Section II - Lessons in Combat Support

Artillery Fire Direction

Item: Fire direction procedures for a reinforced artillery battalion in a guerrilla warfare environment.

Discussion: The subject environment has required the displacement of an average of one battery per day, with up to four displacements per day; the employment of batteries by platoons with different directions of fire; with technical fire direction of separated platoons from the battalion FDC, and the ability to fire and/or mass fires quickly anywhere in a complete circle. Although technical fire direction is normally centralized only for weapons organic to the battalion, the requirement still exists for the battalion FDC to be able to produce or check firing data for any attached weapons. Two lessons were learned: First, that standard FDC chart procedures are not suitable for the above organization and situation; second, that certain firing battery procedures had to be revised to cope with the situation.


Firing Chart. The length and width of the firing chart must be twice the maximum range of the longest shooting weapon system in the composite unit. All data is taken from a grid intersection at the center of the chart, and permanent azimuth/deflection indices are drawn on the chart every 100 mils. The indices are each approximately two inches in length, drawn so that the ends protrude above and below the mil arc of the range deflection protractor. Each index is labeled at the top with grid azimuth and at the bottom with deflection. All calibers use the save referred deflection at any azimuth; in this case, the chart system is based on all batteries being laid on grid azimuth 6400, referred deflection 2600. Therefore, the chart index at azimuth 6400 is labeled 64 at the top and 26 at the bottom. The rest are labeled accordingly. Only the, right-most 100 mil increment on the mil arc of the RDP is used, with the right-most 100 mil graduation to its left labeled zero. To read azimuth to the nearest 100 mil (which will be sent to the battery in the fire command), merely look at the relationship of the left edge of the arm of the RDP to the labeled indices; to read deflection, the hundred value is one hundred less than the number that can be seen immediately adjacent to the left edge of the arm of the RDP. Tens and units values are read from the right-most 100 mil increment on the mil arc of the RDP, from left to right, using the index that falls within that increment. To compensate for the actual locations of the firing batteries- relative to the center of the firing chart a template is constructed from transparent grid sheet material, on which the center of the chart and all battery centers are plotted in their actual locations. This template is then turned upside down, and is always used in this upside down orientation. To obtain chart data, the center of the template is placed over the target, the grid lines of the template are then aligned exactly parallel to the grid lines on the firing chart, the vertex of the RDP at the center of the chart, and then a map pin is stuck in the template location of the battery. The RDP is then used to determine range and deflection of the pin at this location. Chart data for other batteries is obtained by shifting the pin to the template location of those batteries. Miscellaneous chart procedures, such as data for replot and conversion of observed firing data to surveyed data, can be accomplished by several techniques that can be derived if the basic concepts are understood.

Firing Battery Procedures. Firing battery procedures are modified to complement the revised chart procedures. Two sets of aiming posts (with night lighting devices) are mandatory to eliminate potential problems. Aiming posts are put out 3200 mils apart at the referred deflections corresponding to the azimuth of lay. For example, if laid on azimuth 6400, the aiming posts would be put out at deflection 2600; however, if laid on azimuth 6300, the aiming posts would be put out at deflection 2700. Because firing is so frequently done in directions opposite the initial azimuth of lay, it has been found that an azimuth reference system for the chief of section not only reduces the possibility of errors - particularly in night firing - but also speeds the rough lay when trails are shifted. Therefore, azimuth reference stakes are set out every 800 mils around each piece, and the azimuth of fire (to the nearest 100 mils) is included as the second element of the command from FDC Other firing battery procedures remain unchanged.

FDC Organization. The school and textbook solution for the physical organization of the FDC has been improved upon. Every element of the FDC must be organized so that nothing can interfere with the passage of fire missions, data and commands between the FDO, RTO's, HCO's VCO and computers. One physical organization that satisfies this requirement is to have all these individuals facing inboard with their equipment, and no walkways between. When the FDG will remain in a semi-permanent location, all equipment, such as charts, radio remotes, EE-8's and maps can be mounted on one central table specially constructed to accommodate these items and to compliment the functioning of the FDC.

Observation: Artillery S-3's consider the adoption of the above techniques.

60MM Mortars

Item: Experimental use of 60MM Mortars with small patrols has proven its effectiveness.

Discussion: 81MM mortars were taken on company-size patrols during April 1965 as an immediate area fire weapon for use against targets in excess of the range of the M-79 or 3.5 rockets. It was soon discovered that the size and bulk of the 81MM mortar made it extremely difficult for the patrol to maintain an acceptable rate of march. 60MM mortars were appropriated on a loan basis and subsequently employed with small patrols. Accurate fire was quickly delivered. It is capable of being set up for firing in one-fourth of the time required for an 81MM mortar, and the crew was reduced to six per weapon. The light weight of the 60MM mortar and its ammunition make it a highly desirable weapon in the rough terrain and tropical climate of Vietnam. Its capability to fire direct or indirect fire at targets beyond the range of M-79's or 3.5 rockets, but which do not warrant artillery or air support because of target value, or time factor, is evident.

Observation: When available a section of 60MM mortars should be taken on rifle company patrols.

Reconnaissance of Landing Zones

Item: In some cases LZ reconnaissance practices are neither adequate nor commensurate with operational requirements.

Discussion: Reconnaissance immediately prior to an airmobile operation should be fitted into the general pattern. Aggressive use should be made of Rangers, Special Forces, reconnaissance companies, pathfinder teams, etc., equipped with superior communications. These units must be used rapidly to probe potential enemy positions, and to gain definite intelligence with minimum exposure of our own resources. Better and continuous use of aerial photographs should be made.

Observation: That reconnaissance be made [illegible], and surveillance be updated on available LZ's.

Artillery Support/Airmobile Operations

Item: There should be more artillery support for airmobile operations.

Discussion: Whenever feasible, artillery should be deployed to positions from which fire support can be rendered to the airmobile force. If artillery is not available, fire support must be provided by mortars or continuous close air support. The heliborne command post must be able to shift artillery fire in order to integrate these fires with the overall support of the assault force.

Observation: With the advent of longer range artillery into, the theater, i.e., 8-inch howitzer and 175MM gun, in addition to the airlift capability of the l05MM howitzer, this capability will be enhanced.

Extract from Battlefield Reports. A Summary of Lessons Learned, Headquarters, US Army Vietnam. Volume 1. 30 August, 1965

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