Chapter VII: Section IV: Behind the support trenches the C. T. should be constructed (1)

on the traverse principle of _Section I_, so that the same defensive features existing for the support trenches as should exist for the firing line. In doing this, however, it should be kept in mind to provide rapid transit for troops behind these supporting lines. This is best done by continuing the zigzag system right through support trenches as shown. When necessary, this C. T. can be blocked.

It is always a possibility that support trenches may be lost, but not a probability. Therefore, undue weight should not be given against the convenience of adopting as soon as possible again the zigzag C. T. of _Section II_, the latter supplying all requirements of rapid transit and allowing the introduction of straight stretches in loophole traverses wherever required.

TELEPHONE LINES

It is generally found that artillery telephone lines are laid on the north and west side of a C. T.; infantry lines on the south and east. Lines are generally laid about two feet from the bottom of the trench, picketed inter-grooves being cut into the side of the trench. These lines must be given absolutely every protection possible by the infantry and by any one using the trenches. Far too much carelessness has at times existed which destroyed communication with artillery and infantry when it was of vital importance that it should be open.

Infantry in the trenches depend for immediate support upon their artillery, and if, through lack of supervision on the part of the officers in charge, these lines are destroyed or temporarily torn down by careless men not understanding their significance and importance, then that officer or officers is guilty of a very serious crime.

RECESSES

These are usually made in C. T. to allow for the passing of troops or bearers of stretchers, or parties passing up and down to the line carrying the many things that are necessary for the upkeep of that line.

It is advisable that these should always be placed in the same corresponding place in each stretch, as shown in SECTION III, just before the turn, so that men know where they are to be found. The first man of a party coming up having arrived at a turn, and seen or heard others coming down, can give necessary protection to his party, and a great deal of unnecessary and very exasperating and fatiguing movements, and sometimes retracing of steps, is avoided. It is also often the cause of a great many casualties in a trench where these recesses are not made, as parties of men coming and going very often, while struggling to get past one another with their loads, are caught by heavy shell fire.

The recesses should be about 8 feet long and at least 2 feet wide, and the soil excavated from these recesses could be used for strengthening the parapets of the C. T.’s at these turns. Generally, when time allows and energy permits, close to the firing line these recesses are made longer and deeper, oftentimes running to 12 and 18 feet long by 6 and 10 feet deep, although it is not advisable to crowd them too much. Recesses of this kind may also be heavily roofed and used as a very temporary shelter for stretcher cases, stores of bombs, ammunition, etc.

At every second or third stretch in these C. T.’s, either steps or an easy runway to the top of the trench should be made. This saves time on a great many occasions when parties coming over the top for speed and comfort find themselves stopped and have to take to the trench on short notice. It is also good when a serious obstruction occurs, and it is necessary to leave a C. T. and enter it again farther on.

NOTICE BOARDS

These boards should be fixed at every entrance and junction in a trench system, stating the name of the trench and the places to which it leads, and where there are trenches expressly for up and down traffic, these boards should state it. Some people argue that such notices assist the enemy when they get into our trenches, but the argument does not hold as it is very often the case they do not know the names used in the sectors, as they vary up and down the line, and generally they have a very good idea of the system they will find themselves in anyway, and there is a very small chance that a majority of them will be able to read them anyway.

Care must be taken that these notice boards are not used for what is known as “boiling up,” building fires, in braziers, etc., as the absence of these boards causes a tremendous amount of confusion when new troops are coming into the line. All officers must know the shortest routes from their own headquarters to those of companies on their flanks, as well as their own battalion headquarters, and every officer, N. C. O. and man must know the position of his immediate commander’s dugout, as well as his company headquarters, and every man must know the name of the trench that he is in and helping to hold, and this is not possible when these notice boards are destroyed.

TRENCH DRAINAGE

Efforts at drainage, which is the greatest trouble during the winter months to troops occupying the line, must be as systematic and thorough as possible. Tinkering is of very little use and brings no results but causes a great and tiring expenditure of labor as far as the men are concerned, with no end of work in sight. When taking over a sector of line, the drainage system must be thoroughly studied and a line of campaign mapped out and strictly adhered to. Thorough work in the initial stages will save any amount of subsequent unnecessary fatigue and labor. The system to be applied depends entirely on local conditions, but full advantage must be taken of the assistance which nature affords. Water running down hill is a marvelous fact; nevertheless it is often overlooked. Field drains and natural streams anywhere near the trench must be kept clear of obstructions. These are usually attended to by the overworked farmers in peace times, but as they do not work near a trench system, it must be looked after by the army. Neglect of the natural watercourses has been the cause of much of the difficulty of draining the trenches themselves.

During the winter months a trench is never really drained. A mixture in the trenches which is neither water nor good, sticky mud, but a beautiful liquid combination of water and dirt, which is thick enough not to run, is formed. Sometimes it becomes sufficiently like water to be pushed or assisted to run down hill with scrapers, boards, and anything else that is handy. Sometimes it becomes sufficiently heavy enough to be shoveled over the parapet or put into sand bags. In either of these cases it is only overcome by persistent labor, but when the mud is in its true clayed self it is a waste of time and labor to attempt to move it, and the only way, without a large amount of cursing, is to sit tight and pray for the sun to dry it.

When a valley or dip is close to the side of a C. T. a few narrow gullies through the side, of about 18 inches in width, should be made so that liquid mud can be swept along the trench and on through the gulley to a natural fall. These little gullies or ditches should start at a place or places where there are dips in the level of the trench and must be dug straight through the side, as it then becomes easier to keep clear and gives no obstruction to the flow of mud; but if facing the enemy, it should not be in a straight line, as it then allows rifle fire into the trenches. If no other way is possible, then overhead traverse or other means of protection should be taken at that point. Sometimes, when it is not possible to complete these gullies, they should be dug out as far as circumstances will permit and a block of soil or very large sods be put at the junction of the gulley to the trench and the liquid mud dipped out of the trench and dumped into the gulley, where it will be prevented from running into the trench again by these collections of sods. This process is very slow, but conditions frequently make it the easiest and most convenient way of ridding the trenches of some of the mud. This work can be carried on by what is sometimes known as a “trench patrol” or maintenance squad, which is generally detailed from the company in the support line and which patrols the system of trenches held by their battalion during the day. The N. C. O. in charge generally reports serious collapses to his company officer, who in turn reports it to the engineers, who immediately take steps to have it repaired.

The width of drainage gullies should not be less than 18 inches, thus allowing easy use of brushes issued. With these brushes and adequate gullies, very long stretches of trench can be kept in excellent condition when the trench is wide enough to allow the drying effect of wind and sun to reach the bottom. The time spent in making these gullies is saved over and over again. If there be no natural valley or dip, a sump-pit is generally dug, the size depending on the energy of the troops digging it, but generally it is about 10 feet below the level of the trench it drains, and anything from 8 feet on in diameter. It is dug some fair distance from the trenches and in a position that will allow the maximum amount of gullies to be led to it from that particular section of the trench.

After having this system worked out, the next thing is to ascertain what parts of the rest of the trench system will not be affected by this drainage, and there to dig similar sump-pits just to the side of the trenches drained, small gullies leading to them. These need only be about 6 feet deep below the trench level and 4 feet in diameter. A short gulley, 12 to 15 inches wide and 2 feet long, should lead from the trench to the sump-pit, as shown in sketch of trench system.

Sometimes the sump-pit may be semi-circular and cut into the side of the trench, but in this case some barrier must be put across it to prevent men falling in while traveling at night. The former system is far more satisfactory, and especially so when the trench is hardly wide enough to allow the passing of traffic without touching the sides of the trench.

Entrances to these sump-pits must always be kept clear of all obstructions. Very often a ridge of mud from a man’s foot-mark is enough to put a sump-pit out of action. They should be continually emptied by pumping the contents over the parapet, or carrying in pails to the nearest gulley.

The side sump-pits must never be cut under the wall of a trench. On very short notice the roof will take the place of the excavated soil and there will be no sump-pit.

It is not always that pumps are available, and the few of those which are, are of no practical use for a length of time sufficient to be of any value; in fact, they hardly repay the fatigue entailed in getting them to the trenches. For ordinary trench drainage several small pumps are of far more use than one large one, as the range’s limited by the difficulties of removing it or by the length of pipe attached. These pumps, whether large or small, must be given a large and substantial platform, placed in some central position among a number of sump-pits. Each pump must have not only a discharge pipe, but a suction pipe, the latter being movable from one pit to another in the pump’s area without moving the pump. The placing of these pumps must be thorough and systematic, and those sump-pits not reached by pumps must be kept empty by means of pails.

FLOORBOARDS

Although these are rarely available in sufficient numbers to be laid continuously along the entire length of the trench, it is unwise to throw one down on a particularly muddy spot in a trench as a remedy. The result is that when it becomes covered with mud it sinks out of sight, and another one is thrown down with the same result. Then, when an attempt to drain is made, much to somebody’s disgust they run into a layer of floorboards, quit work, and the trench never becomes drained. Patchy repairs to a trench bottom are as aggravating and as useless as bad revetment. When only a few floorboards are available, then they should be laid in one length and that length made as nearly perfect as possible, until more may be had, then that length continued. Patching here and there is of no use and never leads anywhere. Trench bottoms are treated in different ways up and down the line, depending on localities and materials on hand. In some places the trench bottom is of concrete blocks and bricks, with a small trench ditch of about 6 inches running along the side. This is not a very happy combination, as men traveling up and down the trenches at night with heavy loads sometimes stumble, their feet go in, the trench ditch becomes full of mud and blocked up, and your trench gradually becomes flooded up and down its length, unless very great care is taken. Where time and labor are available, long lengths of trench may be put and kept in good condition and the trench question partially solved if two rows of stout 4-foot sticks are driven well into the bottom of the trench, about 3 feet apart. Wooden rails are then nailed along the top of the stakes and cross-bars nailed and fastened to the rails. This work must be done thoroughly, though, or weak places will occur and become very dangerous for men traveling at night with heavy loads, as a fall through a hole in one of these bottoms generally means a broken ankle or some other accident.

In some parts of the line it has not been necessary to use anything for a trench floor, the ground itself being sufficient, with a small drainage ditch dug at the side, as in the case of those trench bottoms covered with cement and brick.

BRUSHWOOD AND STRAW

Brushwood should not be placed in a trench bottom, except under very exceptional circumstances, and, as a matter of fact, is very seldom used, its value lying more in the manufacture of hurdles. Once brushwood has been trodden into the mud it is absolutely impossible to remove it, and there is no means of removing the mud and properly repairing the trench bottom. Straw under no circumstances should ever be put in a trench bottom, and when put into dugouts or shelters, should be cleared out and burned where possible (which will not be in front line) as soon as it becomes sodden or sour. The floor of the dugouts and shelters must be thoroughly cleaned of all this old straw, sand bags and bad soil before fresh straw is put in. It is possible in large dugouts such as are found in reserve and support lines, to make bunks out of wire netting on the same style as the berth in a steamer, and in a modern dugout enough of these bunks may be made to accommodate a company. In all German dugouts this is the practice, although it is not possible in close proximity to the front line. Advantage must be taken of what material is at hand.

WORKING PARTIES

The routine of a battalion which is doing, for the sake of illustration, we will say six days in the trenches, is roughly as follows:

Six days are spent in what is generally known as a Brigade Reserve, which means living in the reserve dugouts or billets, depending on the closeness of a village to the firing line. During these six days the battalion supplies working parties to assist the battalion holding the line in the upkeep of its trenches. Very often this necessitates continuous work night and day for the men, more especially so during the winter months. At the end of the six days they go to the trenches and are in turn assisted by the working parties of the battalion relieved.

These working parties may sometimes be actually in the front line with the battalion that relieved them, or on the communication trenches leading to the front line, or on the second line defenses or reserve and support dugouts. This work is carried on under the supervision of engineer officers generally acting under orders from their brigade and divisional commanders. A request is made daily through the battalion commander for so many men to form the various working parties for that day and night, and the battalion commander keeping the brigade or division informed of his actual strength, protects his battalion from impossible allotments of work. These working parties are then detailed with the officer in charge, and he is generally given sufficient notice that he may have some idea of the task ahead of him. It is then to that officer’s benefit, knowing the amount of men who will have to do the task and what the task is like, for him to study out before leaving for the place where the work is to be done, just exactly what he intends to do and what sort of an organization it will require to do the work with the least possible friction.

This is absolutely essential, as naturally men coming from a six days’ tour of the trenches and being ordered on a working task, are not keen on the job, and when an officer has not studied beforehand what he intends doing and how it shall be done, it winds up in endless confusion, disgusts the men more than ever, and precious little work is done.

RELIEFS. The total time occupied in digging trenches is generally divided into parties called reliefs, usually of four hours. Shorter periods than this means much time wasted in commencing work and in delays; but, as a matter of fact, the time spent on the job and going to and from it will run to from 7 to 10 hours.

In digging trenches, the usual extension is to two full paces per man. Where there is little probability of attack the following method may be adopted: Halt party about four paces in rear of the left flank of the general line of trenches required to be dug; then form single rank, march ahead of party to the commencement of task and indicate to the first man his task, stepping off the next two paces for the next man, and so on until you have your party all placed. This takes a very short time and is one of the best methods. Allow the men to remove their equipment, but do not allow them to throw it any place they like. It is a general rule to place it about four paces to the rear of their task. Where attacks are possible, rifles must be kept within easy reach.

TRAVERSED FIRE TRENCHES

The following is a method for extending men to dig by night a traversed and recessed fire trench which is not already traced:

1. Detailing a covering party to guard against sudden attack.

2. Extension of the remainder to two paces.

3. Number quietly down the line by 4s.

4. Nos. 1 and 4 stop 2 paces back (these men then become traverse
men).

5. Nos. 2 and 4 drive in their picks (half way between themselves
and left-hand neighbors and in line with their toes).

6. Front rank to mark out tasks (Nos. 2 and 3 commence from the
pick between them and mark out 7½ feet each way, that is, 2½
pick-handles’ distance).

7. Rear rank mark out tasks (commencing from pick between Nos. 1
and 4 to end of each recess).

As soon as this is done the men commence work, the officer going down the line at once to check any errors before they have gone too far. While this may sound very complicated it will be found that after a little training the men become accustomed to it and it is a very simple matter. This method renders unnecessary the giving of many orders in the dark once the men are extended, and prevents a great amount of confusion. There will always be a slight amount of readjustment of the work, such as the widening of traverses, etc., but it is easily done after the work has been started and even after the trench has been dug to some depth.

OBSTACLES AND ENTANGLEMENTS

The purpose of an obstacle is to obtain the control of the enemies in respect to direction and speed during an attack, and to deflect troops into areas favorable to their destruction by the defenders. They break up the unity of action, deflect parties isolated into the best swept fields of fire and hold them under close fire of the defenses. An obstacle should be close to the defender’s position, not more than 80 yards away at the most. A system is now in use on the Western Front where entanglements in front of trenches are placed approximately 20 yards from the parapet, as that has been found to be the distance at which the deadliest bombing can be done. They should be sheltered or screened, when possible, from enemy artillery, giving no cover to the enemy and be so placed as to surprise the enemy. They should not interfere with any counter attack necessary to be made and have occasional gaps, which may be mined. Types of obstacles are low wire entanglements, their height depending on the condition existing in No Man’s Land; high wire entanglements, barricades, mines, inundations, etc. Wire plays the important part in most of the obstacles now being used on all fronts, and is generally used, first, as a trip wire stretched just above the ground, or fastened in loose coils to short pickets. Flares and alarm guns and tin cans may be used in connection with this; second: a simple fence to cause delay and confusion to the enemy at night; third: as a concealed obstacle in fords and standing crops or long grass; fourth: as a help towards making hedges and brushwood impassable, and as a wire entanglement solely.

The wire entanglements are the best obstacles, as they are quickly and easily made, are very difficult to destroy and offer no obstruction to fire in view of the defenses.

LOW WIRE ENTANGLEMENTS. Stout sticks, 36 inches long and 1½ to 2 inches in diameter, are driven into the ground on level at 6-foot intervals. These should be driven in at least three rows so arranged that the sticks in one row are opposite the centers of gaps in the next. The heads of the sticks are connected by strong wires crossing diagonally from 12 to 18 inches above the ground.

HIGH WIRE ENTANGLEMENTS. To be effective, high wire entanglements should prevent the enemy from crawling through it at or near the ground level, and when possible, should be screened from enemy artillery observation. This obviously is utterly impossible as far as wire entanglements in front of the firing line is concerned, but it is possible to a certain extent to screen these high entanglements from observation in front of support lines and second line systems. Under conditions existing at the front, the wire work is often and generally, for very good reasons, of a hasty character, and it is best, therefore, to limit the first stage to just enough to form a nucleus of the whole entanglement, in order that the required area may be covered by obstacle before serious interruption occurs. To do this, the obstacle is best constructed in two zones, with a small space between. The pickets should be from 5 to 8 feet long and average five inches in diameter, being placed at irregular distances and with varying heights in order to make more difficult the passage over them by means of hurdles and planks. The outer pickets should be very firmly driven and stayed to prevent the enemy dragging the obstacle away. It is also nice to drive large nails into the tops of the posts with half their length projecting. After the posts are driven in, they are first joined diagonally, that is, from head to foot and foot to head, by winding the wire around each post and securing it by staples. Each set of posts should be stayed by four wires. There should be a trip wire 9 inches from the ground, or even less, running continuously round the outer posts, and another one foot from the top of the middle posts. The barbed wire can then be hung in festoons between the posts on no fixed pattern and fastened to them. It must also be fastened to the other wire where it crosses, by short lengths of wire especially cut beforehand. Slack wires are of more hindrance when cut than taut wires. Tight wires help the enemy’s advance by giving support to hurdles and other methods used to get across these entanglements. One method once used by the Germans was the carrying out of mattresses and endeavoring to cover the wire obstacles in that manner, and had the wire been taut it would have been a success, but as it happened, it was not.

The ground on the enemy’s side and within the entanglement, as a matter of courtesy, is strewn with broken glass and tangled wire. The whole system of entanglement should be under well-controlled machine gun fire from special points and should be widest where the fire of the defenders is least effective by night. There should be one sentry at least to each 50 yards of entanglement.

ABATIS. A form of obstacle made by trees cut down and laid side by side as close as possible with their branches towards the enemy is used. These should be in a hollow and screened from view to make it of any value. The butts of the trees should be firmly secured by burying them in the earth, or by laying logs of timber across several butts. Wire and barbed wire must then be interlaced between the boughs, which should also be sharpened to points on the enemy side. Some of the lower branches may be pegged to the ground, if thought necessary, to insure the maximum resistance.

BARRICADES. These are used for the defense of streets, roads, bridges, etc., and are made of any available materials, including furniture and vehicles, either overthrown or with wheels removed, carts filled with earth, railings, bales of goods, etc. Where trees are growing along the roadside, fell them across it and entangle with wire.

It must be kept in mind, though, that passages are required through these barricades to allow outposts to advance or retreat, that these passages, viewed from the front, must not appear as openings. To avoid this the barricade should be made in two parts, one overlapping the other. Sometimes, where there is a gap in a row of houses, or a sharp bend in the road, a barricade may be made in one part and a passage round one end left for traffic.

INUNDATIONS. They may be formed by damming streams at convenient points, specially in the valleys, or by damming up the arches of bridges. In the latter case, care must be taken not to endanger the stability of the bridge. The ditches of field works form a good obstacle when flooded. Destroyed trenches in front of a breastworks may be filled with water, and with barbed wire thrown into it, will prove an effective obstacle.

FOUGASSES. These are used in connection with obstacles and are really land mines loaded with stones, bricks, etc. An excavation is made in conical shape with an axis inclined to about 40 degrees toward the enemy horizon. A box of powder is then placed in a recess at the bottom and on the box is placed a wooden platform or shield 3 to 4 inches thick, over which stones are piled.

A fuse is placed in a groove cut at the back of the excavation. A line of least resistance must be so arranged that by placing the excavated earth on the back edge of the fougasse, the powder will act in the direction of the axis and not vertically. A fougasse charged with 80 pounds of powder may be constructed in this manner to throw five tons of brick and stone over a surface about 160 yards long by 120 yards wide.

All of the foregoing are labors of working parties, as well as construction of dugouts, carrying of supplies, ammunition, etc., drainage and building of the trenches and the many other jobs behind the lines. Always, no matter how small the job, careful forethought must be given to the planning and arrangement necessary to carry it out.

ORGANIZATION OF BOMBING SQUADS

Every infantry soldier must and does receive instruction in grenade throwing. Some men do not possess the temperament and qualifications necessary to make efficient bombers, and for this reason in every platoon there should be a bombing squad of one N. C. O. and 8 men, with a higher degree of training and efficiency as bomb throwers than the remainder, although all hope must not be given up for the remainder.

These men are available either to work with the platoon or to provide a reserve of bombers for any special job, such as raids, cutting-out parties, and clearing trenches just occupied. Only the very best men in each platoon should be chosen, taking into consideration physique, courage and steadiness, although it is not always the big man physically that makes the best bomber. The responsibility for the training of these men rests with the battalion and company commanders.

TRAINING

The first step is to overcome a man’s natural fear of the grenade itself. This is only done by explaining how it is to be used, the method of lighting and the length of time taken for the fuse to burn. A good idea is to have some of the fuses of the length used lighted and the men told to count while the fuse burns out. Dummy grenades with fuses attached can then be introduced and the men taught to light them, observing carefully how long it takes for the fuse to burn down to the grenade.

The second step is to develop accuracy in throwing. Normally, the bomb should be bowled overhand, although it is certainly not wrong to throw, but it has been found in tests that a man throwing bombs has tired a great deal quicker than a man bowling them overhand.

Stick grenades may be thrown over short distances like a dart, although this is unhandy and can only be done by a carefully trained man. Great care must be taken while in the trenches in throwing percussion bombs, as very often a man swinging his arm back to throw such a bomb has exploded it in the trench, with disaster to himself and those near him.

Men should be taught to throw standing, kneeling and prone. It should be impressed upon them from the beginning that if a grenade with a time fuse is dropped in the act of throwing there is ample time to pick it up and throw it out of the trench before it explodes, but this must be done immediately.

A is a diagram of a bombing field where men are trained in practice with dummy bombs. 1 is the target marked on the ground and having the same general plan as a firing target, with Bull, Inner, Magpie, and Outer, the score counting 5, 4, 3, & 2 respectively, or according to the instructor’s taste. 2 is the first line, 20 yards from the center of the inner ring. The men _must_ be trained to a high degree of accuracy at this range. 3 is the second line, 25 yards from the center of target. There are lines every five yards back until the 40 yard line is reached, which latter is the extreme range for bombing practice.

At each range the men should practice standing, kneeling, and prone. At 35 and 40 yards bombing from the kneeling and prone positions is very difficult and the time spent on practice here should not interfere with the obtaining of great accuracy at the shorter ranges.

At all ranges the men should be allowed to throw any number of dummy bombs, but should not be permitted to fatigue their arms.

B is a diagram showing the arrangement for trench practice with dummy bombs. Small trenches are built on the surface of the ground by screens of wire mesh covered with burlap or other similar material. 1 is the thrower’s trench and is built so high that he cannot see over the top. From this he throws, using a periscope for observation. 2 represents part of a traverse and fire-bay, the front part of which is about 20 yards from the throwing trench. 3 is a section of straight trench about 25 yards half right from the thrower’s front. 4 is a section of curved trench about 20 yards half left from the thrower’s front.

The general custom in the practice trenches is to give the man any desirable number of dummy bombs, say 18; 6 for each trench. Four out of six are required to be put in No. 2, and 3 out of 6 in Nos. 3 & 4. Men must not be kept at bombing practice too long at a time as it spoils both their interest and their aim.

In taking a line of trenches, it is well to remember that the attack will take place on a relatively small front by a large number of men, and therefore when the trenches are finally reached, there is liable to be great overcrowding in them. This can only be prevented by extending them along the trenches as quickly as possible, and is of the utmost importance as heavy casualties will result from allowing this overcrowding. To make this extending possible, it is the duty of the bombing parties to work along to both flanks of the trenches and take advantage of the temporary confusion of the enemy by obtaining as much of his trenches as possible, thus allowing for the extension of men. In a narrow trench the only portion of an attacking party coming into contact with the enemy is the head, or what is known as the Bayonet Man. The bombing party is composed of the following:

1. Bayonet man,
2. First thrower,
3. First carrier,
4. First spade man,
5. N. C. O. first squad,
6. Second bayonet man,
7. Second thrower,
8. Second carrier,
9. Spade man, in charge of second party.

These parties will work up a trench until they come to a junction, when the first party in charge of the N. C. O. will continue straight on and the second party branch to the right or left, as the case may be, and as they come on other parties keep working up behind them, and the infantry gradually following taking possession of the line and starting consolidation work at once.

Communication throughout these lengths of grenade parties is very difficult with men extended in single file, and the attendant confusion which accompanies such a stand.

A system is required which will enable supplies of bombs to be passed up and casualties replaced automatically. This system cannot be laid down on any cut and dried lines, but must be figured out before the attack, with due consideration being given to the line of trenches to be attacked and the difficulties which will be encountered in getting supplies to that line, and it is only on the spot that such a system can be worked out.

During an attack three grenades per man are issued to each unit detailed to open the attack, and these grenades are turned over to the bombers or used by the men themselves if necessary. When out of grenades themselves, the men take over the casualty’s, and it is the duty of a casualty when he is so able to, to leave his grenades and ammunition to the care of some other man before “going down.” Small depots should be established at frequent intervals along the trenches from which the attack starts, with careful consideration given to their safety from shell fire, if at all possible. Other depots must be established in the support and assembly trenches, and these will generally be supplied through a central station probably controlled by a brigade or division.

Before starting the attack, every man and party should have had explained them in detail exactly what is required of them, and generally the following system is adopted:

First bombing party of group--

Two bayonet men to protect grenade throwers,

First bomber,

First carrier,

Second bomber,

Second carrier,

Group leader (N. C. O.),

Two bayonet men to protect the group leader and the rear of party.

* * * * *

Second bombing party--

Formation as above. The head of the party must be in touch with
the rear of the first party. Officer commanding in rear of
second party.

* * * * *

Third and fourth bombing party--

Formation as above. Second in command in touch with rear of
fourth party.

Machine gun detachment, if available or considered necessary.

The machine gunners are generally used at the rear of a party, so that they can bring their guns into action from behind and sweep the top of the ground around the trenches being attacked, in order to prevent an overland attack on the bombing party. In all these formations the number of men detailed must allow for casualties. Rapidity of movement is essential, as crawling and stalking will give the waiting enemy an advantage. The leading bayonet men generally move along the trench, from corner to corner, in a succession of rushes, followed by first bomber, and the thrower hurls as directed by the bayonet man. The duty of the bayonet man is to protect the thrower and carrier at all costs. Second bomber and carrier follow the leader, keeping one corner behind to replace casualties. Each party must be regarded as reserves to the party in front, and some method must be found every time a new attack is carried out for giving the aerial service notice of trenches occupied. If the head of a party is checked, that which has been gained must be held by throwing up a barricade. In all attacks bombing parties are supported by a party of sandbag men, under an experienced N. C. O., so that while bombers keep the enemy at bay a strong barracade may be put up as quickly as possible.

This is generally done by placing what is known as a demolition tube about 1½ feet from the bottom of the trench and in each side of the trench. This will bring down enough of the sides of the trench to make a good enough barricade for the moment, but great care must be taken that while watching and protecting the barricade the enemy do not come overland and drop in behind the barricade, with disastrous results to the garrison.

Although the main defense of a line of trenches is infantry supported by artillery and machine gun fire, parties of bombers should be distributed throughout the front system of trenches. The best position is in the support trenches close to the main communication trenches, where they can make an immediate counter-attack should the enemy succeed in gaining a footing. A bombing trench back about 20 yards in the rear from which bombs may be thrown into the front trench, is a distinct advantage.

The bombs stored in the trench should be kept ready-fused and with detonators inserted. They must be distributed in a number of dry, enclosed, as nearly as bomb-proof depots as possible, established at frequent intervals along the trenches. A good type of grenade depot is one built in a “T” shaped trench, slightly off the main trench.

EXPLOSIVES

Relative strengths of explosives: Gunpowder 5; cordite 8; dynamite 9; guncotton 10; gelignite 10; gelatine dynamite 11; blasting gelatine 12. Guncotton is available in two forms, wet and dry. The dry, while being utilized in making bombs, is mostly used to explode the wet guncotton. For this purpose it is made up in one-ounce primers, which are perforated in the center for a detonator. These primers are packed in metal cylinders, each containing ten threaded on a tape. Each case contains six cylinders. In this state, although not as powerful, dry guncotton is much more dangerous to handle than wet, being susceptible to both shock and friction.

Wet guncotton is that which has absorbed 30% of its weight in water, and is made up in 15-ounce slabs 6 x 3 x 1⅜ inches, and packed in tin foil and air-tight boxes containing 16 slabs each.

Whether wet or dry, guncotton, like other explosives, can be exploded by one detonator, so long as the charges or slabs are in direct contact with each other.

Dynamites include the following compounds: (1) dynamite; (2) gelignite; (3) gelatine dynamite; (4) blasting gelatine. All of these are now being used. Their advantages over guncotton are that, being soft and plastic, they can be used in bombs where it would be impossible to use guncotton slabs or primers on account of size and shape. Dynamite and its compounds freeze very easily (42° F.), becoming hard and brittle. In this state they are exceptionally dangerous, and they should be thawed before use, but this process should not be attempted by any one other than a competent person. Wooden implements should always be used for cutting and piercing holes for detonators in any of these explosives, and care should be taken to protect them from damp, as when wet they become highly dangerous. Dynamite explosives are usually supplied in parchment cartridges weighing two ounces, and are packed in boxes of 5 or 50 pounds.

Lyddite and picric acid are both high explosives, used mostly in shells. They are easily melted and in this way the shell is filled. They are very safe and difficult to detonate.

Ammonal. A new explosive which is absolutely safe to handle, not being sensitive to shock or even bullets. It does not freeze and can only be exploded by means of a detonator. It easily absorbs moisture and should be kept dry.

Cordite. Is made in strands and is the explosive used in small arms ammunition.

BOMBS

There are three kinds of bombs: (1) _percussion_; (2) _ignition_;, and (3) _mechanical_. It is not possible to describe every bomb in use under these three headings, but the most typical are selected for description, although it does not follow that they are all in use at the present time, but will give a fairly good idea of what is required.

PERCUSSION BOMBS.

1. Hand Grenade No. 1.

2. Hand Grenade No. 2, formerly known as Mexican Hand Grenade.

3. Rifle grenade No. 3, formerly known as Hale’s Rifle Grenade.

_Hand Grenade No. 1_ consists of a brass case screwed on to a block of wood, to which is fixed a small cane handle about half way up the case. Outside it is a cast iron ring serrated into 16 parts. The upper end is covered by a moveable cap with a striker pin in the center. On the cap are the words “Remove,” “Travel,” and “Fire” in duplicate. These are marked in red and can be made to correspond with red pointers painted on case. To prepare a bomb, turn cap so that pointer is at “Remove,” take off cap, insert detonator in hole and turn it to the left until the spring on the flange is released and goes into position under the pin; replace cap and turn to “Travel,” which is a safety position. When the bomb is to be thrown, turn cap to “Fire” and then remove safety pin. This bomb explodes on impact, and to insure its falling on the head, streamers are attached. Care should be taken that streamers do not get entangled. The bomb must be thrown well into the air.

_Hand Grenade No. 2_ is similar to the above, except that a special detonator is screwed in from the head, and that the striker pin, in this case, is at the bottom. The detonator having been inserted in the bomb is ready for throwing as soon as the safety pin has been drawn.

_Rifle Grenade No. 3_, more commonly known as Hale’s Rifle Grenade, consists of a serrated steel case filled with T.N.T. and a composite explosive. At the bottom of the case is a brass ring fitted with wind vanes, which keeps in place two small steel retaining plugs, securing the striker. In order to prepare this grenade for firing, the steel rod attached must be put down the bore of the rifle. The safety pin is then withdrawn, the collar pulled down and the wind vane given a slight turn. The rifle is then loaded with a special cartridge containing 43 strands of cordite. When charging the rifle the bolt must be well pushed home. When the rifle is fired, the explosion of the cartridge speeds the grenade on its way and the air passing through wind vanes causes the ring mentioned above to unscrew, and the two retaining plugs to fall out. The striker is now free, and when the grenade reaches its destination and comes in contact with the ground the shock compresses the creep spring and the needle of the striker is forced into the detonator, exploding the grenade.

Special screw-in detonators are supplied with this grenade, as well as in Grenade No. 2, and care should be taken not to mix the two detonators, as the Rifle Grenade Detonator is slightly longer, and if fixed in the wrong grenade will cause premature explosion and much sadness. These grenades have an accurate range of from 250 to 350 yards.

IGNITION BOMBS. The following bombs come under this heading:

Hand Grenade No. 6.--Grenade light friction pattern.

Hand Grenade No. 7--Grenade heavy friction pattern.

Hand Grenade No. 8--Formerly known as double-cylinder light
pattern.

Hand Grenade No. 9.--Formerly known as double-cylinder heavy
pattern.

Battye Hand Grenade.

Pitcher Hand Grenade.

Oval Hand Grenade.

Ball Hand Grenade.

_Hand Grenades Nos. 6 and 7_ consist of metal cases filled with T.N.T and a composite explosive and are exactly alike, except that No. 7 contains shrapnel bullets or scrap iron, while No. 6 contains only explosive. At the top of each case is a place to fix the friction igniter, which is supplied separately. When these bombs are to be used, detonator fuse and igniter are put in and firmly fixed. Before throwing the becket on, head of igniter should be pulled smartly off.

_Hand Grenades Nos. 8 and 9_ are similar to the above, except that the fuse is lighted by a Nobel Patent Lighter[1]. The _Battye Grenade_ consists of a grooved cast iron cylinder filled with explosive. The top is closed by a wooden plug pierced centrally for insertion of detonator and fire.

[1] _The Nobel lighter_ consists of two cardboard tubes, one
fitting over the other. Inside the top end of the outer
tube there is a layer of friction composition; fixed to the
top end of the inner tube is a forked brass friction head,
which is held in position by a safety pin fastened through
both tubes. Inside the other end of the inner tube is a
small copper band, into which the fuse is fitted. At the
joint of the two tubes there is a narrow tape band with a
loose end. To light the fuse, pull off tape and safety pin,
then press down outer tube and turn slightly. This lighter
has a five-second fuse attached.

_The Pitcher Hand Grenade_ is very similar to the Battye, only different in that it is slightly heavier and having a different patent lighter. This lighter is somewhat complicated and special instructions should be given before the grenade is used.

_BALL HAND GRENADE._]

_The Oval Hand Grenade_ is an egg-shaped cast iron receptacle filled with ammonal. One egg has a steel plug and the other a flanged brass plug bored centrally, to which a hollow copper tube is fixed to take the detonator. This grenade is set off by a Brock fuse and lighter[2].

[2] _The Brock lighter_ consists of a match-head and fuse
combined. The head consists of a small cardboard cup filled
with friction composition and covered with waterproof
paper. With this type of lighter an armlet covered with
match composition is worn by the bomber on the left
forearm. To ignite fuse, first pull off waterproof paper
and then strike head against armlet. Time of fuse 5 seconds.

_The Ball Hand Grenade_ consists of a cast iron sphere, 3 inches in diameter, filled with ammonal and closed by a screwed steel plug which has attached to it a covered tube to take detonator in the center of grenade. It is also lighted by a Brock lighter.

JAM-POT BOMBS. In the early stages of the war it was found necessary to make bombs on the spot. The material used was generally a jam tin filled with shrapnel bullets, scrap iron, powdered glass and grass, etc. This was exploded by 2 one-ounce primers, two ounces gelignite, blastene or ammonal, and detonated by a No. 6 or 7 detonator, to which was attached a five-second fuse. The time could be regulated by length of fuse.

MECHANICAL BOMBS. _Hand Grenade No. 5_, known as _Mills’ Hand Grenade_. Mills’ Hand Grenade No. 5 weighs about one and one-half pounds and is in constant and steady use at the front, being the best known of all grenades. It consists of an oval cast iron case, containing explosives and serrated to provide numerous missiles on detonation. In the center is a spring striking pin, kept back by a lever or handle, which, in its turn, is held in position by a safety pin.

Detonators and percussion caps connected by a short length of fuse are supplied with these bombs. When the bomb is to be used the bottom is unscrewed and the combined detonator and percussion cap is inserted in the space provided for it, the percussion cap being placed in the boring under the striking pin. When this is done the bottom is screwed on again as tightly as possible, using the special spanner provided for this in each box. Before throwing, the safety pin is removed and the bomb held with the lever in the palm of the hand. When the bomb is actually thrown the lever or handle is released; this releases the spring, which forces striker down on to the percussion cap, ignites fuse, sets off detonator and explodes bomb.

GAS WARFARE

The use of poisonous and asphyxiating gases, which was first adopted by the Germans in the Ypres salient in April of 1915, is now becoming an accepted fact in the present war. It is to a certain extent in one shape or another, before one every day of his life in or near the trenches. Every one should therefore be well acquainted with the various ways in which gases are used in an attack, as well as precautionary methods to be taken in counteracting its effects while on the defense.

In an attack there are only two methods which can be used--emanation and shells and grenades. The emanation method can only be employed under very favorable circumstances and in a few cases where rather a long chance was taken, it reacted very badly on the enemy. The first thing to make a gas attack successful must be a favorable breeze of about five miles an hour, as if the wind blows any faster it does not give the gas a chance to settle down into the trenches. The object of this gas is to create a poisonous and irritant atmosphere, and this is accomplished either by a gas forced through tubes in the direction of the enemy, or a liquefied gas stored in cylinders under very high pressure. To be successful, as before mentioned, the wind must be a steady breeze of not much over 5 miles per hour, no rain, and the element of surprise must figure very largely. The gas used must be heavier than air and not allow of being held back by any protective measures taken by the enemy. If the wind is too strong, it is obvious that any gas employed will be carried too quickly over the enemy’s trenches, so that it cannot settle to any degree which will allow of its obtaining the desired effect. If the wind is too light, it will be carried up into the air by local eddies, or may even be blown back.

For these reasons it is impossible to fix a definite hour for gas attacks, as everything depends on the wind.