The Remote Control Ambush

Yesterday’s post on remote control warfare reminded me of a nifty little trick my platoon pulled during training while I was in Hawaii. It’s a blend of (then) state of the art technology, and redneck engineering.

Remember these?


WD-1 field telephone wire on a DR-8 spool with RL-39B reeling kit.


Claymore mine M57 electrical firing device.


First, the redneck engineering. One mission we practiced almost constantly in Hawaii was the ambush. Most especially, the night ambush. An ambush is a sudden planned attack on a moving or temporarily halted enemy force. And for most missions, the plan was to initiate the ambush with Claymore mines.


But while we had plenty of inert Claymores to practice setting up and aiming, they were pretty useless for force on force training, as they had no “signature” to cue the OpFor that they’d been whomped by a Claymore.

One bright fellow figured out that he could take apart a flash cube into four individual bulbs, and connect a length of WD-1 wire to the electrical posts on the bulb. He could then splice the wire to a surplus bit of Claymore firing wire to plug into the M57. One press of the clacker, and the bulb would flash. On a dark night, there was no doubt in anyone’s mind that a “Claymore” had gone off. Prepping these improvised training aids became a routine part of planning to go to the local training areas.

I spent about half my tour in Hawaii as the Platoon Leader’s Radio Telephone Operator, or RTO. In addition to carrying the PRC-77, I was also de facto responsible for all the other communications and electronics in the platoon, with the exception of night vision equipment. That included the TA-312 telephone, four TA-1 field telephones, four RL-39s with spools and wire, eight PRC-68 walkie talkies and a few other items.

We had one other bit of equipment that we rarely used, because it was rather bulky, and was seen as unreliable, and not terribly useful.

That was the TSR-2(V) Platoon Early Warning System, or PEWS. PEWS was a set of 10 seismic/acoustic sensors that would transmit the presence of people or vehicles in their vicinity via either radio or field wire back to a hand held monitor.



As you see, PEWS was somewhat bulky.  It was also quite finicky. Each remote sensor had two aluminum spikes that screwed into the bottom. Those were what detected moving personnel or vehicles. Each detector theoretically had a detection range of 50 meters for personnel, but in practice, it was closer to 10-15 meters. And great care had to be used in selecting exactly where the remote was emplaced. Ideally it would be firm ground near an area that the enemy would most likely pass through.  And while the detectors had an advertised radio range of 1500 meters, experience showed it was more realistically about 500 meters, provided great care was taken that no terrain blocked the line of sight back to the receiver.

The idea was that the PEWS would be used by light infantry platoons as, well, early warning devices while they were established in patrol bases. But the care and training needed to get even modest results from the system meant they weren’t used often. That and they were an additional 13 pounds of equipment to be hauled around by the platoon, and the risk of losing one of the (expensive) detectors meant most platoons left them at home.


My Platoon Leader at the time insisted we bring ours. And since as his RTO I was in charge of the PEWS, I set about training myself to really understand how to set up and use the PEWS. And between the LT and I, and our really, really sharp platoon Sergeant, we came up with a plan.

Our next trip to the woods was, like so many others, focused on practicing the ambush. We’d crawl through the steps of the ambush during the morning, then walk through them in the afternoon, and then at night, one of our company’s other platoons would provide a squad to serve as the OpFor, and walk through our ambush. Typical infantry training.

The PL and PSG had the bright idea that rather than using the PEWS to guard the patrol base, we would  emplace detectors along the likely routes leading into the kill zone. Knowing the enemy was a couple hundred meters away would give plenty of advance warning, and help ensure the success of the ambush.

It actually worked pretty well.

Then one of the squad leaders had the bright idea. If he had to dispatch a fire team to emplace the detectors, why not have them emplace one or two of the flashbulb “Claymores” at the site as well, and simply roll out the wire on the way back to the ambush site?

Two detectors would be emplaced on each likely avenue of approach. The first gave a “heads up” that someone was coming. The second was to announce the enemy was in the remote kill zone. The receiver would give an indication of which detector was sensing movement. All that had to be done was plug in the proper “Claymore” and wait for the second detector to signal.

The first time we tried it, sure enough, a sensor about 300 meters away pinged, and I pointed it out to the PL. He plugged the wire into the clacker. And sure enough, about a minute later, the second sensor pinged, and LT O squeezed the clacker. A bright flash in the distance assailed our night adjusted eyes, and almost instantly, the disgusted cry of “Dammit!” came floating back to our ears.

Eventually the OpFor squad managed to get themselves squared away, and continue in to the real kill zone and get themselves slaughtered by a conventional ambush. 

Afterwards, they couldn’t figure out how we had managed to set off the “Claymore” without a trip wire. We pulled that trick a couple more times before sharing the tactic with the rest of the company.

We didn’t always use the PEWS, but it was there and ready if we needed it.