Chapter VI

MARCHES, CHANGE OF DIRECTION OF MARCH, CAMPS AND BIVOUACS.

MARCHES.

_Arrangement of troops._

The different elements on a march are:

(a) The independent cavalry.
(b) The advance guard.
(c) The main body.
(d) The flank guard.
(e) The rear guard.
(f) The train (including field hospitals,
ammunition, supply and pack trains).

In marches in peace time or at a distance from the enemy, cavalry and artillery may march in rear of the infantry or on a different road. Large bodies of cavalry and horse artillery should not, as a rule, be intermingled with foot troops, except so far as is necessary for their safety.

Auto truck trains may be routed on a separate road from wagons and troops where safe and practicable. A good road should be selected for their movement as they suffer greater proportionate delay on a poor road than either troops or wagons.

The combat trains ordinarily accompany their organizations, except that the artillery combat trains are usually in rear of the last infantry organization. The firing batteries should be as a rule near the head of the main body with a battalion or an entire regiment of infantry immediately in front of them. A column of artillery or wagons more than a mile in length should ordinarily have some infantry in the middle for protection against a sudden attack in flank.

Trains follow in advance, precede in retreat, the position of the trains thus usually indicates the direction for retreat. Sometimes trains are sent on a separate road, on unexposed flank. The field trains are usually combined under the command of an officer, who is designated only in the first order or when a change is made.

There should generally be a small body of cavalry or other mounted men at the head of the main body especially in a flank march, and a few mounted men with the train, 6 to 12 men under an officer, designated in orders if train is separated from main body, and not sufficiently exposed to require a stronger escort.

Brigade trains in a forward march follow the main body at ½ to 2 miles. In a flank march they are usually closed up. In retreat they are sent well ahead. If separated from the main body they should have an escort if there is any risk. Often a few mounted men in addition to the slightly wounded and footsore infantrymen on the wagons (who are still able to fight) will be enough. Also the field trains are usually accompanied by a number of armed men in addition to the wagoners, including sergeants, cooks, mechanics, clerks, etc. Supply and ammunition trains are likewise habitually accompanied by a number of armed men. Engineers are very useful as an escort as they can facilitate the progress of the train. The escort, if any, should be mentioned in orders when train is separated from troops. It should always be under the command of an officer, preferably one senior to the Q. M.

Field trains may (a) Follow without distance (b) Follow at a certain distance (c) Remain behind (d) Follow to a certain locality and there remain (e) Precede at a certain distance or as rapidly as possible (f) Move by a different route to the same or another locality. In (a) and (b) no special escort is necessary. In the other cases circumstances decide. The arrangement of field trains in column should generally be the same as that of the troops to which they pertain. This is a matter of course, and need not be mentioned in orders, at least not after the first order. It is desirable to have the field trains join their organizations at the end of the march. But if tactical considerations demand, the troops can subsist for several days without their trains. Trains should never be taken through a defile or over a bridge if a combat is imminent, especially if retreat is possible. Keep them well to the rear, and off the main road when entering a fight. If it be necessary to separate the command from its trains for a considerable period an extra reserve ration or two may be issued to the troops before the separation. In a division action some or all of the ammunition train would usually accompany the troops into action, the remainder of the trains being left at or sent to a safe place in rear. (See Chap. XVII.)

In passing a defile have a strong body of infantry at the head of the column. It is usually inadvisable to have a strong body of cavalry _immediately_ ahead of the infantry in such a situation. A defile should be reconnoitered carefully, preferably on a broad front, before allowing any considerable number of troops to enter.

The companies in a battalion and the battalions in a regiment may alternate daily in position (this is not prescribed in orders of supreme commander). But beyond this, daily changes in the order of march are not advisable as they produce confusion and fatigue. The same troops may remain as advance guard for several days at a time, say for one series of marches--5 or 6 days--unless for some good reason, such as their having suffered severely in combat, it seems advisable to relieve them.

A rear guard is exceptional in a forward march--an advance guard in a retrograde movement. In the former case the rear infantry regiment, without orders, puts out a small rear guard (behind the trains), in the latter case “leading troops” (designated in orders) precede the trains. In a flank march both advance and rear guards as well as a flank guard may be necessary--all designated in march order.

Troops should be camped or quartered conveniently with reference to their position in column on arrival and on departure. It is well to camp in column of route along the road if command is not too large and conditions permit. It saves time and fatigue on both arrival and departure.

If there is an independent mission for the cavalry beyond the sphere of the advance guard and if the cavalry is relatively strong enough it should be made independent. Otherwise the bulk of it is attached to the advance guard. If a combat is imminent the tactical use of the cavalry to develop the enemy and operate against his flanks and rear may take precedence over other considerations, in which case the cavalry may better be kept in hand (assigned to advance guard).

The supreme commander may march (a) Between support and reserve of advance guard (b) At head of reserve (c) At head of main body. If he is with the advance guard a commander should be designated for the main body. The supreme commander may go wherever his presence is necessary. He generally designates a certain place (as “head of reserve”) to which messages are to be sent, and if he is not there when they come in, an orderly takes them to him. When he is with the advance guard its commander will usually accompany him. The supreme commander should generally march with the advance guard if combat is at all probable. In retreat he may join the rear guard if the enemy is pressing the pursuit.

In a flank march the distances between elements should generally be less than in a forward march--the entire column is “closed up.”

_Time of Starting._ Infantry and other foot troops should have an hour of daylight prior to commencing the march. Hence the first troops to march should start about sunrise. Mounted troops should have two hours of daylight before starting. Hence they should march about an hour after sunrise. These are the proper hours for starting, and orders should be arranged accordingly. Circumstances may require an earlier start, at daybreak or, in exceptional cases, even a little earlier. But there should be cogent reasons for a very early start. It is well to avoid the _habit_ of early starting. Both men and animals rest well in the hours just preceding dawn. To habitually interfere with this rest will rapidly lower the efficiency of the troops. If the number of mounted troops is _small_, and tactical considerations require it, their comfort may occasionally be disregarded, and they will start with the infantry at sunrise. As a rule the cavalry will not trot in starting a day’s march, they should walk at least a mile. In any case the gaits should be left to the judgment of the cavalry commander. The independent cavalry, if it moves by a separate road, may start _later than the infantry_, as it can make up for lost time by increase of gait. Ordinarily it should not be sent past foot troops on the same road (unless it be wide and paved) as this will cause confusion, delay and discomfort.

Trains may be started out considerably earlier than troops if necessary, as they are not subjected to such great fatigue. This, of course, will never be necessary when trains follow in rear of troops, but in retreat they should be sent on about 2 hours ahead of the troops, or even sooner if necessary for their safety and to get them out of the way. Hence they, with their escort, will frequently march before daybreak.

In considering the probable movements of the enemy, always make allowance for what might happen if he marches at daybreak or earlier still, for he has this option. Are there any reasons why he might wish to start early? If he arrived late at his camping place (after 3:00 p. m.) this indicates the possibility of his making a start early the next morning.

A late arrival (after 3:00 p. m.) is even more objectionable than an early start, unless hours of march have been arranged with a long rest to avoid the heat of mid-day. It is better to break camp before daylight than to make it after dark.

Night marches of any considerable length should generally be avoided except in cases of extreme urgency. If indulged in to any great extent they will soon wear out both men and animals. Troops which have made a long night march will not be in good trim for active operations on the following day. Night marches are sometimes made in hot weather to avoid the heat of the day. They may also be made for the purpose of surprising the enemy, as to secure a favorable position from which he may be attacked at dawn, in the retreat or pursuit of a defeated force and in certain other special cases.

Under the conditions that obtain in modern warfare the movements of large bodies of troops during daylight will seldom escape detection by the enemy’s aerial scouts. Accordingly the cover of darkness will at times be used for the concentration of reserves at critical points on the field of battle. If the troops can be concealed at the end of such movements it will often be advisable to allow them to rest during a portion at least of the day following their night movement. This will restore their vigor and render them fresh for active operations. For night marches it is desirable that the troops be accompanied by guides. (See also Chaps. XI and XIII.)

Movements by rail are usually not practicable except for long distances (more than 40 miles) and when well protected from the enemy by distance or covering troops. They pertain to strategical concentrations, but seldom to tactical operations on a small scale.

Movements of troops in large or small numbers and over considerable distances are successfully accomplished by the use of motor cars. Motor transportation is adaptable to campaign, in that cars may start or end a journey almost anywhere in the theater without regard to a fixed rail right of way. They load, dispatch and unload without formality; they require no sidings nor elaborate terminals.

In a large command the advance guard will be some distance in advance of the main body. Therefore the time of starting of the latter should not be set so early that advance guard must march before sunrise. Hence a large force cannot make an early start as readily as a small one, unless it camps in column of route.

Standard Times of Sunrise and Sunset at Gettysburg, Pa., 40° N lat.

(Authority--Prof. R. H. Willson, Harvard Univ.)

(Correct to within 5 minutes)

+-------------+----------+-----------+
| Date | Sunrise, | Sunset, |
| | a. m. | p. m. |
+-------------+----------+-----------+
| January 1 | 7:30 | 4:50 |
| February 1 | 7:10 | 5:20 |
| March 1 | 6:40 | 5:50 |
| April 1 | 5:50 | 6:20 |
| May 1 | 5:10 | 7:00 |
| June 1 | 4:40 | 7:20 |
| July 1 | 4:40 | 7:30 |
| August 1 | 5:00 | 7:10 |
| September 1 | 5:30 | 6:40 |
| October 1 | 6:00 | 5:50 |
| November 1 | 6:30 | 5:00 |
| December 1 | 7:10 | 4:40 |
+-------------+----------+-----------+

NOTE: For intermediate dates, interpolate.
Daybreak and dusk occur about an hour (more or
less) before sunrise and after sunset. They are
indefinite times, and it is better not to use such
expressions in orders, but to give standard times.

_The Start._ The start is arranged as described under “Advance Guards.” A large body cannot be assembled at one point. The initial point should preferably be at a crossroad, which organizations can reach by a number of different routes. If there is any danger of confusion or interference the routes of different organizations to the initial point should be prescribed. In a large command, where the advance guard and main body are separated by a considerable distance, an initial point should be designated for each. The order of the supreme commander will designate the hour at which the main body will start from its initial point and the hour at which the advance guard will clear _its_ initial point, or preferably, the distance at which the advance guard will precede the main body (in starting). This latter arrangement allows the advance guard commander to select his initial point, which is usually desirable. During the march the main body will usually regulate its march on that of the advance guard if the latter be larger than a battalion. In a small command the same initial point is used for the advance guard and main body. The order of the supreme commander in this case will ordinarily designate the hour at which the advance guard is to clear the initial point and the hour at which the main body starts therefrom, or the distance at which it is to follow the advance guard. Each subordinate commander is responsible that his command takes its proper place in column at the proper time without interference with other organizations. In an assembly order for a large command troops whose starting times do not differ by more than ten minutes would be grouped under one time heading. See also remarks under “The start,” and “Assembly order,” in the Chapter on advance guards.

It is not always possible to foresee the end of a day’s march. In such cases the order should direct the march “provisionally” on some intermediate point in the right direction, arrival at which without interruption is reasonably certain.

_Length and speed of marches._ Marches often cause greater losses than battles. A forced march may cost more than a fierce engagement. Hence avoid forced marches and all unnecessary hardships. A long march should not be undertaken with green troops. The early marches of a campaign should not be more than 8 or 9 miles per day for infantry or mixed troops. From this they can be gradually increased to a maximum of about 15 miles for a brigade or smaller force. Small bodies can make longer marches than large ones. Thus a battalion might march 16 miles, whereas 12 to 13 would be the usual limit for a division. Anything more than 15 miles for infantry or 25 for cavalry, is a forced march, except for small commands of seasoned troops.

The average speed of infantry without halts is 3 miles per hour (a mile in 20 minutes) or, including halts, 2½ miles per hour. There should be a halt of 10 minutes in each hour, and if the march extends into the afternoon a long halt of about an hour near noon. Troops should be informed of duration of halts.

Troops cannot march continually. After 5 or 6 days of steady marching (or less if combats also are included) even seasoned troops need a day of rest. Tactical requirements are paramount, but one must not forget that endurance of troops, even of cavalry, has a limit. Unnecessary hardships must be avoided. The fighting power of a command is considerably below the normal immediately after a forced march, and almost nil after a night march. Night marches may require half again as much time to cover the same distance as those executed during the day, in the case of a large command.

It is not safe to assume a speed of more than 2 miles an hour for a wagon train. Field Artillery can keep pace with infantry, unless roads are very poor as in some mountainous sections of the U. S. On good roads and for moderate distances Light Field Arty. can keep pace with cavalry, but horse arty. is better for service with a cavalry command.

The following table shows the marching rates of various arms:

+----------------+----------+------------+------------+------------+
| | Miles/hr | Miles/hr | Miles/day | Miles/day |
| ARM | At drill |on the march| Ordinary | Forced |
| | | with halts | march | march |
+----------------+----------+------------+------------+------------+
|Infantry or | | | | |
| mixed troops | 3 | 2¼ to 2¾ | 12 to 16 | 16 to 30 |
+----------------+----------+------------+------------+------------+
|Cavalry | | | 20 to 25 | 25 to 50 |
|Walk | 4 | 3¼ to 3½ | | |
|Trot | 8 | | | |
|Gallop | 12 | | | |
|Alternating | | | | |
| walk and trot | | 5 | | |
+----------------+----------+------------+------------+------------+
|Wagons | | 2 to 2¼ | 12 to 20 | |
+----------------+----------+------------+------------+------------+

NOTE. _Empty_ wagons on good roads can make longer
marches. Small convoys of light auto trucks can average from 5 to
10 miles per hour, according to the nature of the road and other
conditions. (See Chap. XVII.)

_General Remarks._ The elongation of a column (over road distances given in F. S. R.) may vary from nothing at the start to 20 per cent at the conclusion of a day’s march. 10 per cent is a fair average.

For a rapid current the limiting depths fordable are, for infantry 3 ft., for cavalry 4 ft., for artillery or wagons 2½ ft. If current is sluggish allow ⅓ more for infantry and cavalry.

Usually march on the main or best road. The distance may be somewhat greater, but the time required will usually be less. The best roads in the U. S. are none too good. During the march troops should remain on the road, but in taking position for combat both troops and artillery may move across country. Even in such a case it is best to remain on the road as long as possible.

The front is always in the direction of the enemy. Thus in a retreat the _right flank_ guard would be on the _left hand_ of the column. The head of a column is in the direction of march, which may be to the rear.

Do not use words “sunrise” or “daybreak” in orders, but give standard time.

Troops usually march better and suffer less from fatigue in cold weather than in very warm weather.

It is not ordinarily practicable to march artillery or trains in double column on roads in the U. S. But trains or troops in rear of other trains may be brought to the front by halting the wagons ahead of them on one side of the road. It is very embarrassing for artillery to have to countermarch on U. S. roads. But it is _possible_. During a march one side of the road should be left clear for the passage of messengers.

In connection with subject of marches read also “Advance,” “Rear and Flank Guards,” and “Cavalry tactics.”

_Change in direction of march._ A change of direction of march usually results from a change in the situation causing a change of mission. An example of this would be a case in which the main body unexpectedly encountered the enemy in force. In such a case it would ordinarily be the duty of all detachments within reach to rejoin for the main battle--“march to the sound of the guns,”--abandoning for the time being their less important missions. Upon arrival such detachments should as a rule not attack the enemy independently, but should send word of the time and place of their arrival and place themselves under the orders of the supreme commander. While it is the rule that all detachments within reach should rejoin for the main conflict, yet there will be cases where a detachment is justified in staying out of a battle it might have joined. Of this the best example is where the detachment can “contain” a relatively larger force of the enemy, thus keeping it out of the main combat. If the enemy opposed to the detachment is of less strength than itself it may be contained by a portion of the detachment, while the rest marches to join the battle. A detachment should not allow itself to be contained by an inferior force.

In making the change of direction some suitable point to the former front should be selected and occupied by the advance guard to cover the change of direction. If there be any danger from the direction of the former front the advance guard continues its march as a flank guard, a new advance guard being pushed out from the main body. For such a movement two roads at suitable distance are required (see “Flank Guards.”) In making a change of direction it is well to avoid countermarching troops, and especially artillery, if practicable.

In making a change of direction the safety of the trains must be carefully considered. If the detachment is joining the main body for battle, its trains (if with it) may well be sent by the shortest practicable route, escorted if necessary, to join those of the main body, or to some other safe place. If danger is to be anticipated from the former front now become a flank, the trains should preferably be moved on a parallel road on the unexposed flank.

ORDER--CHANGE IN DIRECTION OF MARCH.

Detch., 1st Div., 1st Blue Army Corps,
HUNTERSTOWN, PA.,
Field Orders, } 17 Nov., '12--11:20 a. m.
No. -- }
Gettysburg-Antietam 3" Map.

1. Our division is engaged with the enemy in force near BONEAUVILLE. A hostile detachment estimated at 5 bns., a battery and a troop, apparently unsupported, is intrenching near NEWCHESTER. The 1st Squadron, 1st Cavalry, defeated the hostile troop near road junction 594, and drove it back towards NEWCHESTER.

2. This command will march southeast in two columns, to join the division. Former march conditions now cease.

3. (a) The cavalry will continue in observation of the force near NEWCHESTER, delaying it in case it attempts to advance, and will reconnoiter to the north and through NEW OXFORD to the east.

(b) The advance guard, reinforced by a platoon of the 1st Sq., 1st Cav., will march southeast via 585--573--586--R. F. WEAVER on 572, and as left flank guard cover the march of the main body.

(c) The main body will turn south at 554 and will march provisionally on 562.

The Commanding Officer of the 2nd Inf. will send forward 2 companies as advance guard to precede the main body at about 600 yards.

4. Messages to head of main body.

A,
Brig. General.

Verbally to staff, C. O. Adv. Gd. (1st Inf.).

By mtd. messenger to C. O. 2d and 3d Inf., 1st Sq., 1st Cav.

Report of dispositions to C. G., 1st Div., by aide.

Note: In this case the trains of the detachment are with those of the division. Hence all reference to trains is omitted from the order. This order as dictated will be written by the staff present and copies sent to officers not present.

CAMPS AND BIVOUACS.

Troops should not be bivouacked in the open except for very cogent reasons. A comfortable camp on a sanitary site is always desirable, provided tactical requirements permit the selection.

Troops should not be kept in column at the end of a day’s march but should be placed in camp immediately upon their arrival so as to give the men as much rest as possible. Hence the halt order should be issued well in advance, should be brief, and if practicable a staff officer accompanied by a surgeon should be sent ahead to make the necessary preliminary arrangements, and be ready with the aid of assistants to assign and lead organizations to their camps upon arrival, with a minimum of delay and confusion.

The important considerations in the selection of camps, aside from those of a tactical nature are:

1. A plentiful supply of water, streams or wells. It is usually assumed that any stream shown in blue on the map has water in it. The troops should be camped with reference to the water supply so that all may reach it as conveniently as possible. Along the banks of the same stream infantry or other foot troops should preferably be camped _upstream_, and cavalry, artillery and trains, _downstream_.

2. A camp should preferably be near a crossroad, as this gives a choice and multiplicity of routes for movements and facilitates communication generally. It is always desirable that a camp be _near_ the main road, for the sake of convenience in arrival and departure, and if it be a large camp, roads through the camp and even a railroad for convenient supply are desirable. The camp should not be so close to an important road as to be disturbed by the noise and dust of traffic.

3. Fuel is an essential requisite, and forage desirable.

4. The available area should be sufficient to accommodate the command. (See ante for table of camp areas.)

5. Especially in cold weather a southern exposure with a hill or wood to give protection from the prevailing winds is desirable. In summer, if the weather is very warm, an _open_ wood which gives shade without interfering with the circulation of air, makes an excellent camp site.

6. Firm ground, such as good turf or gravel, with good drainage (ground water not too high), is very essential. These features may, of course, be artificially improved.

Troops should be assigned to camp conveniently with reference to their manner of arrival and departure. A camp in column of route facilitates placing the troops as well as resumption of the march. It is therefore, to be preferred for a short stay (over night) when tactical requirements allow it. The usual regimental camp is a column of battalion camps. (See also Chap. XVII.)

The health and efficiency of the troops are often best conserved by utilizing buildings for shelter, especially in cold or inclement weather. When tactical considerations permit troops may be billeted. Public buildings, warehouses, etc., if available, are to be preferred to private residences.