U.S. Marine Corps - Small Wars Manual (1940 Edition)

Chapter V. INITIAL OPERATIONS.

SECTION II
MOVEMENT INLAND

					Par.	
Point of departure 				5-7
Mobile columns and flying columns 		5-8
Streugth and cornpositionof columns 		5-9
Protective measures covering movement 		5-10
Establishment of advanced bases inland 		5-11
Movement by rail 				5-12

5-7. Point of departure.--a. As in all forms of warfare,logistic requirements must be given careful consideration in preparing strategic and tactical plans; in fact such requirements are frequently the determining factor. Before a movement inland is undertaken an analysis and estimate of the local transportation and supply facilities must be made in order to insure a reasonable rate of advance with replacement of supplies.

b. The movement inland will not always be a movement. from a seaport to the interior. Frequently the movement will be made from the capital or principal city, located at the terminus of a railroad at the head of navigation on the upper part of a large river, or on a well-developed highway, with well-defined lines of communication connecting it with the seacoast. In any case the point of departure becomes a base of operations as well as a base of supply until other bases more advanced are established. Should the small-war operations be initiated by the establishment of neutral zones, one or more of them may later become a base for extended operations.

c. If the point of departure for the movement inland is to be other than a seaport, the movement to the point is made by the most convenient means. The movement will be of the same general nature. as an advance in major warfare in the presence of the enemy. The special features of a movement by inland waterways are presented in chapter XII.

5-8. Mobile columns and flying columns.--a. When the successful prosecution of the campaign requires the execution of measures beyond and/or supplementary to the establishment of neutral zones, the control of seaports, or key cities along lines of communication in the affected areas, mobile columns must be projected inland from the points of departure, for the purpose of pursuing, rounding-up, capturing, or dispersing any existing irregular forces; of covering productive areas; or of establishing chains of protected advanced bases in the interior

b. Mobile colums as suck differ from the so-called flying colums in one great essential-supply. A flying column is defined as a detachment, usually of all arms, operatin at a distance from, and independent of, a main body or supporting troops, lightly equipped to insure mobility and sufficiency strong to exempt it from being tied to a base of supplies through a fixed line of communications. A mobile column is of the same description as the flying column with the exception that it is self-supporting to a lesser degree and is dependent for its existence on its base of snpplies.

c. The movement may be made by a large force operating along a well-defined route, hit, will usually be made by several mobile columns operating either along separate lines of advance or following each other independently along the same route of advance at an interval of about 1 day. In some situations, columns may start from different points of departure and converge on a city or productive area. The columns may vary in size from a reinforced company to a reinforced regiment, but thr size best adapted to such operations has been found to be a reinforced battalion.

d. When fortified posts with permanent garrisons are established flying columns should operate therefrom. This is the most arduous of all operations; the idea being to combat the native guerilla at his own game on his own ground. At the beginning of such operations, the column may be of considerable strength-a company of infantry accompanied by a machine gun and howitzer detachment preceded by a mounted detachment. As the guerilla forces are dispersed, combat patrols (mounted or dismounted) consisting of two or more squads may suffice. The mission of the flying column will be to seek out the hostile groups, attack them el)er~etically , iLncl then pursue them to energentically, adn then pursue them to the limit. Therefore, there should be nothing in its composition or armament that would tend to reduce its mobility or independence of action beyond that absolutely necessary for combat and subsistence. Except for supplies which can be carried by the men, the column as a rule will dpened upon permantant garrisons. These posts must be established in sufficient numbers to permit of such supply-a post always being within 1 or 2 days' march of another post.

e. A flying column should never be dispatched to any area unless it is amply supplied with cash. With available funds, not only may subsistence be purchased, but often information of the hostile forces and the terrain (guides and interpreters). The money supplied the flying column should be in SMALL denorninations, principally silver; it is difficult, frequently impossible, to change bills in rural communities.

5­9. Strength and composition of colurnns. -- a. The strength and composition of mobile columns will depend upon the probable resistance to be encountered, the terrain to be traversed, the type and condition of existing transportation, ancl the means of communication. Normally, the addition of mounted detachments, armored cars, and aircraft is desirable in such columns. If a march through an extensive area of undeveloped country is contemplated, an engineer unit should be included. The use of light field pieces has been limited in the past, but with the increase of armament by all classes of powers and the improvement of defensive means, they cannot be dispensed with unless there is every assurance that they will not be needed. However, as a general rule, nothing should be added to the mobile column that would tend to decrease its mobility and which is not absolutely necessary.

b. The column should be of sufficient strength to enable it to cope with the largest force likely to be encounterecl. While weakness in the strength of a column is dangerous, yet excessive strength should be avoided. The supply requirements of a large column necessitate considerable transportation, results in a proportionately larger train guard as the length of the column increases. A larger train also decreases the mobility of the column.

c. If the movement is made over broken country with poor roads and trails, the column often will be forced to move in single file. A column of excessive strength for its mission will march irregularly due to the elongation of the column. Such a column will arrive at its destination in a more exhausted condition than a smaller force which is able to maintain a regular rate of march. In case an operation necessitates a large column with the corresponding large train, the train may be broken up into two columns in addition to separation of the combat force. This will prevent elongation of the column and allow a regular rate of march.

d. The numerical strength of a column may be decreased by the inclusion of an increase of automatic weapons and supporting infantry weapons above the normal allowance. The increase of ammunition necessitated thereby will not be proportionate to the decrease in the amount of subsistence. Such a decrease will also decrease the amount of transportation required.

e. By means of the modern portable light radio sets (one of which at least should be assigned to the column) and contact planes, a column can be readily reinforced when necessary. Columns moving in the same general area are better able, due to these means of communication, to keep in close touch and to render mutual support This, with the offensive support available from aviation, must be considered in determining the composition and strength of the column.

f. Radio and contact planes may be the only reliable means of communication at the beginning of a movement. However, all means of communication must be considered, not only in deciding upon the strength of the column but also the route to be followed. Telegraph and telephone lines may be destroyed, and in the early stages of the operations it may not be worth while to repair and maintain them. If not interfered with, or when control is established and repairs effected, these land lines should be utilized. Dispatch riders (runners, foot or mounted) may not be of much value until conditions become fairly settled, but at times they may be the only means available, or they may be used to supplement other means. Where the country lends itself to the employment of armored cars, they may be used for courier service. Any courier service on a regular time schedule and via restricted routes is dangerous.

5­10. Protective measures covering movement. -- a. When a column starts its movement, it is immediately concerned with the general means of insuring its uninterrupted advance through hostile territory. Usually all parts of a column are vulnerable to attack. In major warfare an army usually has such an extent of front that its rear and base are reasonably secure, and attacks are launched by the enemy at the flanks and front. In small wars, however, the front age of the regular force is relatively narrow and the column of regular troops is liable to attack by encircling detachments of the irregular forces, Therefore the column must insure itself from an attack from every direction.

b. In major warfare, this security is effected by outposts, by advance, flank, and rear guards, by scouts, by combat patrols and connecting groups, by deployment in depth, and by means of air reconnaissance. In small wars, the principles of security are the same but their application varies with the hostile tactics, armmnent and the terrain over which the forces operate. The guiding principle of security is to prevent the hostile fire from being effective against the main body of a march column. The enemy should be denied all terrain from which he may inflict losses upon the column, and the advantage of superior armament and accuracy of fire maintained to prevent the opponent from closing in to effective range of his own weapons even though he be superior numerically.

c. The nature of the terrain has a marked influence on security measures. Often in the theaters of operations, thick low brush interspersed with cactus extends along the main trails and roads making an almost impenetrable jungle, too thick for the movements therein of even small combat groups. In such cases the use of flank guards for a marching column is practically impossible, the lack of which at times permits the hostile force to establish favorable ambushes along such a route.

d. An active hostile force bent on small depredations and armed with rifles and automatic weapons will have ample opportunity to ambush the main body of a column after the advance guard has passed unless patrols are kept continually moving through the underbrush on both sides of the road at a distance from which the ambush position would be effective (normally about 20 to 40 yards). The progress of such flank patrols, however, will be slower than that of the main body with the result that these patrols will be continually falling behind. This necessitates sending out frequent patrols from the head of each organization. To prevent uncovering the head of each organizatino by these detachments therefrom, the pawtrols should be started out well ahead of the organization when opposite the rear.

e. On mountain trails with heavy growth of brush and timber which restricts or prohibits the use of flank patrols, a column may be obliged to march in single file. Its only security in this case will depend upon a prompt return of a heavy volume of fire from the part of the column attacked. When the column is restricted in its march formation, it should be divided into a number of small combat teams, each being capable of independent action.

5-11. Establishment of advanced bases inland.--a. After the mobile columns have successfully dispersed the larger groups of the hostile forces in any area, the next step is the establishment of advanced bases and fortified posts inland for the prosecution of the next phase-the operation of flying columns into the interior.

b. The particular functions of a fortified post are as follows:
(1) To cover productive areas and their lines of communication with their markets.
(2) To afford protection to the local population in that area.
(3) To form a base of supply, rest, replacement, and inforrnation for flying columns.

c. As a general rule, these posts should be locatecl at the heads of valleys on main roads or waterways leading from seaports, and at the apexes of valley and intervalley roads and trails leading to the more difficult wooded and mountain regions --the final theater of operations.

d. The site of the post should if possible have the following characteristics:

(1) Be capable of defense by a relatively small detachment.
(2) Be of sufficient extent to permit the bivauac of a flying column of not less than 100 men with a mounted detachment.
(3) Be so situated as to control any town in the vicinity and all approaches thereto, especially roads and ravines.
(4) Be located on commanding ground overlooking the surrounding country.
(5) Be accessible to water supply and main roads.
(6) Be located near terrain suitable for a landing field.

e. In many cases, old forts, redoubts, or isolated masonry buildings with compounds can be organized for defense. Often however it will be found that conditions will warrant the construction of an entirely new fortified post from the material available in the vicinity.

f. The main requirements of a fortified post, garrisoned as it will be by only a few men is that is must not be vulnerable to a sudden attack or rush. This requirement can be met by the construction of a double line of defense; an outer line of defense (occupied only when the flying column is present) to inclose the bivouac area, and an inner line of defense to inclose the depot facilities and permanent garrison, provision being made in both lines for free use of automatic weapons and grenades. (For further details concerning the defense of towns, etc., see ch. VI)

g. Communication with fortified posts should primarily depend upon radio and aviation. All such posts should be equipped with a radio set capable of communicating not only with its headquarters, and other nearby posts, but also with the air service. A landing field at times may not be available in the vicinity of the post so recourse must be had to the use of the pick-up and drop message method of communication.

5-12. Movement by rail. --a. If the movement to the point of departure is opposed, or the adjacent territory not under complete control, a movement by rail will involve many tactical features not encountered in a simple rail movement. Even after the railroad is functioning and the hostile forces dispersed, raids and other operations by guerrillas may require the use of armored trains with train guards. Guards may be necessary at stations, briclges, junction points, and other critical points along the railroad.

b. In case a country, or an extensive part of it, containing railroads is to be occupied as a part of the campaign plan, then the operation order for the seizure of the seaport terminus of the railroad should include instructions directing the seizure of the rolling stock and the terminal and shop facilities. This action may prevent their destruction or their removal from the seaport area. Rolling stock having been seized in accordance with the aforesaid instructions, measures must be taken to continue the operation of the railroad service, provided the strategical plan involves the establishment of a point of departure at some place along the railroad line or at some inland terminus thereof. Opposition to such use of the railroad may be encountered in the form of organized military resistance, or by sabotage.

c. The first step taken to operate a railway train over the line where opposition may be expected, is to provide a pilot train. The engine of this train should be protected by placing armor, usually improvised, over the vital parts, supplemented by additional protection of sandbags or similar material. Several cars loaded to fullweight capacity, preferably flat cars or gondolas, that do not obstruct the view from the engine and rear cars, should be placed ahead of the engine to serve as a buffer. These flat cars will then serve as a test-load element, over mines laid in the roacl bed, or over bridges and viaducts that have been weakened through sabotage. The car immediately in rear of the engine should be a box or cattle car from the top of which rifle and machine gun fire may be directed over the engine to the front. The remaining cars in the pilot train should be flat cars, gondolas or cattle cars, from which troops protected by sandbags or similar material may deliver all-around fire. Some of the personnel accompanying the pilot train should consist of engineer troops to be employed in counter-dernolition work and in inspecting the roadbed for mines and the bridges and viaducts for structural weakness. Where such mines are found, these engineer troops should accomplish their destruction, and in the case of weakened bridges, etc., should make the necessary repairs. The main body of the troops embarked on the pilot train should consist of sufficient personnel to protect the train and the working parties of engineers and laborers. A number of volunteer local civilian laborers may be added to the complement in order to obviate the necessity of using the combat troops as working parties with the engineers. The combat troops should be armed with a large proportion of automatic weapons, light mortars and 37 mm. guns. Some fire-fighting equipment should also be carried with this pilot train. A few light chemical tanks, water barrels and tools for beating out a fire, should be placed in one of the cars. Irregular forces not provided with demolition equipment will probably resort to burning the wooden bridges and railroad trestles usually found in the theater of operations in small wars. Material available for putting out a fire of this nature in its initial stage will gain many hours of valuable time in the advance inland. A troop train should follow the pilot train within close supporting distance; it should contain sufficient troops, properly armed, as to be capable of dispersing any hostile forces until the arrival of additional troop trains. If the use of artillery is contemplated later in the combat operations, some of it should be carried on this troop train.

d. This troop train should have some flat cars or gondolas ahead of its engine and should also be equipped with improvised protective material for the troops. The troops on the forward flat cars or gondolas shonld be armed with machine guns and howitzer platoon weapons. The remainder of the train should be composed of railroad cars readily adapted to all-around defense and of such type as to permit the rapid debarkation therefrom of the troops. Depending on the capacity of the trains available, cletachments of troops from the first troop train or another closely following it should be debarked at critical points along the railroad line for its protection. These protective detachments should iustit ute a system of patrols along the line to prevent sabotage and interruption of the railroad line at points intermediary between the critical points. Aviation may render most valuable aid to these trains in the initial movement inland as well as during the period of operation of the line. On the approach to a city, defile, or other critical points, the troop train should close up on the pilot train and a reconnaissance should be made by ground troops to supplement the information furnished by the aviation. Positive information from the aviation can usually be acted upon; however, negative data from the aviation may be misleading and if acted upon, may lead to fatal results.

e. Where a good road parallels closely a railroad, a flank covering detachment in trucks may expedite the train movement.