Nice to Know What’s Going On

On August 15, 1968, the Viet Cong hit the Nui Ba Den remote signal site in a coordinated night attack. Twenty-four American defenders died. The site’s vulnerability was no longer a theory.

The mountain didn’t help. Steep grades, boulder fields, blind spots everywhere. The western slope was the worst of it — a chaos of rock the defenders could never fully cover. The Viet Cong knew it too. They probed the perimeter for months and stayed away from that sector every time. Made the defenders think it was safe. It wasn’t. It was bait.

The sappers came in platoon strength and caught the defenders cold. Ten minutes. That’s all it took to go bunker to bunker, killing men and blowing up every piece of radio gear they could find. Clean, methodical, planned. The Viet Cong proved something that night: they could take on the U.S. Army and win.

Seven months later, I got orders to Nui Ba Den. Executive officer and signal officer, the whole mountain, both jobs at once. Whatever happened next, it wasn’t going to look like August.

The 1968 defense had a hole in it nobody had fixed: no way to know fast which bunker was under attack. Eighteen perimeter bunkers, each wired to the command bunker by landline phone. Fine in theory. Useless the second the shooting starts — nobody’s picking up a phone to report taking fire.

So I built something else.

An ammo can. Relays. Toggle switches. Eighteen red lights, one per bunker, mounted on the face of a .50-cal can bolted to the top of the switchboard. The parts came from dead radio equipment scavenged around Tay Ninh Base Camp — nothing new, nothing requisitioned, nothing that would show up on a supply report. Just salvage and wire.

The idea was simple. A bunker under attack throws its switch. A light comes on in the command bunker. That’s it. No phone call, no report, no delay — just a light, and now everyone knows exactly where the enemy is.

I started with the western perimeter, the weak side, the side that got hit in ’68. Once we saw how fast it worked, we wired all eighteen bunkers the same way.

June 1969. The Viet Cong came again — same playbook, another sapper assault on the perimeter. This time the lights worked. My Reaction Team knew which bunker was under fire in seconds, not minutes, and seconds were the whole game. Every second was time the enemy didn’t have.

Not a single U.S. Army relay site went offline due to enemy action.

They came back to finish what they started in 1968. This time, we knew what was going on.