The U.S. Army Infantryman Vietnam Pocket Manual

Chris McNab

• Publisher: Casemate
• Year: 2021
• ISBN:
  9781636240312
• Topic: Storia
• Subtopic: Guerra del Vietnam

Between 1964 and 1975, 2.6 million American personnel served within the borders of South Vietnam during the Vietnam War, of whom an estimated 1–1.6 million actually fought in combat. At the tip of the spear was the infantry, the "grunts" who entered an extraordinary tropical combat zone completely alien to the world they had left behind in the United States. In South Vietnam, and occasionally spilling over into neighboring Laos and Cambodia, they fought a relentless counterinsurgency and conventional war against the North Vietnamese Army (NVA) and Viet Cong (VC). The terrain was as challenging as the enemy – soaring mountains or jungle-choked valleys; bleached, sandy coastal zones; major urban centers; riverine districts. Their opponents fought them with relentless and terrible ingenuity with ambushes, booby traps, and mines, then occasionally with full-force offensives on a scale to rival the campaigns of World War II. This pocket manual draws its content not only from essential U.S. military field manuals of the Vietnam era, but also a vast collection of declassified primary documents, including rare after-action reports, intelligence analysis, firsthand accounts, and combat studies. Through these documents the pocket manual provides a deep insight into what it was like for infantry to live, survive, and fight in Vietnam, whether conducting a major airmobile search-and-destroy operation or conducting endless hot and humid small-unit patrols from jungle firebases. The book includes infantry intelligence documents about the NVA and VC threats, plus chapters explaining hard-won lessons about using weaponry, surviving and moving through the jungle, tactical maneuvers, and applications of the ubiquitous helicopter for combat and support.

CHAPTER 1

TRAINING AND ORIENTATION

During the Vietnam War era, the process of turning a new recruit into combat-ready infantry typically took about 16 weeks, consisting of an eight-week Basic Training (BT) program followed by an additional eight weeks of Advanced Individual Training (AIT). These programs gave the soldier the fundamental tactical and procedural skills to operate as infantrymen. AIT also included a spell at Tigerland, the name of the semi-tropical U.S. Army training camp located at Fort Polk, Louisiana, which offered a swampy, hot, and vegetation-choked environment that was deemed approximate to the conditions experienced in Vietnam.

The American infantryman in Vietnam was essentially locked into two wars, that against the enemy and that against the climate and terrain. The most pervasive and inescapable problem for infantry on operations was Vietnam’s elevated heat and humidity, which when combined with the physical exertion of patrolling or combat brought the perfect pressure-cooker conditions for heat exhaustion. During one infantry action in April 1967, for example, 60 men became heat exhaustion casualties in just the first three hours of the operation.

But Vietnam had other adverse weather effects, outside of the clammy heat. During the monsoon season (May–October), there could be rainfall of the most extraordinary volumes on a near daily basis. In one instance on October 5, 1969, the city of Hue received 22 inches of rain in just 24 hours. Outside the city, such rains turned the landscape into leg-sucking agonies of movement, while also rotting uniforms, equipment, weapons, and human skin.

The Vietnamese jungle, which covered large extents of the country, was not the only battleground for the U.S. infantry, but it was the most physically challenging. As FM 31-30, Jungle Training and Operations (1965), here explains, just moving through the jungle landscape was problematic, especially when trying to execute tactical maneuvers. Dense-packed vegetation could slow the pace of advance to a crawl while also wrapping itself around the infantryman in a claustrophobic experience. Any exposed skin would quickly receive small, easily infected cuts and puncture wounds from sharp grasses and thorns. Then there was the wildlife—leeches, spiders, biting flies and centipedes, venomous snakes, rats, even big cats. Worst of all were the mosquitoes, which attacked the soldiers in relentless clouds. One soldier remembered how, during the monsoon season, it was raining so hard that he was struggling to breath, so put his face down with his hands making a protective cup around his nose and mouth. Almost immediately, the space within his hands was entirely filled with mosquitoes. Aside from the discomfort, the mosquitoes also brought malaria, a major cause of non-battle casualties.

The first manual extract given is from FM 31-30. Although the American military had gained experience of jungle warfare in World War II, those memories were much faded by 1965 when this manual was written, and when the first major infantry deployments were sent to Vietnam.

From FM 31-30 Jungle Training and Operations (1965)

CHAPTER 2
THE JUNGLE

Section III. MILITARY ASPECTS

17. General

Movement either by vehicle or on foot is extremely difficult in jungle areas. Minor terrain features can present major obstacles to movement in combination with the dense vegetation. Because bridging equipment generally will not be available at any depth in the jungle, it is necessary to improvise for almost every river crossing where fording is not possible. Planning criteria must first be developed on the time factors involved rather than the distance to be covered. Defensive action in jungle terrain is considerably aided by natural features. Small units are the essential element in all jungle operations. They must be kept fully informed of the known situation, so they can make competent plans and decisions.

18. Observation and Fields of Fire

a. Observation. Ground observers are at a distinct disadvantage in jungle areas. The range of horizontal visibility is extremely limited. Aerial observation will provide little useful information because the jungle canopy will conceal most activity underneath. This activity may include movement of substantial bodies of troops over fairly long distances. Undetected movements of this type can mean disaster if defending troops cannot properly man defensive positions before the attack. Conversely, the attacking forces may also use the jungle cover and concealment to get into positions undetected by and unknown to the defenders. In these areas of limited observation and fluid frontal conditions the control of the fighting becomes doubly difficult. Flanks can be turned, fronts can change, and the leaders of the operation may never know that these events have occurred.

b. Fields of Fire. The traditional employment of automatic weapons is impractical in jungle areas. It is not normally advisable to clear fan-shaped fields of fire to provide maximum arc and coverage of sectors with these weapons. To do this would indicate clearly to the enemy the friendly fields of fire. Rather, “fire tunnels” should be carefully hollowed out of the vegetation to define the sectors of fire. For the most part coverage will be limited to the control of trails and other routes of movement and fire will be confined to very shallow areas. Even the range for snipers will be very short. Short range, quick-burst, quick-response weapons are the most useful.

19. Concealment

In nearly all types of vegetation in jungle areas the concealment potential is tremendous. The opportunity to conceal troops from most types of surveillance devices is afforded in all types of vegetation except the very young secondary growth group. If camouflage techniques are used properly there are very few situations or conditions in which troops cannot be concealed from ground observers. Seasonal changes of coloration must be studied. Stringent discipline must be maintained in all movements and bivouacs to insure against unnecessary clearing of overhead cover and thereby permit aerial observation. Many of the vegetative features that afford concealment because of their opaque surfaces provide no resistance to bullets. It is easy for troops to mistake concealment for cover.

20. Cover

Except in the primary evergreen rainforest, the trees in most jungle areas will not provide extensive cover. Average tree trunks are generally not more than 12 inches in diameter; in areas where large trunked trees are located the trees are usually widely spaced. Most of the cover in jungle areas will be afforded by surface irregularities, such as ravines, gullies, and large rocks. These are to be found in abundance.

21. Obstacles

The jungle itself is the obstacle. This feature with its attendant psychological pitfalls and its physical adversities must be overcome before any thought can be given to an enemy force. The stresses placed on men to merely traverse the ground and the heat generated by such stresses induce a type of hypnotic spell in which the next step becomes the most important consideration, all of which dulls the mental discipline necessary to remain alert. Augmenting the natural conditions that serve to break down the spirit and fighting will of the soldier are the manmade obstacles erected by the enemy. If these obstacles are encountered when troops are in a state of fatigue they may forget that the obstacles are almost always controlled by maximum enemy firepower. Only a determined, disciplined force in peak physical condition can hope to move and fight successfully in the jungle.

22. Key Terrain Features

All features that expedite movement, resupply, and evacuation may be key terrain features. Roads are the most critical; trails that afford relatively easy access are next in priority. Navigable waterways are also significant. Any clearing in which a helicopter can load or unload may tactically be a key feature in a major operation. Villages, bridges and prepared fords must also be considered. Unlike conditions in more barren areas, high ground is not necessarily important; from the heights the possibility of controlling or observing trails or critical approaches through the valleys is rather remote.

23. Avenues and Routes of Approach

It is not possible to provide a formula for deciding the approach route that would serve the needs of the commander best. If he has a choice, his immediate needs and the time/ distance factor will guide him in his decision as to routes for movements. Consideration should be given to the fact that in any movement security is of major importance. Although the terrain may permit movement along trails, ridgelines and valleys, normally these routes will be guarded by enemy forces. On the other hand, while travel across ridgelines and valleys will normally offer more security, it will be much slower and extremely tiring for the troops, especially so if large quantities of food and ammunition are to be carried.

CHAPTER 3
JUNGLE TRAINING

Section I. THE INDIVIDUAL

24. General

A practical appraisal of the abnormal difficulties inherent in jungle operations will reveal that the only remedies for such conditions are training and experience. Unless, however, experience is based on sound, thorough, realistic and constant training it is liable to be quite costly. Therefore, the individual soldier and operational units should be prepared to live and fight in jungle environment before such a mission is actually assigned. Training conducted in actual jungle constitutes the ideal training situation; however, application of guidance herein described, in areas other than the jungle, will benefit the soldier, in the event jungle areas are not available. Under circumstances of the nonavailability of jungle terrain, commanders must employ vigorous and imaginative approaches to training for jungle combat taking advantage of the opportunities offered by dense woods, river beds, swamps, marshes or thickets for training purposes. Application of night fighting techniques when utilizing conventional or relatively barren terrain for training will prove to be quite effective in simulating the reduced ranges of assault, restricted movement, and control difficulties imposed by the jungle.

25. Initial Training Objectives

a. The first concern of commanders who are faced with the task of preparing individuals for jungle combat is the physical and mental acclimation of troops to the oppressive jungle environment. Psychological conditioning and knowledge imparted through sound instruction are the only means to eliminate the common fear of snakes, insects, animals, and unknown, foreboding terrain. Troops must not only be physically hardened; in addition, they must be able to adjust to weather, climate, and temperature changes to be expected when deployment to wet tropics from temperate areas takes place.

b. The objectives of jungle training are to prepare the individual and unit to function effectively in jungle environments. Training situations should be created which require execution of missions by small units operating independently. Control of units should be decentralized requiring reliance upon the junior leaders and even the individual soldier. Training should demand individual self-reliance, teamwork, skill, and determination on the part of participating troops. The scope of the training program should extend from survival of the individual in the jungle, to participation of units in combined operations.

26. Acclimation to Heat and Humidity

a. General. One of the secrets of successful training or fighting in a wet tropical climate is the knowledge and proper use of information regarding the acclimation process of the body, heat disorders, and basic heat rules. It must be emphasized that understanding and remembering this information are not enough; only by proper use of this knowledge can troops avoid becoming heat casualties.

b. Heat. Heat is a physical form of energy generated through combustion, chemical action, or friction. There are two types of heat which are of interest to the soldier, the heat of the environment caused by the sun, and the heat of the body generated by converting food into energy. The normal temperature of the human body is between 98° F and 99° F depending on the individual. When excess heat acquired by the body from the environment or from energy producing foods is not dissipated, and this internal temperature departs significantly from normal, serious sickness or even death will result. The human body dissipates excess heat in three ways: conduction, radiation, and evaporation. Conduction of body heat occurs when the temperature of the air is less than the body temperature. Radiation of body heat occurs when the surface temperature of surrounding objects is lower than the surface temperature of the skin. Normal responses to heat stresses are dilation (enlargement) of the blood vessels and an increase in the rate of heartbeat. These adjustments increase the temperature of the skin and thus increase heat loss through conduction. When radiation is not sufficient to maintain the normal body temperature, the activity of the sweat glands increases and evaporation of the perspiration from the surface of the skin becomes the most important means of cooling the body.

c. The acclimation process. Acclimation can be defined as the adaptation by the individual to work in the heat with maximum efficiency and least discomfort. If the body does not become accustomed to heat, the individual becomes irritable and sluggish and is unable to sleep. In general, the performance of this individual becomes substandard and inefficient. Some soldiers may never become acclimated but, fortunately, the percentage is very small. The acclimation process is automatic. The ease and rapidity with which the body becomes acclimated depends upon several variables. One such variable is the degree of temperature change between the two climates involved. Troops going to the wet tropics from a southerly location in the mid-latitudes will become acclimated easier and faster than troops from a place farther to the North. A similar condition would exist if such a move is made in the summer instead of the winter. A second variable is the abruptness of the change from one climate to another. Troops who are transported to wet tropical areas by surface transportation will not experience as much discomfort when they arrive as would troops who are transported by air.

(1) Characteristics of the acclimation process.

(a) Acclimation begins the first day of arrival in the wet tropics and is well developed by the fourth day.

(b) As the process continues, sweating increases and begins more readily, but salt loss becomes less.

(c) Physical exercise speeds the acclimation process by inducing profuse sweating.

(d) The body will remain acclimated from one to two weeks after departure from wet tropical environment.

(2) Proper clothing for the acclimation process.

(a) Clothing must fit loosely. Tightly fitted uniforms will become saturated with sweat and will hinder the cooling process of evaporation and air circ...