British Trench Warfare 1917-1918

British dugout life near the Somme

This page is a small reprint from the British reference manual on Trench Warfare, British Trench Warfare 1917-1918. The manual was originally prepared by the General Staff at the British War Office. It offers a tutorial in state-of-the-art trench construction. This book was recently reprinted by London's Imperial War Museum and the Battery Press and it is with thanks to both of them that we can view it today. The chapter reproduced here represents only a small section of the manual. The book is 200 pages with almost half of that being diagrams.

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Information for ordering a copy can be obtained via email from Dick Gardner ( of the Battery Press. ø Click here to view their online catalog of many quality WWI reprints.




    The importance assumed by trench warfare and the progress made in the application of field fortification and in the science of the attack and defence of elaborate systems of trenches, have rendered necessary special instruction in the details of trench construction and trench fighting. It must, nevertheless, be clearly understood that trench fighting is only a phase of operations, and that instruction in this subject, essential as it is, is only one branch of the training of troops. To gain a decisive success the enemy must be driven out of his defences and his armies crushed in the open. The aim of trench fighting is, therefore, to create a favorable situation for field operations, which the troops must be capable of turning to account.


    1. Three facts in particular give to modern trench fighting under present conditions most of its special characteristics. These are:
      1. The continual proximity of the opposing forces.
      2. The length of time for which they have generally occupied the same ground.
      3. The fact that neither side has a flank so long as it remains on the defensive, so that every attack must be frontal.
    2. As a result of the length of time the opposing forces have been in close proximity on practically the same ground, the original trenches dug at the end of a period of maneuver operations have grown into a complicated system of entrenchments. The design and organization of these have been influenced lay the nature of the artillery, up to calibers far heavier than could be utilized in ordinary field operations, which the stationary nature of the fighting has made it possible to bring up. Arrangements have been made by a carefully thought out system of intercommunication for the maximum cooperation between artillery and infantry, both in attack and defense, and artillery has had time to register on all targets within range. Thus either side has it in its power to concentrate heavy fire at very short notice upon any selected target, and to maintain that fire for a length of time which difficulties of ammunition supply would put out of the question in maneuver operations. Consequently, the rapidity with which artillery can form a barrage to meet attack makes it necessary that the moment of the assault should come as a surprise, and the trenches from which an attack is to be made should therefore be within close assaulting distance of the opposing front line.
    3. A system of trenches must therefore be designed which facilities the preparation and launching of an unexpected assault, and at the same time is adapted to meet a sudden attack by the enemy. The organization of a trench system to facilitate attack is an important point which is frequently neglected. If additional trenches have to be hastily made when an attack is intended, the intention to attack will be obvious to the enemy by aerial reconnaissance, and surprise will be out of the question.
    4. Modern field fortifications owe their elaborate form to the means employed in attack and defense respectively. A general idea of what those means are is therefore necessary. The aim of the first stages of attack is to obtain a footing in the enemy's defenses and to consolidate and extend the gain thus made. Penetration is effected by means of an infantry assault, which, as 'has been said, must unavoidably be frontal and depends for success on a certain measure of surprise. The infantry attack may be assisted by any or all of the following methods:
      1. The previous destruction, by bombardment or explosion of mines or a combination of both, of the enemy's material defenses, including obstacles.
      2. The shaking of the morale and destruction of the personnel of the defending force by bombardment or by the employment of one of the new agents of war, such as asphyxiating gas or jets of liquid fire, prior to assault.
      3. Keeping down hostile fire over the area to be crossed by the attacking infantry long enough to enable the assaulting troops to reach the cover of the enemy's defenses.
      4. The isolation, by artillery barrages, of the area to be assaulted, so as to prevent the arrival of reinforcements.
      5. The dispersal or destruction of troops collecting for counter-attack.
    5. To meet these measures the defense employs the following means:
      1. Constant close observation, with a view to the detection of any signs of impending attack.
      2. Concentration of fire on any detected assembly which might be the prelude to assault.
      3. Concentration of fire of artillery, machine guns, and rifles, from as wide a front as possible, over any part of the zone lying between the two lines, so as to prevent the penetration of the defense.
      4. Obstacles to delay the assaulting troops as long as possible under this fire.
      5. Barrages of fire to prevent the reenforcement of, or the sending up of materials, ammunition, or supplies to, any body of troops that has succeeded in penetrating the defense.
      6. Disposition of works so as to localize and confine the effect of penetration at any point.(2)
      7. Destruction by artillery fire of any enemy troops that have penetrated.
      8. Immediate counterattack, to drive out the attackers before they can have recovered from the confusion of the assault and have established themselves securely in the captured area.


    A consideration of the above shows that there are certain features which are essential in a system of trenches. They must be strong, to resist heavy bombardment; they must be sited and designed to favor, by the utilization of oblique and enfilade fire of rifles and, above all, of machine guns, the development of the maximum volume of fire over any part of their front; they must be protected by a strong and well-hidden wire entanglement, in order to retain attacking infantry under this fire; they must provide protection for the garrison against weather and against the effect of artillery fire. Fire and shelter trenches must be numerous in order to accommodate the additional troops to be placed in them previous to an attack on the enemy's line, and also, in the defense, to induce dispersion of hostile artillery fire to permit the temporary withdrawal of the garrison from a heavily shelled zone, and to accommodate troops for local counterattack in close proximity to the points where they may be required. Communications must be ample, to admit of the rapid reoccupation of temporarily evacuated trenches, to minimize the interference of hostile fire with reenforcement and supply, and to facilitate local counterattack. Close observation of the enemy must be provided for by listening posts in advance of the front line and by observing stations in or behind it. Finally, the system of trenches must admit of immediate readjustment of the front, so that the effect of penetration at any point may be localized and need not weaken the hold of the defense on adjacent trenches.


    The attack on such a, system of defenses as has been described demands in all ranks dash and gallantry of a very high order, and in the subordinate leader, clown to the lowest grades, a quick perception, rapid decision, and intelligent initiative. It is more than ever' the case that success depends upon qualities of leadership in subordinate commanders, upon rapid appreciation and readiness to accept responsibility on the part of the man on the spot. Much can be done in peace training to foster these qualities and to impress on even the most subordinate leaders the necessity for acting, in cases of urgency, on their own responsibility. At the same time, the state of comparative inactivity, which is the normal condition of life in the trenches, is very unfavorable to the development of these qualities in officers and men. There is an insidious tendency to lapse into a passive and lethargic attitude, against which officers of all ranks have to be on their guard, and the fostering of the offensive spirit, under such unfavorable conditions, calls for incessant attention. Minor local enterprises and constant occupation during the tour of duty in the trenches furnish the best means of maintaining the efficiency of the troops. The repair, maintenance, and improvement of the trenches furnish ample work to afford employment to the troops, who must be made to understand that this work reacts in their own favor in the shape of increased security and comfort and conditions more favorable to health. Constant activity in harassing the enemy may lead to reprisals at first, and. for this reason is sometimes neglected, but, if persevered in, it always results in an ultimate mastery, it gives the troops a healthy interest and wholesome topics of conversation, and it achieves the double purpose of raising the morale of our own troops whilst lowering that of the enemy. Every effort should be made to obtain the mastery over the enemy's snipers.


    The proximity of the opposing lines, the progress of aerial reconnaissance, and the close and continuous watch which either side maintains over the other, have increased the importance of night work. Many of the daily operations incidental to trench warfare can only be carried out under cover of darkness. The construction of new trenches in sight of the enemy, and much of their maintenance and repair, the construction, repair, and improvement of obstacles, and in many cases the bringing up of materials and stores and the relief of the garrison, can not be carried out by daylight. The assembly of troops and many of the final stages of preparation for an attack, as, for instance, the removal of our own obstacles, can only be kept from the enemy's knowledge by carrying them out at night. The close reconnaissance of the enemy's front line and his obstacles and of the ground to be. crossed by an assault is the work of night patrols, and much of the identification of the troops opposed to us -- a very important duty -- can only be effected by small enterprises carried out by night against the enemy's patrols or listening posts or sometimes against a small section of his trenches. Training in all these branches of night work is an important part of the instruction of troops before leaving for the front.


    The hardships, discomfort, and dangers of life in the trenches make great demands upon the endurance of the troops; the frontal attack on an enemy in a position strengthened and defended by every device, that ingenuity and forethought can conceive calls for exceptional resolution and determination, and the defense of trenches against an attack, preluded generally by a protracted and severe bombardment, and often by the employment of some entirely new and unforeseen agency, requires the utmost steadfastness and devotion. No infantry will possess those qualities to the requisite degree that has not a, very high standard of discipline. The first and greatest aim of all training should therefore be the establishment of the strictest discipline. To attain this there is no other method than constant and precise drill, strict enforcement of march discipline, insistence on a rigid exactness in the performance of even the dullest details of camp and barrack routine, and unceasing attention to apparently trifling detail in time of training. Without such previous preparation the silent and thorough execution of work and performance of duties, in darkness and in danger, in the presence of the enemy, and often without direct supervision of a superior, which distinguish good from bad troops and spell success, are impossible of attainment.


    The present type of warfare in the trenches has involved the training of a proportion of men in infantry units in duties of a special nature, e. g., grenade throwing, pioneer work, sniping, etc. A word of warning is necessary as regards the training of these men. They must be made to realize that their training in these special duties is in addition to their ordinary training as infantry soldiers and must not be allowed to interfere with their performance of the ordinary duties of infantry soldiers, except when they are required for the special duties in which they have been trained.

Trench Diagrams - All images are less than 8Kb in size.
View Various trench patterns: normal, equal trench and traverse, recessed sentry posts.
View Various trench patterns: curved, dog legs, tenaille, T's and L's, occasional forward traverse.
View Various trench patterns: flanking, bastioned, dummy.
View Basic communication trenches.
View Communication trenches: zigzag, elbowed, traversed, island traverses, bridge traverses.
View Portion of front line trench layout.
View Larger view of front line trenches.
View Alternative front line layout.
View Strong point patterns.
View Keeps.
View Fire trench - cross section.
View More details of fire trench - cross section.
View Wet soil fire trench - cross section.
View Communication trench - cross section.
View Revetments.