2C – BOOBY TRAPS WESTERN PERIMETER

One of my first projects as the executive officer on Nui Ba Den was to conduct a study of the strengths and weaknesses of our defenses. In the 1968 attack, the perimeter defenses were so pathetic, the Viet Cong just walked into camp, blew up all the signal equipment, and killed anyone they could find. It was a slaughter, brought about by complacency and inadequate defenses. I was determined that another Viet Cong victory was not going to happen on my watch. I became obsessed with trying to make our mountaintop outpost impenetrable to the Viet Cong. It was an impossible task considering what I had to work with, but I had the persistence and luck to find some good men who believed in me. Together, we took on the task of strengthening the defensive perimeter beyond the Army standards. One of these men was our First Sergeant Harry Meyers, a professional infantry soldier who cared about his men and supported my ideas. I planned to radically change some of our defenses so we could stop our adversaries before they could realize what we had done. Our enemy was not stupid, they fought the Japanese and French forces in previous wars, so they had adequate experience in defeating fixed defenses.
Our first mission was to find out which bunkers were poorly defended and needed strengthening. We charted the eighteen bunkers in numerical order, then rated them according to how easily an enemy could defeat them. All the bunkers except 5, 6, and 7 had adequate fields of fire and could easily stop an attacking force, especially when you consider the steepness of the mountain. On the other hand, those three bunkers were a defender’s worst nightmare. The vast field of various-sized boulders in front of them deprived the soldiers of a clear view of the perimeter. Enemy soldiers could hide behind the larger boulders and easily work their way towards the perimeter until they were close enough to destroy the bunkers.
My challenge, since it was impossible to stop an enemy attack, was what additions could we add to our defenses to slow down an enemy penetration until my Reaction Force could intercept and kill them. Harry and I spent hundreds of hours studying the western perimeter, pretending we were the Viet Cong, looking for passages through the boulders where the Viet Cong could not be observed. It was an overwhelming task and we almost admitted defeat until I thought about the Ho Chi Minh Trail and wondered about our chances of getting some of the sensors used on the trails. It was a long shot, but I wrote a letter to my brigade intelligence officer and pleaded my case for the sensors. To my surprise, six sensors arrived the following week, with instructions that only I was to use them, and any sensors not destroyed were to be returned to the brigade. I immediately went to work and placed the sensors in front of bunkers 3, 4, 5, 6, 7, & 8 and began the monitoring. To get clear signals, I had to mount the receiver on the tower we had built over the pagoda. It was the highest point on the mountain, almost forty feet above the ground. Every night from 11:00 to 3:00 in the morning, I would climb the tower and check the signals. After two weeks, a pattern of enemy activity had formed around bunkers 6 and 7. The other bunkers with the sensors showed no activity, and this only ratified my belief that an attack, if it came, would be towards bunkers six and seven. Now that I had an upper hand on where the attack might come from, we went to work upgrading our defenses. The very first addition was to add a third row of triple concertina wire to the outer perimeter and to kill any vegetation with herbicides. Next, we went crazy adding tanglefoot wire to such an extent that none of our men wanted to enter the field.
To further strengthen the western perimeter, my team built two camouflaged bunkers, each located fifty feet behind bunkers five and seven. They were each fitted with a .50 caliber machine gun and positioned so each gun could provide covering fire for the bunker line. These bunkers were only to be used during a final stand and were kept camouflaged during the daytime. If the enemy staged a major attack and pierced the outer perimeter these guns would help to even the odds. (I never bothered to get permission to install these guns. It was mentioned to Major Campbell, but I took full responsibility.)
Sergeant Meyers had his three mortar teams plot the fronts of the three bunkers for a mortar barrage along with giving two fire bases in our area the coordinates for fire missions further down the mountain.
I continued to monitor the perimeter for another month until the beginning of May when I decided to see if I could disrupt the enemy activity in front of the bunker line. Our mortar team would randomly fire 2 or 3 high explosive 81mm rounds in front of the bunkers, but they never resulted in any enemy casualties. I was more convinced of where the attack would come from, so I wanted to give the enemy something to think about if they continued the probing. I devised a plan to utilize two bunker-buster shaped charges as a booby trap. (It was like tying 10 Claymore mines together, just a little louder.) My first challenge was getting two M-3A1 shaped charges from the Army Engineers and setting them to be command detonated from bunker six. The charges were positioned fifty feet apart and laid on their sides. To maximize the killing fields, we placed a spool of coiled barb wire in front of each charge and camouflaged everything with shrubbery. One night when the sensors showed high activity, I had the two charges detonated five seconds apart. When those charges went off, the whole sky lit up and I could feel the concussions up on my tower. The next morning, we sent a patrol out to check the area; they found blood trails scattered over the entire kill zone, but no bodies.
I checked the sensors for another two weeks, but the enemy never probed this sector again until the actual attack on 6/16/1969. I considered our experiment a success. (During the attack, Bunker 7 was the first bunker to be destroyed!)
This was just one of the defensive modifications I made to our perimeter while serving on Nui Ba Den. With the Viet Cong controlling ninety-five percent of the mountain, we could not afford to let our guard down again. It was either kill or be killed.