Jungle warfare

JUNGLE WARFARE

(NAVMC— 3131)

Published:—
For Instructional Purposes Only.

MARINE CORPS SCHOOLS

MARINE BARRACKS, QUANTTCO, VIRGINIA

1943

TABLE OF CONTENTS

CHAPTER I

GENERAL CONSIDERATIONS

Paragraph Page

Definition 1 1

Movement 2 1

Special Features 3 1

Training 4 2

CHAPTER II

INDIVIDUAL CONSIDERATIONS

Food

Sleeping

Clothing

Medical Care

Bathing

Snakes

Crocodiles

Wasps and Bees

Poisonous Insects

Leeches

Care of Small Arms

Expedients

•

CHAPTER III

JUNGLE DISEASES

SECTION 1

General 17

SECTION 2
DISEASES

Insect and Animal Borne Diseases

Water-Borne Diseases

Fungus Diseases

Snake Poisoning

5

3

6

3

7

4

8

4

9

5

10

5

11

5

12

5

13

5

14

6

15

6

16

6

18

10

19

11

20

11

21

11

i

CHAPTER IV
THE ARMS

Infantry

Field Artillery

Mechanized Units

Engineer and Pioneer Troops

Aviation

Parachute Troops

Paragraph

Page

22

13

23

14

24

15

25

15

26

15

27

16

CHAPTER V
SECURITY

General

Counter-Reconnaissance
Maintenance of the Initiative

Antiaircraft Security

Antimechanized Security

CHAPTER VI

MARCHES AND BIVOUAC

SECTION 1

MARCHES

28

17

29

17

30

17

31

18

32

18

33

19

34

19

35

20

36

20

General

March Instruction . .
Meeting an Ambush
Trail Cutting

SECTION 2
BIVOUAC

Requirements 37 22

CHAPTER VII

ATTACK AND DEFENSE

SECTION 1

ATTACK

Paragraph Page

Forms of Attack 38 25

Formation 39 25

Reserves 40 26

SECTION 2
DEFENSE

General 41 27

Discussion 42 27

Preparation 43 28

CHAPTER VIII

SPECIAL OPERATIONS

Patrols 44 31

Night Attacks 45 32

Ambushes 46 32

Attack and Defense of River Lines 47 33

CHAPTER IX

SIGNAL COMMUNICATION

General 48 35

Appendix I 37

CHAPTER I
GENERAL CONSIDERATIONS

1. Definition. — Jungle warfare will include all operations in
a region characterized by a high annual rate of rainfall result-
ing in heavy growths of vegetation which hinder vision, move-
ment, and fire. Jungle country may vary from the vast forests
of Malaya, Burma and the highlands of Africa to the scrub-cov-
ered low hills of East Africa, India and the Middle East. The
features common to these areas are: scarcity of roads and
railways; limited visibility for both ground and air forces;
and difficulties presented to cross country movement of all
troops and vehicles. Much of the typical jungle country is
broken by grassy open plains or sabanas where the vegetation
is sparse and visibility good. These plains usually exist on
ridges or upward toward the crest of mountains. The slopes
of grassy sabanas are often steep and become very slippery
when wet, making them difficult to ascend, particularly with
heavy weapons.

2. Movement. — The jungle, although not impenetrable, is
difficult to traverse. Movement through it is generally limited to
narrow trails which either already exist or which must be cut
by troops for the specific purpose. Old trails are usually in poor
condition and so winding as to make following a compass direc-
tion while moving on them extremely difficult. Large swampy
areas and streams are often numerous; bridges are usually
either non-existent or very poor. The high annual rate of rain-
fall will make most trails virtually impassable to motor vehicles
and armored mechanized units much of the time.

3. Special Features. — A distinctive type of combat is neces-
sary to surmount the difficulties presented by nature in jungle
warfare. The special features of the jungle must be exploited
to advantage by the use of tactics suited to the particular condi-
tions. Because of low visibility, poor means of communications
and the difficulties of movement and control, jungle warfare is
conducive to the efforts of small semi-independent, self-sustain-
ing units, able to operate efficiently on their own initiative under
their own commanders. Commanders must, therefore, develop
initiative and quick tactical perception. They must appreciate
the vital necessity of personal control. The normal system of
control through staff and signal communication facilities is
often too slow to meet the rapidly moving tactical situation;
therefore, all staffs must be highly trained and facilities for
signal communication be of such a nature as to permit a maxi-
mum of control by commanders under the most adverse con-
ditions.

a. When contact is imminent, commanders must be well
forward, ready at all times to evaluate the type of resistance

encountered and to seize the tactical initiative. The success
of any jungle operation will depend primarily upon the initia-
tive and training of individuals and small units. More than any
other type of combat, jungle fighting is a contest of indi-
viduals. When the fight has begun its outcome will be the
result largely of the degree of training received by the com-
mand to fit them for jungle combat. Instruction must be such
that subordinate commanders and men are made to understand
the conditions which may confront them when they approach
and close with the enemy in the jungle. Failure to prepare
troops thoroughly for actual conditions which will be encount-
ered in this type of combat will result in their being surprised
both mentally and physically. A standard of training must be
attained which will enable us to defeat the enemy under the
most adverse condition; that is, when he has superiority on
ground, sea and in the air. The difference between trained and
untrained troops in jungle warfare is so marked that, even
under such conditions, it will be possible to wrest the tactical
initiative from the enemy provided we are prepared for the
particular conditions imposed by the jungle and not surprised
by them.

4. Training. — A training program for troops who will take
part in jungle combat should include components designed to
develop the prime requisites of initiative, resourcefulness, con-
trol of small groups in the jungle, stalking, instantaneous reac-
tion in ambush, and aggressive action at all times. Special em-
phasis must be placed on night training in offensive and defen-
sive maneuvers as well as scouting and patrolling. A maximum
of the training time should be spent under field conditions in
the application of tactical principles necessary to success in
jungle combat for it is of the utmost importance that troops
be conditioned to withstand the extreme rigors which jungle
warfare imposes both physically and mentally.

a. All phases of training should be positive and direct,
with the ultimate purpose of developing teamwork and indi-
vidual initiative in all units. Collective and individual mobil-
ity, initiative, resourcefulness, self-sufficiency, the power to
endure and the desire to close with the enemy and kill should
be the attributes of all commands.

CHAPTER II
INDIVIDUAL CONSIDERATIONS

5. Food. — Jungle service will require that most foods be
ready to eat without cooking, and all food carried give the
maximum food value for the minimum weight. Dried foods
which are easily carried and have a high nutritive content are
desirable in such operations, because they are less likely to
spoil in a humid climate and are easily carried. Two pounds
per day of such dried foods as rice, dried beans, dried cooked
meats, dried fruits and vegetables, powdered milk, and coffee
essence give ample nutrition, vitamins, roughage, and volume
for prolonged hard marching. The C, K, and D Rations have
been found very satisfactory for operations in jungle country,
although it is not advisable to use the "D" ration in situations
where water is not plentiful because of the thirst this ration
will create.

a. It is essential that all men engaged in jungle opera-
tions have at least a rudimentary knowlege of cooking. Uten-
sils for this purpose need include only a light vessel for boiling,
such as the aluminum canteen cup, and a spoon. Most foods
obtainable in the jungle can be cooked over an open fire.

b. Clean food is essential. A lifelong disease such as
amoebic dysentery may be contracted from eating even the
smallest amount of unclean or contaminated food. Flies must
be kept away from all foodstuffs; leftovers should not be
eaten — food will spoil in a few hours in a tropical climate.
Wash and disinfect all eating vessels and utensils before and
after eating. A little chlorine or iodine solution will kill germs.
Whenever possible mess gear should be sun dried. Native
houses are one of the worst sources of disease and must be
avoided. Individuals should be cognizant of those edible foods
(berries, roots, fruits, etc.) which grow wild and are indigen-
ous to that area in which he is operating. Bananas, papaya,
taro, cabbage palm, pineapples, coconuts, and citrus fruits
will be found in practically every jungle country. Some of
the eatable kinds of meat found in the tropics are, wild
chicken, duck, pigeon, cattle, pigs, flying fox, fish, and fresh
water crawfish.

6. Sleeping. — Jungle conditions will require that all men
take special steps to insure adequate rest. The ground in the
jungle will often be too wet to permit the individual to sleep
comfortably without making some arrangements beforehand.
No man should sleep on the wet ground unless it is impossible
to do otherwise. To do so may seriously impair his combat
efficiency by depriving him of adequate rest, as well as making
him more susceptible to disease.

a. Branches laid together to form protection from the
wet ground may be used to advantage. When time and the
situation permit, a crude bed may be constructed by driving
four forked sticks into the ground to support a frame of two
inch poles. Across this frame thinner poles are lashed and
covered with light branches. The shelter tent and mosquito
net may then be pitched over this, or the mosquito netting
alone in dry weather. Hammocks may be improvised from a
shelter half or blankets hung between trees. It is important
that the mosquito net be used at night, for it is at this time
that many disease carrying insects are most active. The upper
part of the body should be warmly covered at night as the
tropical nights are often cool. A sleeveless sweater or flannel
shirt should be worn while sleeping.

7. Clothing. — In general, clothing items of cotton and can-
vas are most suited to conditions met in jungle combat. Cloth-
ing should be loose fitting, porous and highly resistant to saw
grass, thorns, brambles and insect pests. The light-weight
poncho, which serves a number of purposes, will be more satis-
factory than a raincoat. The helmet liner Ml has been found
more satisfactory than either the fiber tropical helmet or
the fatigue hat for jungle wear. A head net and gloves which
are mosquito proof are inseparable parts of each individual's
equipment. Shoes should be new when beginning jungle opera-
tions, and kept oiled to prevent wet rot. Lightweight canvas
and rubber shoes have been found useful for scouting.

8. Medical Care. — The individual will provide much of his
own medical care in jungle operations, therefore a knowledge
of first aid and the rules of personal hygiene is essential. In
addition to his issue First Aid Pack each man should carry,
easily available, a small bottle of iodine, adhesive tape, insect
repellent, salt tablets, and sulfa drugs in form of pills and
powder. These as well as atabrine or quinine should be avail-
able in every platoon headquarters, since jungle combat will
often call for the independent operations of small units. The
nature of jungle combat is such that small cuts and scratches
may result in serious infection. Each man must be careful to
keep such wounds clean and protect them from jungle filth
through his own initiative. The excessive sweating which re-
sults from heavy muscular exercise in the jungle will produce
a deficiency of fluid and salt (sodium chloride) in the body.
Thirst is created, and further intake of water will merely result
in additional loss of salt. To offset this all men must increase
their salt consumption during periods of heavy muscular exer-
tion, by using more salt on their food, drinking salt water, and
taking salt tablets. Usually 10 to 15 grains of salt per day
will be sufficient to maintain the salt balance of the body dur-
ing these periods. A criteria would be 10 grains of salt for
each canteen of water drunk.

9. Bathing. — One of the important functions of the skin
is to regulate the body temperature through perspiring, there-
fore it is important that all men exercise scrupulous personal
cleanliness while engaged in jungle operations in order to
permit the bodily cooling system to equalize the effects of
the heat. The skin also excretes waste through the pores and
frequent bathing will be necessary to keep these pores free
from oil and accumulated dirt and germs. The skin is the
individuals best weapon against disease and infection. It
actively works to prevent the ingress of germs into the blood
stream. It is, therefore, important that the best possible care
be taken of the skin by frequent bathing in warm or hot wa-
ter with a mlid germicidical soap. Caution should be exercised
that no water gets into the mouth. Sponges are breeding
grounds for germs and should never be used. Do not bathe in
jungle streams unless the water is approved by a medical
officer.

10. Snakes. — Although snakes of many varieties inhabit
most jungle countries, the snakes in the tropics are less dan-
gerous than those found in New Mexico or Florida, insofar
as the chances of being bitten is concerned. Many tropical
islands are completely free from snakes. Snakes will seldom
bite a man unless molested. All ordinary precautions should
be taken to avoid snakes and areas likely to be infested with
them. Particular care should be taken to avoid snakes when
clearing ground for a bivouac area, trails and fields of fire.

11. Crocodiles. — Crocodiles infest many tropical regions.
These reptiles will seldom attack a man, however caution
should be exercised when swimming in rivers and jungle lakes ,
that no crocodiles are present. When approaching or attempt-
ing to kill a crocodile care must be taken to avoid the powerful
sweep of its heavy tail with which it can easily break a
man's leg. The crocodile can move rapidly across country, but
is unable to change direction readily, therefore if pursued
by a crocodile it is best to change direction often.

12. Wasps and Bees. — Wasps and bees are abundant in
many jungle areas, but need not be feared since they will not
ordinarily attack unless their nests are disturbed. In some
localities a small bee known as the "sweat bee" will be found
which collects on exposed parts of the body in large numbers
during the dry season, especially if the individual is sweat-
ing. These bees will not sting and can easily be brushed off.

13. Poisonous Insects. — In the tropics large centipedes and
scorpions are found which can inflict painful, although not
deadly stings. These insects like dark places, and may be
found in blankets, clothing or shoes. Spiders of poisonous
variety may be found in some jungle areas and although
most of their bites are not serious, they are very painful.

Ants are a possible danger to injured personnel lying on the
ground and unable to move.

14. Leeches. — Leeches are common to most jungle areas.
They are found especially in swampy areas and streams of
most jungle country. Although not poisonous the bite of leeches
can cause infection if not cared for because the small wound
made by the leech may provide a point of entry for the organ-
isms which cause tropical ulcers or "jungle sores". All men
should be on the alert for leeches on the body and remove
them before they have a chance to bite. If they have taken
hold of the skin do not pull them off forcibly but make them
release their grip by touching them with a moist piece of
tobacco mixed with red pepper, or by touching them lightly
with the burning end of a cigarette or cigar.

15. Care of Small Arms. — Because of the high humidity in
jungle country, the individual must be especially careful of his
small arms. Unless all weapons are given scrupulous care and
attention with daily cleaning and oiling, rust will render them
unserviceable in a very short time. Each man is responsible
for the weapon issued to him and must be cautioned to keep it
ready for action.

a. Officers and non-commissioned officers must be alert
to see that all weapons in their command are kept in a state of
efficient readiness at all times.

16. Expedients. — Jungle conditions will require that the in-
dividual be especially adept at devising expedients to meet the
varied situations that will arise. Of the many methods and
devices that are most useful in the jungle, the following are
of especial value:

a. Carry matches in a completely waterproof container,
otherwise perspiration and the jungle humidity will soon ren-
der them useless.

b. Never go anywhere without a compass that you
know how to use.

c. A good pocket or sheath knife is essential in the
jungle as both a tool and a weapon.

d. A watch should be carried to help in estimating dis-
tance, direction, and to tell time.

e. Although running water is usually purer than still
water, all water should be boiled or chlorinated before being
drunk. Most mud and solids can be removed from water by
straining it through a cloth or filtering through sand. (Refer
to Marine Corps Schools Text, "First Aid and Field Sanita-
tion.") When on the trail, the use of 2 or 3 drops of iodine
per canteen is the easiest and most convenient method of
purifying water.

f. Cardboard containers are undesirable for use in
tropical climates because of the high humidity which will cause
them to disintegrate rapidly.

g. In many situations it will be advisable for men to
carry two canteens of water. At all times men must be care-
ful to observe water discipline and use their supply sparingly.

h. Keep your shirt on. Tropical sun contains a danger-
ously high percentage of nerve destroying infra red rays as
opposed to the health giving ultra-violet rays which predom-
inate in more temperate climates.

i. Many jungle vines can be used in place of string or
rope.

j. If you lose your matches or other fire making de-
vices, a magnifying glass or lens (including most spectacles)
may be used to start a fire by focusing the sun's rays.
By shredding the dry, fiberous lining of bamboo stalks, a
satisfactory tinder can be made. Dry leaves, grass, or the
bark of some trees can also be used. Another method of
starting a fire is by use of a cartridge. Eemove the bullet
from a cartridge; pour about half of the powder charge on
the tinder you have selected; plug the end of the cartridge
with an oily rag and fire upon the ground. This will usually
ignite the oily rag.

k. To prevent hookworm, never go barefoot in the
jungle.

1. When wounded or disabled move off the trail, out
of sight and call for help in a quiet voice. Trails are good
fields of fire — get off them when wounded.

m. To counteract the affects of early morning chill
of the jungle, eat a hot meal and drink a hot beverage in the
mornings whenever possible.

n. Sulphur taken internally or dusted in the socks
and underclothing will help repel redbugs or chiggers.

o. Edible fruits and herbs can usually be identified by
signs of animals having eaten them. Avoid eating unknown
fruits and plants except in dire emergency.

p. If lost in the jungle remember that by going down-
hill you will ultimately reach a stream ; by going down-stream
you will reach a larger body of water or inhabited valley. By
having a proper knowledge and training in woodcraft, and by
using your head you can travel and live in the jungle inde-
finitely.

CHAPTER III

JUNGLE DISEASES

SECTION 1

GENERAL

17. General. — The tropical jungle calls for many special
safeguards beyond those of a tactical nature. For example,
it is only through thorough training and correct precautionary
measures that the deleterious effect of jungle climates can be
minimized. Particular care must be taken against malaria,
dysentery, and other tropical diseases. These require rigid
training in, and adherence to, important sanitary principles.
Men who are not accustomed to the tropics — and even those
who are, including natives — are not capable of as much physi-
cal accomplishment in a given period of time as in more mod-
erate climates and less difficult terrain. Inhabitants of the
temperate zones, when transported to the tropics, require a
period of physical adjustment to the increased heat and humid-
ity and the greater power of the sun's rays before they can
undertake long periods of hard physical exertion without dis-
comfort and loss of efficiency. All these things a commander
must take into account in conducting his forces through the
rigors of a tropical campaign.

SECTION 2
DISEASES

18. Insect and Animal-Borne Diseases. — Insect and animal-
borne diseases are those in which the agent that causes the
disease is transmitted from man to man by a bloodsucking in-
sect or animal. The causal agent may be introduced into the
blood stream or tissues of man during the bite of the infected
insect, or it may be deposited upon the skin by the insect dur-
ing the process of biting or stinging. The irritation resulting
from the insect bite causes scratching and inoculation of the
wound with the infectious matter. It is necessary, therefore
for all troops to exercise every precautionary and preventive
measure in order to avoid infection. Some of the carriers of
these diseases which may be met in jungle operations are:

a. Mosquitoes. — (1) Type: Anopheles, Aedes, and
Culex. These mosquitoes transmit malaria, yellow fever, den-
gue fever, and nlariasis. To combat the menace of these dis-
eases to troops in the jungle, any collection of water should be
examined as a breeding place of the mosquito. In a stable situ-
ation it is essential that such breeding places be denied the
insect by drainage, use of oil, and by safeguards designed to
prevent the collection of stagnant pools of water in gutters,
containers, or low ground in the zone of operations. However,
since jungle warfare is largely one of movement, the control of
mosquito borne diseases will be based largely upon protection
of the men from bites by the use of netting, salves, repellents,
and inoculation.

b. Ticks. — Ticks transmit the following diseases: Re-
lapsing fever, Texas, Mexican, Central American, South Amer-
ican, and African types ; Sao Paula typhus ; South African tick
typhus; Indian tick typhus; Kenya tick typhus; and Fievre
butonneuse. Frequent inspection of exposed skin surfaces and
the prompt removal of ticks is essential in those jungle areas
where ticks are found. Care must be taken that the entire
tick is removed without leaving the mouth parts in the bite,
or squashing the tick in the process. The application of alcohol
or ether on the tick will cause it to relax its hold permitting
its safe removal. Antiseptic measures should be taken imme-
diately after the removal of the tick to prevent infection from
the wound. Native buildings and animals in tick infested
areas should be avoided. When native villages are to be oc-
cupied by troops it is usually best that the area be burned be-
fore its occupation.

c. Fleas. — The rat flea is the most common carrier of
bubonic plague, endemic typhus and other typhus-like diseases,
although the fleas of other rodents may also transmit these
diseases. Since rats are the usual host of fleas, the elimina-
tion of these rodents is the best preventive measure. Food

10

should be stored so that rats cannot get to it, and all garbage
should be burned. In camps, trapping and poisoning should be
resorted to as soon as rats appear. Native buildings should be
avoided or burned since they will often be overrun with rats.

d. Mites. — Mites transmit tropical, scrub, Malaya, and
Sumatra typhus. The use of repellents by the individual is
the only control measure. Among the effective repellents are
sulphur ointment, pine oil, and rotenone. Ten grains of flowers
of sulphur or powdered sulphur taken internally prior to enter-
ing the field each day will act as a repellent because of the hy-
drogen sulphide then excreted in the perspiration.

19. Water-Borne Diseases. — The principal diseases in this
group which occur in the tropics are amoebic dysentery, bacil-
lary dysentery, cholera, helminthic infection (worms), para-
typhoid fevers, protozoal dysenteries, typhoid fever, and un-
dulant fever. These diseases are usually transmitted by eating
or drinking contaminated food or water.

a. In the jungle, all perishables which cannot be stored
in a refrigerator below 40° F. should be cooked immediately
upon receipt, except that frozen meat should be cooked imme-
diately after thawing. All nonperishable foods should be
stored in vermin free boxes or chests. Every precaution must
be made to prevent contamination of foodstuff at all times.
It is essential that no water be drunk or used in cooking which
has not been properly treated to render it free of infectious
content.

20. Fungus Diseases. — Dhobie itch, athlete's foot, pinta, (a
fungus disease of the skin which is characterized by pigmented
patches) and trichosporosis, (a fungus disease of the hair)
are the principal fungus diseases.

a. These diseases may be avoided by personal cleanli-
ness. The body should be bathed as frequently as possible.
The armpits, groin, and feet should be given especial attention
and washed daily with soap and water. Foot powder used
under the arms, about the groin, and between the toes will
help prevent fungus disease. Socks should be washed daily, if
possible, in boiling water. At the first symptom of fungus in-
fection, prompt use should be made of the prescribed medicine
carried in the individual or group first aid kits. In the event
of excessive inflammation or itching, a medical officer should
be consulted as soon as possible. Frequent inspection of the
feet of the men should be made by the officers to insure early
treatment.

21. Snake Poisoning. — In many jungle areas poisonous
snakes will abound. Each man should be instructed in the
identification of such snakes as are likely to be met, and have
a knowledge of the prescribed methods of first aid for snake
bite. (Refer to Marine Corps text, "First Aid and Field Sani-
tation," Para. 37 a & b— FM 31-20, Para. 14.)

11

CHAPTER IV

THE ARMS

22. Infantry.— Infantry is the general purpose arm in jungle
warfare. The nature of jungle terrain is particularly suited
to the movement of lightly equipped troops armed with weap-
ons which can be brought into action immediately. A compro-
mise must be made between mobility and armament which will
result in a highly effective fighting force able to move with
stealth and speed to strike sharp, telling blows where the
enemy least expects it.

a. Combat will frequently resolve itself into a series of
personal encounters between individuals or small groups. For
this reason, every man must be trained in hand-to-hand fight-
ing and be proficient with the rifle, automatic weapons, bayo-
net, and knife. The entire command must be trained to
withstand protracted periods on limited rations and water
under strenuous field conditions. The arduous aspects of jun-
gle warfare will make it mandatory that all men so engaged
be in excellent physical condition.

b. Because of heavy undergrowth, obtaining optimum
fields of fire for the specific weapon employed is quite often im-
possible without extensive clearing of fire lanes. Along jungle
trails fifty yards is generally the longest field of fire that will
be available. On the other hand, excellent fields of fire may
be found on the open ridges often found in jungle country, or
along streams in the upper reaches wiiere they have a straight-
a-way run for some distance. Since most jungle combat will be
at extremely close range and practically all targets will be
those of opportunity only, light weapons capable of a heavy
fire power should be extensively employed. Instruction in
"snap shooting" should be stressed in the jungle training
program.

c. Scouting and patrolling must be emphasized in
training. Practice in quiet movement and observation in
heavily wooded areas will prevent casualties later from enemy
ambush. The jungle terrain is particularly suited to the em-
ployment of ambush; therefore troops should have a knowl-
edge of the most effective methods of ambushing the enemy
as well as an instantaneous, aggressive reaction to similar
activity on his part.

d. All units and individuals must be impressed with
the importance of maintaining all-around, continuous security
against attack from any direction. In terrain where move-
ment by the enemy is largely screened by the profuse vegeta-
tion, patrolling must be continuous to the front, flanks, and
rear.

13

e. In jungle operations the tactics and methods of the
early Indian fighter can be applied most effectively to infan-
try— stealth, cunning, deception are enhanced by the nature
of the jungle and should be employed to the utmost.

23. Field Artillery. — In relatively stable situations, field
artillery supports infantry in jungle operations much the
same as in operations in more open country by utilizing the
range and flexibility of its weapons. Its fire is particularly
effective in heavy woods or jungle due to the high percentage
of tree bursts against which overhead cover is necessary for
protection of personnel.

a. In moving situations, the availability of field artil-
lery will depend largely upon the existence of suitable roads
and trails. Roads must be available to move the motorized
equipment of the organic field artillery of the Marine Infantry
Division. Pack artillery can move over trails with the same
mobility as infantry supply elements. In continuous action,
the limited organic transport of Marine field artillery units
makes ammunition supply a major problem at distances
greater than five to eight miles from a base of supplies, in
which case additional transport is required.

b. The serious limitations to observation in the jungle
will require that forward observers operate with the most
forward infantry elements. In many situations it is desirable
to provide forward observers in larger numbers than the
tables of organization specify, in order to adequately cover
densely wooded terrain. Observers, liaison, and intelligence
personnel should participate in patrol activities in order to
thoroughly familiarize themselves with the zone of action.
Efficient intelligence work is invaluable, particularly in plac-
ing unobserved fires on enemy positions such as assembly
areas, bivouacs, command posts, supply installations, and
routes of communication and supply.

c. Efficient communication between artillery and in-
fantry units is of the utmost importance in all jungle opera-
tions. Limited visibility will require the extensive use of all
means of signal communication to maintain contact between
these arms and between batteries. It is important that suffi-
cient liaison personnel operate with regiments and smaller
units to enable supporting batteries to be brought into action
quickly when they are needed.

d. Due to the usual absence of definite lines and fixed
positions, and the inherent instability of jungle warfare, field
artillery positions must be such that wide zones of fire, some-
times as much as 360 degrees, can be covered. This involves the
use of additional emplacements to permit batteries to change
front, formations permitting all-around fire, and facilitate free
movement to nearby alternate positions. Clearings must be
available for battery positions. If no suitable clearings are

14

available they must be cut. Such cuttings must be concealed
by careful camouflage utilizing naturally growing vegetation
whenever possible since cut vegetation will wither rapidly in
the intense heat. Artillery positions must be closer together
in jungle country than in more open terrain in order to proper-
ly provide for local security against infiltrating enemy troops.
Although local security is coordinated with the general security
plan of the force in the normal manner, field artillery units
must rely less on the presence of other troops and more upon
integral security detachments from each battery.

24. Mechanized Units. — In heavily wooded jungle mechan-
ized units will have limited combat effectiveness, although
they can be used to advantage on beaches, grassy ridges and
other cleared terrain which will be found usually in jungle
country. Seldom will roads be found which will permit the pas-
sage of armored wheeled vehicles without some improvement.
When mechanized units constitute a part of a force operating
in jungle areas, pioneer troops should be attached to the mech-
anized elements to cut passage through jungle obstacles and
improve roads essential to the wheeled elements of the com-
mand. The abundant concealment offered to enemy tank de-
stroying units will require that all tanks operate with mutually
protecting infantry.

25. Engineer and Pioneer Troops. — It is essential that En-
gineer and Pioneer Troops accompany all jungle columns.
They will be used to construct bridges, prepare obstacles and
demolitions or clearing of obstacles, trail making and main-
tenance, water purification, and the construction of permanent
emplacements and defensive works. When air support is assist-
ing infantry, these troops will often be required to clear and
prepare landing fields and construct runways.

26. Aviation. — While conditions of observation will limit
somewhat the use of aviation in the jungle, this arm will be
an invaluable support to the operations of infantry. Aviation
will be used to strafe and bomb enemy positions, protect troops
from enemy air attack, naval bombardment, and observation,
as well as to conduct both close and distant reconnaissance
missions. Both land and carrier based planes are employed to
soften enemy shore defenses in the establishment of beach-
heads, and to cut off and destroy enemy supplies and rein-
forcements coming in by land or sea. As a vital factor in the
supply and evacuation of troops in the jungle aviation is becom-
ing increasingly important. Aviation is used advantageously to
transport troops, artillery and supplies when other methods
are either too slow or impossible because of the nature of the
terrain or enemy action.

a. Great care must be taken in the employment of
aviation on close support missions in the jungle. Unless there
is a natural boundary such as a river, edge of clearing, ridge

15

line, etc. to mark the lines, it is dangerous to request strafing
and bombing missions against enemy positions, since panels
will seldom be visible and planes cannot distinguish friend from
enemy.

27. Parachute Troops.- — Parachute troops are used effect-
ively to reinforce jungle columns, to carry out raids on enemy
supplies and installation in the rear, and to establish beach-
heads and bridge heads. Although these troops may land
with comparative safety in the jungle, it is usually preferable
that cleared ground be chosen for the landing to facilitate the
rapid assembly of troops in a minimum of time.

16

CHAPTER V
SECURITY

28. General. — In jungle operations the conventional idea of
the front and flanks must be discarded. Seldom, if ever, will
there be lines defining a "no man's land" between friendly and
enemy positions. Flanks can never be considered secure and
safe against encircling movements by the enemy. In such
regions as the jungle where covered routes of approach abound
and offer excellent opportunities for infiltration, security must
be maintained continuously by all units. Security will embrace
all measures taken by a command to protect itself from obser-
vation, surprise and annoyance by the enemy, and includes
also those necessary to obtain freedom of action for itself.
No matter how remote from the foremost troops a unit may
be, it is always in danger of observation and attack at any
time. Every officer and man must have his assigned post in
event of enemy attack. This applies to all headquarters and
supply installations as well as combat troops. Men must be
impressed with the importance of unceasing vigilance ; special
measures must be taken to minimize infiltration through our
lines.

29. Counter-Reconnaissance. — To overcome the liabilities of
the terrain, counter-reconnaissance measures must be ex-
tended to cover all possible routes of approach which offer con-
cealment to enemy patrols. By the use of wire and other
obstacles, booby traps and road or anti-personnel mines, the
movement of enemy groups toward our position can be canal-
ized to some extent. All obstacles must be covered by the
fire of automatic or antitank weapons. Outposts should be
numerous and supplemented by highly mobile patrols whose
mission it is to maintain contact between outposts, intercept
enemy infiltration and keep under surveillance the entire front,
flanks and rear of the position. Jungle outposts must be strong
and armed with a high percentage of light automatic weapons.
They should be well concealed for their best security lies in
denying the enemy knowledge of their location. Supplementary
positions should be prepared for occupation at night. Every
effort should be made to provide outposts with sufficient signal
communication equipment to enable them to maintain contact
with higher echelon at all times.

30. Maintenance of Initiative. — Maintenance of the initiative
is the best form of mental and physical security. The enemy is
then forced to conform to our movements and must hold his
troops in a position of readiness. Even when our mission is of
a defensive nature, the initiative can be denied the enemy by
utilizing the offensive in local and general counter-attack
against him.

17

31. Antiaircraft Security. — In a moving situation in jungle
operations, it will often be impossible for antiaircraft artillery
to keep up with the column; therefore all units will provide
for immediate protection against low flying attack aviation by
using their own weapons which are suitable for that purpose.
The concealment offered by jungle growth provides a great
degree of passive protection to troops against enemy aviation,
and it should be a general rule that all men will withhold fire
unless discovery is certain.

32. Antimechanized Security. — The limitations which jungle
terrain imposes on the operations of mechanized units will
simplify the details of antimechanized security. Approaches
such as roads, improved trails, stream-ford, etc., which lead
into positions along the outskirts of the jungle should be
blocked by antitank obstacles and mines which are covered
by fire. Individuals should be trained to make the maximum
use of the concealment which the jungle affords foot soldiers
in fighting tanks. This terrain favors the action of small
units utilizing explosives, "Molotov Cocktails", and other ex-
pedients for destroying tanks.

18

CHAPTER VI

MARCHES AND BIVOUAC

SECTION 1

MARCHES

33. General. — Marches in jungle operations will be affected
by the size of the unit involved, capacity and number of trails,
distance to be covered, season of the year, methods for supply
and evacuation and means of transportation. It is essential
that all movement in the jungle be planned carefully in advance
with these factors in mind. Route reconnaissance and a study
of maps and aerial photographs will enable the commander to
select routes offering the least physical resistance to his
troops. Native guides, when they are available and considered
reliable, will be of assistance to troops on cross country move-
ments.

34. March Instruction. — Before beginning a march in jungle
operations each man should know: the formation, what
action to take if attacked, and what to do when the objective
is reached. It is essential that every man who has a map
know the compass bearing to be used and the distances to be
marched on each bearing in order to arrive at the objective.
Since jungle combat requires a great measure of individual
initiative and independent action, the entire command should
be informed of the situation as it affects them in order to
insure concerted action by all units.

a. The formation to be adopted will depend largely on
the terrain. Limitations of visibility will usually require that
units adopt formations which are relatively vulnerable to
enemy fire in order to provide adequate control of the column.
Most movement will be on or astride roads and trails which
are, for the most part, cut through dense jungle growth. Such
being the case, troops will deploy only as much as practicable
to retain control and mobility. Whenever possible units should
be reinforced by attaching elements from weapons companies
to enable them to function as efficient combat teams in event
of sudden attack. To increase mobility, light machine guns
are preferable to heavy machine guns which may slow the
progress of the column. If it becomes necessary to move off
the trail the light machine guns can be more easily man-
handled than the heavy guns, and can accomplish the same
missions covering the march.

Commanders must be well forward with their units
where they can maintain control in any situation with no
loss of time. Trains are located centrally in the column, while
the rear should be protected by rifle units, reinforced with

19

machine guns guarding against attack from that direction.
(See Small Wars Manual; 1940.)

(1) Because heavy growth along trails will make
it difficult for flank patrols to keep up with the column, secur-
ity on the flanks will depend mainly on the vigilant and con-
stant observation of all members of the command. Flank
security units should be sent out to cover all lateral trails
until the column has cleared open areas should be reconnoitered
by scouts before the column is allowed to cross them. On
jungle trails men must be prevented from bunching up. It
is especially important that the point be well dispersed in
length to the limit of visibility in order to prevent multiple
casualties from a sudden burst of fire along the trail, pre-
serve the point as a fighting unit in case of attack, and confuse
an enemy which habitually holds its fire until the point has
passed.

35. Meeting an Ambush. — The best preparation against the
disorganization and demoralization of troops who may be
ambushed is to prepare them mentally for the shock of an
ambush. They must be steeled to withstand a sudden blast
of fire at close quarters and to react to it in a manner which
will unnerve the enemy. To accomplish this troops must have
a thorough understanding of what is likely to happen when
ambushed and be trained to react aggressively and positively
to meet the situation.

a. To assure coordinated action within each unit, prior
to the march subordinate elements should be assigned sectors
or areas of responsibility. When fired upon, troops at once
hit the ground and crawl or roll to cover, and each subordinate
unit faces the sector for which it is responsible. The fire will
be returned immediately by all men who have located a target
within their area of responsibility. Leaders will gain control
of their units and commence to put into effect the prear-
ranged scheme of maneuver which the situation indicates.
This scheme of maneuver will cover supply trains, automatic
and supporting weapons, and rifle units ; it will determine the
manner in which the maneuver group will be selected. That
unit which is the best position to disengage itself from the
fire fight and move into a position from which the ambush
can be outflanked should do so of its own initiative, and attack
aggressively under the covering fire of other elements of the
column.

36. Trail Cutting. — In many cases it will be necessary for
jungle columns to cut new trails to accomplish their mission.
Trail cutting is done by teams with a leading cutter charged
with direction on an azimuth or previously determined direc-
tion followed by a second cutter who widens to the right, a
third who widens to the left, and so on depending on the

20

number of cutters and the width of the trail desired. Map
reconnaissance to determine the best and quickest route
should be made previous to beginning the march. Selection
of the route will be determined largely by the ease with
which the trail can be cut. Slight detours will often save time,
while zig-zagging trails up steep inclines will be easier to
traverse than a straight trail. Frequent rotation of cutters
within each small unit or detail will speed the cutting of the
trail and bring relief to the cutters. (See Appendix I for rate
of trail breaking and clearing.)

21

SECTION 2

BIVOUAC

37. Requirements. — Three essential requirements of a biv-
ouac area to be occupied by troops on the march are: that
it be a good natural defensive position where the security of
troops can be maintained, especially during the hours of
darkness and dawn; that it facilitate the distribution of sup-
plies ; that it serve as an initial point for the next days opera-
tions. Patrols which precede the main column should select
and reconnoiter the bivouac area, lay it out and partly clear
it, if possible, before troops move in.

a. The bivouac should be selected primarily for its
value as a defensive position. The ideal area will be close to
a water supply and on high, well drained ground which pro-
vides ample overhead concealment to troops from enemy
aviation, and is surrounded by wide cleared spaces offering
favorable fields of fire for rifles and automatic weapons. When
no overhead cover exists, troops should move into the bivouac
after dark.

Since optimum fields of fire will seldom be found in the
jungle, the clearing of fire lanes should have a high priority
in the establishment of the camp site.

b. The bivouac defense must be planned to give all
around protection to the troops which will occupy that area.
Machine guns and automatic weapons sited on the perimeter
of the area will provide close-in protection. The fire of these
weapons should be as mutually supporting as possible. This
will require extensive clearing of fire lanes placed to enfilade
an attacking enemy. Riflemen and automatic riflemen should
be spotted to protect those areas unable to be covered by
machine guns. Beyond this band of defensive fires will be
an outpost composed of small listening posts and observation
posts supplemented by highly mobile patrols. Extensive patrol
activity is necessary to protect the small isolated posts, and
may serve to mislead the enemy as to our disposition. The
use of night patrols will call for highly trained personnel and
definite plans of action. The patrol plans should be known
by all friendly troops, otherwise there is danger of troops
firing upon their own patrols, or letting infiltrating groups
of the enemy pass through the lines believing them to be a
friendly patrol.

The intervening area between the outpost line and auto-
matic weapons should be organized with booby traps, trip
wires, flare disks and similar devices designed to protect and
warn troops against enemy infiltration. It is imperative that
all bivouacs be organized in depth with a highly mobile, central
reserve held ready in case of enemy break-through. To facili-
tate organization and control, the bivouac should be divided

22

into compartments which are allotted down to the squad.
Within the bivouac area a minimum of movement should be
allowed. Strict care must be exercised to see that no men
make unnecessary noise or use lights of any kind.

c. All troops must dig slit trenches or individual fox-
holes as protection against enemy mortar, artillery, and rifle
fire. Troops on the perimeter should be liberally supplied with
hand grenades which are especially effective for dispelling
night attacks. In event of an attack only volley firing, con-
trolled by responsible leaders, should be allowed. Every pre-
caution must be taken to prevent indiscriminate firing for
this will result in the premature disclosure of our positions,
waste of ammunition and possible casualties among friendly
troops. All men must be trained to hold their fire until they
are reasonably sure of their target, refusing to be duped by
enemy diversions designed to force them into disclosing their
position.

23

CHAPTER VII

ATTACK AND DEFENSE

SECTION 1

ATTACK

38. Forms of Attack. — Jungle terrain lends itself favorably
to the two main tactical maneuvers : envelopment and the pene-
tration.

a. The penetration is particularly suitable for use
against an enemy position which aims at attaining width and
security of flanks by the sacrifice of depth. This attack must
be made on a narrow front with one or more spearheads
driving in to a given objective. When used in conjunction with
infiltration the penetration can achieve the best results.
Lightly equipped troops infiltrating in advance of as well as to
the flanks of the main attack create and exploit weak points
in the enemy lines, permitting the main effort to drive into the
breach thus developed.

b. Because operations in the dense jungle present an
almost impossible task in locating exactly the enemy flanks,
enveloping actions should be habitually wide with the mission
of driving past the flanks to hit him deep in his own territory.
The envelopment, to be successful, must be made quickly by
highly trained troops capable of rapid movement across coun-
try, and able to sustain themselves for long periods on limited
supplies. This force should avoid contact and interference with
enemy patrols during the approach march as this will entail
loss of speed, surprise, and minimize control. The envelopment
in depth, characterized by separate columns fanning out and
encircling the enemy's rear to strike a succession of blows deep
in his territory, is especially effective in jungle combat. The
presence of navigable streams or open water areas on the en-
emy flanks may provide a favorable avenue of approach for
the enveloping forces if water transport is feasible.

39. Formation. — The formation for the attack will, of neces-
sity, be one which permits the maximum of control and main-
tenance of direction as well as security and the ability to deploy
rapidly. Such requirements will usually necessitate a compact
column formation, or where trails are available, a series of
parallel columns. Supporting weapons should be so distributed
that smaller units will be efficient, independent fighting teams,
ready and able to attack with a minimum of delay. When close
to the enemy, trails parallel to the axis of advance should be
used to widen the front of the attack as well as provide flank
security for the attacking force. In light jungle it is generally
better to cut new trails when in proximity to the enemy to

25

permit a partial deployment of the attacking force. It is
essential that in this stage of the attack that the plan of
attack be understood by all members of the command. Each
subordinate unit must have its own definite assigned objectives
at which they will reorganize and advance on orders or accord-
ing to plan. Such objectives will ordinarily be more limited
and closer together in jungle warfare than in other types of
combat.

b. Further deployment of the separated columns
should not be made until contact with the enemy has re-
sulted. At this time units must complete the deployment
quickly and attack aggressively. To gain the initiative it is
essential that the initial action be pusned vigorously to deny
the enemy time to recover and counterattack. Full use
should be made of all supporting weapons before and during
the attack. Troops should be alert to take advantage of the
time interval after the supporting fires have lifted to press the
attack against the enemy.

40. Reserves. — Great care must be exercised when an objec-
tive has been taken that all the enemy pockets are wiped out.
It will be comparatively easy for numbers of the enemy to lie
undetected until the attack has passed by unless positive meas-
ures for their elimination are taken by the reserve following
closely behind the attacking echelon. Reserves must follow the
assault echelon closely and in a condition of readiness to be com-
mitted at any moment after the attack begins. For this reason
it is necessary that the commanders of reserve units be familiar
with the ground and progress of the attack at all times so that
they will require a minimum of time for reconnaissance and
the issuance of orders when the reserve is needed.

26

SECTION 2
DEFENSE

41. General. — Static defensive tactics are not favored in
jungle warfare since the factors by which jungle operations
differ from other operations will greatly limit the use of those
defensive tactics that rely on mutually supporting terrain fea-
tures held by relatively few men, supported by machine guns
and other automatic weapons of great fire power. Seldom will
such mutually supporting localities be found in the jungle, and
the use of automatic weapons on final protective lines is greatly
restricted. Concealed avenues of approach, on the other hand,
will abound, making conditions for the attack ideal. The flanks
of a defensive force can be kept under observation only with
great difficulty; they can never be considered secure. Wide
streams, or areas of open water on one or both flanks of a posi-
tion should not lead to a false sense of security. It must be
expected that an alert, agressive enemy will employ water-
borne troops to outflank or encircle the position. Not only
must the commander assure positive observation means, both
ground and air, to warn of such attack, he must also be pre-
pared to meet and destroy such attempts by the enemy.

a. When conditions make it impossible to seize the
initiative at once, units may be forced to take up defensive
positions, or in the course of offensive operations it may be
necessary to pause and consolidate a position while communi-
cations are improved and supplies replenished. It must be ap-
preciated at this time, however, that the defense will fail if it
remains static. A successful defense in jungle combat must be
offensive in spirit, utilizing combat patrols, local offensive
actions, counterattacks, and the constant improvement of
position. Secrecy must be utilized to the utmost by the de-
fender through skillful use of camouflage, concealment of the
location of reserves, frequent shifting of gun emplacements,
and active counter-reconnaissance measures.

42. Discussion. — Jungle defense is all around defense. From
the highest to the lowest, units must provide for all-round de-
fense of their positions. Where cover and concealment abound
in such profusion as in the jungle, an aggressive enemy may be
expected to hit from any direction. It will be virtually impos-
sible to prevent the infiltration of small enemy units ; therefore
troops must be prepared at all times to meet him in unexpected
places. A defensive position in the jungle must be as closely
knit as the terrain dictates. In particularly heavy jungle coun-
try, this may call for a "shoulder-to-shoulder" disposition of
the defending troops. Other terrain may be adequately de-
fended by troops posted to defend points which block avenues
of approach, tied together by highly mobile patrols designed to
maintain contact between units as well as guard against an

27

enemy break-through along less likely routes to the position.
To achieve any degree of success all jungle defense must be
organized in depth. Positions must be backed by deep, highly
mobile, numerous, local reserves, with a general reserve of
sufficient strength and maneuverability to move rapidly and
counter an enemy break-through at any point on the peri-
meter. The exact location of the local reserves is dictated by
their mission: to support the forward defense areas by fire;
to make local counterattacks to eject an enemy who has en-
tered the forward defense areas; to prevent further advance
by the hostile force. When an attack by the enemy has been
successfully repulsed, mopping up parties should be sent out
to comb the position for any enemy which may have remained
in hiding on or near the position.

43. Preparation. — In the preparation of a defensive position
in the jungle, extensive fields of fire must be cleared to increase
the effectiveness of the defending weapons. Insofar as possible,
lanes should be cut which will place attacking enemy ranks
under enfilade fire by automatic weapons. When cutting these
lanes the bottom branches of trees, and low vines and under-
growth should be cut leaving the upper branches to prevent
hostile ground and aerial observation of this part of the defen-
sive scheme. Barbed wire double apron fences and protective
wire should be used extensively on the front, flanks and rear of
the position. Devices such as tin cans filled with small stones,
booby traps, etc., should be placed along the wire to warn of any
enemy interference. The use of the Concertina is recom-
mended because of the heavy gage wire which makes cutting
difficult. By the extensive use of wire and other obstacles,
covered by fire, the enemy will be forced somewhat to conform
to our defensive position, and thus relinquish some of the
initiative he holds as the attacker.

a. All men must dig in. The slit trench and the stand-
ing type foxhole with an overhead covering which offers pro-
tection from grenades have been found most suitable for jungle
combat. When the situation permits, all troops should dig
supplementary and alternate positions to guard against attack
from any direction. In many cases it will be expedient to
prepare night positions to the rear of that position occupied
during the day. This will confuse the enemy and make recon-
naissance preparatory to an attack difficult. Riflemen should
be situated in trees or well concealed foxholes to intercept any
enemy attempt to infiltrate into our positions for the purposes
of destroying automatic weapons. All positions should be care-
fully camouflaged, utilizing the abundant materials easily ob-
tainable in the jungle. Whenever possible live vegetation
should be used in preference to cut vegetation which will
wither rapidly in the jungle climate. Artificial means of
camouflage colored green with a high content of yellow to
blend with the jungle will be satisfactory when natural means
of camouflage are not practical.

28

b. Because of the extensive clearing which must be
done in the preparation of fields of fire, the normal engineer-
ing tools provided for a force preparing a defensive position
should be augmented by axes sufficient to provide at least 25
percent of the command. Each jungle soldier should be
equipped with a machete. A soldier trained in the use of the
machete and axe can, with these two tools, completely clear
100 square yards of trail or about 200 square yards of fire
lane in five hours. (See Appendix I.)

c. Security detachments should be placed along all
avenues of approach to the defensive position to observe and
delay a hostile approach. Patrolling must be active both
along the approaches and between security detachments, since
the characteristics of jungle terrain permit easy capture or
destruction of isolated forward elements. These security ele-
ments should vigorously oppose an advancing enemy, denying
him the use of trails or other routes of approach, forcing him
to deploy prematurely, and inflicting as many casualties as
possible.

29

CHAPTER VIII

SPECIAL OPERATIONS

44. Patrols. — In jungle combat the security and effective-
ness of both the defender and attacker will depend largely on
the activity of their patrols. Patrols have three paramount
missions: to deny the enemy access to certain terrain; to se-
cure information; and to harass the enemy.

a. The security patrol will operate to intercept, delay
or break up the enemy movements which threaten the front,
flanks or rear of the main force. These patrols must be main-
tained continuously and must be aggressive, mobile units if
the initiative is to be gained or retained.

b. Reconnaissance patrols will function in the jungle
in much the same manner as in other operations. Since events
move so rapidly under jungle conditions, special means for sig-
nal communication must be employed to enable the commander
to act on information received. The use of the portable radio,
pyrotechnics, flags, etc., depending on the particular situation
will greatly increase the effectiveness of the reconnaissance
patrol.

c. The combat patrol operates with the mission of
harassing the enemy by operations against his lines of com-
munication, supply installations, flanks and rear. These oper-
ations delivered with speed and pushed aggressively serve to
demoralize the enemy, weaken his will to resist and deplete
his forces. Jungle terrain makes the efforts of combat patrols
especially valuable, enabling small, lightly equipped patrols to
move rapidly around the enemy flanks or through his lines, to
strike punishing blows where he least expects it. The strength
and composition of the combat patrol will be dictated by the
mission assigned and the terrain. The size usually will ap-
proximate at least one platoon, equipped with a high percen-
tage of light, automatic weapons capable of delivering heavy
fire. Formations for the combat patrol are based upon concen-
tration and all around security. The leader must be able at all
times to insure the quick and coordinated action of all his men
and to meet an attack from any direction.

(1) Orders must be based upon the greatest pos-
sible advance information. They must contain much detail
and at the same time must provide for independent emergency
action by small groups if the necessity for such action arises.
It is imperative that members of the patrol have all available
information in advance regarding the mission, the route both
to and from the objective and any rendezvous which may be
prescribed. The tactics of the combat patrol are based upon
surprise. It will move with stealth and take all measures
necessary to preserve the secrecy of its movements.

31

(2) In jungle combat- there should be little dis-
tinction made between "combat" and "reconnaissance" patrols.
To restrict a patrol leader to pure reconnaissance (except in
isolated instances)" is to hamper seriously and even endanger
that patrol. Jungle patrols must be aggressive when the
situation demands; it is often their only means of defense. A
patrol should always seek information, but likewise, it should
seek to cause as much discomfort to the enemy as possible.

(3) Unit leaders should be alert to observe those
men in their command who show a natural inclination toward
scouting and patrolling. These men usually will be those who
have grown up in country surroundings, are used to hard-
ships, and clever in woodcraft. Thorough preparation of the
entire command in patrolling is a prime requisite for all jungle
combat. A high percentage of patrol training should be under-
taken at night with stress placed on silence in moving through
heavily wooded terrain, swift marches under the most dif-
ficult conditions and operating over long periods of time on
limited rations and supplies. All patrol members as well as
all combatants in jungle operations must be impressed with
the importance of patience under the most adverse conditions.
When the natives of the particular theater of operations are
known to be friendly, every opportunity should be made to
use their knowledge of the terrain by our patrols.

45. Night Attacks. — The factors which make a night attack
difficult in normal operations are accentuated in jungle combat.
Vision, control, coordination and secrecy are much more dif-
ficult to attain in the closed, heavily wooded terrain present in
jungle combat than on more open terrain. Night will increase
the difficulties so much that such operations will be of limited
value in most jungles. Night attacks will be made by smaller
units operating over terrain through which selected routes
have been reconnoitered. Trails, streambeds or similar fea-
tures easily identifiable and followed at night should be em-
ployed. Extra time must be allowed for the delay of columns
caused by the increased lack of vision and the obstacles to con-
trol and maintenance of direction which the jungle imposes.

46. Ambushes. — In the jungle where concealment is easily
obtained and where movement is closely restricted, ambushes
may be employed with good effect in either defensive or offen-
sive operations. A correctly organized ambush must take sev-
eral factors in consideration: Location, concealment, depth,
field of fire and route of withdrawal.

a. The location of the ambush will be determined by
exacting reconnaissance of enemy supply routes, trails, etc.,
as well as an appreciation of the terrain, in order to choose a
location which will provide the most profitable targets to the
ambushing group. Suggested ambush locations are twisting
trails, water points, enemy defensive positions occupied only
when the area defended is threatened, supply routes used by

32

carriers and jungle stream trails. In any of these locations it
is often possible to ambush large enemy parties, patrols, or
supply convoys.

b. Concealment is highly necessary in ambush opera-
tions as any suspicious appearance will foil all ambush
attempts against an alert enemy. Strict measures must
be taken to prevent men from littering the area of the
ambush with cigarette butts, paper scraps, ration tins, foot-
prints and bruised and broken vegetation. All members of
the ambush party must be trained in camouflage discipline
and patience, for a high degree of both will be required in a
successful ambush.

c. By depth of ambush is meant the distance which
the enemy must penetrate into the ambush position before
his leading elements pass out of the line of fire. This depth
will depend upon the size and formation of the enemy party
that is to be trapped. When the enemy is fully in position,
there must be fire both in front and behind him to prevent
his escape in either direction.

d. It is seldom possible to place weapons in an ambush
so as to make use of the optimum field of fire for each. Every
effort should be made to bring point blank fire to bear on the
enemy if possible. In this way the fire itself will be extremely
effective and the attendant roar of weapons will add to the
confusion of the enemy making his capitulation or annihilation
more probable.

e. Careful consideration must be given to the route of
withdrawal to be employed by members directly after the am-
bush. The threat of enemy reprisal in force makes it manda-
tory that one or more favorable routes of withdrawal be desig-
nated to a previously determined assembly point. Provisions
should be made for the order of withdrawal to provide a cover-
ing force whose mission it is to protect the orderly withdrawal
of troops to the assembly point.

47. Attack and Defense of River Lines. — The general doc-
trines of attack and defense of river lines are discussed in
Marine Corps Schools text, River Crossings, and FM 100-5.
Jungle conditions will usually modify the tactical application
of these doctrines as follows :

a. Attack. — Because of the difficulty which will be en-
countered in cutting numerous trails to the riverbank, with a
resultant loss of time and surprise, most attacks on a river
line will be on a narrow front. Reliance must be made on
speed, surprise and firepower. Feints will be practical only
on a more limited front but should not be omitted for that
reason, because concealment afforded by the jungle can often
be used to get small groups across secretly, and the confusion
and uncertainty that small harassing groups can cause may

be of decisive importance in assisting the crossing of the main
effort.

(1) Much of the material for bridging and ferry-
ing may be obtained locally in the jungle. Seldom will it be
possible for ponton trains and other engineering equipment
to accompany the column. Reliance should be made on stream
crossing expedients for the initial stages of the attack.

(2) Usually the supporting fire of light automatic
weapons only will be available. These must be placed along
the near bank itself to obtain observation. Weapons will
usually have to be manhandled into position through the jungle
and time for such movements must be allowed unless the at-
tacker relies solely on the surprise of a quick rush from the
point where his trail meets the stream, supported only by the
fire of such weapons as can be quickly emplaced near the trail.

b. Defense. — (1) In jungle warfare the main line of
resistance will often be placed along the riverbank since —

(a) The jungle and usual lack of trails,
roads and other routes of movement are deterrents to rapid
counterattack or movement of rearward reserves; therefore,
it is undesirable to permit the enemy to gain a foothold on
the defender's side of the river.

(b) Positions for supporting weapons ordi-
narily can be found only on or close to the river bank itself.

(2) Suitable areas for crossings by the main at-
tack forces ordinarily will be fewer in number than in more
temperate climates and more thickly populated areas. How-
ever, the advantages of concealment and cover favor the cross-
ing of small groups at any point.

(3) The defender must provide protection for his
flanks and rear. The ease with which small, highly trained
groups can cross and operate stealthily in the jungle area to
harass troops and damage or destroy installations requires that
special measures be taken to protect against such hostile ele-
ments.

34

CHAPTER IX

SIGNAL COMMUNICATION

48. General. — The characteristics of jungle warfare will
tend to increase the importance and use of signal communica-
tion. Since the transmission of orders and enemy information
is vitally important, means of communication should be in-
creased above the normal allotments to units. Reliance should
not be made on any one means of communication, for coordi-
nated action by troops in jungle combat will require that
communication facilities operate at all times.

a. The care of signal equipment is of great importance,
especially in the rainy season. Prior to beginning jungle opera-
tions, every possible measure should be taken to dry out and
protect equipment. Electrical equipment requires special care.
If waterproof covers for electrical instruments are not issued,
they should be made from salvage material such as raincoats
and tentage. Signal equipment should never be placed on the
ground. All pack animals carrying signal equipment must be
led by hand. Frequent inspections should be made to determine
that the equipment is traveling securely. Frequent testing and
examination of all equipment should be made whenever time
and the situation permit.

b. Work at the message center must be done under
adverse conditions in the jungle. All message center personnel
must be trained to work with headnet and gloves. Due to the
heat it is seldom practical to use closed tentage. All lights
must be adequately shaded or concealed to prevent hostile
observation. The jungle offers abundant material for the cam-
ouflage of message centers which should be utilized extensively
to preserve the secrecy of its location. All message centers
must take special measures to provide their own security. An
alert enemy will infiltrate to command posts by following sig-
nal communication wire, therefore care must be taken by the
message center and adequate security be posted to prevent
hostile infiltration.

c. The messenger is the primary and most reliable
means of signal communication in jungle warfare. They should
be carefully selected men, with a high degree of intelligence,
courage and aggressiveness. Their training should include in-
struction in jungle lore, trail knowledge and the use of the
marching compass. All messengers must be kept familiar with
the location of adjacent units. In many cases under severe
jungle conditions it will be necessary to employ messengers
in pairs. As added security it will be best to send identical
messages by different messengers traveling by different routes.

d. Although visual means of signalling will be of little
value in the jungle itself, when sufficient open space or high

35

ground exists these means may be employed to advantage.
Pyrotechnics will be less reliable in the jungle because of the
humidity, therefore their use should be supplemented by other
signalling devices whenever possible.

e. Atmospheric conditions and jungle growth will limit
the range of radio. Light portable radio sets employing hand
generators and fishing pole antennae are necessary. Because of
their weight and bulk, the use of large and more powerful sets
will be confined mainly to areas immediately adjacent to trails
and to rear areas. Continuous-wave signals provide greater
range and are preferable therefore to voice or tone modulated
signals.

f . It will often be impossible for wire communications
to keep up with troops in the attack. In the defense, however,
wire communication is indispensable, and should be laid to
connect all echelons in such a way that constant contact is
maintained between units. Wire will often be threatened by
small infiltrating groups, therefore whenever time and the
situation permit all wire must be concealed. Dummy wire and
booby traps may be used against infiltration to mislead and
destroy the enemy. Exposed wire will not only give away the
location of our message centers and command posts, but will
enable the enemy to tap the wires with a resultant loss of
secrecy.

g. Passwords, signs and countersigns should be used
extensively and changed often in jungle combat. The words
chosen should be those difficult for the enemy to pronounce
and used only when other means of identification are imprac-
tical. Since the Japanese mispronounce certain groupings of
English letters, words employing any two or all of these letters
will certainly be mispronounced. The following short table in-
dicates the manner in which the Japanese would pronounce
certain groupings of English letters ; note that they substitute
"r" for "1", "su" or "za" for "th", and "b" for V:

English Letters Japanese Phonetic

Pronounciation

La Rah (soft "r")

Ly Rye (soft "r")

Th Su (soft "s" as "soft")

The Za or Zeh

Very Bedy ("y" like double

"e" in "see")

Velvet Berubet

h. Challenging at night should be done skillfully. The
challenger must remain unseen in the shadows of a tree or
building. He should challenge "Halt, who goes there?" and
closely survey the party before allowing him to proceed. He
should not permit the party to come within knife range. If

36

the party is recognized sufficiently he should be permitted to
carry on. The password should not be used unless more posi-
tive "identification is necessary, and then should be spoken only
in a whisper.

JUNGLE WARFARE

APPENDIX I

STAFF DATA FOR JUNGLE WARFARE

dumber

1

Area

of meu

Distance

Width

(square

(1

(yards) ' (yards)

yards)

Hours

Tools

scjnad)

Trail breaking . .

12

3,000

%

2,000

3-6

Machetes.

Trail clearing . .

12

1,000

1

1,000

12

Machetes, axes.

Bridge building

!

(animal) .

12

6

3

18

4

Do.

Corduroying, cut-

!

ting and placing.

12

100

3

300

12

Do.

Area clearing . .

12

1,000

1

1,000

12

Do.

Trail blocking . . .

12

Time for felling

trees

Do.e

Road building,

dirt, passable

12

50

3

150

12

Machetes, axes,

for 1 vehicle.

',

shovels, picks.

Fire lane cutting

12

1,000

2

2,000

18

Machetes, axes.

Tree felling

2

Can fe

11 a single tree fi

om 10

Axes.

(cutting)

to 2C

inches

in diame

ter in

-

15 to

45 minutes.
1

12613 MCS QUANT1CO, VA. 11-13-43-7500

37