CHAPTER 6

COMBAT TECHNIQUES

Section I. THE INDIVIDUAL AND NORTHERN WARFARE

6-1. Problems of Northern Warfare

Two opponents face the soldier in northern warfare--the enemy, who must be defeated, and nature, which must be made an ally. We fight the enemy, but we must accept nature as it is, making nature fight with and for us. Proper clothing and equipment will help overcome the hazards of nature. Training teaches the individual how to use natural conditions for movement concealment, and protection, as well as how to operate efficiently when the weather is good or bad, and in all types of terrain. The trained soldier moves, fights, lives, and works easily and confidently because he knows his job.

6-2. Nature of Northern Warfare

a. During winter the vast, empty spaces of the northern regions permit unrestricted maneuver and movement for troops sufficiently equipped and trained to operate in these circumstances. Dispersion is simplified; hostile artillery and mortar fire can be evaded or avoided. A mobile force can gain surprise and strike deep in the flanks and rear areas of the enemy, disrupting his lines of communications and finally destroying him. However, the mountainous areas of the northern regions will have the same limitations to movement as those in more temperate climates.

b. The principles of war remain unchanged. Tactics used in the northern latitudes are the same as anywhere else in the world. The waging of successful warfare in the extreme cold depends on the use of a great number of techniques. For the purpose of carrying out their mission, all individuals and units concerned must be indoctrinated and thoroughly trained in these techniques.

c. There is always opportunity for each soldier as an individual to display his initiative. Initiative is shown not only in combat, but also in the small things which can be done to make life more comfortable and more interesting in the North.

d. In the isolated areas of the North it is most essential that a system of teams be developed. Pair men together as "buddies" and insure a higher standard of efficiency, safety, and morale. If it can be avoided, never send one man alone on a mission--at all times try to keep "buddies" together.

Section II. INDIVIDUAL WEAPONS AND INSTRUMENTS

6-3. Effects of Northern Conditions on Weapons and Instruments

The year-round necessity for supervised care, cleaning, and maintenance cannot be overstressed. Effects of cold weather on various types of weapons are covered in detail in appendix D.

6-4. Care, Cleaning, and Maintenance

a. Weapons will function under extreme conditions, provided they are properly maintained. Normal lubricants thicken in cold weather and stoppages or sluggish actions of firearms will result. DURING THE WINTER, WEAPONS MUST BE STRIPPED COMPLETELY AND CLEANED WITH A DRYCLEANING SOLVENT TO REMOVE ALL LUBRICANTS AND RUST PREVENTION COMPOUND. The prescribed application of special northern oils should then be made. These lubricants will provide proper lubrication during the winter and help minimize the freezing of snow and ice on and in weapons.

b. Soldiers must insure that snow and ice do not get into the working parts, sights, or barrels of weapons. Even a small amount of ice or snow may cause malfunction of the weapons. Muzzle and breech covers should be used. Before firing, the weapon must be examined carefully, especially the barrel, which may be blocked with ice or snow and will burst when fired. Snow on the outside, if not removed, may drop into the breech and later form ice, causing malfunctioning of the weapon.

c. Condensation forms on weapons when they are taken from the extreme cold into any type of heated shelter. This condensation is often referred to as "sweating." For this reason weapons should be placed near or at the floor level where the temperature will be lower and there will be less condensation. Every effort must be made to remove condensation as soon as possible or the film will freeze when the weapons are subsequently taken into the cold. The ice so formed may seriously affect the operation of the weapon unless it is manually operated until the moisture freezes. This prevents the parts from freezing together and allows continued operation. If security conditions permit weapons should be left outdoors, in racks or unheated shelter.

d. When weapons are taken into a heated shelter, "sweating" may continue for as long as 1 hour. When time is available, men should wait 1 hour and then remove all condensation and clean the weapon.

e. During the freezeup and breakup seasons, the danger of rust and corrosion is at its greatest. In the winter the lack of moisture in the air decreases this danger, but the problem of ice and snow will necessitate frequent checking and cleaning of weapons.

f. Should parts of a weapon become frozen, warm them slightly and move them gradually until unfrozen. If the weapon cannot be warmed, all visible ice and snow should be removed and parts moved gradually until action is restored. Ice in the barrel can be removed with warm (standard issue) gun oil if slow warming is not possible.

g. When firing, do not let the hot parts of the weapon come in contact with the snow. The snow will melt and, on cooling, form ice. When changing barrels, do not lay them on the snow; rapid cooling may warp them.

h. Snow, even of the lightest variety, has a tremendous smothering effect on fragmenting munitions. Even a few inches of light snow can drastically affect the lethality of this type munition. Understanding this, commanders must insure that antipersonnel mine directional paths are cleared in snow to prevent loss of velocity to fragments and deflection of fragments by snow. Grenadiers should always attempt to obtain airbursts by placing fire on the brush in the target area rather than in the snow. Indirect fire weapons should make maximum use of airbursts provided by time and proximity fuzes.

6-5. Ammunition

Extreme cold does not materially affect the accuracy of weapons nor the performance of small arms ammunition. Ammunition should be kept at the same temperature as the weapon. It should be carried in the bandoleers and the additional ammunition placed in the pockets of the outer garment and in the rucksack. Ammunition clips, and magazines must be cleaned of all oil and preservative and must be checked frequently; all ice, snow, and condensation should be removed. Cartridge containers, magazines, and ammunition drums must be kept closed in order to prevent the formation of rust or ice.

a. Ammunition should be stored in its original container, raised off the ground, and covered with a tarpaulin. Ammunition so stored should be suitably marked in order to locate and identify it in the event it becomes covered with snow.

b. Resupply of ammunition may be restricted. All personnel must be made aware of the necessity for ammunition economy and fire discipline. Loaded clips, magazines, or single rounds dropped into the snow are quickly lost; therefore, careful handling of ammunition is essential.

6-6. Care and Maintenance of Special Items

a. The liquid in the lensatic compass, aiming circles and in weapons sights congeals in extreme cold. This situation will cause sluggish movement of the arrows and bubbles and increase the probability of error. The compass should be carried near the body in inner clothing in order to keep the liquid warm and thin. Other instruments and sights should be kept as warm as possible and should be exposed to the cold only during periods of actual use.

b. Binoculars and other liquid-free optical instruments are not affected by cold weather. However, condensation does form when these instruments are taken from cold air into warm air. Therefore, these instruments should be left outside.

c. Extreme cold will lower the efficiency of all batteries and eventually they may freeze. Batteries must be kept from freezing and, if possible, men should carry radio and flashlight batteries close to the body in order that full efficiency will be available when needed.

d. Low temperature dry cell batteries may be issued for cold weather use. These batteries are distinguished by 2000 series-type numbers, such as BA-2030 for a flashlight battery. These batteries must be stored at temperatures near 0� F. to conserve their shelf life.

Section III. FIRE AND MOVEMENT

6-7. Blowing Snow and Fog

a. These restrictions will affect both friendly and enemy forces, Full advantage must be taken of them in order to effect concealment, surprise, and eventual success.

(1) Defense positions should be located on high ground, thus forcing the enemy to attack uphill in deep snow. Each weapon must be assigned a field of fire and emplaced on an improvised platform which will insure fire being brought to bear at man-height level on the likely enemy approaches. Thus during fog, storm, or darkness, effective unobserved fire can be brought to bear. (2) In areas of fog, if possible, outpost and observation post positions should be located where warmer air or wind eliminates fog or at least makes it less dense.

b. By proper reconnaissance and the use of trailmarkers it may be possible for an attacking force under cover of fog or blowing snow to approach very close to the enemy before the final assault. During blizzards or blowing snow the attacker should, if possible, attack downwind or at a slight angle to it in order that he will force the enemy to face into the full force of the storm.

c. Ice or vapor fogs are very common in extreme low temperatures. Such fogs are primarily the result of natural phenomena, but also result from many other causes such as vehicle exhausts, cooking, breathing, and weapons firing. Fogs of this nature hang overhead and could be clear markers of a position. They will also limit visibility. The observed fire of automatic and direct fire weapons is handicapped considerably by the fog, smoke, and whirling snow caused by muzzle blast. Placing observers away from the weapons positions may be necessary to control the fire. Placing tarpaulins under the guns, or packing or icing the snow, will assist in reducing the effect of muzzle blast. Pauses in firing or change of position may be necessary in order to obtain better fire effect.

6-8. Fire Positions

a. Digging firing positions in soft or hard snow is relatively easy and quick. In a static position every effort must be made to improve the position and, if time permits, to dig it into the frozen ground. The use of explosives to dig emplacements and fires to thaw the ground will help. A position in the snow is only temporary and cannot withstand artillery and continuous small arms fire. Icing of the position or use of tree trunks and branches will afford added protection (fig. 6-1). Sandbags filled with snow may be used quite effectively for this purpose.

b. The digging oppositions in snow and the types constructed are, in general, similar to those discussed in FM 5-15. Foxholes, trenches, and other types are used.

c. Every effort must be made toward improvement of positions; snowblocks, iceblocks, sandbags, logs, and branches can be used to strengthen them. In addition, water may be poured onto the snow to form ice. In static positions, when time allows water mixed with dirt, sand, or gravel can be poured into wooden forms. This is called "icecrete." The icecrete must be well tamped as it is poured to make it compact. Usually there is no necessity for removing the forms unless the wood is required for other purposes. Icecrete is darker than ice and will absorb more heat from the rays of the sun, causing melting. Icecrete construction must therefore be covered with snow, both to overcome its melting and to camouflage its contrasting color. Icecrete is much stronger than ice, provides considerable protection from small arms fire and shell fragments, and is a useful material for preparation of defensive positions. Icecrete, however, is brittle, and sustained fire reduces its protectiveness, thus requiring frequent repairs.

d. The action of winds and tides during winter rips the sea ice surface and then forces the ice into high piles extending in lines for miles, These ice barriers afford excellent firing positions and protection because of their thickness and the fact they command the usually flat expanses between ridges. Iceblocks can be cut from numerous sources and used to strengthen a position. The ice should be covered with packed snow which will help camouflage and assist in eliminating the possibility of ricochets, shell fragments, and lethal ice splinters.

e. In a woods the thickest and strongest trees provide the best protection for the individual. In order to use the added protection afforded by the trees, perimeter positions should not be on the edge, but should be slightly deeper in the woods, depending on its density and consistent with the required fields of fire (fig. 6-2), A tree 50 cm (20") in diameter will provide protection from small arms fire. If the tree selected is smaller, packed snow, dirt, branches, or deadfalls may be used to increase protection.

f. The improvement of fields of fire in woods is most important. The lower branches of trees, up to 2 meters (6') high, which restrict fields of fire must be removed. Underbrush and perhaps even a few trees will have to be cut; however, do not strip the area. In the first phase of improvement, crisscrossing snow tunnels under the trees is carried out. Then, if time allows, those fields are extended wider and deeper. In the final phase, obstacles and traps are constructed and mines laid in these areas (fig. 6-2).

6-9. Use of Ski Poles and Sleds in Firing

a. When firing in snow, it is necessary that a firm support be used, as snow will compact. On hard packed snow the weapon may slide. Therefore, any item available in the area or n the men's possession should be used to insure a solid base; e.g., branches, skis, snowshoes, or sleds.

b. Skis and ski poles can be used in a variety of ways to form weapons rests while firing on the move. Figure 6-3 illustrates the standing position. Use this position only in hasty situations, as when surprised by enemy fire.

c. Ski poles may be used as an elbow rest or as weapon support when firing from a kneeling position in shallow crusted snow (fig. 6-4). For firing in deep, soft snow the position of the poles can be reversed for added stability.

d. When firing from the prone position, the skis or ski poles may be used as an elbow rest or as supports for the weapon (figs. 6-5, 6-6, and 6-7).

e. Automatic weapons may be fired from the prone position using a snowshoe or ski pole basket as a rest for the biped (fig. 6-8). A fairly wide strip of canvas maybe permanently attached to each leg of the biped. On opening the biped, the canvas will stretch out between the legs over the snow and stop the legs from sinking.

f. To prevent weapons from sinking in deep snow, machineguns may be fired from sleds in case of emergency (fig. 6-9). The weapons can be mounted either with regular or improvised mountings. However, it is essential that weapons be placed in a dug-in position as soon as possible.

6-10. Strength of Snow, Ice, and Frozen Ground for Cover

a. General. The soft, spongy ground of the North in the summer, and the snow surface in the winter, have a smothering effect on fire from all types of weapons. Hard frozen, bare ground or ice, when not covered with snow, greatly increases the number of ricochets and fragmentation effects. The resistance or protection offered by snow, ice, or frozen ground against enemy fire is variable.

b. Penetration. A rifle bullet rapidly loses its penetrating power depending on the density of the snow. Snow packed in layers tends to deflect the bullet at each new layer. Loose snow spread over a defense position will help smother ricochets. The minimum thickness for protection from rifle bullets and shell fragments is shown in the following table:

6-11. Effect of Snow, Ice, Frozen Ground, and Muskeg on Shells and Grenades

a. Loose snow greatly reduces the explosive and fragmentation effects of shells. The depth, type of snow, and ammunition are naturally the main consideration. The use of a delayed action fuze will generally cause the shell to penetrate the snow blanket and explode underneath, smothering and reducing the effect of the fragmentation. One meter (3') of snow will provide some protection against most light artillery fire. A superquick fuze setting will increase the effect of artillery fire, while airbursts will inflict still more casualties on surface targets.

b. In the summer the many areas of muskeg and water will also limit the effects of artillery fire. On ice or frozen ground, and during periods of freezup, the effect will be greatly increased as the result of flying ice splinters and frozen clods of ground. In these seasons and areas, covered positions must be increased in strength. Overhead protection must be sought whenever possible.

6-12. Crew-Served Weapon Positions

a. Detailed information and guidance for construction of emplacements and shelters is contained in FM 5-15. The dimensions are applicable for both winter and summer. The gun emplacements for MG's, rocket launchers, and recoilless rifles are square-type positions. The gun platform can be made from packed snow and is about waist high. Open space must be left behind the gun to allow for the back blast of the rocket launcher and recoilless rifle.

b. Mortar positions in snow are normally round shaped (fig. 6-10). Because of the frozen ground a mat made from tree branches or sandbags filled with snow must be placed under the baseplate when firing. See FM 5-15 and FM 23-90.

c. Bunker-type positions will give better protection for the gun crew against enemy fire and weather than will open positions (figs. 6-11, 6-12, and 6-13). A hasty bunker-type position is normally built as follows:

(1) A square shaped hole is dug in the snow, the dimension depending on the purpose of the bunker position. (2) A heavy log or a tree trunk is placed lengthwise on each side of the snow hole. They are supported by four heavy, forked poles. (3) A layer of logs is placed crosswise in the top of the two support logs. (4) A layer of boughs is placed on the first layer of logs in order to prevent melting snow from dripping into the bunker. (5) Two or three more layers of logs are placed on the top of the boughs. (6) Finally, the roof is covered by smoothing and packing the snow in order to eliminate any sharp features that may produce shadows. (7) A small embrasure reinforced with sandbags and snow is left open, in the direction of the field of fire. (8) The rear entrance is covered with a white tarpaulin or a white camouflage suit.

d. Tents are often used in temporary defense positions to shelter the men. They must be close to the combat positions and should be in defilade. The tents must be dug into the deep snow, or even into the ground in order to protect the men against enemy fire. The tent ropes must be well anchored by using deadman anchors or upright poles placed deep in packed snow. Immediately outside the tent, defense positions must be dug for use in case of sudden alert (fig. 6-14).

e. When near the surface the covering snow is easy to dig with individual entrenching tools; the difficulties will start when ground is reached. Several small holes should be dug in the ground and attempts made to break the frozen ground between them. The men should temporarily exchange the different types of entrenching tools in order to make the digging faster. During darkness, or in areas not under the enemy's direct observation, heavy tools such as picks, crowbars, and shovels are used so that positions can be completed rapidly.

f. Using explosives provides the easiest and fastest way to break the frozen ground. However, the use of demolitions will be restricted when under enemy observation. Composition C-4, tetrytol, and TNT are the best explosives for use in northern operations because they retain their effectiveness in cold weather. Dig a hole in the ground in which to place the explosive and tamp the charge with any material available to increase its effectiveness. Either electric or nonelectric circuits may be used to detonate the charge. For a foxhole, 10 pounds of explosive will usually be sufficient. Another formula is to use 2 pounds of explosive for every 30 cm (1') of penetration in frozen ground. Shaped charges can be used very efficiently to make holes in frozen ground as described in TM 5-349.

g. Some improvised means as listed below may be used to break the frozen ground when no others are available:

(1) In rear areas frozen ground can be thawed by starting a campfire in the place where it is desired to dig. (2) Two or three handgrenades tied together can be used to blast a hole in the frozen ground. (3) Existing craters caused by enemy or friendly artillery fire can be utilized.

h. Often the tops of ridges or hilltops will be rocky and with very little snow on the ground because of wind action. If the time and situation allow, the snow situation can be improved by erecting snow fences in the place planned for defense positions. Within a few days the snow fences will collect drifting snow in banklike forms in which it is easy to dig positions.

Section IV. FIGHTING TECHNIQUES

6-13. Formations

Squad and platoon formations for tactical movements remain basically the same as for temperate regions; however, terrain and deep snow cover will necessitate some modifications. In deep snow, when speed is of the essence, a column formation may be preferable to a line formation because it will require fewer trails. Old, well-settled snow will normally provide good flotation and will facilitate skiing for the individuals. Since the trailbreaking requirement is reduced and may under favorable circumstances be nonexistent, line formations may be used without loss of speed. Downhill movement, even in deep snow, may also indicate the use of line formations when it would not be considered feasible on level terrain under the same snow conditions.

6-14. Handling of Ski and Snowshoe Equipment and Individual Weapons

a. The purpose of using skis or snowshoes in combat is to expedite the movement of individuals over deep snow in the most rapid manner, thus exposing them to hostile fire for the shortest possible period of time. In order to obtain the maximum advantage of skis they should be used as far forward as possible, leaving them behind only when the objective can be reached more quickly and easily on foot. It is finally up to the small unit leader to decide at which phase in the attack this may be done. As a rule of thumb the skis are left at the final coordination line, because close combat on foot is more effective and easier to execute than if mounted on skis. Conversely, deep snow may force units to close into the objective on skis. Individuals using snowshoes may keep them on through all phases of the attack. Under favorable snow conditions they may be left piled together at the final coordination line or fastened to the individual's equipment where they will least hinder him.

b. As friendly forces approach the effective range of enemy weapons, they move by fire and maneuver. The individuals proceed by short rushes on foot, on skis, or on snowshoes whichever is most feasible. Rushing on foot, the skis are dragged by holding them together by the tips (poles through the two straps) in one hand, with the weapon readily available for action in the other (fig. 6-15). Skis may also be tied to the belt with the emergency thong slipped through the holes at the ski tips.

c. The quick-release feature of the All-Terrain ski binding provides the means to quickly dismount from skis when hostile fire becomes effective. Under favorable snow conditions, as well as in emergencies, the ski bindings are kept on when lying down and firing between rushes (fig. 6-16).

d. When contact with the enemy is not expected, the individual weapon is carried across the back with the sling over either shoulder, the butt at the side or attached to the rucksack (if carried by the individuals) (fig. 6-17). When contact with the enemy is imminent, the weapon is slung around the neck and in front of the body thus releasing both arms for rapid skiing (fig. 6-18). When contact with the enemy has been established, the weapon is carried in one hand and the ski poles in the other so the weapon is readily available for action (fig. 6-19).

e. Under conditions where the depth of the snow is less than 50 cm (20"), skis may be left in the attack position if it becomes evident that launching an attack on foot can be executed in a more rapid and efficient manner than using skis.

f. As soon as the objective has been seized, the skis, ski poles or snowshoes may be recovered and brought forward. A two-man team can quickly make a ski bundle (fig. 6-20) and drag the skis of an entire squad at one time.

6-15. Additional Techniques

a. In deep, loose snow under hostile fire it may be more advantageous to advance in a high crawl position by holding the skis with hands through the toe straps and taking full advantage of snowdrifts and bushes. A position such as illustrated in figure 6-21 should be adopted. Snowshoes may be used in the same manner.

b. Sliding forward in a low crawl on skis is another method of advancing, especially over firm snow (fig. 6-22). The rifle can be slung over the shoulder or laid on the skis directly in front of the individual. The latter is possible only when the snow is hard so that it cannot get into the rifle.

c. In deep snow, trenches may be dug in the snow leading in the direction of the objective when it is too difficult to be reached by oversnow movement. Snow trenches are dug on a zigzag course (fig. 6-23) by throwing the snow out under cover of darkness or, in an emergency, the digging may be masked by smokescreens. The snow shoveled from the trench should be placed on the enemy side of the trench to allow the individuals to crawl along the trench without being observed by the enemy.

d. Snowdrifts and vehicle tracks may be utilized when found in the battlefield. Snow fills in ditches and rolling ground and tends to flatten the terrain in general. The wind builds up snowdrifts and cornices and can change the contour of the ground a great deal. Snow-covered terrain must be continually studied and every feature utilized. On the downwind side of every obstacle, tree, house, and bush there is always a hollow which may provide an excellent observation point or firing position (fig. 6-24).

e. The wind, particularly in open areas, may form long, wavy snowdrifts which are almost natural snow trenches. They may at times be used as an approach to the objective.

f. Frozen streams or sunken riverbeds may be used as another means of advance (fig. 6- all 35) ; often they may represent a longer but safer route.

g. An early fall frost will form a layer of ice on creeks or streams when the water level is high. Later, when the flowing water becomes lower and reaches its winter level, the top surface will again freeze so that there are two layers of ice. This is called shell ice or overflow ice and is not always safe.

h. Certain swampy areas do not freeze solidly during the coldest periods of winter. They are often covered with snow, hiding the water underneath and making the swamps an obstacle. Only experience and the knowledge that they exist in the local area, will prevent accidents. Suspected areas should be avoided and bypassed with no attempt made to cross.

i. Snowbanks beside plowed roads and tracks often provide excellent cover in wintertime. These banks or drifts will remain far into the spring thaw period, especially in areas of heavy snowfall.

j. The tracks left by tanks and oversnow vehicles in snow may provide routes of advance. Continuous traffic packs the snow and may allow movement on foot without skis or snowshoes. In the advance, infantry may utilize tracks left by their advancing armor.

k. In static situations the ski equipment becomes vulnerable to small arms fire and shell fragments. When troops are expected to remain in the same position for an extended period of time, skis, poles, and snowshoes should be placed in a covered position.

Section V. CAMOUFLAGE AND CONCEALMENT

6-16. General Considerations

a. In winter the whiteness of the countryside emphasizes any item which may not blend in naturally with the surroundings. Furthermore, every movement by vehicles or dismounted troops leaves tracks in the snow. Before every movement, consideration must be given to how these tracks can be kept to a minimum. Nature may assist by covering tracks with newly fallen snow or by providing a storm in which movement will be concealed. Camouflage and concealment from air observation is of the greatest concern.

b. In the northern landscape, backgrounds are not necessarily all white. Rocks, scrub bushes, and shadows make sharp contrast with the snow.

c. Snow-covered terrain in the wooded regions, when viewed from the air, reveals a surprising proportion of dark areas.

6-17. Vapor Clouds

Firing of weapons, vehicle exhausts, and breathing will, in extreme cold, cause local fog or vapor clouds which can be seen by the enemy even though the weapon, vehicle, or soldier is well concealed. Smoke from fires hangs immediately above and will disclose the position if there is no wind to blow it away. Under certain conditions, if the position is on a high point, smoke may flow downward into depressions and may be used as a deceptive measure. It may be necessary to move weapons frequently, shut off vehicle motors, or leave vehicles in rear areas. Conversely, deception or concealment might be gained by deliberately creating vapor fogs or clouds.

6-18. Sounds

The still, cold air of the North carries sound much farther than in temperate climates. All sounds must be kept to a minimum. Noise caused by motors, men coughing, and skiers breaking through snow crust may warn the enemy of activity at extreme distances.

6-19. Visibility

The long hours of daylight in the North during the summer allow for longer periods of aerial reconnaissance and increase the possibility of detection. The short hours of daylight during the winter months materially decrease the time available for reconnaissance. As an example, during the period 15 December to 15 January at 68� N. Lat. the sun will never appear over the horizon. Daylight will consist of only twilight and will last for only 4 or 5 hours.

6-20. Tracks

a. Tracks made in a soft surface may become quite firm if the temperature drops during the night, and will remain indefinitely as indications of movement. Special consideration must be given to the tracks in bivouacs and base camps. Number and size of trails must be kept to a minimum. All unnecessary "streets," turnaround loops, and parking areas must be avoided. Individuals may be forced to use only a certain trail. From the air, tracks, even through wooded areas, appear like a white scar. Coniferous branches can be laid in a staggered pattern on each side of the track as well as on it. Strict track discipline both during movement as well as in bivouacs and base camps must be maintained at all times.

b. Aerial photographs are closely examined and from them can be gathered a great deal of information. The depth of a track will show the amount and the direction of movement. Vehicle or sled tracks may indicate the type of vehicle and conclusions can be made as to the type of weapons. Every effort must be made to mislead the enemy. It may be advantageous to make more tracks or trails and show greater signs of strength. All marks made in the open are generally visible to the camera.

6-21. Camouflage Materials

a. White is the predominant color in winter and snow is the most important camouflage material, By intelligent use of camouflage clothing and equipment together with what nature makes available, effective individual and group camouflage can be achieved.

b. Improvised camouflage clothes can be made from sheeting, tape, whitewashed sacking, or painted canvas. White paper, when wet, can be applied and allowed to freeze on all kinds of surfaces. Snow thrown over the object helps to increase the camouflage effect.

c. White paint has many uses in winter camouflage. Weapons, vehicles, skis, and sleds can be effectively painted with white non-glossy paint.

d. On occasion, white smoke may be used to help the camouflage plan. The major problem is to make the installation blend in with the countryside.

e. Camouflage face paint, white and loam color combination, may be applied to exposed areas of the face and hands to blend effectively in with the snow cover.

6-22. Individual Camouflage and Concealment

a. During the summer the normal principles of using camouflage clothing will apply. However, as winter approaches, men must use partial white winter camouflage to match the changing conditions; men should be trained to avoid areas of local growth and dark outlines (fig. 6-26).

b. In fairly open forest areas during the winter, men wearing "whites" should avoid the dark background of trees. In the same manner, if wearing dark clothing, men should stay under trees and avoid the open.

c. In mixed surroundings frequent changes of camouflage clothing become necessary. The use of mixed clothing is often the most preferable (fig. 6-27).

d. All equipment worn on the outside should be camouflaged. Contrasting equipment worn on the camouflage suit will increase the possibility of enemy detection. Loose items such as grenades or fieldglasses should be kept concealed inside the suit.

6-23. Camouflaging Equipment

Skis, rifles, and sleds may be painted white prior to issue. If they are unpainted, white camouflage paint or improvised local materials can be used. Sleds will be issued with white covers for concealing the load. Finally, individual weapons can be camouflaged with strips of white garnish or white adhesive tape. The tape also provides protection for the hands when handling the weapon in extreme cold.

6-24. Camouflage and Concealment of Small Groups

a. In selecting a position, enemy ground and air observation must always be considered. A location which requires the least amount of modification is the most suitable, since there is less requirement for disturbing its "natural" appearance. The camouflaging of a position commences before occupation of the position. The most suitable covered approaches must be used and tracks, if not hidden, must be kept to a minimum. Where possible, approaches should be made under the concealment offered by trees or bushes, behind snowdrifts or slopes, and in shaded areas. Poor camouflage at this point may make position camouflaging ineffective. If tracks cannot be concealed, then tracks should lead through the position to one or more dummy positions. On occupation of a position, disturb its appearance as little as possible. Snow or earth removed from the position should be thrown to the enemy side. If the position is of snow or ice construction, it must be rounded off in order to avoid reflection and marked shadows. Overhead tarpaulins or camouflage nets should be used to cover any extensive digging in snow or earth.

b. In placing the individual and the weapon it is most important that he is not silhouetted or contrasted with his background. Low positions that Mend into the background is the secret.

c. If time allows, positions can be greatly improved by constructing an overhead cover of suitably camouflaged materials such as branches, nets, blankets, etc. (fig. 6-28).

d. The tent is one of the largest items to be camouflaged (fig. 6-29). Although large, by careful site selection using both artificial and natural camouflage material, it can be readily hidden. A decreased number of tents and stoves, due to tactical reasons, will automatically assist in keeping the bivouac area camouflaged. Occasionally, the camouflage of the tents in sparse vegetation, barren tundra, and especially under winter conditions becomes very difficult. Use white materials such as individual overwhites or snowblocks to protect the dark material from observation. In emergencies the white inside liner may be removed and placed on the top of the tent. Frequently all fires in the stoves as well as the open fires must be extinguished and the warming factor sacrificed for camouflage and safety reasons.

6-25. Camouflage of Vehicles

a. In winter all vehicles should be painted white to fit the predominantly white terrain. In forested areas it is relatively easy to darken a white vehicle with issued or improvised camouflage material. In areas with definite contrasts, for example in the wooded areas, or during breakup and freezeup periods, a mottled effect should be used. See FM 31-71.

b. In addition to the vehicle painting, each vehicle should be equipped with an all seasonal camouflage net to be used when required. Concealment will be more effective if vehicles are parked close to dark features or in shaded areas. Always try to break the silhouette and avoid vehicle shadows. Try to make it appear flat when observed from the ground or air.

c. In wooded areas lean-tos can be built to conceal vehicles. In a static situation a snow shelter can be constructed to provide cover and concealment.

d. In extreme cold consideration must be given to the exhaust from vehicles since it will form ice fog and provide the enemy with additional means of detection.

6-26. Deception

a. More opportunities for unit or individual deception exist in the North during winter than possibly in any other areas. However, deception measures are not sufficiently effective to lessen the requirement for good concealment. Unless unit and individual camouflage is effective, the value of any deception plan will be greatly reduced. Deception must be based on well-coordinated plans which must be logical and not too obvious. Dummy positions must be positioned to follow the tactical plan, but far enough removed from actual position so that fire directed at the dummy position will not endanger the real position (fig. 6-30).

b. A few skiers or oversnow vehicles can create a network of trails or tracks to mislead the enemy as to direction, strength, location, and intentions.

c. Regular pneumatic deception devices are inoperable and should not be used in temperatures below zero degrees. Improvised devices, however, can be made from snow, branches, canvas; and any other available material. Dummy weapons, positions, tents, and vehicles of all kinds can be constructed (fig. 6-31). They must not appear obvious but should appear camouflaged and only "discovered" as a result of a camouflage violation. A dummy bivouac area must appear to be occupied. Small gasoline or oil flames may be used to simulate stoves or idling engines. In a bivouac area the place must appear to look occupied; a fire or smoke could easily be used to produce this effect.

Section VI. MINES AND OBSTACLES

6-27. Use of Antitank Mines

a. Antitank mines must be placed on a solid base, otherwise when pressure is applied they will sink into the soft ground or snow and lose much of their effectiveness. In shallow snow a hole may be dug and the mine placed on the frozen ground. In deep snow they must be supported. Additional charges will help overcome the smothering effect of deep snow. The snow may be tamped down or frozen, or the mine may be placed on a plank or something similar to provide the required firm support (fig. 6-32). In all cases they must be covered with snow or dirt, but not buried too deeply; otherwise the top layer may accept the weight and not detonate the mine. A piece of cardboard over the mine will protect it from moisture which may freeze and hinder the working parts.

b. In snow-covered terrain, the mines should be painted white to aid in concealment. All minefield must be marked and recorded.

6-28. Antipersonnel Mines

a. Antipersonnel mines are adaptable to northern operations. If using pressure-type igniters, solid support for the mine is necessary. If mines are buried too deeply in snow it is possible that the snow will provide a "bridge" and prevent the mine from detonating. Therefore, when using the pressure-type igniters, place the mine about 3 cm (l") beneath the snow.

b. Tripwires should be placed at various levels above the snow when using pull-action igniters. Tripwires placed beneath the surface of the snow often freeze in and fail to function. Time permitting, tripwires should be painted white.

c. Mines can be placed on ski or snowshoe trails (fig. 6-33). Tripwire firing systems are the best when using antipersonnel mines in this manner. If pressure-type igniters are used, insure that the mine is placed in such a manner that the maximum weight of the individual will be brought to bear on the mine. Care should be taken to insure that the mine will not be "bridged" by a ski or snowshoe, and fail to detonate.

6-29. Use of Demolitions in Ice

a. In summer, the thousands of lakes, rivers and swamps of the northern regions provide formidable obstacles to armor and personnel. In winter, however, when frozen to sufficient depth, they provide excellent avenues of approach. They also lengthen the frontline of a given sector, requiring more troops and weapons to defend it than in summer. Necessary action must be taken to deny these natural routes to the enemy under winter conditions.

b. Preparing Ice Demolitions.

(1) In order to create water obstacles during winter conditions, explosives are used to blow gaps in lake and river ice to make it impassable to enemy personnel and armor. To install the demolition in ice (fig. 6-34), holes are sunk 3 meters (10') apart in staggered rows by use of axes, chisels, ice augers (fig. 6-35), steam point drilling equipment, or shaped charges. The shaped charges will not make a hole large enough to pass the charge through but must have the hole widened by other means. Charges are suspended in the water below the ice by means of cords tied to sticks bridging the tops of the holes. The charges should be of an explosive not affected by water. Plastic explosives should be protected from erosion by water currents. Demolitions laid early in the winter must be placed deep enough so that they will not be encased in the ice as it grows thicker.

(2) The normal thickness of fresh water ice is approximately 120 cm (4') or less. In extremely cold areas 150 cm (5') of ice is not uncommon. At the time the minefield is established, it is difficult to determine how thick the ice will be at the time the ice demolition is detonated. As a rule of thumb, if the ice is expected to be 120 cm (4') thick the charges should be approximately 10 pounds. In the event the depth of the ice is expected to exceed 120 cm (4'), an addition of 2.5 pounds per additional 30 cm (1') of thickness should be emplaced. Electrical firing devices are attached to three charges in each underwater demolition, one in each end charge and one in the middle charge. The rest of the charges may be primed with concussion detonators or electrically primed. The large number of charges does limit the use of electrical means of firing. An ice demolition may consist of several blocks of charges echeloned in width and depth and has at least two rows of mines, each row alternating with the one before it. Blowing a demolition such as this creates an obstacle for enemy armor and vehicles for approximately 24 hours at -24� F (FM 5-25). (3) Great care must be exercised when handling electrical firing devices under winter conditions. Because of improper grounding of an individual caused by the snow and ice covering on the ground, the static electricity that builds up might possible detonate the device. Individuals must insure that they are properly grounded prior to handling any type of electrical firing devices. Care should be taken to insure that no radio transmitters are operating in the immediate area. The type of radio signals emitted by this type of equipment can detonate electrical firing devices.

c. Advantages.

(1) Long sectors of the frontline may be cut off at a critical moment from enemy infantry and armor. (2) Number of personnel and AT weapons needed to defend a given sector is reduced. (3) Friendly troops may advance or withdraw at any place over the charges without being restricted to the cleared lanes. (4) Charges laid under thick ice are difficult, and often impossible, to detect by use of mine detectors. (5) When the holes over the charges have refrozen, the field is very difficult for the enemy to breach. (6) The charges are not affected by weather or snow conditions. (7) After a snowfall, detection of the demolitions by the enemy is extremely difficult.

d. Disadvantages.

(1) Emplacing the explosives requires considerable time even when ice cutting equipment is available. (2) The charges can be set off when hit by artillery fire. (3) The gaps blown in the ice tend to freeze over rapidly in low temperatures. (4) Continued exposure of the demolition firing system to weather reduces the reliability of the system.

e. Tactical Use. Ice demolitions are used for protection from frontal or flanking attacks. Normally, one or more sets of charges are laid close to the friendly shore and others farther out in the direction of the enemy (fig. 6-36). If desired, the enemy may be allowed to advance past the first set of charges and then both detonated at the same time. The enemy thus will be marooned on an ice floe, unable to continue to advance or retreat, and can be destroyed. The same trapping method may be used against enemy armor, or the charges may be detonated directly under the advancing tanks. Ice demolitions must be kept under observation and secured by friendly fire.

6-30. Natural Obstacles

a. Snow-Covered and Icy Slopes. A steep slope is an obstacle to troops and vehicles even under normal conditions. When covered by deep snow or ice, it becomes much harder to surmount. The bogging-down action and the loss of traction caused by deep snow frequently create obstacles out of slopes which might be easily overcome otherwise. Pads of track-laying vehicles should be removed when encountering this type terrain.

b. Windfalls. Occasionally, strong winds knock down many trees in a wooded area. These fallen trees are known as windfalls. They are very effective obstacles when covered with snow, especially to personnel wearing skis or snowshoes.

c. Lakes and Streams. Not all natural obstacles are equally effective in the winter as in the summer. Normally, bodies of water are considered natural obstacles, but under winter conditions the ice which forms may turn these former obstacles into excellent avenues of approach. This illustrates an important reason for reevaluating defensive positions before cold weather arrives.

d. Avalanches. An avalanche makes an excellent obstacle for blocking passes and roads. Since it occurs in mountainous country where there are few natural avenues of approach, an avalanche can have a far-reaching influence over combat operations. The problem with those avalanches which occur naturally is that, unless their timing and location are just right, they may be of help to the enemy. It is possible to predict in advance where an avalanche can and probably will occur. Then by the use of recoilless rifle or artillery fire, bombs, or explosives it is possible to induce the avalanche to slide at the desired time. This type avalanche is an artificial obstacle in the technical sense. Generally it will be of more value than the natural type. Precautions against avalanche hazard are covered in FM 31-72.

6-31. Artificial Obstacles

a. Barbed Wire. There are artificial obstacles used under many types of summer conditions which are appropriate for winter use. Barbed wire normally employed makes an effective obstacle in soft, shallow snow. Triple concertina is especially effective since it is easy to install in addition to being difficult to cross. As the snow becomes deeper and more compacted, a point is reached where it is possible to cross the barbed wire on top of the snow. One type of barbed wire obstacle built to overcome this problem is known as the Lapland fence (fig. 6-37). Types of wire entanglements and winter obstacles are covered in FM 5-15.

b. Lapland Fence. The Lapland fence uses a floating type of anchor point or one which is not sunk into the ground. Poles are used to form a tripod. The tripod is mounted on a triangular base of wood. Six strands of wire are strung along the enemy side of the fence, four strands along the friendly side, and four strands along the base. As the snow becomes deeper, the tripods are raised out of the snow with poles or by other means to rest the obstacle on top of newly fallen snow. The base of the tripod and the base wires give enough bearing surface to prevent the fence from sinking into the snow.

c. Abatis. An abatis is similar to a windfall. Trees are felled at an angle of about 45� to the enemy's direction of approach. The trees should be left attached to the stump to retard removal. Along trails, roads, and slopes, abatis can cause much trouble for skiers and vehicles.

d. Iced Road Grades. A useful obstacle can be made by pouring water on road grades. The ice that forms will seriously hamper vehicular traffic.

6-32. Means of Improving Obstacles After Heavy Snowfalls

a. Knife Rests. Knife rests are portable barbed wire fences, usually constructed prior to the snowfall. The fences are constructed by tying two wood poles at their center, forming an X. A similar X is made out of two other poles and then the two Xs are lashed at either end of a 3 meter (10') to 3.50 meter (12') pole. This forms a framework to which barbed wire is fastened on all four sides. The obstacle can be stored until needed and then easily transported to the desired location (fig. 6-38).

b. Concertina Wire. Concertina wire is another quick way to improve on snow-covered obstacles. The concertina comes in 15 meter (50') sections which can be quickly anchored to the top of existing obstacles.

c. Additional Barbed Wire. The possibility of using additional barbed wire strands should not be overlooked. Frequently, obstacles will have protruding poles to which extra barbed wire strands can be tied. Also, additional strands placed underneath such floating obstacles as Lapland fences and knife rests will help prevent the enemy from tunneling under these obstacles.