these cannot be foreseen, and their use is 
 dependent upon the course cf the fight. 
 
 Does the commander intend to receive the attack 
 of the enemy on a position of his own choosing, with 
 a view to wearing him out and making him disclose 
 his intentions, in order then to pass to a resolute and 
 determined attack? If so, the original defensive 
 organization must be more thoroughly planned and 
 executed than in the first case. At the same time 
 care must be exercised not to resort to such excessive 
 strengthening of the position as may influence the 
 enemy not to attack. For this will defeat the inten- 
 tions of the commander and injure the morale of the 
 troops who, experience has shown, are loth to quit 
 elaborate fortifications constructed at the expense of 
 
31 
 
 much time and labor and affording them excellent 
 cover. 
 
 Does the commander seek merely to hold his 
 ground in other words, to make a passive defense 
 for the purpose of gaining time? Then his defensive 
 organization must be still more comprehensive and 
 elaborate and limited only by the time and resources 
 available. Of this character were the several forti- 
 fied positions of the Russians in Manchuria, which, 
 while fulfilling their object so far as frontal attacks 
 were concerned, nevertheless failed because their 
 flanks were turned. 
 
 But whatever the object to be served by the 
 defensive organization of lines, the same general 
 principles are applicable. These principles may be 
 summarized as follows: 
 
 1. The defensive position must have sufficient 
 depth. 
 
 2. The defensive line is discontinuous laterally. 
 The defensive organization in depth is merely 
 
 the adaptation of defensive measures to tactical for- 
 mations. The attack will be made as a succession 
 of efforts or impulses to which the defense will re- 
 spond by a succession of resistances. The succession 
 of resistances may take the form of a series of suc- 
 cessive prepared lines, each offering resistance in 
 turn, or a single prepared line of resistance succes- 
 sively strengthened from the rear by the bringing 
 up of the supports and reserves. The former 
 method is represented by the French school of thought 
 with its advanced posts, advanced combat line, main 
 line and second line (position de repli) while the sec- 
 ond method is represented by the German school of 
 thought. 
 
 The method of successive prepared lines of re- 
 sistance, while theoretically sound, is open to the 
 
-32 
 
 objection that troops will not hold so long nor so well 
 if they know that there are in rear, other prepared 
 defensive lines. This view of the effect of succes- 
 sive fortified lines is supported by the results of the 
 Manchurian campaign in which the Russians fre- 
 quently offered but feeble resistance from their ad- 
 vanced lines. This yielding and falling back of the 
 foremost lines is injurious to the morale of the de- 
 fense as a whole. 
 
 The concentration of all defensive measures on 
 a single prepared line, relying upon mobile supports 
 and reserves for the necessary organization in depth, 
 is more conducive to the best morale of the troops 
 and more in keeping with the maintenance of the 
 offensive spirit. It is, therefore, on the whole, con- 
 sidered preferable. 
 
 The principle of the lateral discontinuity of the 
 defensive organization is in compliance with the 
 principle of the economy of forces, is better adapted 
 to the tactical handling of organized units, and takes 
 advantage of the long range of modern weapons. 
 Its practical result is that the defensive organiza- 
 tions are grouped at certain points along the front, 
 leaving intervals of greater or less extent which are 
 defended by the cross and flanking fire of adjacent 
 organized points, as well as by the play of their sup- 
 ports and reserves. The interval between successive 
 organized points is dependent upon the topographical 
 features of the terrain and the necessity for recip- 
 rocal flanking fire, which limits this interval to 800 
 or 1,000 yards. 
 
 Such organized defensive points located along 
 the front of a prepared position are called support- 
 ing points. Formerly it was deemed necessary that 
 closed works, in the nature of forts or redoubts, 
 should constitute the organization of supporting 
 points; and this to a certain extent still obtains in 
 
-33- 
 
 the case of permanent fortifications and provisional 
 works. The underlying idea of closed works is that, 
 by virtue of their all round defense, they will be 
 capable of maintaining themselves after the line is 
 pierced and thus afford opportunity for the defense 
 to reestablish itself. In field fortifications, especialy 
 in hasty works for use on the battlefield, closed works 
 find little or no application. Such works are difficult 
 to conceal, and, unless very strongly organized with 
 bomb-proof shelters and interior communications (for 
 which time is ordinarily lacking in field fortifications), 
 they will become veritable shell traps, liable to sub- 
 ject their garrison to annihilation by artillery fire. 
 To secure the fullest development of fire effect from 
 modern weapons there is required a wide extent of 
 trenches rather than the limited faces of closed works. 
 All the objects formerly sought by the use of the 
 old types of closed works, with their massive profile 
 and geometrical trace, can be better realized by a 
 proper grouping of simple rifle trenches, either alone 
 or in conjunction with some existing natural or arti- 
 ficial feature, such as a village, group of buildings, 
 or a clump of woods. If deemed necessary, such 
 trenches can be so laid out, that, although discontin- 
 uous, they can bring fire in any and all directions; 
 be entirely surrounded by obstacles; and, in connec- 
 tion with dispersed covers, perform all the functions 
 of a closed work with far better concealment, better 
 protection and infinitely less labor. In the rare cases 
 where a closed work may be used, such as a support 
 for a wing or behind or in a specially weak or dan- 
 gerous portion of the front, it will ordinarily take the 
 form of a simple ring trench enclosed by a continuous 
 line of obstacles and will have a fixed garrison assigned 
 to it. Fig. 2, Plate II, shows a form of ring trench 
 with overhead cover as recommended for the German 
 service. 
 
-34 - 
 
 Closed works of the character used by the Rus- 
 sians in their positions at Liaoyang and Mukden, 
 although field fortifications, belong rather to the class 
 of provisional fortifications and may find application 
 under similar situations, that is, where there is abun- 
 dant time and the works can be constructed with the 
 assistance of civilian labor. But even here the same 
 results can be obtained by the proper combination of 
 rifle trenches, obstacles, covers, communications and 
 their accessories. Fig. 1, Plate II, shows one of the 
 Russian redoubts at Liaoyang, while Plate III shows 
 a form of Japanese redoubt. The latter, approximat- 
 ing a ring trench in the simplicity and ease of its con- 
 struction, is a decidedly better form for field fortifica- 
 tion than the former. 
 
 The term supporting point, as now understood, 
 refers to an area of ground organized defensively for 
 a definite object by the troops themselves with the 
 means usually available. Only very exceptionally 
 will it present a closed form with a continuous fire 
 line and then generally only in the shape of a ring 
 trench. Except for permanent and provisional works, 
 supporting points in the nature of forts and redoubts 
 of monumental construction will find no application. 
 In Fig. 1, Plate IV, is shown the general layout of 
 the Russian works on 203 Metre hill, the whole pre- 
 senting an excellent example of a group of trenches 
 constituting a strong supporting point. Fig. 2, Plate 
 IV, shows the supporting point on Redoubt hill, apart 
 of the outer Russian line at Liaoyang. 
 
 A prepared fortified line of resistance will, there- 
 fore, consist normally of a line of supporting points, 
 the intervals being such that mutual defense by cross 
 and flanking fires is assured. The supporting points 
 themselves may be natural topographical or existing 
 artificial features (villages, woods, etc.) organized 
 defensively, groups of rifle trenches, or combinations. 
 
35 
 
 Each supporting point will be organized and defended 
 by a tactical unit. The principle of discontinuity is 
 not limited merely to the intervals between successive 
 supporting points. In extended battlefield positions 
 still larger intervals may be left between the larger 
 tactical units, such as divisions and army corps, the 
 object being to tempt the enemy to make an attack 
 upon the interval and thus to expose himself to 
 counter attacks behind the line. In the Russian outer 
 line at Liaoyang there was an interval of one and one 
 half miles between the positions of the I and III Sibe- 
 rian Corps, which the Japanese, however, refrained 
 from attacking. 
 
 The flanks of a position will always be tempting 
 points for the enemy's attacks, and should therefore 
 be secured by resting them on impassable obstacles, 
 or if this cannot be done, by echeloning them to the 
 rear and keeping strong reserves close at hand. 
 
 Long trenches are not desirable, even where the 
 ground permits of their application, which it ordinar- 
 ily does not. Any part of a long trench once found 
 by the enemy easily leads to the disclosure of the re- 
 mainder. A long trench penetrated at any point will 
 generally become untenable. For these reasons it is 
 considered preferable to limit the length of single 
 trenches to that required for a company and if a 
 greater development of fire is needed, additional 
 trenches of company, platoon* or even squad length 
 may be constructed. The several trenches of a group 
 need not, and generally would not be on one line, but 
 might be separated in depth as well as laterally. By 
 this dispersion of works a certain flexibility is ob- 
 tained, permitting the best adaptation to the ground 
 and lending itself to concealment and protection. 
 
 The size of the tactical unit assigned to a sup- 
 porting point depends upon the tactical importance 
 of the supporting point and upon the intervals sep- 
 
arating it from the adjacent supporting points. A 
 battalion forms a very convenient tactical unit and 
 will be most often used. A portion of the battalion 
 will be employed in the firing line and the remaining 
 portion as a support to reenforce the firing line. 
 
 For the conduct of the combat and to fix respon- 
 sibility, the entire defensive front, if of any extent, 
 will be divided into sectors, to each of which will be 
 assigned a complete tactical unit. The division into 
 sectors is influenced by the topography, the strength 
 of the forces, and the intentions of the commander. 
 With a large force the initial division into sectors will 
 be made by the commander-in-chief, who will assign 
 the larger tactical units, such as field armies or divi- 
 sions, to definite portions of the front and give to each 
 its mission. The larger sectors are further subdivided 
 into smaller sectors by the commanders of larger units 
 down to brigades and even regiments. By this means 
 responsibility is fixed and the exercise of command 
 simplified. 
 
 Each sector, large and small, will ordinarily have 
 a sector reserve at the diposal of the commander of 
 the sector. The strength of this reserve will depend 
 upon the tactical object in view. Where it is merely 
 a question of holding ground the reserves will not be 
 so strong as where a decisive issue is sought. In ex- 
 tended battlefields, portions of the front will be or- 
 ganized with a view to offensive action, and the 
 strength and location of the reserves will be governed 
 accordingly. 
 
 The practical method of organizing a defensive 
 line depends upon the time available and requires 
 the cooperation of all the arms of the service, in- 
 cluding the technical troops. It will manifestly be 
 impracticable for the commander-in-chief of a large 
 force say several field armies to inspect personally 
 the entire front and to decide upon the details of the 
 
37 
 
 position and of the works to be constructed. Only 
 general directions, based upon the map and upon the 
 military situation can be given by the commander of 
 a large force. These directions will merely specify 
 the fronts to be occupied by the larger units, their 
 mission and designate the general reserves and their 
 location. 
 
 Ordinarily the time available will permit no 
 higher than division commanders to make a recon- 
 naisance (either in person or by a designated staff 
 officer) upon which to base the details of a defensive 
 line. When such reconnaissance is made prior to 
 the issue of orders the division commander, or his 
 delegated staff officer, should be accompanied by the 
 commander of the artillery and engineers for the 
 purpose of coordinating the work of the latter arms 
 with that of the infantry. Not infrequently, a prior 
 reconnaissance by the division commander is imprac- 
 ticable and it is then possible for him to make dispo- 
 sitions of a general character only, based on the map 
 and the general situation, leaving to brigade and reg- 
 imental commanders the decision as to details. 
 
 The necessity for a good understanding of the 
 organization of defensive positions on the part of all 
 line officers therefore becomes apparent. Without 
 such uniformity of application, the use of field works 
 to strengthen the terrain will produce no satisfactory 
 results. 
 
 Use of Engineers 
 
 It is now accepted as a principle that all hasty 
 field works must be constructed by the troops who 
 are to defend them, and all troops, infantry, artillery, 
 and cavalry are equipped with tools for this purpose. 
 The need for hasty works under present day con- 
 ditions is so frequent and so extensive that their 
 construction cannot be delegated, as was formerly 
 
38- 
 
 the case, to the engineers whose numbers will be 
 quite inadequate for such a purpose. There are, 
 however, many classes of works required in the 
 organization of a position which demand operations 
 for which the other troops are neither trained nor 
 equipped and which can be best carried out by the 
 technical troops. Of this character are the following : 
 
 (a) Demolitions, calling for the use of high ex- 
 plosives in clearing the foreground, and obstructing 
 the enemy's communications. 
 
 (b) Cutting down of heavy timber, for which 
 the infantry tools are not adapted. 
 
 (c) Assisting in the organization of specially 
 important supporting points involving the employ- 
 ment of artificial obstacles and substantial covers. 
 
 (d) Providing communications, especially 
 bridges, in rear of and along the position. 
 
 (e) Executing special constructions such as ob- 
 servation stations, shelters for the wounded. 
 
 (f ) Constructing works on the second line of 
 defense, if such should be contemplated. 
 
 In general, the engineers will be employed on 
 works of general interest not definitely assign- 
 able to any other combat unit, and on works requir- 
 ing special technical skill and tools. 
 
 Since the proportion of engineers is small, any 
 attempt to apportion them uniformly over an ex- 
 tended front must lead to such a scattering of per- 
 sonnel and material as to preclude any practical 
 results. Undue subdivisions will render supervision 
 by engineer officers impossible and will complicate the 
 subsistence and administration of the engineer units. 
 All considerations, therefore, point to the employ- 
 ment of the engineers in tactical units, viz., 
 companies. 
 
 When a reconnaissance precedes the actual or- 
 ganization of a position the senior engineer officer 
 
39 
 
 will be able to furnish advice as to the best employ- 
 ment of the engineer troops to carry out the inten- 
 tions of the commander, and this would naturally be 
 followed in assigning the engineer troops. Where 
 no such reconnaissance can be made the assignment 
 of the engineers will have to be made more or less 
 arbitrarily and their employment decided by the 
 commander of the units to which they may be 
 attached. There being three pioneer companies to 
 each individual battalion, one company may be as- 
 signed to each brigade for the execution of any 
 works deemed necessary by the brigade commanders. 
 The engineer troops are auxiliaries to the other 
 combat troops and can render valuable services in 
 the organization of defensive positions as well as on 
 the offensive. In the latter case they will accompany 
 the leading troops of the attack equipped with demo- 
 lition and pioneer tools and high explosives, prepared 
 to overcome or remove any obstacles interfering with 
 the advance of the infantry, and to assist in the 
 organization of captured points. To secure the best 
 results from the employment of engineer troops on 
 the battlefield it is incumbent that all combat officers 
 should understand their functions, capacity for 
 executing work, as well as their limitations. 
 
Plate II 
 
 SKetch o~f a s~t"ronqlu cons~f~ruc~f ed supporting 
 Point" "for a company at" vvar s~hrenqth, 4^4-cov'ers 
 for 220 men. 
 
 Russian Infan+rLj Redoub~t" at Liaouanq 
 
 Chevaux de frise.... xxw Wire en-fon^lemen+ .... XXXX 
 
 Mili + ary Pits. oO R -. Ramp 
 
 M.M Machine .gun emplacement j ,. 
 
Plaie 
 
 JAPANESE FIELD REDOUBT 
 NEAR K AN @ R IENHSIEN. 
 
 s 
 
 PLAN. Scale <L_S_2_ZLJ2 Feet 
 
 Borr.b Froof s 
 
 "Traverses 
 
 l_ a-frines L 
 
 S + C'-e-room M 
 
 Corrmunica + mq "Trenches C 
 
 F!o^K De-fer.ses F 
 
 D Cross Sec+ion Sec+ion C~D 
 
 Bombproo"f in Fron+ Parapet. 
 
 Sec+icn K-L. Section G-H 
 
 Elevation. Section A-B. 
 Flank Defense. 
 
 Scale for Sections 5 ' 15 go 25 Feef 
 
 Nnfe The dash and dot line represents fh*= 
 original ground surface. 
 
Near the telephone cabinet 
 (marked T)onthe upper' 
 road were small bombprc 
 and dug outs, and a local 
 dressing station 
 
 DEFENSES OF 203 METRE HILL 
 
 R Right Re doubt 
 
 L Left Redoubt 
 
 Wire Entanglements 
 --- - Trenches unoccupied 
 .M_n_ri_ Traversed trenches occupied 
 2-\iy-vi^L Lower(circular)trench 
 ' I'lli'lr- 1 Central Battery with 
 , L connecting trenches 
 Trench on crest-line with communi- 
 cation trench to upper road 
 
 X X Upper rood 
 Y Y Lower road 
 Commandant's 
 
 bomb proof 
 T Telephone Cabinet 
 fP] Dressing Station 
 R R Ra v i ne where the 
 reserves were 
 usally kept 
 * *fbucjasses 
 
 SUPPORTING POINT ON REDOUBT HILL, 
 RUSSIAN OUTER LINE AT LIAOYANG 
 
 A A Splinter Propfs Communicating Trench 
 
 Open Cover Trenches (single Parapet) 
 
 Simple Standing Trench ufwrnup. Traversed Fire Trench 
 Communicating Trench =O=Traversed Comm uni- 
 Cdouble Parapet) eating Trench j. H 
 
 B B 
 
Chapter III 
 
 ACCESSORY FEATURES OF RIFLE TRENCHES. HEAD COVER, 
 TRAVERSES, SHELTERS, OBSERVATION STATIONS, MA- 
 CHINE GUNS, DRAINAGE, WATER SUPPLY, 
 NIGHT FIRING, AMMUNITION RE- 
 CESSES, ETC. < 
 
 IN the usual case, time for the organization of 
 hasty battlefield fortifications will be very 
 limited, even on the part of the defense, and the 
 chances are that the simple standing trench will have 
 to fulfill all requirements. However, it would be a 
 serious mistake on the part of any commander not to 
 endeavor, in the time at his disposal, to render his 
 hasty fortifications as effective as possible. There 
 are two considerations involved, more or less opposed, 
 viz. : 
 
 (a) The fortifications should be made as effective 
 as possible, but 
 
 (b) The troops must not be so exhausted by 
 excessive work as to seriously impair their fighting 
 power. v. 
 
 Fortunate is the commander who possesses the 
 good judgment necessary to attain the happy mean 
 between these two extremes. 
 
 The simple standing trench having been con- 
 structed, there are various accessory means of im- 
 proving it. If it is evident from the first that there 
 will be ample time, these accessory features should 
 be embodied in the original plan; but, in the normal 
 case this will not be practicable, and their considera- 
 tion must be deferred until after a usable trench has 
 been completed. These means of further improve- 
 ment will now be discussed. 
 
 43 
 
44 
 Head Cover 
 
 Head cover is obtained by either notching 
 or loopholing the parapet. The simplest manner 
 of doing the former is by placing small heaps of 
 earth on the parapet, at intervals corresponding to 
 the spacing of the riflemen; each man firing to the 
 right of the heap immediately in his front (see Fig. 
 1, Plate V). This method is of questionable value as 
 the man does not get much protection and, at short 
 ranges, the enemy is offered an excellent aiming 
 point. If mud or sods are available, the sides of the 
 mounds can be made steep (see Fig. 2, Plate V), and 
 the protection then becomes of real value. Any 
 available material may be made use of to sustain the 
 side slopes of the mounds at a greater angle of re- 
 pose than the soil of which they are composed will 
 naturally take. Notched parapets were frequently 
 used by both Russians and Japanese in Manchuria. 
 
 Various forms of loophole are shown in Figs. 3 
 to 9, Plate V. Certain terms are used to define the 
 various parts of a loophole, viz. : the bottom is called 
 the floor or sole, the sides are called the cheeks and 
 the narrow portion the throat. It is evident that the 
 only essential difference between notches and loop- 
 holes is that the latter has a roof; therefore the 
 same descriptive terms apply to the notch. Mater- 
 ials for loopholes will not generally be available for 
 hasty works, but they should be employed whenever 
 practicable as they materially increase the cover and 
 contribute to greater accuracy in shooting. 
 
 The throat may be at the end of the loophole near- 
 est to the rifleman, in which case he gets the best 
 use of his rifle but not such good protection; or it may 
 be at the end farthest away from the soldier, in 
 which case he gets maximum protection but must 
 move about a pivot in order to change his aim; or the 
 
-45 
 
 throat may be located at some intermediate point as 
 a compromise. Various locations are indicated in 
 the figures. 
 
 The Hopper Loophole, Fig. 5, Plate V, is a most 
 effective form, especially if the throat is closed by a 
 steel plate spiked to it. The plate should be about 
 one-half inch thick, if of hard steel, and is pierced 
 by a comparatively small opening for accomodating 
 the rifle. Figures 6 and 7 show the forms of plates 
 used by the Japanese and Russians in the late war. 
 
 If the material composing the loophole, or notch, 
 is hard and resisting, the throat should always be 
 placed to the front, or the cheeks in front of the 
 throat should be stepped to prevent glancing in of 
 projectiles. 
 
 Where the character of fire to be delivered in- 
 volves a wide lateral and a small vertical angle, loop- 
 holes may take the forms of slits. Such a form will 
 result from laying logs, or fascines, lengthwise on 
 the parapet, supported at intervals by sods or other 
 material, as shown in Figs. 8 and 9, Plate V. Various 
 other materials, it is readily seen, may be used in 
 constructing this form of loophole. 
 
 Head cover is valuable chiefly for neutralizing 
 the effect of hostile shrapnel fire, thus enabling the 
 riflemen to man the parapet at any and all stages of 
 the combat. It, however, increases the visibility of 
 the parapet and restricts the field of fire. At close 
 range the notches and loopholes serve as aiming 
 points to steady the fire of the enemy, especially if 
 he can see light through them when unoccupied. In 
 the latter case he waits until the light is obscured 
 and then fires, knowing he has an animate target. 
 It is obvious that the defense must provide a proper 
 background for the openings, or removable screens. 
 Simple curtains made of empty sacks or sand bags 
 will suffice. 
 
46 
 Traverses 
 
 An unbroken, continuous trench would be ex- 
 posed to enfilade fire, and also a shell or shrapnel 
 bursting therein would have wide-spread effect. 
 These difficulties are partially met by constructing 
 the trenches in short lengths. It is, however, desir- 
 able, if time permits, to further subdivide each trench 
 by means of traverses, the interval between adjacent 
 traverses not exceeding eight yards. Better defilade 
 is thus secured, the material effect of any burst is 
 confined to very narrow limits, and the moral effect 
 upon the defenders of observing the destruction 
 wrought by a successful burst is practically elimin- 
 ated. 
 
 The traverses should be about one yard thick at 
 the height of the interior crest. While their efficiency 
 for defilade is a direct function of their height, it 
 must be remembered that inconspicuousness of the 
 trench is of prime importance. It is therefore inad- 
 visable to carry them much, if any, above the general 
 line of the crest, and in no case should this difference 
 of level be greater than 18 inches. 
 
 When practicable, provision should be made for 
 the traverses in the initial laying out of the trenches, 
 failing this they can be constructed later. Figures 
 10 and 11, Plate V, show two methods of traversing 
 a trench, the latter being considered preferable be- 
 cause it does not reduce the space available for 
 occupancy by riflemen. If the first form is used, the 
 sides of the traverse should be made as steep as pos- 
 sible, in order that the reduction of space on the 
 firing line may be a minimum. Traverses arranged 
 as in Fig. .10 are called "attached" traverses and 
 those arranged as in Fig. 11, ' 'detached" traverses. 
 
 Shelters 
 
 In these days of accurate artillery fire it is essen- 
 
47 
 
 tial that, if the trenches are to be occupied for any 
 length of time, some sort of shelter be provided for 
 the men when they are not actually manning the 
 parapet. This shelter should be made as effective as 
 time, materials, and the fitness of the troops for such 
 work, permit. It will vary from the simplest form 
 of splinter-proof to shelter proof against the heaviest 
 siege artillery projectile. The overhead thickness of 
 material for shelter will vary; 6 to 8 inches of earth 
 on thin boards giving protection from shrapnel and 
 splinters, 3 feet of earth on 6 inches of timber to 
 resist light field guns, and 6 feet of earth on 12 
 inches of timber being the least that will afford pro- 
 tection when the fire of siege guns and howitzers is 
 to be taken into account.. 
 
 The great value of the shelters in the trench is 
 that the men are protected in a position from which 
 they can, in time of need, very rapidly man the 
 parapet. 
 
 Various forms for these shelters are shown in 
 the Figs. 12 to 18, Plates V and VI. In Figure 18, 
 Plate VI, is shown a combination of head cover and 
 shelter which is very effective. It will be noted that 
 in some cases the shelter is closed to the rear by a 
 sort of trapdoor or cover which, while not heavy 
 enough to be unwieldy, will still offer considerable 
 resistance to small fragments and splinters. Timber 
 will usually be the material used to sustain the roof, 
 but railroad rails, or other forms of steel beams, are 
 equally suitable. 
 
 Time being available for their construction, pro- 
 vision should be made for the shelters in laying out 
 the trench, but they can also be readily constructed 
 after the completion of the excavation of the trench, 
 and on the field of battle this will be the usual order 
 of procedure. 
 
 In determining the area of overhead cover to be 
 
-48 
 
 provided, allow six square feet per man for tem- 
 porary occupancy,, and twelve square feet per man 
 if the occupation is to be of long duration. 
 
 Observation Stations 
 
 Except when the garrison are actually required 
 to man the parapet, they will all be under cover save 
 a few lookouts whose duty will be to give timely 
 warning of the movements of the enemy. These 
 lookouts must be able, while well protected, to 
 thoroughly observe the foreground. In the normal 
 case there will be trees, or some artificial construction 
 already existing, which may be made of use as a point 
 of observation. Such facilities do not, however, 
 always exist, and specially constructed observation 
 stations must then be provided. These must afford 
 the occupant the maximum amount of cover con- 
 sistent with his being able to efficiently perform his 
 duty as lookout. The two forms, furnishing basic 
 idqas, are shown in Figs. 19, Plate Vl-a, and 20, 
 Plate VI. In the first form the bottom of the trench 
 is lowered so that the man can just look over the 
 superior slope; he must rely upon inconspicuous 
 headgear or a screen to shelter his head from view. 
 In the second form he is given overhead cover. 
 
 In all cases observation stations must be so lo- 
 cated and constructed that they will not disclose the 
 location of the trenches. Where it is practicable 
 they should always be placed in the trenches, but 
 there will be many cases where they will have to be 
 located in advance of or behind them. 
 
 Observation can be carried on by a man crouch- 
 ing below the parapet and making use of mirrors 
 properly placed, but it is not believed that any great 
 reliance should be placed on this method. The mir- 
 rors are too delicate for the rough handling incident 
 
-49 
 
 to campaign and it would require a very high -order 
 of intelligence to employ them effectively. 
 
 Machine Guns 
 
 Machine guns are now an accepted and very 
 potent factor in battlefield operations, and provision 
 for their efficient use in the trenches must be made. 
 Emplacements must be so constructed as to afford 
 maximum protection to the gun detachment consistent 
 with the free use of the weapon. Splinter proof over- 
 head cover is desirable and should be provided if 
 practicable. 
 
 Shelter should be provided for both gun and de- 
 tachment when not engaged in firing. The guns of 
 a platoon should be spaced about twenty feet apart, 
 and adjacent emplacements should be connected by 
 a communicating trench. 
 
 Drainage 
 
 If a trench is to be occupied for any length of 
 time, especially where much ground or falling water 
 is to be encountered, drainage becomes of prime 
 importance. Many years ago a celebrated military 
 authority asserted that "nothing so saps the courage 
 of a soldier as to wet the seat of his trousers." This 
 may be accepted as a true maxim, especially in cold 
 weather, and the trench should therefore be made as 
 dry as possible. The floor of the trench should be 
 given a sufficient slope to the rear where an inter- 
 cepting drain should collect the water and carry it to 
 prepared sumps or to a point from which it can be 
 disposed of by drainage. Provision should also be 
 made for excluding surface drainage from the 
 trenches. 
 
 Wat e r Supply 
 
 A sufficient supply of good drinking water must 
 be assured to the men occupying trenches. The 
 
50 
 
 arrangement to be made will, of course, depend 
 principally upon the length of time the trench is to 
 be occupied. Suitable vessels can be placed in the 
 trenches and kept filled, or water for filling canteens 
 can be distributed at stated intervals. In soils where 
 water is easily reached wells may even be dug in the 
 trenches. 
 
 Night Firing 
 
 The successes of the Japanese in the Russo- 
 Japanese war have given a wonderful impetus to 
 night operations and they may be expected to play 
 very important parts in the wars of the future. On 
 the part of the defense this will necessitate provision 
 for night firing. The best means, of course and 
 these will be employed by both attack and defense- 
 are searchlights. Along an extensive defensive 
 front it is not believed that sufficient searchlights 
 will ever be provided, since it is necessary to illumi- 
 nate the entire extent of front, due to the fact that 
 information is lacking as to the point which the 
 enemy will select for attack. 
 
 If there is sufficient suitable material, bonfires 
 can be prepared, to be lighted when the lookout re- 
 ports the advance of the enemy. This also will 
 seldom be practicable. Other means of illuminating 
 the foreground are star shell rockets, such as were 
 used by the Russians at Port Arthur, and illuminating 
 pistols for firing cartridges of port fire which will 
 burn for eight or ten seconds. 
 
 All means of night illuminations being uncertain, 
 the only remaining expedient is to place during day- 
 light rests such that the rifles, when placed 
 upon them, will sweep a desired area without any 
 aiming on the part of the soldier. These rests may 
 be standards, to which the rifle is fastened by pins 
 and which may be so constructed as to permit of 
 
51 
 
 adjustment for several ranges, or they may be simple 
 battens placed lengthwise along the parapet so that 
 rifles placed upon them are directed at the desired 
 area. See Fig. 22, Plate Vl-a. 
 
 General 
 
 No magazine arrangements are necessary. As 
 noted in Chapter I, ammunition for immediate use 
 may be placed upon the elbow rest. Recesses may 
 be constructed in the parapet and in the shelters in 
 which boxes of small arms ammunition may be 
 placed. 
 
 As far as practicable, telephonic communication 
 should be provided throughout the trenches. 
 
 In loose soils or sand great difficulty will be 
 encountered in making slopes stand at the desired 
 angles. Revetment should be resorted to if prac- 
 ticable. Figs. 23 and 24, Plate Vl-a, show a method 
 of revetting with any available material, such as 
 corn stalks, brush, etc. For more elaborate methods 
 of revetment, see Engineer Field Manual, 19Q9, page 
 371 et seq. 
 
Plate V 
 
Via. 
 
 Machine Gur Emplacement 
 
 Fig.21 
 
 Fig.21b. 
 
 P | an Sectron A-B 
 
 Fig.21c. 
 
 Section C-D 
 
 Sod Cover 
 
 Crushed Stone 
 
 Fig.22a. Fig. 22 b. Fig.22c 
 
 F, 3 .23 >\ 
 
 J.H. 
 
Chapter IV 
 
 ACCESSORY FEATURES IN REAR OP THE FIRE TRENCHES. 
 SHELTERS FOR THE SUPPORTS AND RESERVES, COM- 
 MUNICATIONS, OBSERVATION STATIONS, EM- 
 PLACEMENTS FOR ARTILLERY, LATRINES, 
 DRESSING STATIONS, ETC. 
 
 T T 7E have seen that fortified positions must have 
 * ^ sufficient depth, as otherwise the line is too 
 easily pierced. This depth is secured by the location of 
 the supports and the sector and the general reserves. 
 This organization in depth calls for the employment 
 of certain accessory features in rear of the fire 
 trenches, and these we will now discuss. 
 
 It will frequently be the case that the character 
 of the terrain is such as to afford natural or existing 
 artificial cover for supports and reserves by which 
 they are shielded from the view of the enemy, and, 
 to a greater or less extent, protected from h;s fire. 
 It may even be the case that ravines, folds in the 
 ground and existing concealed roads furnish in addi- 
 tion covered approaches from the above concealed 
 positions to the fire trenches. Such ideal conditions, 
 however, do not by any means always exist, and 
 lacking such natural cover and communications, 
 troops must be prepared to provide them for them- 
 selves. 
 
 Trenches for protecting supports and reserves 
 are called cover trenches, and those connecting the 
 fire and cover trenches are called communicating 
 trenches. Fig. 1, Plate VII, shows the relation ex- 
 isting between the three classes of trenches. 
 
 Supports should be held so near to the fire line 
 that they can readily reenforce it under all emergen- 
 cies. This may compel distances as small as fifty 
 
 55 
 
-66 
 
 yards, notwithstanding the fact that the cover 
 trenches then come inside the dispersion area of 
 artillery fire directed at the fire trenches. The 
 prompt reenforcement of the firing line at the critical 
 moment is a delicate matter. The enemy's artillery 
 fire, having supported his infantry at the decisive 
 range, will be next extended to cover the rear of the 
 position. It is just at this moment that the supports 
 will be wanted to reenforce the fire trench. If, 
 therefore, the supports are placed too far to the rear 
 they not only may not arrive in time, but to come up 
 at all will need cross ground liable to be swept by 
 artillery fire. Reserves, both sector and general, 
 must be so located that they can reach all equally 
 important parts of the fire line with equal facility, 
 or that the length of time necessary for them to 
 reach any point is an inverse function of the im- 
 portance of that point. The reserves should gen- 
 erally be placed far enough to the rear to escape the 
 effect of "overs" from hostile artillery; that is, not 
 nearer than 300 yards. 
 
 Cover trenches for supports and reserves differ 
 from fire trenches in that they are not ordinarily de- 
 signed to deliver fire but are merely for protection 
 of the soldier pending his taking an active part in 
 the engagement. They should afford him the maxi- 
 mum of shelter and comfort, and give him a ready 
 means of egress. To fulfill the latter requirement, 
 trenches may be provided with sortie steps to permit 
 the occupants to advance on a broad front and with- 
 out loss of time. The amount of protection afforded 
 is dependent upon time, materials, and the equip- 
 ment and condition of the troops, varying from the 
 simplest mound of earth to trenches with complete 
 overhead cover. Types are illustrated by Figures 2 
 and 3, Plate VII. There is no limit to the number of 
 styles of cover behind the fire trenches, involving 
 
57 
 
 the existing or natural features, the work of the 
 troops, and a combination of these two. 
 
 The cover trenches being provided, the next 
 thing to do is to give the troops a safe passage from 
 them to the fire trenches. Communicating trenches 
 are intended merely for the concealment of the man 
 while passing through them. Not being continually 
 occupied, and it being impossible for the enemy to 
 discover whether he is doing any real damage to 
 them by artillery fire, there is not much chance of 
 their being subjected to a regular bombardment, 
 hence men passing through are exposed to chance 
 shots only. Of course, the communicating trenches 
 must not be enfiladed by the enemy, and, therefore, 
 the trace of such trenches should make an angle 
 with (i. e. , not be parallel to) the enemy's fire. Where 
 this cannot be done the communicating trenches may 
 be defiladed by traverses, or they may be entirely 
 covered over, as in the case of a communicating 
 trench leading to a fire trench some distance down a 
 forward slope. The earth excavated from the trench 
 is usually piled up on the side toward the enemy, 
 sometimes it is piled on both sides. Figure 4, Plate 
 VII, illustrates a form of communicating trench. 
 
 As regards both cover trenches and communicat- 
 ing trenches we must not lose sight of the fact that 
 the usual time will not permit of their construction 
 on the field of battle and we will, therefore be lim- 
 ited to making the best of any natural, or existing 
 artificial accidents of the terrain. Every effort 
 should be made to improve these however, without 
 imposing an exhausting amount of work upon the 
 troops. The same necessity for concealment applies 
 to these trenches as to the fire trenches, but in a 
 somewhat lesser degree. Both cover and communi- 
 cating trenches may sometimes overlook the fore- 
 ground in portions of their length and may then be 
 
-38- 
 
 used to reenforce the firing line by providing a firing 
 step on such portions. 
 
 Where the communicating trenches change di- 
 rection, returns can be constructed and made use of 
 for latrines and for the establishment of collecting 
 stations, as shown in Fig. 1, Plate VII. These should 
 of course be given the most effective cover possible, 
 the collecting stations particularly demanding over- 
 head cover. The construction employed will be in 
 all respects similar to that used in the trenches. 
 
 Notwithstanding the many scientific adjuncts 
 made use of in military operations, it must not be 
 forgotten that war is in reality a very elementary 
 affair, and that ruses will be as effective today, if 
 well planned, as they were in earlier times. For this 
 reason dummy trenches should, whenever practicable, 
 be made use of. They deceive the enemy both as to 
 the location and as to the number of the defenders. 
 These trenches should be made to simulate, as nearly 
 as possible, real trenches in every way, but should 
 be somewhat more conspicuous. They should be lo- 
 cated in rear, rather than in advance of the fire line, . 
 but at the same time, they should be so placed as 
 not to subject either supports or reserves to chance 
 shots. Much use was made of dummy trenches in the 
 Boer War, and the Japanese, especiallly, made great 
 and effective use of them in deceiving the Russians. 
 Even a furrow run with a plow will at long and mid- 
 ranges present the appearance of a trench. 
 
 One of the most essential requirements of a for- 
 tified position is that easy communication must exist 
 everywhere in rear of the firing line. To this end, 
 roadways as good as practicable, must be prepared, 
 over which reserves can be moved very speedily in 
 any desired direction. Streams must be bridged 
 and ravines either bridged or the banks scarped 
 down. Guide posts must be set up for day use, and 
 
59 
 
 lanterns for night, to insure troops taking the proper 
 directions. The character of these works is so ob- 
 vious that nothing more than a reference to them is 
 deemed necessary. 
 
 Telephonic communication must be provided 
 throughout in order that all operations may be prop- 
 erly coordinated. 
 
 If time suffices, covered stations must be pro- 
 vided for commanding officers. Nothing is so apt to 
 demoralize a force as to be deprived at a critical 
 moment of its directing genius. Any form of cover- 
 ed observation station such as shown in Figs. 19 and 
 20, Plate VI, Chap. Ill, will be suitable for the pur- 
 pose. Very conspicious hill tops are not so well 
 adapted for stations for commanding officers as 
 points which are less prominent but still afford a 
 satisfactory view. The Commanding General of the 
 Japanese XI Division was severely wounded at Port 
 Arthur while in an observing station located, on a 
 conical hilltop. 
 
 No discussion of the accessory features in rear 
 of the fire line would be complete without reference 
 to the artillery positions. In many cases the guns 
 can be placed in numerous positions concealed from 
 view and employing indirect fire, and here no artifi- 
 ficial cover is essential. In other cases the artillery 
 will not be so fortunate, and artificial means of pro- 
 tection for both guns and men will be needed. This 
 is especially necessary in so-called ' 'dagger bat- 
 teries/* i.e., concealed guns placed well to the front, 
 ready to open fire at critical moments on a line of 
 advance or a restricted area. 
 
 The simplest protection that can be given is to 
 fill in with earth the gap between the ground and 
 the bottom of the shields. If more time is available, 
 protection for the gun crew may be given as shown 
 in Figure 5, Plate VII. In this case no shelter is 
 
60- 
 
 provided for the gun, ammunition may be stored in 
 the shelter for the men, and the caisson may be 
 placed as shown. Any additional time will be utili- 
 zed in completing the pit as shown in Figure 6, Plate 
 VII, thereby rendering the gun fairly safe. If it is 
 known from the first that time will be available, the 
 gunpit shown in Figure 7, Plate VII, might well be 
 built, the ammunition being stored as indicated and 
 the limbers hauled back to a place of safety. Adja- 
 cent gun pits should be connected by communicating 
 trenches arranged so that a continuous parapet will 
 be presented, thus making it more difficult for the 
 enemy to locate the exact positions of the guns. 
 Overhead cover for the cannoneers is desirable and 
 should be provided if practicable. 
 
 The above refers to light artillery guns. The 
 heavy artillery will, as a rule, be far enough to the 
 rear not to require any work for its protection. 
 Should exceptional circumstances render artificial 
 constructions necessary, they, would follow very 
 closely the gun pits given, the dimensions being 
 varied to suit and especial attention being paid to 
 the protection of the ammunition, it being very valu- 
 able and its destruction by a chance long range shell 
 being possible. 
 
 Observation stations for the battery commanders, 
 and the higher commanders of the artillery, must be 
 provided. These should be covered if practicable, and 
 provided with some means of inter-communication. 
 
 Dummy gun pits will be especially valuable in 
 drawing the hostile artillery fire, and a simple mound 
 of earth, rapidly thrown up with a log protruding 
 over the crest will serve as such. 
 
Plate VII. 
 
 Rifle Trenches 
 
 WiViVMViVA'Y.YV '.', 
 
 Fig. 2 
 
 Reporting 
 
 Cover behind a 
 steep Slope 
 
 Cover Trenches 
 gj Exit Steps 
 
 to, 
 
 Section a 
 
 Fig. 7 
 
 -*- -\Ct.O-* 
 
 Section c.d. Fig. 6. 
 
Chapter V 
 
 ACCESSORY FEATURES IN FRONT OF THE FIRE TRENCHES. 
 CLEARING THE FOREGROUND. DEMOLITIONS. AD- 
 VANCED POSTS. OBSERVATION STATIONS. 
 RANGE MARKS, ETC. 
 
 WE have seen that the most important require- 
 ment of a fortified position is a clear field of 
 fire, extending, as nearly as practicable, to the effec- 
 tive range of the small arm. This means that 
 everything in the foreground, not of use to the de- 
 fense and which may be of use to the enemy, shall, 
 so far as circumstances and resources permit, be 
 destroyed or its character so altered as to remove 
 this possibility of benefit to the enemy. This organi- 
 zation of the field of fire is known as "clearing the 
 foreground/' and includes clearing out or cutting 
 down and removing woods, thickets and hedges; 
 destruction of buildings, stone and brick walls; 
 trampling down, or otherwise flattening out growing 
 crops; the razing of earthen mounds, manure and 
 stone piles, and the filling of depressions. The 
 clearing of the foreground of all cover limiting the 
 view and field of fire, coupled with the marking out 
 of ranges, is more important than all other defense 
 arrangements. Only with a clear view and un- 
 obstructed field of fire can ones own fire. effect be 
 fully developed. 
 
 In the felling of timber it must be remembered 
 that it will be necessary to cut up and remove the 
 trees, as if left on the foreground they may furnish 
 excellent cover for the enemy. For this reason, 
 owing to lack of time or facilities, it will often be 
 
 62 
 
63- 
 
 best to clear a wood out, leaving the large trees 
 standing. This will especially be the case where the 
 foreground has an uniform slope from the trenches, 
 for with such a field of fire, standing timber, without 
 undergrowth, will neither hinder the defense nor 
 favor the attack. 
 
 Frame buildings, hay stacks and other combusti- 
 ble objects may be destroyed by fire, but this method 
 must be used with caution, as the resulting smoke 
 may obscure portions of the terrain and form a 
 screen facilitating the approach of the enemy. 
 Buildings and structures of all kinds may be de- 
 stroyed by explosives, but care must be exercised in 
 applying this method, since the resulting debris 
 sometimes furnishes better cover for the ^nemy than 
 would the buildings or structures if left standing. 
 
 Standing crops can best be leveled by some 
 species of drag, operated by man or animal power. 
 It is not infrequently the case, however, that stand- 
 ing crops, also hedges and thickets, constitute suffi- 
 ciently formidable obstacles to render their destruc- 
 tion by the defense inadvisable, and the relative 
 value of the better field of fire and the natural 
 obstacle should be weighed before making decision 
 as to the disposition to be made of such natural 
 features. Crops like corn, sugar cane and kowliang, 
 when in full growth, may be broken down about 
 eighteen inches from the ground, as was done by the 
 Russians in Manchuria. This treatment insures a 
 clear field of fire as well as affording a natural 
 obstacle. 
 
 Given a clear field of fire up to and including 
 long range infantry fire, entrenched troops can with 
 their fire alone, unaided by obstacles, stop the most 
 determined attacks, provided the disparity of forces 
 is not too great. Such an ideal field of fire will rarely 
 be found, and there will usually be portions of the 
 
64- 
 line that, owing to the character of the terrain, the 
 enemy can approach under cover. In this case, the 
 enemy having approached to close quarters without 
 appreciable loss, and his morale being consequently 
 excellent, it is questionable whether even rapid and 
 accurate fire will stop him in the short remaining 
 distance he has to travel. It is therefore advisable 
 to introduce something that will impede his progress 
 and thus expose him for a longer time to this most 
 effective fire of the defense. In cases such as this, 
 as well as in cases where, because of great inferiority 
 in numbers, a purely passive defense is contemplated, 
 obstacles, if practicable, are an essential component 
 of the defensive organization. Their object, as seen, 
 is to protect works from surprise, to reduce the mo- 
 mentum of an attack by breaking up the enemy's 
 formations, and to hold the enemy under the most 
 effective rifle fire of the defense. 
 
 To accomplish these results the obstacles should 
 not be more than about 300 yards from the fire trench, 
 for if placed farther away, the enemy, while destroy- 
 ing them, will still be covered by the fire of his 
 artillery. The obstacle, on the other hand, must not 
 be closer to the fire trench than about seventy-five 
 yards, for if the enemy gets within this distance be- 
 fore he is stopped, his too proximate position has a 
 most disturbing effect upon the accuracy of fire of 
 the defenders, and he would, in addition, be able to 
 hurl hand grenades with considerable effect. Owing 
 to the necessity of guarding obstacles at night, it is 
 advisable to locate them as near the inferior limit as 
 practicable. 
 
 If practicable, obstacles should always be con- 
 cealed, naturally or artificially, since there is thus 
 introduced a most disturbing element of surprise for 
 the enemy, and the damage or destruction of the 
 obstacles by artillery fire is reduced or eliminated. 
 
65 
 
 Obstacles are sometimes used to deny to the 
 enemy a certain line of approach which it will be 
 difficult for the defenders to cover with their fire. 
 In this case, they must be of such construction that 
 they cannot be easily destroyed. 
 
 In the usual case of field fortification, the time 
 available will permit nothing more than the marking 
 out of ranges, digging of a trench and some clearing 
 of the foreground, but the value of obstacles must be 
 thoroughly appreciated and they must be made use of 
 whenever possible, if the circumstances are such to 
 render their use desirable. In detached posts, where 
 a stubborn defense is to be made against a probable 
 all-around attack, a complete circle of obstacles is in- 
 dispensible. 
 
 We will now proceed to a discussion of the usual 
 types of obstacles, it being borne in mind that these 
 are merely types, furnishing definite ideals which 
 will be approached as nearly as time, materials, and 
 other considerations will permit. The fact that a 
 commander cannot construct obstacles of the types 
 shown will scarcely be an acceptable excuse for not 
 making the best possible use of the materials and re- 
 sources of which, he is possessed. 
 
 The most effective obstacle is the barbed wire 
 entanglement, of which we have the high and low 
 types shown in Figures 1 and 2, Plate VIII. 
 
 In the high wire entanglement the pickets are 
 about four inches in diameter and about six feet 
 long. They should be sunk in the ground about two 
 feet, the intervals between pickets and rows being 
 about six feet, and the pickets in successive rows 
 being staggered. The wire is then fastened to the 
 pickets by wrapping or by wire fencing staples, or 
 both, in such a fashion as to connect the top and 
 bottom of each picket with the tops and bottoms of 
 all adjacent pickets, and a few strands are run 
 
66- 
 
 around irregularly. A regular barbed wire fence, 
 when strongly built, will also serve as a good ob- 
 stacle. It may be used alone or to reenf orce a regu- 
 lar entanglement. 
 
 The low wire entanglement is constructed on the 
 same general idea, the pickets being lighter and 
 shorter and the wire connecting only the tops. The 
 low wire entanglement is especially useful when it 
 can be placed in low growing vegetation and thus be 
 entirely concealed naturally. Another, and very ex- 
 cellent form of the low wire entanglement, when 
 concealed by vegetation, is constructed by driving 
 the pickets with their heads flush with the ground 
 surface, and leaving considerable slack in the wire. 
 Wire entanglements found extensive application in 
 the South African and Manchurian wars: When 
 there is an insufficient supply of barbed wire, it 
 should be used for the front and rear horizontal wires, 
 smooth wire being employed for the remainder. 
 
 It has been previously mentioned that growing 
 crops, hedges and thickets may serve as obstacles. 
 If interlaced with barbed wire, they become very 
 effective. 
 
 Where wire is scarce, or stakes are difficult to 
 obtain, much good can be accomplished by the use of 
 wire nooses, placed in the grass and firmly pegged 
 down. The advancing soldier catches his foot in the 
 noose, draws it tight around his leg when he endeav- 
 ors to extricate himself. Considering the dangerous 
 position in which he is placed, his efforts to free him- 
 self will take sufficient time to insure his being put 
 out of action. See Fig. 3, Plate VIII. 
 
 Wire entanglements to be effective should have 
 a depth of approximately thirty feet. The wires 
 should not be strung very tightly, as this will facili- 
 tate cutting. This class of obstacle is practically 
 exempt from damage by artillery fire, and will have 
 
67 
 
 very general application on account of the extensive 
 use of barbed wire and the consequent ease of ob- 
 taining it. 
 
 Other forms of wire entanglements are shown 
 in Figures 4 and 5, Plate VIII. 
 
 An abatis is an obstacle presenting the sharp- 
 ened ends of pronged timber to the enemy. In 
 felling trees they may be dropped towards the direc- 
 tion of hostile approach, left attached to the stump, 
 the foliage and smaller branches cleaned off and the 
 ends of branches sharpened, thus forming a very 
 efficient abatis. See Fig. 6, Plate VIII. Several 
 rows of such fellings, the tops of successive rows 
 overlapping the points of attachment of those in 
 front, furnish as good an obstacle as can be desired, 
 especially if interlaced with a few strands of barbed 
 wire. 
 
 Abatis may also be constructed as shown in Figs. 
 7 and 8, Plate Villa, small trees or branches being 
 used. Barbed wire will here too add much to the 
 efficiency of the obstacle. Abatis can be seriously 
 damaged, or even destroyed by artillery. 
 
 Another form of obstacle is the shallow and deep 
 pit. While they have had much use in the past, and 
 the Russians employed them uniformly in their de- 
 fensive works during the Manchurian War, their 
 value as obstacles is hardly sufficient to repay the 
 expense of construction. A low wire entanglement 
 is frequently constructed, covering the same area as 
 the pits, and a somewhat more effective article is 
 thus created. See Fig. 9, Plate Villa. The deep 
 pit has the further disadvantage of furnishing close 
 cover for the enemy if he succeeds in getting into 
 them. 
 
 Two forms of cheveaux de frise are shown in 
 Figures 10 and 11, Plate IX. Any and all parts of 
 them may be of metal or wood. The lances are 
 
vm, 
 
 i 
 
 Tig. 2 
 
 -2:25 
 
 Fig. 3 
 
 Fig. 6. 
 
\ HI a. 
 
 Fin. 7 
 
 Fig.8 
 
 
 Fia.9. 
 
IX. 
 
 F, 3 .10 
 
 Rg.ll 
 
 K- 28 
 
 2S - r 
 
 S 
 
 S-i Fig 12. 
 
 -1C' 
 
 F, 3 .16: 
 
 Fig. 18 
 
IXa, 
 
 '< 3'0 * 
 
 Rg.14 
 
 . 
 
 JX 
 
 Fig.15. 
 
72 
 
 ordinarily about six feet long-. This obstacle is con- 
 structed in short lengths, for ease in transportation, 
 the successive short lengths, when in opposition, being 
 wired or chained together. This obstacle possesses 
 the great advantage that it can be made under 
 cover, can be held in reserve, and can at any time be 
 used to rapidly close the hostile avenues of approach. 
 
 Figures 12 and 13, Plate IX, show similar ob- 
 stacles which were used by the Japanese and Rus- 
 sians in their late war. The first consists of tripods 
 formed by binding poles together at their middles 
 with wire, these tripods being then placed abutting 
 and secured together by wire. The Russian form 
 consists of exaggerated saw bucks, similarly abutted 
 and bound together. A form of wire cheveaux de 
 frise is shown in Figs. 14 and 15, Plate IXa. 
 
 Land mines may be made use of as obstacles, 
 and while they do not effect much actual damage, 
 their moral effect, as was demonstrated in the 
 Russo-Japanese War, is very great. The mines may 
 be controlled, contact, or a combination, depending 
 upon whether their action is intended to be by judg- 
 ment firing, automatic, or by either method at the 
 will of the defender. 
 
 Figures 16 and 17, Plate IX, show simple land 
 mines and fougasses, the latter being designed to 
 throw a shower of stones or fragments in a predeter- 
 mined direction. For the charges to be used in land 
 mines and fougasses, see Engineer Field Manual, 
 1909, pp. 414-415. 
 
 The natural obstacle offered by a running stream 
 may be rendered much more effective by damming 
 the stream and causing an area of overflow. It may 
 also be possible to divert some stream into the fore- 
 ground and thus produce the same effect. Whether 
 fordable or not, such an inundated area will be a 
 very appreciable obstacle to the attack. 
 
-73 
 
 In placing obstacles, it must always be kept in 
 mind that it may at any time be desirable to assume 
 the offensive, and provision must be made enabling 
 the defenders to do so without being impeded by 
 their own constructions. 
 
 While advanced posts must be used with great 
 caution, their use is at times necessary, for instance 
 to afford flanking fire over otherwise dead spaces, or 
 to occupy some point which must be forbidden terri- 
 tory for the enemy. They are also valuable, when 
 garrisoned by a few expert riflemen liberally supplied 
 with ammunition, in bringing early upon the enemy 
 so effective a fire that he will be compelled to deploy 
 and disclose his strength and intention^. They must 
 .always be entrenched, but should be open to fire 
 from the main line in rear, thus preventing their oc- 
 cupation by the enemy, and means must be provided 
 for the safe withdrawal of the garrison to the rear. 
 The construction of these advanced posts differs in 
 no way from the construction of ordinary entrench- 
 ments, except that they are usually of simpler con- 
 struction, and, as mentioned, must be open to fire 
 from the rear. 
 
 It may be desirable to have a few advanced ob- 
 servation stations, to give early information of the 
 enemy's movements. These should be constructed 
 as already set forth in Chapter III, and should have 
 telephonic connection with the main position. 
 
 Elumination of the foreground has already been 
 discussed in Chapter III. Where this is not prac- 
 ticable, men must be placed in observation to the front 
 at night. These men are given as much shelter as 
 practicable, but nothing must in any way interfere 
 with their seeing and hearing in every direction. 
 They must also be protected from the fire of their 
 own side as it will be impracticable for them to fall 
 back after giving the alarm. A form of cover for 
 
74 
 
 an advanced night sentry is shown in Fig. 18, Plate IX. 
 
 One of the great advantages of the defense is 
 that the engagement takes place on ground which is 
 more or less of his own choosing, and about the fea- 
 tures of which he will have much better information 
 than the enemy. Of especial value will be a deter- 
 mination of ranges, enabling him to bring an effect- 
 ive fire upon the advance as soon as perceived. This 
 determination of ranges is second in importance to 
 nothing else, and should be undertaken at once. 
 There will usually be natural, or existing artificial 
 features which will serve sufficiently to identify 
 ranges, but, lacking these, marks must be estab- 
 lished which will convey the desired information to 
 the defender without attracting the attention of the 
 attack. Such marks may be whitewashed piles of 
 stone or stakes with markers attached. Every com- 
 mander of a sector of the firing line, must take steps 
 to ensure the possession of sufficient information 
 concerning ranges to enable his command to bring 
 accurate fire on every portion of the foreground 
 within effective rifle range. 
 
 In all hasty defensive organizations the time and 
 means available will limit the amount of work that 
 can be put on accessory features. Extensive clear- 
 ing of the foreground involves much labor, as does 
 also the construction of artificial obstacles. By care 
 and judgment in locating the fire lines and by the 
 utilization of natural obstacles much can be accom- 
 plished towards securing a clear field of fire and im- 
 peding the enemy's advance without the expenditure 
 of an excessive amount of labor from which it is de- 
 sirable to spare fighting troops as much as possible. 
 
Chapter VI 
 
 EXECUTION OF FIELD FORTIFICATIONS BY TROOPS.- -TOOL 
 EQUIPMENT, TASKS, RELIEFS, ETC. 
 
 'T A HE practical execution of field fortifications de- 
 
 -1 pends upon the tool equipment of the troops, 
 
 their training, and upon the time available for work. 
 
 It is now the recognized practice to equip all 
 troops with tools and appliances for the execution of 
 different classes of works required in field and 
 fortress warfare, in movements and in encampments, 
 and the proper use of these tools and appliances 
 should form part of their peace instruction. 
 
 The ability to prepare cover quickly and under 
 all emergencies is now regarded as so important that 
 work tools should form a part of the portable equip- 
 ment of the troops from which the soldier should 
 never be separated and which is second in importance 
 only to the rifle and ammunition. 
 
 In order to reduce weight and to admit of greater 
 convenience in carrying, the portable tool equipment 
 is considerably lighter and smaller than the cor- 
 responding commercial tools which necessarily re- 
 duces the output of work. In addition to the portable 
 tools, additional tools of larger size and of special 
 patterns are carried in the combat and field trains 
 for use in the more comprehensive organizations of 
 the terrain. 
 
 As a result of the experiences of the South 
 African and Manchurian campaigns, several nations, 
 notably France, Russia and Japan, have materially 
 increased the tool equipment of their infantry. 
 
 75 
 
76 
 
 At present writing, 1914, the portable tool equip- 
 ments of the leading military nations is as follows: 
 
 France, 1 tool per man Germany, 1 tool to 2 men 
 
 Russia, 1 tool per man England, 1 tool to 2 men 
 
 Japan, 1 tool per man Italy, 1 tool to 2 men 
 
 Austria -Hungary, nearly one tool per man 
 
 The portable tool equipment of the United States 
 Infantry is fixed by General Orders No. 42, War 
 Department, 1913, as follows: 
 
 For each squad 1 pick mattock, with carrier. 
 1 wire cutter, with carrier. 
 3 shovels, with carriers. 
 1 cutting tool, with carrier. 
 
 While it is not so specifically stated, it is under- 
 stood that the cutting tools are to be one half hatchets 
 and one half machetes. 
 
 The following is the recommendation of the 
 Cavalry Equipment Board for the portable tool 
 equipment of the United States Cavalry, which has 
 not yet received the approval of the War Department: 
 
 "Each man carries a combination picket -pin and handle 
 for intrenching tool, weight 1 Ib. 9 oz., case 4 oz.; a pick head, 
 weight 9 oz. ; an axe head, weight 1 Ib. 4 oz. ; a spade, weight 
 1 Ib. 1 oz., and case (including case for pick head and axe head), 
 weight 1 Ib. The picket-pin serves as a handle for all three 
 tools." 
 
 The proportion of cutting to intrenching tools 
 varies between wide limits in the different armies, 
 being 5 per cent in the German, 15 per cent in the 
 French, and 50 per cent in the United States. The 
 proportion of cutting to digging tools is influenced by 
 the character of the country in which it is likely that 
 war may be waged. European armies, operating in 
 thickly settled and cleared terrain will have less use 
 for cutting tools than armies operating in tropical or 
 sub-tropical countries with their dense forest and 
 vegetable growths. Types of portable intrenching 
 
77 
 
 tools in use by different armies are shown in Figs. 1 
 to 6, Plate X. 
 
 In addition to the portable tools carried on the 
 person of a soldier a further provision is made in 
 the combat and field trains of the several infantry 
 units. Thus in France each infantry regiment has 
 two regimental tool wagons, each carrying 130 large 
 shovels, 65 large picks, 19 cutting tools and a small 
 supply of explosives. In Germany the regimental 
 combat train carries 30 large shovels, 15 large picks, 
 15 hatchets, 24 axes and 12 cross-cut saws, while the 
 regimental field train carries on one wagon 230 large 
 shovels, 65 large picks, 30 axes and 8 saws. In most 
 of the foreign armies there is still another echelon of 
 large sized tools in the engineer park. 
 
 Under the provisions of General Orders No. 42, 
 War Department, 1913, the following equipment of 
 park tools is laid down for a regiment of infantry: 
 
 Axes 26 
 
 Crowbars : 7 
 
 Nails, Ibs. 95 
 
 Pick mattocks., 149 
 
 Sandbags 450 
 
 Saws, hand 13 
 
 Saws, two-man 13 
 
 Shovels 298 
 
 Wire, Ibs _ 25 
 
 Carborundum wheel 1 
 
 Saw set (for hand saws) 1 
 
 Saw tool (for two- man saws) 1 
 
 Saw files 6 
 
 (Containers are furnished for files, nails, and all 
 edged tools.) 
 
 This regimental equipment is carried on one field 
 wagon furnished for the purpose. The tool wagons 
 of a division will be consolidated into a park, under 
 the charge of the chief engineer of the division. 
 
 Under the provisions of General Orders No. 63, 
 War Department, 1913, each machine gun platoon 
 has certain digging tools furnished by the Ordnance 
 
78- 
 
 Department, which will be available for entrenching. 
 The following is the prescribed park tool equip- 
 ment for a regiment of cavalry (see General Orders 
 No. 42, War Department, 1913): 
 
 Axes ... 52 
 
 Shovels '_ _ 56 
 
 Pick mattocks 52 
 
 These tools are carried upon the squadron com- 
 bat wagons and upon the field wagon of the machine 
 gun troop. 
 
 No special entrenching tools, either portable or 
 park, are provided for the field artillery. 
 
 In the execution of field fortifications the avail- 
 able time, the training of the troops and tool equip- 
 ment are governing factors. In hasty works the 
 portable tools of the infantry will usually be the 
 main reliance of the troops but may be supplemented 
 by the large tools of the trains and tools requisitioned 
 locally (from villages and farms close at hand). 
 
 In the construction of rifle trenches the company 
 forms the normal working unit. The company com- 
 mander, assisted by the platoon and squad leaders, 
 marks out the line of trench, determines the height 
 of the parapet and the location of traverses. The 
 location of the line of the excavation is most con- 
 veniently marked on the ground by the squad leaders 
 laying their packs on the ground or by sticking 
 their bayonets into it. The men provided with 
 intrenching shovels are then deployed on the line 
 and, after being properly posted, each man forces 
 his intrenching tool into the ground close to his feet, 
 thus marking the left (or right) limit of his task. 
 The men then step back several paces, unsling and 
 lay down their packs, pick up their rifles and a couple 
 of cartridge clips and deploy anew on the line marked 
 out. Each man lays his rifle on the ground behind 
 him and then commences work. If an attack is likely 
 
7Q 
 
 t J7 ~ 
 
 during the progress of the work, the first efforts 
 should be directed towards securing a parapet of 
 sufficient height to afford cover for the head and a 
 support for the rifle in the lying down position, after 
 which the trench is gradually deepened to the final 
 requirements of a standing trench, the work being 
 so regulated that the trench may at all stages be 
 usable for defense. Men may be posted 5 feet apart 
 by taking intervals with both arms extended and 
 hands closed and 3 feet apart by taking intervals 
 with one arm extended, hand closed. Dimensions of 
 rifle trenches may be laid off with the intrenching 
 tools, which are 22 inches long. 
 
 If actually under fire and unable to work in a 
 standing position a rifle trench may still be con- 
 structed by the men working in pairs, one using his 
 intrenching tool to excavate a shallow trench on his 
 right side and heaping up the earth so obtained to 
 gain cover for his head and a rest for his rifle while 
 his comrade keeps on firing. Duties are exchanged 
 from time to time by passing the intrenching tool 
 back and forth, one man digging and the other firing 
 until gradually a standing trench is secured. The 
 method of executing a trench under fire is shown in 
 Fig. 7, Plate X. 
 
 If the ground be too hard to admit of the easy 
 insertion of the intrenching shovel it will be advan- 
 tageous to first loosen the earth with the pick. 
 There being but one pick per squad it will either 
 have to be used in turn by each of the three shovel- 
 ers or else one man may be detailed to do all the 
 picking for the three shovelers, working from one 
 end of their combined tasks to the other, each shov- 
 eler in turn stepping from the trench and resting 
 while the man with the pick is employed in the limits 
 of the shoveler's task. 
 
80 
 
 Squad leaders supervise their squads, seeing that 
 the work progresses as quickly as possible, that the 
 desired dimensions are attained and that the trench 
 is made as inconspicuous as possible. Platoon com- 
 manders see that the work of their squads proceeds 
 uniformly, apportion assistance to any squads ex- 
 periencing delay, see that squad leaders are familiar 
 with the ranges determined to recognizable points of 
 the foreground, cause observation of the foreground 
 to be maintained if the enemy is close at hand and 
 arrange for the occupation of the trenches when 
 finished. 
 
 The company commander is responsible for the 
 correct location of the trench or trenches and sees 
 that important ranges are determined for the infor- 
 mation of his company and arranges for the occupa- 
 tion of the trenches when completed. 
 
 The foregoing is the general method followed 
 when intrenching must be carried out in the imme- 
 diate presence of the enemy or under his fire. 
 
 When more time is available the portable tools 
 will be replaced or supplemented by the tools of the 
 trains or requisitioned in the vicinity and more care 
 can be taken in siteing the trenches and accurately 
 posting the workmen. 
 
 The rate of progress depends upon the interval 
 between workmen as well as on the character of the 
 tools employed. The portable intrenching shovel is 
 incapable of the same output of work as the 
 larger tools of the train or regular commercial 
 models, but its shorter handle permits of men work- 
 ing at smaller intervals than do the larger tools. 
 For convenient working with the larger tools an 
 interval of five feet between workmen is about 
 as small as can be used, while with the portable tools 
 men can work at interval of three feet (even two and 
 one-half feet being stipulated in the regulations of 
 
81 
 
 foreign armies). Roughly speaking, it may be as- 
 sumed that the time necessary to complete a trench 
 with the portable tools with the men at three foot 
 intervals is about the same as with the larger tools 
 with men at five foot intervals. 
 
 Since only a portion of the company is equipped 
 with intrenching shovels, all the men cannot be put 
 to work digging simultaneously. In the French ser- 
 vice there are 160 intrenching shovels per company 
 and with three feet intervals 486 feet of trench can 
 be dug at once. This is sufficient for the entire com- 
 pany, allowing two feet of trench per rifleman, which- 
 experience has shown to be about the minimum for 
 the most convenient use of the rifle, although tests 
 carried out by the Maneuver Division at San Antonio, 
 Texas, in 1911, show that men can be placed as close 
 as eighteen inches a/part and still fire satisfactorily. 
 
 The portable tool equipment of the United 
 States service furnishes but three intrenching shov- 
 els and one intrenching pick to a squad of eight 
 men. The length of trench to accomodate a squad 
 should be about sixteen feet, which will necessitate 
 intervals of five feet if each squad is to dig its own 
 length of trench. So great an interval for the port- 
 able tool will entail a material increase of time in 
 construction, which is permissible if the time can be 
 spared. Otherwise two squads must combine to dig 
 one squad length of trench. By doubling up squads 
 a length of trench for half the company can be very 
 quickly constructed. Whether the diggers shall be 
 posted at the larger or smaller intervals and more or 
 less length of trench in greater or less time be under- 
 taken, must be determined by the requirements of 
 the situation. 
 
 The progress of the work is also affected in no 
 small degree by the question of tasks. With long 
 continued exertion the output of work falls off rap- 
 
82- 
 
 idly. If, therefore, the workmen be relieved at fre- 
 quent intervals better progress will be attained. For 
 hasty works executed by troops under great pressure, 
 perhaps also exhausted by marching and fighting, 
 the tasks should be no greater than can be accom- 
 plished in two hours' time. This will conduce to a 
 more rapid progress of the work and will conserve 
 the marching and fighting powers of the troops. If 
 double gangs be employed on each task, the gangs 
 alternating every thirty minutes and working as 
 rapidly as possible, a still faster progress will be at- 
 tained without exhausting the men. This was the 
 method employed by the Japanese in Manchuria, 
 each gang relieving the other on a whistle signal. 
 
 Since but three men per squad will be equipped 
 with intrenching shovels in our service, double gangs 
 can readily be formed in each squad and the work 
 thus expedited. Other means sometimes available 
 for expediting the hasty preparation of cover are 
 afforded by the following: 
 
 (a) The use of the plow to run a few furrows 
 and loosen the earth to a depth of six or eight inches. 
 Plows may be occasionally found convenient to hand 
 at nearby farms, to which, if other teams are not 
 procurable, the teams of the combat train may be 
 harnessed. In more deliberate works extensive em- 
 ployment of farm and road making machinery may 
 be made with advantage. By suitably modifying 
 the draft rigging a plow can be used to loosen the 
 earth the full depth and width of rifle trenches. 
 
 (b) By incorporating into the parapet any avail- 
 able loose material such as fence rails, small logs, 
 stones etc. Such material can be gathered up and 
 placed by the men not actually employed in digging. 
 
 If it is necessary to give the parapet considerable 
 command, say anything over one and one-half feet, 
 it will be desirable to revet the interior slope of the 
 
-83 
 
 excavated material. In hasty trenches this will 
 ordinarily be limited to using the larger lumps and 
 clods of earth and piling them up as steeply as they 
 will stand. Provided the materials are available, 
 a form of hurdle revetment may be made quite 
 quickly by driving stakes at intervals of three or four 
 feet and placing in front of them brush, branches, 
 cornstalk, etc. 
 
 In the interest of concealment it is desirable to 
 save the sod taken from the excavated area for cover- 
 ing the parapet. In hasty work this will not always 
 be practicable and material for covering the parapet 
 will then have to be procured by men . not employed 
 in digging. A convenient way of saving the sod is 
 to cut the turf into strips about 1' wide the full width 
 of the parapet and then roll it up to the front. 
 When the parapet^ is completed the sod is simply 
 rolled back on the 'parapet. 
 
 In the organization of a supporting point formed 
 of a group of trenches, only a portion of the tactical 
 unit assigned to the defense of the supporting point 
 will be employed in executing rifle trenches. The 
 men not assigned to work on the fire trenches will be 
 employed in clearing the foreground, constructing 
 cover and communicating trenches for supports and 
 reserves and in gathering material for head and 
 overhead cover in case the latter is to be provided. 
 
 The time required for the execution of the 
 different classes of work involved in hasty field 
 fortifications depends upon the tools used. It has 
 already been pointed out that the output of the port- 
 able digging tools is about three-fifths of that of the 
 larger tools of park model. Experience has shown 
 that the average output per hour for men working 
 with large tools with two hour reliefs is about twenty 
 cubic feet for medium soils such as can be excavated 
 without a pick. If the workmen be spaced at inter- 
 
84 
 
 vals of 5' the time required for constructing any type 
 of trench, with reliefs not longer than two hours, in 
 medium soil will be the quotient of the number of 
 square feet in the cross section of the trench divided 
 by four. To execute the same work with the port- 
 able tools in the same time the men must be posted 
 at intervals of three feet, or else a longer time will 
 be required. The excavated area of the simple stand- 
 ing trench is 7.4 square feet, hence it can be con- 
 structed in ordinary soils in something less than two 
 hours' time, provided men are posted at 5' intervals 
 when working with large tools and at 3' intervals 
 when working with portable tools. 
 
 The character of the soil greatly influences the 
 time required for constructing earth covers. In 
 stony or rocky soil, the time will ' be very much in- 
 creased and with portable tools may even be imprac- 
 ticable. For more massive profiles, such as occur in 
 more deliberate organizations, the portable tools are 
 of little use, their short handles making it impossible 
 to throw excavated material any distance. Similarly 
 the portable cutting tools of the infantry are suited 
 only to light work. Any heavy work, such as cutting 
 down of large trees, demolition of structures, etc., 
 must be accomplished with the large tools of the 
 combat trains or left to the engineers. 
 
 The most important fact for line officers to re- 
 member is that a simple standing rifle trench can be 
 constructed in two hours or less with the portable 
 digging tools of the infantry and that two hours' 
 additional work with the same tools will convert this 
 into the complete standing trench shown in Fig. 5, 
 Plate I. 
 
Plate X 
 
 Fig 3 ' 
 
 P'rench Jointed Saw. 
 
 Fig. 2 
 
 French 
 
 Intrenching Intrenching 
 
 Shovel 
 
 Pick 
 
 Fig. 4 
 
 U.S. Intrenching 
 Shovel 
 
 R 5 . 5 
 
 U S. Intrenching 
 Pick 
 
 Fig. 6 
 U.S. Pioneer 
 Pack Shovel 
 
 Mask 
 
 r,c,7 
 
 Execution of a trench by two men in prone position 
 
86 
 
 The following table gives the approximate^time 
 required for the execution of the more usual classes 
 of work which may fall to the infantry in campaign: 
 
 Works 
 
 Personnel 
 
 Tools 
 
 Time 
 
 Simple standing 
 
 1 man per yd. 
 
 Portable 
 
 2 hours. 
 
 rifle trench 
 
 
 
 
 Simple overhead 
 
 1 man per yd. 
 
 Park model 
 
 2 hours plus time 
 
 covers 
 
 
 
 for gathering & 
 
 
 
 
 bringing up ma- 
 
 Cutting down 
 
 6 in. diameter: 
 
 2 axes or 1 
 
 3 minutes. 
 
 trees 
 
 2 men. 
 
 jointed saw 
 
 
 
 12 in. diameter: 
 
 2 axes 
 
 15 minutes. 
 
 
 2 men. 
 
 1 jointed saw 
 
 10 minutes. 
 
 
 
 1 cross-cut saw 
 
 5 minutes. 
 
 
 18 in. diameter: 
 
 2 axes 
 
 30 minutes. 
 
 
 2 men. 
 
 1 cross-cut saw 
 
 12 minutes. 
 
 Clearing brush 
 
 20 men: 300 sq. 
 
 Saxes 
 
 1 hr. or 30 sq. yds. 
 
 
 yards 
 
 5 bill hooks 
 
 per tool. 
 
 Abatis 
 
 6 men per 6 
 
 1 axe, 1 saw 
 
 2 hours. 
 
 
 running yds. 
 
 1 bill hook 
 
 
 
 8 rows trees 
 
 
 
 
 deep 
 
 
 
 Wire entangle- 
 
 Preparing 
 
 2 axes, 1 saw 
 
 3 min. per stake. 
 
 ment 
 
 stakes: 3 men 
 
 
 
 
 Placing wire: 6 
 
 1 maul,3cutt'g 
 
 1 hour. 
 
 
 men for 15 to 
 
 pliers, 2ham- 
 
 
 
 18 sq. yds. 
 
 mers. staples 
 
 
 In prepared positions for which considerable 
 time would be available, the works would be planned 
 with care both as to trace and profile and laid out 
 accurately by the engineers. The construction of 
 such positions may often be effected wholly or partly 
 by civilian labor and by the use of excavating ma- 
 chinery. Troops will, however, be frequently called 
 upon to assist in construction, and, in such a case, 
 their work would be supervised by overseers fur- 
 nished from the engineers whose functions will be 
 limited to seeing that the workmen adhere to estab- 
 lished lines and grades of the works. Officers com- 
 manding the troops employed as fatigue parties will 
 alone be responsible for the conduct and efficient 
 working of their men. 
 
Chapter VII 
 
 UTIILZATION OP ACCIDENTAL FEATURES OP THE TERRAIN. 
 PRINCIPLES OP THE ORGANIZATION OF VILLAGES, 
 HOUSES, WOODS, ETC. 
 
 THE highest expression of the art of field forti- 
 cations consists in the utilization of the natural 
 strength of the terrain in the most advantageous 
 manner with the minimum means, including the 
 avoidance of its disadvantages. 
 
 All natural screens, covers, obstacles and com- 
 munications have a distinct advantage Vver artificial 
 creations, not only in the relatively smaller amount 
 of work required, but also in the fact that troops 
 will, as a rule, advance from them more readily than 
 they will from purely artificial works. 
 
 Existing features of the terrain may be utilized 
 either as screens only, as covers, or as both. Some, 
 like road and railroad embankments and cuts, afford 
 better cover than any artificial construction prac- 
 ticable within the time and with the means available 
 in the field. 
 
 Among the more ordinary features of the terrain 
 which may be utilized as fortification may be men- 
 tioned walls, hedges and fences, buildings, villages, 
 woods, road embankments and cuts, ravine and 
 stream banks, quarries, etc. All these features are 
 rarely represented on the ordinary small scale maps 
 used in directing military operations, hence the 
 question of their utilization requires a certain eye 
 for terrain, skill and experience in utilization of its 
 features for tactical purposes and the ability to 
 weigh the value of these features for use as screens 
 and covers. 
 
 87 
 
88 
 
 The utilization of existing features of the terrain 
 for fire lines requires in general the preparation of a 
 firing platform to permit the soldier to fire standing 
 with a good view of the foreground and a convenient 
 rest for his rifle, with good communications along 
 and in rear of the fire line. 
 
 Individual trees or bushes usually afford insuffi- 
 cient cover against the penetration of rifles and ma- 
 chine guns and must be strengthened by an earth 
 cover. Dikes, roads, embankments and like features 
 constitute excellent fire lines. If narrow, the fire 
 line should be organized on the slope away from the 
 enemy as shown in Fig. 1, Plate XL If wide, it is 
 better to construct a firing trench along the edge 
 nearest the enemy connected with the rear slope by 
 communicating trenches shown in Fig. 4, Plate XL 
 If a railroad track occupies the top of the embank- 
 ment the rails will make a good firing crest. The 
 railroad embankment skirting the Shoushanpu ridge 
 in the Russian defenses at Liaoyang formed part of 
 the Russian fire lines and was strongly held. The 
 same embankment was also used as cover by the 
 Japanese in their attack against Shoushanpu. 
 
 Sunken roads, dry water courses, quarry walls 
 and like features are organized according to their 
 nature by arranging the slopes on the side toward 
 the enemy to afford a firing position for the rifleman 
 and access thereto. Scarping of banks, excavating 
 steps, providing ramps and like work is called for. 
 
 Figs. 2 and 3, Plate XI, show methods of organ- 
 izing a ravine bank and road ditch. 
 
 In case the feature constitutes a good obstacle, 
 for instance, a wet ditch with muddy bottom, it will 
 be better to construct a rifle trench some distance to 
 the rear. Long, straight and dry ditches with steep 
 banks may also be arranged to be flanked by con- 
 structing short parapets across them at salient and 
 
89 
 
 reentrant angles. Examples of the use of such fea- 
 tures are afforded by the sunken road at Fredricks- 
 burg, the gravel pits at Gravelotte and numerous in- 
 stances of dry water-courses in the Manchurian cam- 
 paign. 
 
 All classes of property enclosures may be made 
 to serve as screens and covers as well as obstacles. 
 Hedges make excellent screens and if of thorny 
 growth, such as osage orange, a good obstacle, es- 
 pecially if interwoven with a few strands of barbed 
 wire. For use as cover they require the addition of 
 an earthern parapet on the side away from the 
 enemy as shown in Fig. 5, Plate XL \0penings for 
 firing through the hedge should not be spaced too 
 regularly or made too clear cut as otherwise they 
 would reveal the location of the fire line. 
 
 Board, picket, barbed wire and iron fences may. 
 be used as obstacles by moving them in sections 
 bodily to suitable location, or else their material may 
 be employed in providing accessory features in or in 
 rear of the fire trenches. Close board fences also 
 serve as masks and may be used as revetment for 
 fire trenches by throwing up an earth parapet in 
 their front. 
 
 Stone and brick walls afford good cover if suffi- 
 ciently thick (15 to 18 inches for rifle bullets against 
 brick walls). The provision for firing platform is 
 regulated by the height of the wall, several forms of 
 installation being shown in Figs. 6 to 9, Plate XL 
 High walls may be arranged for 2 tiers of fire. Stone 
 walls have the disadvantage of giving a dangerous 
 splinter effect, to diminish which it is well to cover 
 their tops with sod or sand bags. Stone walls are 
 also comparatively easily breached by light field guns 
 at medium and short ranges. When the wall is not 
 too high an earthern parapet in its front as shown in 
 
-90 
 
 Fig. 10, Plate XI, will afford reasonable protection 
 against artillery fire. 
 
 Individual buildings have ordinarily only a lim- 
 ited value for defense. Unless of very solid con- 
 struction their walls can be pierced by rifle bullets at 
 mid and short ranges and demolished by artillery. 
 Notwithstanding their disadvantages history affords 
 numerous examples of stubborn defense from strongly 
 constructed masonry buildings. Unless dangerously 
 exposed to artillery fire strongly constructed build- 
 ings like factories, public institutions, churches, etc., 
 can be readily organized for a strong defense by a 
 few men. The principal works to be carried out are 
 the closing and barricading of all openings on the 
 ground floor, including cellar openings, arranging 
 windows and doors for delivery of fire, proper ar- 
 rangements for flanking fire and guarding against 
 conflagrations by removal of all readily combustible 
 material and keeping a supply of water on hand. 
 
 Villages and woods constitute the larger features 
 of the terrain which frequently find application as a 
 means of defense. Notwithstanding the increased 
 fire effect of artillery due to the introduction of rapid 
 fire guns and howitzers with improved ammunition, 
 villages and woods still continue to serve as strong 
 supporting points in extended lines of defense and 
 have shown themselves capable of stubborn defense 
 in the most recent wars. "All the explosive shell of 
 an entire army corps will not suffice to demolish a 
 village" says General Langlois and this contention is 
 supported by the experience of the recent campaign 
 in Manchuria in which the adobe and brick villages 
 of the Chinese were the scenes of many severe com- 
 bats. 
 
 The importance of villages and woods depends 
 essentially upon their location with respect to the 
 battle lines, their nature as to size and character of 
 
-91 
 
 construction or growth and the method of their or- 
 ganization. When favorably located they possess 
 the advantage of threatening the enemy's line of ad- 
 vance, flanking our own defense lines and when suit- 
 ably organized form supporting points in the whole 
 defensive organization. Their disadvantages consist 
 in the difficulty of directing their defense and the 
 restriction of maneuvers for reenforcing fire lines or 
 making counter attacks. 
 
 The outer edges of both woods and villages are 
 easily distinguishable from a distance and afford 
 good targets for artillery, hence the fire line should 
 not, in the interests of better protection, be coinci- 
 dent with the edges. 
 
 In the organization of villages for stubborn de- 
 fense their perimeters are sub-divided into tactical 
 sections (companies, battalions) care being taken not 
 to use main entrance roads as section boundaries. 
 From to | of the entire garrison is assigned to the 
 section defenses, the remainder forming the general 
 reserve for use in counter attacking the enemy in 
 flank or for covering withdrawal. Each section keeps 
 out a section reserve and organizes its front line into 
 a firing line and supports. The strength of sector 
 garrisons, including supports and local reserves, may 
 be calculated at 1J men per yard of perimeter. 
 
 The front line of defense of a village is now or- 
 dinarily placed 50 to 100 yards to the front of the 
 nearest buildings, using simple rifle trenches or utiliz- 
 ing any suitably located property enclosures organi- 
 zed as already indicated. Where the village is not 
 exposed to artillery fire, for instance when located in 
 a deep and narrow valley, the outer walls of the 
 front building may be selected for the outer defense 
 lines and these buildings prepared for defense. The 
 main entrances of the village should be barricaded 
 
92 
 
 strongly and the main approaches held under heavy 
 rifle and machine gun fire. 
 
 Cover for supports and reserves can ordinarily 
 be found behind the walls of inner buildings. For 
 the supports, which must be near the fire line, cover 
 trenches may be required. 
 
 The interior communications are exceedingly 
 important in the defense of a village. Since the 
 main streets will ordinarily be fire swept and barri- 
 caded, other means must be provided for securing 
 freedom of movement for supports and reserves. 
 Openings must be made in inclosures and house 
 walls to afford short and direct routes to the various 
 points of the front and these routes must be numer- 
 ous and marked by sign boards. 
 
 As in all other cases, the front fire line must be 
 located so as to command the foreground. Detached 
 buildings in front of the main fire line are generally 
 left standing if they do not limit unduly the field of 
 fire. 
 
 Interior defensive lines may be organized pro- 
 viding the village offers any good dividing line 
 generally parallel to the front. A wide street or 
 stream through the village may be employed for this 
 purpose. In any event, it is well, always, to organ- 
 ize defensively one or more strong buildings in the 
 interior or towards the rear of the village to serve 
 as a place of final defense after the front line shall 
 have been pierced. The retention of such a group of 
 buildings as a keep greatly facilitates the recapture 
 of the village by the outer reserves. 
 
 The general principles governing the organiza- 
 tion of woods are much the same as in the case of 
 villages. The front line of defense may be placed 
 some distance in advance of the outer edge or, if the 
 woods be open, a short distance within. The latter 
 location is especially favorable to concealment, but, 
 
93 
 
 owing to the roots of trees, digging is more difficult. 
 If the woods be extensive, troops may be economized 
 by providing abatis along portions of the edge and 
 flanking these from fire trenches located at salient 
 angles. Openings should be left between the abatis 
 and fire trenches to permit of an advance. . 
 
 Interior defense lines may occasionally be prac- 
 ticable in woods along the banks of a stream or 
 on the edges of a clearing. Owing to the absence 
 of buildings, keeps rarely enter into the defensive 
 organization of woods. 
 
 The most important measure in organizing woods 
 for defense is the preparation of interior communi- 
 cations. The organization of these should actually 
 precede the construction of the lines, for without the 
 former the latter will be of little value. Roads or 
 paths parallel and perpendicular to the front in suffi- 
 cient numbers to permit ready movement of supports 
 and reserves must be constructed and will call for 
 much labor if there be heavy undergrowth. If time 
 permits the rear edge of a wood may be obstructed 
 by slashings to delay the enemy breaking through 
 and give them time for counter measures. 
 
 While woods and villages may be readily organ- 
 ized for a stubborn defense perse, their tactical value 
 depends upon their location with respect to the 
 remaining elements of the defensive line as well as 
 upon the adjacent topography. Their value is some- 
 times reduced to that of mere screens for the shelter 
 of sector or general reserves. Sometimes their loca- 
 tion is such that, while not vital to the defense, they 
 may be made to serve as attractions for the enemy 
 and thus relieve the pressure against the real key 
 points of a position. 
 
Plate XI 
 
 Fia--7 
 
 Fig. 10 
 
Chapter VIII 
 
 APPLICATION OP FIELD FORTIFICATIONS TO THE DEFENSE 
 
 OF THE LINES OF COMMUNICATIONS. BRIDGE 
 
 HEADS. BARRIER WORKS. 
 
 Defense of Lines of 
 Communications 
 
 THE uninterrupted service of the lines of com- 
 munications is of vital importance to the ex- 
 istence of an army in the field and the'fr protection 
 consequently a matter of deep concern to the com- 
 mander-in-chief. The front of operations will, 
 therefore, usually be such as to cover the lines of 
 communications in the best possible manner, that is, 
 normal or nearly so to these lines. 
 
 But when the lines of communication are long 
 it will be impossible for the army to protect them by 
 its own front and it becomes necessary to assign 
 special troops for this duty. It will be manifestly 
 impossible to protect adequately every foot of a long 
 line without detaching an undue proportion of troops, 
 nor is this necessary. Attacks on the lines of com- 
 munications will ordinarily be made by raiding 
 parties only, whose security will depend upon their 
 mobility. If all vital points of the lines of communi- 
 cations, such as important bridges, viaducts, tunnels, 
 locks, fuel and water supplies, etc., be guarded, the 
 damages which a raiding party can bring about at 
 other points will be relatively insignificant. The 
 destruction of a mile of track (burning of cross-ties, 
 bending or removal of rails, etc.) will engage the 
 efforts of a fair sized force for quite a time and yet 
 such damage can be repaired within 24 hours, 
 
 95 
 
whereas a single man with a few pounds of high 
 explosives can, in a few minutes damage a bridge 
 or tunnel so as to cripple the lines of communications 
 for week or months. 
 
 A due regard for economy of forces therefore in- 
 dicates that only vital points of the line of communi- 
 cations require guarding and that field fortifications 
 can be usefully employed for this purpose. 
 
 The service of the lines of communication, in- 
 cluding their protection, devolves upon the comman- 
 der of the lines of communication and he is respon- 
 sible for their defense against hostile enterprises. 
 The troops detached for this purpose are under his 
 orders and may comprise all arms of the service. 
 
 The considerations involved in the application of 
 field fortifications to the protection of vital points on 
 lines of communication are somewhat different from 
 those applicable to fortified lines. Since the attack 
 may come from any or all directions it is evident that 
 there must be an all round defense. Furthermore, 
 since no prolonged systematic attack by artillery is to 
 be feared, the importance of concealment for the de- 
 fensive works is less, permitting the use of stronger 
 profiles. Since the defense will be purely passive, 
 closed works with ample obstacles will be in order. 
 
 As in all other defensive organizations the works 
 designed for a defense of a point on the lines of com- 
 munication .must be sited so as to give the greatest 
 effect to the weapons of the defenders, mainly the 
 rifle and machine gun. The topography will there- 
 fore dictate the location of the works and this may 
 necessitate placing them on commanding ground at 
 some little distance from the object to be defended. 
 To insure the immediate protection of structures like 
 tunnels, bridges, viaducts, etc., additional works will 
 sometimes be needed to prevent access to the struc- 
 tures by individuals or small parties. 
 
97 
 
 Since only a passive defense with minimum num- 
 bers is contemplated, the character of the works will 
 be such as to permit of an all round defense. They 
 will therefore consist of small redoubts, blockhouses, 
 or even groups of trenches surrounded by a continu- 
 ous line of obstacle. For the protection of an impor- 
 tant bridge the defensive arrangements might consist 
 of several closed defensive points on each bank, occu- 
 pying commanding ground and a good all round field 
 of fire with the addition of a trench or blockhouse at 
 each end of the bridge. To prevent access to the 
 bridge piers and abutments by boats, the piers and 
 abutments should be held under fire from the works. 
 A type form of defensive arrangements ^or- the pro- 
 tection of a bridge by two companies of infantry is 
 shown in Fig. 1, Plate XII. The defensive arrange- 
 ments for tunnels would be made in a similar manner, 
 consisting of several closed defensive points on 
 heights adjacent to the portals with a blockhouse or 
 field redoubt at each portal. 
 
 Blockhouses are small bullet-proof buildings 
 roofed in to protect their garrisons from the weather. 
 They may be constructed of timber, plate iron, rails, 
 corrugated iron or combinations of materials. Timber 
 alone will no longer stop bullets unless of extraordi- 
 nary thickness and must be reenforced by earth and 
 metal. A simple form of timber blockhouse with 
 galvanized iron roof is shown in Fig. 2, Plate Xlla. 
 
 Another form used by the British in South Africa 
 is shown in Fig. 3, Plate Xlla. This latter was con- 
 structed of corrugated iron drums made bullet-proof 
 by stone and gravel packing as shown in the figure. 
 When surrounded by a continuous obstacle and with 
 entrances secured, blockhouses of the type described 
 enable their small garrisons, 12 to 20 men, to offer a 
 stubborn resistance. They can be destroyed only by 
 
Scale 200yds=iin. 
 
 Cl Closed Field Work for 3 /4 Co 
 
 b Block Mouse for X A Co 
 
 C Trench for ICo. 
 
 d Communicating Trench. 
 
XHa, 
 
 B I ock House 
 
 used by British in 
 
 South Africa 
 
 Section C-D 
 
- 100 
 
 artillery with which only large raiding parties would 
 be supplied. 
 
 When field redoubts are employed on the defense 
 of the lines of communication they will be of small 
 size (for garrisons of one half to one company) and 
 may be simple ring trenches or have a somewhat 
 stronger profile as shown in Fig. 4, Plate Xlla. 
 
 The defense of a line of communications involves 
 not only the security of points vital to the line as 
 discussed above, but also a service of information, 
 which, in connection with mobile troops, will enable 
 reinforcements te be hurried to threatened points. 
 The wireless telegraph is especially valuable as a 
 means of reporting the near presence of hostile raid- 
 ing parties and is not subject to interruption like the 
 ordinary telegraph or telephone lines. Whenever 
 the flatter are used, any interruption 'of the service 
 must be taken as an indication of the presence of the 
 enemy. Mobile columns held in readiness at con- 
 venient points along the line must be set in motion as 
 soon as the enemy makes his appearance and en- 
 deavor to defeat his attempts at injuring the line. 
 On railroads such mobile columns may be moved 
 rapidly along the line on special armored trains, 
 carrying machine guns and artillery. The country 
 on either side of the line should also be observed and 
 patroled to some distance by sentinels and cavalry in 
 order to give timely warning of the enemy's ap- 
 proach. A system of visual signals (heliograph or 
 flags for daytime, rockets or signal fires for night- 
 time) should be established as a means of communi- 
 cation between sentinels and the garrisons of the 
 defenses. 
 
 Bridge Heads 
 
 Bridges on the lines of communicattion over wide 
 and deep streams are of such vital importance as to 
 
101 
 
 call for special treatment. Not only must the bridge 
 structures themselves be protected from all pos- 
 sible damage but provision must also be made to 
 cover the deployment of the army in an advance and 
 its withdrawal in case of a retrograde movement. 
 Field works constructed to meet the foregoing re- 
 quirements are called bridge heads and consist of a 
 line of works enclosing the bridge on the side of the 
 enemy and located at such a distance therefrom as 
 to protect the bridge structures from hostile artillery 
 and to enclose sufficient ground to insure some man- 
 euvering power to the army. 
 
 The principles governing the organization of a 
 bridge head are the same as those governing the or- 
 ganization of defensive lines except that the flanks 
 of the bridge head, by resting on the stream above 
 and below the crossing, are secure, whereas in defen- 
 sive lines the flanks are frequently in air. Bridge 
 heads, being intended for passive defense only, will 
 consist of works more strongly organized with a view 
 to economy of forces, and the supporting points may 
 be closed works. 
 
 Stream crossings are in effect nothing but short 
 defiles and a bridge head, therefore, is a form of the 
 defense of a defile at its exit, that is, on the side of 
 the enemy. If attacks are likely to be made on the 
 stream crossing from the side of the stream away 
 from the enemy, that is, on the entrance to the de- 
 file, a line of works should be constructed on this 
 side also. When a stream crossing is thus defended 
 on both sides the works constitute a double bridge 
 head. 
 
 For large armies a single bridge would not afford 
 sufficient means for crossing a stream and several 
 bridges would be required, part of which would be 
 military bridges specially built for the purpose. The 
 several bridges if not too far apart, would all be en- 
 
102 
 
 closed by the same bridge head, as was the case of 
 the Russian bridge head at Liaoyang, which formed 
 the arc of a circle of some 2J miles radius and cover- 
 ed 7 bridges including the railroad bridge. 
 
 Barrier Works 
 
 Barrier works are such as are designed to close 
 defiles, mountain passes or stream crossings to the 
 enemy, usually on the flanks of a field army. Closure 
 of defiles may be effected either at their exits or en- 
 trances, and, in the case of mountain passes, in their 
 interiors also. When it is a question of a purely 
 passive defense the best location for barrier works 
 will be at the entrance of the defile, that is the side 
 away from the enemy. If, however, an advance 
 from the defile is held in view, the defense must be 
 made at the exit and should enclose sufficient ground 
 to permit of deployment. 
 
 The principles governing the construction of bar- 
 rier works are similar to those governing the con- 
 struction of bridge heads. The works in general will 
 consist of a line of supporting points affording mutual 
 support and organized in a manner similar to the sup- 
 porting points in a defensive line. As the defense 
 will usually be passive only the supporting points 
 will be strongly organized and may take the form of 
 closed works with a belt of obstacles. 
 
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