Vietnam Studies
Field Artillery 1954-1973

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This page has excerpts from:
"Vietnam Studies, Field Artillery 1954-1973"
by Major General David Ewing Ott

Department of the Army, Washington D.C., 1975
Library of Congress in Pub. Data
1st Printing - Stock #008-020-00556-8

In 1975, Major General Ott was Commanding General of the US Army FA Center and Commandant of the US Army FA School, Ft. Sill, OK

Document credit: Davo Holdorf

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Background recording compliments of Sgt James R. Claeys
("29er Charlie") Pleiku-An Khe (1969-70) 6/29 Arty & 2/11 Arty

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INDEX

• Artillery Safety

• MACV Rules of Engagement

• Incident/Accident Profile

• Target Acquisition

• ARVN Artillery Posture, 31 December 1971

• ARVN Artillery Losses, 31 March - 10 April 1972

• Basic Ammunition Load

• Prescribed Stockage Objective

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Safety

Artillery units at all levels took every reasonable precaution to insure the safety of allied forces and noncombatants. The requirement that artillery units obtain both political and military clearance was but one of many rules that the artillery was required to observe in engaging the enemy. The rules were published in a directive entitled MACV Rules of Engagement, cited below. They are evidence of the unusual care that was required of all soldiers and commanders to insure that friendly casualties were held to an absolute minimum: 

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MACV Rules of Engagement

1. UNINHABITED AREAS.
    a. Fire may be directed against VC/NVA forces in contact in accordance with normal artillery procedures.
    b. Unobserved fire may be directed at targets and target areas, other than VC/NVA forces in contact, only after approval by Province Chief, District Chief, Sector Commander, or Subsector Commander and US/FWMAF Military Commander, as appropriate, has been granted.
    c. Observed fire may be directed against targets of opportunity which are clearly identified as hostile without obtaining Province Chief, District Chief, Sector Commander, or Subsector Commander and US/FWMAF Military Commander's approval.
    d. Approval by Province Chief, District Chief, Sector Commander, or Subsector Commander and US/FWMAF Military Commander, as appropriate, is required, before directing fire on targets or opportunity not clearly identified as hostile. 

2. VILLAGES AND HAMLETS.
    a. Fire missions directed against known or suspected VC/NVA targets in villages and hamlets occupied by noncombatants will be conducted as follows:
        (1) All such fire missions will be controlled by an observer and will be executed only after approval is obtained from the Province Chief or District Chief, as appropriate. The decision to conduct such fire missions will also be approved by the attacking force battalion or task force commander, or higher.
        (2) Villages and hamlets not associated with maneuver of ground forces will not be fired upon without warning by leaflets and/or speaker system or by other appropriate means, even though fire is received from them.
        (3) Villages and hamlets may be attacked without prior warning if the attack is in conjunction with a ground operation involving maneuver of ground forces through the area, and if in the judgment of the ground commander, his mission would be jeopardized by such warning.
    b. The use of incendiary type ammunition will be avoided unless absolutely necessary in the accomplishment of the commander's mission or the preservation of the force. 

3. URBAN AREAS.
    a. Fire missions directed against known or suspected VC/NVA targets in urban areas must preclude unnecessary destruction of civilian property and must by nature require greater restrictions than the rules of engagement for less populated areas. 
    b. When time if of the essence and supporting weapons must be employed to accomplish the mission or to reduce friendly casualties, fire missions will be conducted as follows:
        (1) All fire missions will be controlled by an observer and will be executed only after GVN/RVNAF/US approval. The decision to conduct fire missions in urban areas will be retained at corps/field force or NAVFORV level. Approval must be obtained from both the corps commander and the US field force level commander. This approval is required for the employment of any US supporting weapons in urban areas to include those US weapons in support of RVNAF. 
        (2) Prior to firing in urban areas, leaflets and loudspeakers and other appropriate means will be utilized to warn and to secure the cooperation and support of the civilian populace even though fire is received from these areas.
        (3) Supporting weapons will be used only on positively located enemy targets. When time permits, damage to buildings will be minimized.
        (4) The use of incendiary type munitions will be avoided unless destruction of the area is unavoidable and then only when friendly survival is at stake.
        (5) Riot control agents will be employed to the maximum extent possible. CS agents can be effectively employed in urban area operations to flush enemy personnel from buildings and fortified positions, thus increasing the enemy's vulnerability to allied firepower while reducing the likelihood of destroying civilian property. Commanders must plan ahead and be prepared to use CS agents whenever the opportunity presents itself. 

4. THE ABOVE STATED PROCEDURES WILL NOT BE VIOLATED OR DEVIATED FROM EXCEPT, WHEN IN THE OPINION OF THE RESPONSIBLE COMMANDER, THE SITUATION DEMANDS SUCH IMMEDIATE ACTION THAT THESE PROCEDURES CANNOT BE FOLLOWED. SUCH SITUATIONS INCLUDE THE PRESERVATION OF THE FORCE OR THE RIGHT OF SELF-DEFENSE.

5. RVN/CAMBODIAN BORDER AREA.
    a. Fire missions within 2000 meters of the RVN/Cambodian border will be observed, except under circumstances where fires are in defense of friendly forces and observation of such fires is not possible. These requirements are in addition to applicable control procedures stated elsewhere in this directive. 
    b. Fire missions with intended target areas more than 2000 meters from the RVN/Cambodian border may be unobserved, subject to applicable control procedures stated elsewhere in this directive. 
    c. Fire missions will not be conducted where dispersion could result in fire being placed on or over the RVN/Cambodian border.
    d. Commanders will review and comply with the provisions of MACV Rules of Engagement-Cambodian when planning for operations near the Cambodian/RVN border. 

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Major commands subordinate to Military Assistance Command frequently published directives that interpreted the MACV rules, expanded them in greater detail, and often added qualifications which made them even more restrictive. 
Field artillery units adopted the following procedures in the employment of their weapons to insure accuracy and preclude friendly casualties:
    1. Firing a smoke shell set for a 200-meter height burst as the first round for most observed missions. Smoke was relatively safe; thus, if the target location was improperly reported, supported ground troops would not be hurt. The forward observer made any correction necessary to insure that subsequent high explosive rounds fell in the intended locations.
    2. Double-checking or triple-checking all data at each echelon from the forward observer to the howitzer. This procedure created a problem for some units because of personnel requirements. In many cases, especially in force artillery units, a battalion did not control its batteries. When the battalion controlled the batteries and retained a technical fire direction center either the battery or the battalion computed the mission and the other checked the data. When the batteries operated separately, each battery center had to be augmented so that it would have two shifts or two computers and two chart operators for the double-check system. Data sent from the fire direction center by one computer were monitored by the other computer. The executive officer post received the the data and read them back. Data were then passed to the guns through the executive officer post. One practice called for placing an AN/GRA-39 remote radio set at each gun. This permitted all members of the section to hear the data being transmitted to the guns. One section then read back the data received. 
    3. Conducting periodic gunner (firing) inspections and drills for subordinate units.
    4. Separating and segregating, by lot, projectiles and powder for separate-loading ammunition.
    5. Insuring that howitzers were boresighted at least twice daily and that batteries registered twice weekly.
    6. Conducting frequent staff inspections of subordinate units to see that safety policies were being complied with. 

Friendly casualties resulting from misplaced artillery fires were thoroughly investigated whenever the combat situation permitted. Often the mistake was unavoidable, and, for that reason, investigation first determined whether the mistake was an accident or an incident. A firing accident was defined as an occurrence not caused by human error or neglect. Malfunction of ammunition or equipment, civilian casualties in previously cleared areas, and personnel hit by debris or secondary fragments were classified as accidents. A firing incident, on the other hand, resulted from human error or neglect. Plotting errors by the forward observer or fire direction center, crew errors in setting quadrant elevation or deflection, and errors in transmitting unit locations or firing data, in obtaining proper clearance, in following the rules of engagement, or in identifying friendly units contributed toward firing incidents. If the firing error resulted in an incident, its precise cause was determined and necessary action was taken at all levels to prevent similar errors in the future. 
The investigation of artillery accidents brought to light a problem in illumination missions. The impact point of the baseplate and the projectile body could not be accurately determined because of the erratic trajectory after fuze function. Consequently, it became necessary to establish a buffer zone around the grids of illumination and impact. Clearance to fire into these buffer areas was required before illumination could be fired.
A study conducted in 1969 by the U.S. Army, Vietnam, into the causes of artillery, mortar, and aviation incidents and accidents set out to determine if incidents and accidents followed any discernable patterns so that commanders might be forewarned to give careful attention to certain specific areas. The study showed that a majority of the accidents and incidents involved direct support units firing observed fire. The following chart outlines the incident and accident profile developed in the study as well as recommended corrective action: "1969"

   

   

   

Artillery units were concerned not only with the safety of friendly forces and noncombatants on the ground but also with that of aircraft. Aircraft safety was assured by the establishment of aircraft warning centers. These centers normally were set up and operated by field artillery liaison sections at maneuver battalion and brigade. The liaison section was notified by artillery units in the area before firing and given the direction of the fire, the maximum ordinate of the trajectory, and the point of impact of the projectile. Aircraft entering the area could then be advised of artillery firings and provided with recommended safe routes through the area.
In most cases Army control of air space over the battle area was not contested by the Air Force. Where it was contested, local agreements were made between representatives of both services. The most common agreement was that air space below 5,000 feet would be controlled by the Army and that above 5,000 feet by the Air Force. In certain areas such as Bien Hoa, Tan Son Nhut, and Da Nang, where the activity of the Air Force aircraft was the greatest, the Air Force controlled all air space.

   

Target Acquisition

Targets must be found and their location pinpointed if field artillery is to be effective. In Vietnam, as in past wars, forward observers augmented by aerial observers were the principal means to identify artillery targets. Despite the development and improvement of other target acquisition means, observers were, and promise to be for some time to come, more reliable, flexible, and responsive than any other system. This does not say that other target acquisition means are not valuable. Radars, sound and flash ranging, and sensors were all employed profitably in Vietnam.
Three target acquisition batteries were deployed to Vietnam. They were Battery F, 2d Target Acquisition Battalion, 26th Artillery, and the headquarters batteries of the 8th Target Acquisition Battalion, 26th Artillery, and the 8th Target Acquisition Battalion, 25th Artillery. Each of the headquarters batteries was assigned to a field force headquarters to co-ordinate field force level target acquisition activities. Battery F established sound and flash bases in the XXIV Corps area to monitor the Demilitarized Zone. This was the only sound ranging equipment employed, and though the equipment failed to detect a large number of targets, all sound targets that were engaged resulted in secondary explosions.

     

      

      

Supply by road in insecure areas was frequently accomplished every two or three days. On those days the road was swept for mines in advance and secured by ground forces long enough for the convoy to complete its run. Daily needs such as rations, water, and ice could then be supplied by helicopter.
All firing batteries carried sufficient supplies and ammunition with them during their move to permit them to start construction and fire supporting missions immediately upon occupying a fire base. Stocks were increased or replenished in subsequent supply deliveries. No generalizations can be made as to the amounts and types of bunker and barrier material a unit would carry or receive later. Ammunition requirements, on the other hand, were established in written directives. Firing units were required to carry a basic load with them at all times. Basic loads varied somewhat depending on the area of operation and location of the ammunition supply point. 
The following basic load is representative:

      

      

While occupying a position a firing unit was continuously supplied at a rate which allowed it to maintain a prescribed stockage objective. The stockage objective was established above the basic load and was used as an aid in ammunition supply management. A typical stockage objective for high explosive ammunition is as follows: