STRENGTH AND COMPOSITION
Subject to variation according to the situation, one twentieth to one third of a command may be a.s.sumed as a suitable strength for the advance guard. The larger the force, the larger in proportion is the advance guard, for a large command takes relatively longer to prepare for action than a small one. In large commands it is usually composed of all arms, the proportions depending on the nature of the work, character of the country, etc.
DISTANCE FROM THE MAIN BODY
While the distance between these two bodies should be great enough to prevent needless interruptions in the march of the main body, and to give the latter time to deploy should the enemy be encountered, it should never be so great that timely support of the advance guard becomes impracticable.
[Ill.u.s.tration: PLATE SHOWING the IDEAS INVOLVED IN an ADVANCE GUARD
As you go from the point to the main body note that the distances are greater as the groups become larger. Larger groups require more time and s.p.a.ce, when getting ready for action, than small groups. A very important thing to remember in connection with this plate is that you have only such groups in an advance guard as are necessary to insure protection for the main body.]
DISTRIBUTION OF TROOPS
An advance-guard order generally describes the following distribution of troops:
Advance cavalry.
Support.
Reserve.
The manner in which the advance-guard cavalry is employed depends upon the situation. Its proper place is in the direction of the enemy, and generally all or the greater part is used as advance cavalry. If weak in numbers, it may be a.s.signed to the support.
ADVANCE CAVALRY
The advance cavalry is that part of the advance-guard cavalry preceding the support. It reconnoiters far enough to the front and flanks to guard the column against surprise by artillery fire, and to enable timely information to be sent to the advance-guard commander.
SUPPORT
Following the advance cavalry is the support, varying in strength from one fourth to one half of the advance guard. In mixed commands it consists of infantry, to which engineers may be attached. If there is no advance cavalry, some cavalry should be attached to the support for reconnoitering duty.
As the support moves out it sends forward an advance party several hundred yards, the distance varying with the terrain and the size of the command.
The advance party supplements the work of the advance cavalry, reconnoitering to the front and flanks to guard the support against surprise by effective rifle fire. The patrol preceding the advance party on the line of march is called the point, and is commanded by an officer or an experienced noncommissioned officer.
With the advance cavalry in front but little reconnoitering by infantry is necessary, and the advance party is relatively small--one eighth to one third of the support. If there is no advance cavalry, the advance party is made stronger (about one half of the support) and the flanks are guarded, if necessary, by additional patrols sent out from the support and even from the reserve.
The support commander ordinarily marches with the advance party, but goes wherever needed. He sees that the proper road is followed; that guides are left in towns and at crossroads; that necessary repairs are made to roads, bridges, etc., and that information of the enemy or affecting the march is promptly transmitted to the advance-guard commander. He endeavors promptly to verify information of the enemy.
RESERVE
The reserve follows the support at several hundred yards" distance. It consists of the remainder of the infantry and engineers, the artillery, and the ambulance company. The artillery usually marches near the head of the reserve, the engineers (with bridge train, if any) and special troops at the rear.
RECONNAISSANCE
In conducting the reconnaissance the patrols are, as a rule, small--from two to six men. If additional protection is necessary, a flank guard covers the threatened flank. The flanking patrols, whether of the advance cavalry or advance party, are sent out to examine the country wherever the enemy might be concealed. If the nature of the terrain permits, these patrols march across country or along roads and trails paralleling the march of the column. For cavalry patrols this is often possible; but with infantry patrols and even with those that are mounted, reconnaissance is generally best done by sending the patrols to high places along the line of march to overlook the country and examine the danger points. These patrols report or signal the results of their observations and, unless they have other instructions, join their units by the most practicable routes, other patrols being sent out as the march proceeds and as the nature of the country required.
Deserters, suspicious characters, and bearers of flags of truce, the latter blindfolded, are taken to the advance-guard commander.
Civilians are not permitted to precede the advance guard.
Communication between the fractions of an advance guard and between the advance guard and main body is maintained by wire, messenger service, or signals.
ADVANCE GUARD OF A SMALL COMMAND
In forming the advance guard of a command smaller than a brigade, the foregoing distribution is modified, depending upon the situation. A company or troop usually sends forward only a point, a battalion or squadron, an advance party; but a battalion or squadron at war strength should put a company or troop in the advance guard and a regiment should put a battalion or squadron, if an enemy is liable to be met. Whenever the advance guard is less than a battalion, there is no reserve.
REAR GUARDS
The rear guard is charged with the important duty of covering the retreat.
When a commander decides to retreat, he issues the necessary order.
During a retreat the outpost for the night usually forms the rear guard of the following day.
STRENGTH AND COMPOSITION
The strength of a rear guard depends upon the nature of the country and the strength and character of the pursuing force. It can not, like the advance guard, count on the support of the main body.
Machine guns are especially useful in the pa.s.sage of defiles and in covering the crossings of rivers.
Engineers and ambulance companies are usually a.s.signed to rear guards.
The troops of a rear guard are selected from those that have had previous local successes, or have suffered little loss and are comparatively fresh.