There are two kinds of reliefs, General and Interior reliefs.

A General Relief is one where a large unit, such as a division or an army corps, is relieved from its position on the front.

An Interior Relief is one where a small unit, such as a company, battalion, or regiment, is relieved from its area by another unit of the same division within the position.

A general relief takes place for the following reasons:

In order to send a unit far to the rear to good billets for complete rest and perhaps for recruiting.

To withdraw and gather together the units of a corps, for the purpose of training for an offensive.

To permit the strategical movement of large units along the entire front.

General reliefs should not be made any oftener than necessary as they hinder methodical and continuous organization of the defense, observation of the enemy, and the preparation of contemplated offensives. It is for the express purpose of decreasing the number of general reliefs that troops are disposed in depth in a position so that continuous defense of the sector will be assured by means of successive interior reliefs. As an example of interior reliefs, we will consider a division holding a part of the front with two regiments disposed in the first position, one regiment near the second position in billets, and the fourth still farther to the rear in complete rest. These regiments, by a system of interior reliefs, will rotate to equalize the tours of duty in the first position. Similarly the battalions of the regiments in the first position will rotate to give equal divisions of time to each in the first lines. Assuming that a period of six to eight days spent in the front line is a fair average, and considering the fact that troops are disposed in depth throughout the three lines, different combinations of reliefs are possible. The work of making out the schedule of reliefs falls upon a division of the general headquarters.

The sector period is variable with the activity of the enemy and conditions of life in the trenches. During the German offensive at Verdun the sector period was four days, while in Lorraine during that time the same size unit could remain in the trenches for three months without necessity of relief.

Time to Prepare the Relief. Usually the order for the relief is issued from the general headquarters to the regiment forty-eight hours previous to its execution. Sometimes, however, for tactical reasons, such time cannot be allowed and the regiment may have to go immediately into the trenches. In such case, the different operations of the relief, which are taken up in this chapter, are shortened but must not be carelessly executed. In the present condition of trench warfare the proper execution of a relief is of the greatest importance.

Preparation. A relief is executed at night. Thirty-six hours before the relief is made the men of the relieving units proceed to clean and get in shape their arms, equipment, and clothing. When the relief is not for a special offensive operation, the troops go into the trenches with full equipment. All non-regulation articles are left behind with the regimental train, in care of the non-commissioned officer left with it. Also, the files, books, and official papers of the unit are left here. The regimental train establishes itself in rear of the sector of its regiment.

Besides this material preparation, the officers of the relieving companies are responsible for the morale of their troops. Before going into the trenches there may be some apprehension on the part of the troops, which must be dispelled by the officers. The great factor of depression is the mystery of what is not known of the sector about to be entered. Platoon leaders and company officers try to clear up this difficulty by telling their men what is known of the sector they are going to hold, and otherwise speaking words of encouragement.

Reconnaissance. Prior to taking over a sector, a preliminary reconnaissance is made by a certain number of officers and orderlies. They are:

For the Regiment—The colonel and part of his headquarters staff (adjutant, intelligence officer, telephone officer, engineer officer, medical officer, supply officer).

For the Battalion—The battalion commander and his adjutant.

For the Companies—The company commander and one officer for each company. Machine gun company commander and one machine gun officer. The commander of the 37 mm. gun platoon.

Messengers and telephone men at the discretion of the adjutant and the company commanders.

The above reconnaissance parties will go into the trenches on the morning of the day preceding the night relief. They must start early enough to permit a certain number of officers of these parties to return to the billets with all details and information necessary for the movement of the relief into the sector. The adjutant and the lieutenants of each company remain in the trenches until the relief arrives. During the intervening time they must acquaint themselves with all details of the sector necessary for the execution of its defense.

This preliminary reconnaissance affords an opportunity to the different leaders and chiefs of services to note the particular things of interest to each.

For the Colonel or Battalion Commander—The general organization and defense of their area.

For the Adjutants—The works under construction, precautions against gas attacks, etc.

For Officers of the Regimental Headquarters Co.—Information as follows:

Information Service—Activity of the enemy, microphones, observation posts and observatories, carrier pigeon posts, signal rockets.

Telegraph Service—Telephone systems, flashlight posts, wireless or ground telegraphy installations.

Engineer and Ordnance Service—Depots and supply (material and ammunition), special engineer works, trench mortar emplacements.

Medical Service—Dressing stations, evacuation of the wounded, hygiene (latrines, etc.).

Supply Officer—Emplacements of the kitchens, food supply.

For the Company Commander—Location of the platoons (number of men holding the first line and distribution of same; platoons in the cover trench and support line). Shelter accommodations, alarm signals, artillery support (limits of barrage fronts and barrage calls). Counter attacks (troops and directions for counter attacks). Information of the enemy (observation posts of the support point). Supply (engineer dumps, kitchens, ration supply parties, water).

For the Machine Gun Company Commander—Distribution of machine guns and emplacements, limits of machine gun fire sectors, emergency and special uses of M. G.

When such a complete reconnaissance cannot be made, only commanders of units precede their troops and make a short reconnaissance of one or two hours.

Relief Orders

(1) Regimental Orders. Usually the general order for the relief of a sector is settled on in conference by the colonels of the relieving and relieved regiments. This order is sent to the battalion commanders, if possible, before the reconnaissance.

The order of relief contains the following paragraphs:

Day and hour of the relief, designating the relieving and relieved units.

The name, limits, and division of the sector with designations of the neighboring units.

Information of the artillery support, its composition and emplacements.

Orders for the reconnaissance, its composition, and the hour when it must be finished.

Orders for the movement of the relief; march of the regiment from the initial point to the point of dispersion where the battalions branch off to their particular areas. If the regiment is transported in motor trucks, points and orders for entraining and detraining. Hours of departure of each battalion from the dispersion point and special itineraries for each.

Movement of the relieved troops. Assembly points of these battalions.

Movement of the regimental trains, relief of the kitchens, supply measures for furnishing of provisions, orders for the sanitary personnel.

Hour at which the new colonel takes command of the sector.

(2) Battalion Orders. All details for the relief are fixed in the battalion relief order issued by the battalion commander. This order is sent out immediately upon his return from the preliminary reconnaissance and in accordance with the regimental order.

The battalion relief order contains the following points:

Hour of leaving the dispersion point.

Order of march of the units (the companies march in the order in which they are to relieve the units in the sector, from right to left in the first line, and similarly in the support line).

Itinerary to the entrance of the trenches.

Meeting of the guides, hour and point of rendezvous, function of the guides of the relieved battalions.

Movement of headquarters, and rendezvous of the messengers that each company sends to headquarters to establish liaison.

Order of supply.

Additional details (result of the reconnaissance).

Departure. Before departure, each company is inspected by its company commander, who must see that each man has his canteen full, his rations for the day, a full supply of cartridges, the magazine of his rifle loaded (no cartridges in the chamber), and his gas mask in good condition. In winter the relieving troops will find a supply of blankets and trench boots in the sector. Usually each man should carry an extra supply of cartridges above that laid down by regulation, and two sandbags. There should be a certain number of flashlights and candles to the company (each corporal carrying a minimum of two candles). Just previous to departure or entraining the battalion commander himself makes a general inspection of his unit.

March to the Rendezvous Point of the Guides. Usually the regiment marches, but it is sometimes transported in motor trucks, up to a point in the rear of the sector, called the point of dispersion, from which the different battalions branch off successively to go to their respective areas. This practice avoids the crossing of units. A short meal may be had by the regiment at the point of dispersion. The distance of this point behind the sector and the time of arrival of the relieving unit must be carefully calculated so that the relief may be finished early enough to permit the unit relieved to get out of sight of the enemy before daylight.

When the battalions leave the rendezvous point, each company sends to the battalion headquarters two messengers for the purpose of liaison. The units now follow the prescribed itineraries up to the rendezvous point where the guides are met.

Guides. During the reconnaissance, the company to be relieved details certain men to act as guides for the incoming company. An average of two guides is furnished for each platoon, one for each company headquarters, and one for each battalion headquarters. These guides await the arrival of the different units at a certain point called the rendezvous point of the guides. Usually this point is at the entrance of the boyau. As several guides are usually grouped at the same rendezvous point, they must be alert to meet the unit to which they are assigned. A non-commissioned officer of the retiring battalion is in charge of this group and he is responsible that each guide finds his unit. Each guide, of course, must know the best and safest route by which to conduct the unit to the position it must occupy.

March in the Boyaux. From the rendezvous point, the companies continue their march in the boyaux which are assigned to them. One guide leads each platoon while the second guide brings up its rear. The leading guide must inform the platoon commander of the different points of interest that are passed, such as each line of the sector, regimental or battalion command posts, depots, water points, etc.

The march in the narrow boyau of an unknown sector, in the darkness, and with full equipment, is difficult and depressing. Consequently, the rate of march must be slow. When the head of the column meets an obstacle, a warning word is passed to the rear along the single file. This rule is above all useful to prevent accident to telephone wires.

The march must be executed without noise. Orders are given in low tones. Smoking or the use of flashlights is prohibited. No disciplinary measure is too severe that will prevent the enemy from discovering the relief. It is absolutely prohibited to talk over the telephone concerning a relief otherwise than in cipher.

Details of the Relief. If the two units have the same number of men, the relieving of one unit by the other is simple enough. But often the relief is complicated by the fact that either the extent of front or the number of effectives is different. In such a case, the officers of the two units must settle, during the reconnaissance, upon the necessary modifications for an effective and expeditious relief.

When the company arrives at the command post of the captain, the platoons are relieved from right to left in the first line, then in the cover trench in the same order. If there is a platoon in the support line this is next relieved.

In the first line, the relief of the platoons is executed in two parts. First of all, the sentinels, observers, watchers, men in the listening posts, and the N. C. O. of the watch are relieved. When this is done, the remaining men of the platoon are relieved. The men of the old platoon occupy their places at “Stand To.” The relieving platoon files in and steps up on the firing step. At the command “Pass” which is given quietly, the old and new platoons change places.

Each retiring leader, of whatever command he may be, hands over his orders and information to the corresponding leader who relieves him. For example, one platoon leader will turn over to the other all information concerning guard duty, defense of the line, condition of the barbed wire entanglements, patrolling, and shelter accommodations. This must be executed rapidly but with precision.

The platoon relieved assembles at the entrance to the boyau, and leaves the trenches under the chief of platoon. This is not done, however, until the platoon leader has reported to his captain, by means of his guides, the execution of the relief. The old captain fixes a point for the assembling of his platoons, but this point must be far enough to the rear to avoid blocking of the boyaux and out of reach of hostile grenade and trench mortar fire.

In the meantime, at the command post of the support point, the new captain acquaints himself with all information and orders pertaining to the support point from the old captain. When this is finished he telephones the command post of the center of resistance the completion of the relief, and asks if his predecessor may retire. The relieved company then takes up the march, following the prescribed route up to the assembly point of the battalion.

It may be stated here that the relieved units must leave their trenches in as clean and sanitary a condition as possible. The work of clearing up the shelters and latrines must be thoroughly done before the arrival of the new units. Depots must be left in good condition and contain the amount of supplies called for by regulations. The platoon commander is responsible that his men do not forget, tools and cooking utensils in the trenches.

Duties after the Relief. In each support point, the new captain immediately establishes liaison with the command posts of the neighboring units to right and left. Communication between the captain and his battalion commander is obtained by means of the two messengers detailed to the battalion for that purpose and who now return to their company.

When the battalion commander has received the information from all his captains that the relief of his area is finished, he reports the same by telephone to his colonel. A confirmation of this report will be made the next morning in his daily written report which will cover the following points:

The general condition of the relief.

Hour of completion of the relief.

Casualties during the relief.

Living conditions in the trenches.

Requests for tactical modifications (new dispositions of the garrison).

The relief finished, the battalion commander must also establish his liaison laterally and to the front and rear, but especially with his artillery support, by means of the artillery N. C. O. detailed to his area for that purpose.

Finally, the battalion commander investigates and perfects the organization of the food supply.

In the sector headquarters, the new sector commander will find on file all records, reports, orders, and detailed information concerning all the elements of defense of the sector. The sector file will contain the following documents:

Plan of organization.

Plan of defense.

Files of information concerning:

Machine guns.

Trench mortars.

Artillery support (table of barrages and other fires).

Liaison (telephones, runners, signalling, etc.).

Supply and evacuation.

Measures to combat gas attacks.

Besides these are the files of the different reports:

Sector daily reports (kept by the adjutant).

Intelligence reports (kept by the intelligence officer).

Construction reports (kept by the engineer officer).

Maps, sketches, and aËroplane photographs (kept by int. officer).

Inventory of the sector depot (kept by engineer officer).

Any officer of the sector, as for example a machine gun officer, has access to this file to more thoroughly acquaint himself for the execution of his duties.