NVA Fortified Living Areas

The major trench system used to mask the approach to Khe Sanh paralleled the existing road network between the base and the village. The terrain throughout this area was gently rolling and formed a plateau which extended from the main access road east to the Riviere de Rao Quan. The overhead cover offered by the woods and heavy brush along the plantation roads provided excellent camouflage for the trench system.

The approach trench system was well camouflaged and followed the natural terrain features whenever possible. The trenches changed direction every 10 to 20 feet and were serpentine-style. Large roots which could not be circumnavigated were left undisturbed. The depth of the trench was increased for added protection in open areas. Cooking utensils were scattered throughout the complex. Many of the vents and smoke holes had large boards placed over them at a 45 degree angle to deflect smoke and shield the hole from observation (Figure 8). This was the only area where posts and braces were encountered in bunker construction. It gave the bunkers a much stronger overhead cover, and maximum protection to the occupants. It allowed the weight to be evenly distributed and provided for somewhat larger construction.

The staging and living areas branched from the system at periodic intervals and were well camouflaged with grass and shrubs. The area along the plantation road from XD 864400 to the base at XD 850415 was extensively trenched, one branch running east of the access road toward the eastern end of the runway and the other running west of the road toward the Khe Sanh Combat Base. The NVA had used the French plantation extensively for staging and living bunkers. Communications wire was noted throughout the area.

Antiaircraft and mortar positions were strategically placed within the bunker system and were well camouflaged. A large bunker complex measuring 200x400 meters and containing 73 living bunkers was constructed at XD 858409 (Figure 10). The area was open to observation but had been skillfully and carefully camouflaged in the elephant grass and scrub growth. There was little evidence of the spoil normally seen beside the trenches and each bunker had overhead cover in which grass and bushes had been planted.

Antiaircraft positions had been placed on the outer perimeter of the complex and could bring fire to bear on the eastern approach to the airstrip (Figure 11). Other complexes were reported at XD 879389, XD 878398 and XD 849389 (Figure 12). All were interconnected to the main trench system.

The bunker complexes in the plantation area were constructed with material procured from the village and abandoned US and ARVN positions outside the base. Engineer stakes, sandbags, 4x4x7 feet standard cut timber, tin sheeting, and clear and green plastic waterproofing were all used throughout the complex. The bunkers closest to the base were the best constructed, having more than 3 feet of earth cover. Figure 13 shows a typical bunker of this type. A ceiling of solid engineer stakes followed by a layer of waterproofing or tin material, three feet of earth, logs and sandbags was not uncommon. Partially covered L-shaped fighting holes were also located in the area. The simplicity of the system and the ease with which the main trench system could be reinforced along covered routes was remarkable.

The entire plantation area had been extensively bombed and shelled from Khe Sanh and the 175mm artillery positions at Camp Carroll and Thon Son Lam. One B-52 strike was observed on the southwest portion of the plantation road. Crater analysis was easily performed in the soft laterite soil. Distinguishing between the various sized bombs was difficult, however, three types of craters were evident throughout the area, from which the following assumptions were made:

The bombs which made the largest craters destroyed any evidence of bunkers or other positions that may have been there. Within the positions only superficial damage was observed. Numerous craters were found within 10-15 feet of the access trenches.

The adjoining bunkers (Figure 14) were not damaged by bomb fragmentation. Concussion effects were speculative. In areas where the craters intersected the trenches and bunkers, extensive damage to both resulted. This was especially noticeable on the west side of the plantation road in the vicinity of XD 856405. The use of napalm against the trenches was of no value unless the trench supporting the living bunkers was connected for such use. Likewise, elephant grass burned only at the roots leaving the tops green. The amount of ammunition needed to neutralize a bunker complex of this size was determined by the degree of observation and skill in employment. In many cases the close air support and radar bombing missions were made parallel to friendly lines to insure safety whereas the trenchlines extended toward the base in a "spider-web" design. Attacks made perpendicular of these targets considerably reduced the probability of damage.

Assault Trench Complexes

A major portion of the trenchlines on the perimeter of the base was explored in an attempt to determine their extent and tactical significance. The assault trenches extended from the living areas discussed above, north to the base perimeter XD 853417. The serpentine system followed the existing road and trail network throughout the XD 8440, 8540, and 8541 grids. The area was generally flat with gently rolling hills. There was no elephant grass immediately outside the base perimeter, thus permitting excellent observation into the trench system from the air. No attempt was made to camouflage the trenches and the soil was piled on either side forming an 18- to 24-inch berm.

A casual serpentine pattern was followed, with little regard for severe changes in direction; usually every 20-30 meters. Their objective was apparently to dig directly to the perimeter. In several places heavy roots were bypassed and there was no evidence of partitioning of sections. None of the trenches were covered and only two small one-man side shelters were found in over 2000 meters of trenchline. The trenches averaged 24 inches wide and 4 feet deep, and in certain sections, this was expanded to widths of 4 feet, possibly to accommodate heavy weapons. As the main approach trenches neared the base, they narrowed and followed defensive terrain features more closely. When ended, each trench was crossed at right angles by a fighting or assault trench (Figure 16). Each 'T' contained multiple fighting positions which extended 30 feet on either side of the approach trench. Each fighting position accommodated one or two standing men, and was expanded or connected to other trenchline systems. In two of these type trenches were found barbed wire breaching poles made from three 3x10 foot poles tied together with bamboo strips.

Supporting arms were quite effective against the trenchline closest to the base, especially where they had crossed the 'T' with fighting holes. Several of these positions were heavily bombed, and were caved in and made ineffective as fighting positions. Hundreds of artillery craters were located throughout the area, ranging from 105mm to 175mm. In certain areas near the end of the system closest to the perimeter, bomb craters had completely obliterated the system for 50-60 meters. Many personal items such as canteens, helmets and packs were found in the trenchline. In a few areas napalm had successfully cleared openings in the scrub growth and thickets, however, its overall value remains doubtful. Again, the burned area was limited to a diameter of 30-40 feet, with little effect beyond the center. The NVA soldier did not live in these trenches. No evidence of living areas in the trench system was uncovered closer than the XD 8540 grid. An occasional AA site was connected to the main trench, but there was little evidence of a defensive plan to any of the battle trenches. The living trenches, however, contained multiple, mutually supporting AA sites.