Part 2

Fire-bays generally are from 12 to 18 feet long (defendable by 4 to 6 men, but accommodating 8 to 12, when necessary) plus a 2-ft. covered sentry box recessed into the traverse and giving room for one more man; this depending entirely on the energy and initiative of the men occupying the section.

Every traverse averages 9´ x 9´ which includes a fairly liberal allowance for wear and tear, and is the minimum allowance for stopping enfilade fire and localizing fire. As the width from front to rear varies, depending on the amount of shell fire, it should be wide enough to allow a certain amount of lateral traffic without interfering with those who may be firing. Three feet may be taken as the maximum width at the bottom of the trench, that is, 1½´ for traffic and 1½´ for those firing, with a slope to the sides of from 10 to 15 degrees from perpendicular, thus lessening the tendency of the walls, whether revetted or otherwise, to slide in.

The depth of the trenches varies also, for the same reasons that cause the width to vary. Recesses should also be dug at various and favorable places for the storing of ammunition and bombs.

When digging entrenchments without regard to concealment, the excavated soil is first of all thrown to the front or enemy’s side of the trench, thus temporary cover is obtained. When the entrenchment has reached the proper depth the artificial raising of the ground is leveled. The artificially raised portion is known as the parapet. On the completion of the parapet, the soil is thrown to the rear side of the trench, thus forming the parados which gives a protection from the rear. It is not a good policy to excavate in front of the parapet, but to get additional height and thickness as quickly as possible this is often done. Unless carefully watched, men will dig this dirt from places as near the parapet as possible, resulting in the weakening or total undermining of the parapet or trench wall. The more gradual the forward slope of the parapet, the more does it approximate as it should to the glacis of a fort, consequently giving less cover to an attacking enemy. Make use of the ditch or holes from which the dirt was obtained, as a strong obstacle immediately in front of your trench, where the enemy at the last moment may be held up to go under a very severe rifle and bombing effort. In normal circumstances, by which I mean when not exposed to an unduly vigorous machine gun or artillery fire, the soil should not be taken from in front of the trench in the manner described above, closer than 10 to 15 feet from the actual parapet, unless the holes are adequately protected by trip wire, as well as barbed wire. Cases have occurred when valuable information has been obtained by the enemy lying in holes thus dug and not properly protected.

The parapet should be kept as low as possible and made to blend with its surroundings as much as possible. This is done by taking great care to cover any signs which show that fresh work has been done, even to the extent of actually planting grasses, weeds and roots, such as grow in the immediate neighborhood, and giving every encouragement to those that already grow. This greatly hinders the enemy’s artillery, as it changes positions up and down the line; interfering with and hindering the observations and accurate ranging by their forward observing officers, checking charts turned over by relieved batteries.

Bullet-proof nature of a parapet naturally depends on the soil of which it is composed. Although it is not necessary to memorize the minimum of safety, you should keep a general rule in your head. The parapet should not be less than five feet, regardless of the kind of soil. When the trench has been carefully sited for the actual field of fire from a ground level, this thickness is best obtained by raising the ground level artificially as little as possible and getting the necessary depth by digging, unless prevented by moisture.

Unnecessary casualties are caused by the practice of putting a single row of sand bags along the top of a parapet for temporary purposes of concealment, as it gives a faulty idea to the men in the trench as to the real height of the parapet.

The parados gives protection from the effect of shell fire bursting behind the trench, and should be made fire-proof as soon as possible, although it is not necessary unless concealment is possible to level it down in a similar manner to the parapet. As a matter of fact, it should be at least a foot higher than the parapet, thus providing a background for the parapet. It has been known to happen that when the occupants of a trench have been reached by the enemy they have vacated their trench and used the parados as a parapet, much to the surprise and disgust of the enemy. In a high and irregular parados, places could even be found which when not used steadily provide unexpected and safe observation and sniping posts, but care must be taken that they are not used too often.

If a trench were used merely for firing, 4½ feet from bottom of trench to top of parapet would be a sufficient depth. During attack, however, when fire from loopholes is too restricted, exposure of head and shoulders over the parapet becomes necessary, but it is not necessary to expose men moving along the trench and not actually firing. If the trench should be 7´ or 8´ deep, you must provide a platform at the bottom of the front wall 1¼´ wide and 4½´ from the top of the parapet. This is called a fire-step. The rest of the trench can be deepened to any desired depth, depending on the energy displayed. If of an extraordinary depth, steps must be cut to the fire platform.

In a great many different parts of the Western Front, especially Belgium, it was found that after digging to a depth of one to three feet water was encountered to such an extent that it became impossible to dig any sort of a trench which would give adequate protection to the men involved.

When these conditions are run into, breast work parapets must be artificially built up above ground level with soil, sods and sandbags, supported by sandbags, hurdles or close wire netting, revetment and stakes. The same principles of thickness, depth, width, slopes, and in fact everything that applies to a dug-in trench, applies to breast works.

The “T” trench has many more advantages than the few mentioned in the opening of this chapter. T fire-bays may be single, double or treble (that is with one, two or three bays). Fire-bays in any length up to 15 feet with 8 feet traverses are for firing purposes only, and the control trench, sometimes known as the lateral communication trench, as its name implies, giving lateral communications, is used for that purpose only. Therefore, the fire-bays and control trenches can be narrower than trenches which have to be used for both purposes, thus lessening the amount of repair and revetment work required. And the intervening ground between these fire-bays gives the same result as a traverse used in a traversed trench system, and saves the labor of digging a more intricate system. The control trench gives an officer or N. C. O. in charge of the T bays a chance to handle his men and fire in these bays without struggling around innumerable traverses and wasting time very often when a minute lost or gained means lives lost, or part of a trench system in the hands of the enemy.

T bays may be sited with due and careful consideration while facing the enemy in an existing trench system. Thus it gives you the advantage of being able to take into consideration all the requirements of the field of fire, control of isolated areas, and the obtaining of maximum results from enfilade fire. These T trenches may be dug out from the old system without undue exposure of your men and if distance between the lines permits, and it is entirely possible to construct a new and generally more favorable line of trenches within 100 to 200 yards of the enemy’s trenches. Intervening ground between these T bays must be completely controlled by entanglements and mobile machine guns, or automatic rifles, able to operate from different alternating recesses in the control trench. Fire platforms should be placed in recesses at intervals in the control trench from which covering fire can be given. Artillery fire, to damage a T trench, must be very accurate. In a traversed trench a shell destroys not only lateral communication, but the defenders as well, whereas with a T shape, both fire-bays and control trench have to be ranged and hit. The success of the enemy is entirely local when capturing one of these T-bays, and he may be shelled by your own artillery without any danger or risks to those defending their T-bays. Control trenches should be dug first and zigzagged with the longer stretches facing the enemy. This gives you another fire-trench as well as a communication trench, and is also ready for use at any time needed before the T-bay is completed. On the completion of the T-bay, the corners of the zigzagged trench must be rounded off to make it easier and quicker for the movement of troops and carrying of stretchers.

DUGOUTS

It is only under very exceptional circumstances that under-cutting a trench wall is allowed, and then the shelter should be cut in the rear wall only. These shelters must be carefully supervised and watched by the officer, as men are very often careless, with the result that the shelters are dug in a hurry and poorly. Then it rains, the shelter falls in, and the men are no more. It should be high enough for a man to sit up straight, and long enough for him to lie down in, and deep enough for two men to lie side by side. It should be raised at least a foot above the floor level in the trench to prevent water from the trench floor coming in. A shelter smaller than these dimensions is useless. It has a demoralizing effect, destroying all activity, mental and physical. These shelters can only be properly made by cutting into the rear trench wall the necessary depth and length and right to the top. Then, with any material which is convenient, such as corrugated iron, brushwood, old rubber sheets, revet the sides and back. A corrugated iron roof is supported on posts at a depth of about a foot to a foot and a half below the normal level of the ground. Then, when possible, cover this with rubber sheets. If not possible to procure rubber sheets, simply cover with dirt excavated from shelter, taking care that it does not rise higher than your parados.

A fire-trench, however, is not a proper place for shelters, and they are generally better as a weather protection than a shell-proof shelter. Even this should not be favored too much, as it tends to cause obstruction, delay and inconvenience in the passing of troops. The real dugouts for the accommodation of men holding a line are generally behind the fire-trenches in an immediate support line, or as in the case of T-bays, in the control trench and communication trenches leading to and from them. These are large dugouts, having a depth of 30 and 40 feet, and in some cases capable of holding 100 to 250 men, generally having from 5 to 10 exits and entrances. Here the men stay during bombardments and are generally safe from any caliber shell which may light on top, unless a half dozen should light in the same particular spot.

This work is generally of a very skilled and technical kind. Plans, drawings and labor are supervised by the engineers, expert tunnelers being used in constructing work, although the infantry supplies working parties to dispose of the dirt, etc., resulting from these excavations and to carry the materials and tools needed and required in the construction.

The design and general scheme of a small dugout which can be made by the infantry under the supervision of an officer, without the aid of an engineer, are here given. The dugout should be approximately 6 feet from floor to roof and about 8 feet wide, with an approximate length of 12 feet, thus allowing men to lie down and yet leave room for passage through. The width depends upon the number you intend to have occupy it. Each man requires 18″. Depth to be dug below ground depends entirely to what extent you may raise the roof upon the ground without making an unduly exposed hump which will at once tell the enemy a dugout is there. The thickness of the roof should be approximately 6 feet, constructed with side posts, cross beams, corrugated iron, waterproof oilcloth, sandbags and soil. Sandbag revetments should be used in the strengthening of side posts. When possible, although hardly ever so, walls should be lined with waterproof oilcloth and entrances so placed that they get as much sun as possible.

Great care and attention must be given to these dugouts, and even though taking a little longer than seems necessary, care must be taken to see that they are substantially constructed, otherwise they are in a constant source of danger of cave-ins during heavy shelling and bad weather. Not more than 10 men should occupy one of these dugouts. Then, if accidents happen, your casualties are not so great.

The roof of these dugouts should be prepared in a manner tending to withstand as high shell shock as possible, and for this purpose the following table would be of some use, any part of which, or a combination of all, will give some idea of what is required.

RESISTANCE OF ROOFING MATERIALS

(a) Shrapnel bullets--Stout planks suitably supported and covered with corrugated iron and 12″ of earth or 3″ of shingle.

(b) Ordinary guns of 3″ caliber--Strong timber supporting 4 ft. of earth with a top layer of heavy stones or broken bricks to cause early shell burst.

(c) Field howitzers (of less than 6″ caliber)--12″ logs, supporting 8 ft. of earth with top layer of heavy stones or broken brick and lightly covered over with some earth.

(d) “Jack Johnsons”--20 ft. of earth or 10 ft. of cement concrete, reënforced with steel and covered over with a covering of heavy stone or broken brick.

It is very often the case that there is a line of trenches with very few dugouts. Those that exist are mainly occupied by first aid stations with a medical officer in charge, and officers’ headquarters. When such is the case, very narrow, deep trenches, known as retirement trenches, are dug roughly from 20 to 50 yards behind the firing line, so that every one, except those on sentry duty, may retire there during the heavy shelling. It is very obvious that excellent communication must be kept up between this trench and the firing line.

DUMPS

Sandbags, corrugated iron, floor boards, ladders, pails, brushes, rubber boots, periscopes, barbed wire, etc., are what are known as “trench stores.” These are generally brought up by carrying parties during the night and taken to some convenient spot picked out by whosoever may be commanding that particular section of trench, ready for distribution in the morning. This place is known as a “trench dump.” Here every morning each junior officer goes to his company commander with a request for his stores for the day. When this has been handed in and approved by his company commander, he then has a party detailed to go and collect his stores. These are again placed in his particular little sector of the lines and he receipts for their care and proper use; all stores not used are turned over to the relieving troops and a receipt taken for same. These dumps must be made in a central location, both as regards the company dump and the platoon. The company dump is not a permanent home for the stores or utensils brought up, but is merely what might be called the distributing center. When a company commander turns over his trench stores and utensils to the relieving commander, the fact that he has all his stores and utensils in the company dump does not show merit, but merely inefficiency, that the distribution, which should have taken place, has not been carried out, and, therefore, that some of the men under his command probably have not the required tools to work with or the material that is necessary to the small units to carry on their daily lives. Stores should not remain in their center dumps. But each platoon commander should know exactly how much he has in hand, and how much he needs. It is also plainly evident that in a scattering of dumps in this manner, any captured by the enemy do not constitute a “knock out” as far as the trench stores are concerned.

LATRINES

The cleanliness of the trenches and latrines requires the closest supervision of all officers and non-commissioned officers. The bucket system of latrines is entirely unsatisfactory. The ground where the buckets are in use becomes unsanitary, and so does the ground in which the contents are buried. Double labor and carriage is involved, and as often as not a polluted soil is sooner or later to be found in the line of a proposed communication trench. The method used in the French armies is very good and by far the cleanest. It involves no unpleasant labor and is satisfactory. A pit about 12 feet deep, 3 feet wide and 12 feet long is dug in some place which is fairly easy to get at by those who are to use it. Generally thirty to forty feet behind the fire-trenches and off one of the communication trenches. The pit is boarded over, the boards being laid across the width, that is from front to rear; every other board space being omitted. A pail of disinfectant is kept standing nearby, and the deeper the pit is, the better and longer it will remain in use, but should be filled in when contents are within 6 feet of the top. This makes subsequent unpleasantness very unlikely. Care must be taken that men using these places have some protection from stray shells, and are out of sight of the enemy.

When possible, there should be a refuse pail for every section of men, and care should be taken to impress on the men that they must throw in all tea leaves, dregs, all scraps of food, and refuse in general, and should be covered over with disinfectant. If this is not done, thousands of flies and insects are attracted, with the inevitable rats, and disease and unsanitary conditions will follow. Tin cans, etc., should under no circumstances be thrown over the parapets as the same results will occur there.

REVETMENTS

When fire trenches are to be occupied for any length of time it is necessary to revet them. By that I mean the walls, and especially front walls, have to be faced or strengthened by sand bags, boards, corrugated iron or other material that is needed. This work to be of any use at all must have solid foundations and be thorough from top to bottom. Careless revetment work is of no use and a source of endless labor and trouble. All such work should be supervised by officers or N. C. O.’s who have a thorough understanding of such things, and they will be amply repaid if they take an active part in the work with their own hands. There are several forms of revetment, according to the materials available and the conditions of the walls to be revetted, but the usual materials are the sandbags, corrugated iron, stakes, boards, wire netting, etc., and these can be used either separately or in a combination. All these materials are generally kept in engineer dumps, some little way behind the firing line. Requisitions are made during the day by the officer commanding the sector of trench which requires revetting, and at night the men are detailed in carrying parties to go down to the engineer dumps and carry these things up for work the next day.

SANDBAGS. Sandbags are usually available in large quantities, but it is well to remember that generally only half the number indented for reach the indentor. The rest generally go around the men’s feet and legs to keep them warm at night, and very often are used as a sort of mattress in the dugouts. This should not be allowed as it creates a tremendous wastage. The sandbags should only be about three-quarters filled, thus allowing for the choke or neck end, after tied, being turned under the back when laid in position. This also gives something to catch hold of when laying and brings the weight to something manageable, about sixty pounds. A bag three-quarters filled measures approximately 20″ x 10″ x 5″. Laid sand bags are called headers, when laid with bottom of the bag facing the center of the trench, and stretchers, if laid with the side facing the trench as per sketch. The neck end should always be tucked well in the bag in the case of the stretcher; the side seam, which is a weak spot in the sandbag, should be kept from exposure, that is, should be turned from the center of the trench.

When the front wall of a trench is to be revetted and only sandbags are available, the wall should first be cut to a slope of from 10 to 15 degrees from the perpendicular, and the loose soil obtained, if dry, placed in the sandbags. When there is an unrevetted fire platform, this should be also cut away and put, if dry, in the sand bags. A bed should then be dug about 6 inches into the solid bottom of the trench (disregarding the soft mud which for foundation purposes is of no use) and sloping down into the parapet at right angles to the slope of the front wall. Into this bed place a row of headers. On this row place a double row of stretchers. Joints must always be the same manner as brick-laying; that is, care taken that the joint where the ends of the stretchers meet does not come immediately over the joint between the headers and the lower row. Sand bags should now be beaten down flat, generally with a wooden mallet provided for this purpose; then alternate rows of headers and stretchers laid; each layer being flattened out with the mallet until the top of the parapet is reached. The top layer should always come out as headers.

Twenty-five headers or twelve stretchers, or sixteen mixed, is the average required for revetting every superficial yard of trench.

The slope of a front trench wall, even when from 10 to 15 degrees from perpendicular, is apt gradually to assume the perpendicular, and then fall in, owing to the sinking of the trench bottom or the actual thrust of the earth in front. This can, however, be checked by using 6´ to 8´ stakes driven well into the front wall foundation, and at the same angle as the front wall. Then, wiring the head of these stakes to what is known as an anchor-stake driven about 10´ into the ground in front of the trench.

Sandbags come in bales of 250, which are again divided into bundles of 50 each. On a carrying party it is an average rule that each man carry 100 sand bags.