Blackhorse Hoofbeats

Echoes from the Regiment’s Service in Vietnam 1966 – 1972

Don Snedeker, 11th ACVVC Historian

1st Qtr 2021


The Secret Code Book


On 5 August 1971, the 10-man Combat Reconnaissance Intelligence Squad (CRIS) conducted its first ambush patrol.  The members of the CRIS were all volunteers.  They had trained for this ambush for weeks – but this wasn’t training anymore, this was the real thing.  Were they up to the test?  Had they trained hard enough?  Did they have enough ammunition, the right equipment, appropriate standard operating procedures (SOPs)?  Would the artillery and Air Cav Troop gunships come in time when called?  Would they find the bad guys that the S-2 Intelligence Officer had briefed were surely there?

First Lieutenant Dennis Cline and his fellow Eaglehorse CRIS Troopers needn’t have worried – not only were they up to the test, they would find something that made headlines in the secret corridors of US intelligence centers all the way to the top.

The Regiment – minus 2/11 and Air Cav Troop – had departed Vietnam exactly five months before the CRIS’ first ambush patrol.  Echo, Fox, and Golf Troop were virtually the only US armored forces left between Saigon and the Cambodian border – everyone else had gone back to The World.  The war was winding down for the US Army and it was time to see if Vietnamization was working.  The 1,500-man 2nd Squadron, 11th Armored Cavalry was under the Operational Control (OPCON) of the 3rd Brigade, 1st Cav Division. But, for all practical purposes, 2/11 was on its own, securing Rome Plow operations in the upper Boi Loi Woods – a traditional sanctuary for the North Vietnamese Army (NVA) and Viet Cong (VC) – and working with Army of the Republic of Vietnam (ARVN), Regional Forces (RF), and Popular Forces (PF) at the troop and platoon level.  The local NVA and VC units never seemed to run out of mines and at least one ambush patrol a week seemed to make contact, especially between the hours of 1700 – 2100 (5:00 to 9:00 PM) and 0430 – 0600 (4:30 to 6:00 AM).  And there were strong indications of increased sapper training activities, leading the intelligence analysts to conclude that there was an increased likelihood of attacks against fire support bases and military installations by the end of August.

The Air Cav Troop and its Aero-Rifle Platoon (ARPs), while still wearing the Blackhorse patch, were almost never available to be used exclusively by 2/11.  Third Brigade – the only remaining brigade of the Airmobile Division in Vietnam – always seemed to have a higher priority mission for them.  Thus, 2/11 was mostly on its own to counter the infiltration and to obtain more information about enemy capabilities and intentions. Small numbers of helicopters were made available on a daily basis, which took care of most of 2/11’s requirements. That typically did not include the ARPs.

The Eaglehorse brain trust thought that establishing and employing a small core of elite Troopers, well-trained in dismounted reconnaissance and setting ambushes, might help to find those who were planting the mines before they could wreak their deadly havoc, to disrupt the nightly NVA/VC resupply activities, and dig up some timely intelligence on possible future attacks.  So, a call for volunteers went out; scouts, tankers, and artillerymen were interviewed, and the best were selected.  They trained day and night, perfecting silent patrolling techniques, ambush SOPs, map reading, radio procedures, calls for fire, rally points, and all the myriad details that could mean the difference between life and death in the tangled darkness of the Boi Loi Woods.

Finally, LT Cline said they were ready.  Based on the most recent intelligence, the S-2 selected a target area in the southern Boi Loi Woods, about mid-way between Tay Ninh City and Saigon astride the Saigon River Corridor, known to be a major infiltration and supply route between the Cambodian border and the capital.  The 82nd Rear Service Group was thought to be active in the area, preparing base camps and establishing supply caches for units preparing for or returning from operational missions.  They had been in the area since May and it was time that they were welcomed to the area, Blackhorse style.

The ten members of the CRIS were briefed on the enemy situation, on radio call signs, and emergency procedures.  Weapons, ammunition, claymores, and radios were checked one final time before leaving Fire Support Base (FSB) Warrior and then they were on their way.  This was it – the big time, their first ambush.  Time to see if the theory was right, the training appropriate, and the Eaglehorse up to its latest challenge.

Dropped off at 1415 (2:15 PM), the patrol carefully made its way toward the target – a major trail junction that ran generally north-south along a Rome Plow cut.  By 1710, the CRIS had set up its ambush.  LT Cline called in their coordinates and they settled in to wait for the bad guys.  They didn’t have long to wait.

An hour and twenty minutes after setting out their claymores and getting into their hide positions, the CRIS theory and training were translated into reality.  Six enemy were moving in a single-file column off to the side of one of the trails, along the brush line, leading to the junction where the Eaglehorse Troopers waited.  The point man – armed with an AK47 rifle – was 20 feet ahead of the next man in line, with about 5-foot intervals between the next five.  They were all wearing the green and blue uniforms of the NVA.  A couple even sported a blue and white checkered headband.  The second guy in line seemed to have an RPG (rocket-propelled grenade) launcher.  The fourth man in line was armed with a pistol – probably an officer!

At the predetermined signal when the NVA entered the kill zone, the Eaglehorse CRIS opened up with everything they had – an M60 machine gun, M16 rifles, M18 claymore mines, and an M79 “blooper” grenade launcher.  The point man and the third and fourth NVA soldiers in the column went down immediately.  The second man with the RPG was wounded, but was able to get away to the northwest into the brush.  Numbers five and six, seemingly unwounded, evaded to the north.  The whole fight was over quickly – certainly not more than two minutes from first to last round, maybe less.

After giving the cease fire order, LT Cline directed the CRIS patrol to sweep the ambush site, check for the three NVA who got away, and then collect the weapons, equipment, and documents from the three NVA who had been killed in the initial fusillade.  And, oh what a collection it was.  In addition to the standard inventory of Russian and Chinese made weapons (one AK47 rifle, one K54 pistol, one Makarov 9mm pistol, and a B40 RPG launcher), there were two M26 hand grenades (made in the US of A), 20 rounds of pistol and 120 rounds of rifle ammunition, and an eclectic assortment of equipment odds and ends – ranging from an American pistol belt to five hammocks, eight ponchos, three packs, two flashlights, two transistor radios, one cigarette lighter, GI insect repellent, a city map of Saigon and another map showing the area between Tay Ninh City and Saigon, a VC newspaper dated 25 June, and a bunch of personal and official mail.  About the same sort of stuff that a GI would carry in his rucksack.

There was also a bag of rice (including instructions on how to cook it), a bag of dried fish sauce (nouc mam), some peppers for spicing up the rice, one can of powdered milk, 20 fish hooks, and a C-ration can opener (even the NVA thought the P38 was one of the greatest inventions known to man).  No Tabasco sauce or pound cake, but along the same lines of what most GIs carried to make C rations tolerable.

But there were also some very unique items among the things collected by the CRIS on the night of 5 August 1971.  For example, one of the canvas and rubber packs contained a brassiere, a blouse, and other women’s clothing.  Was one of those who escaped a woman?  None of the ten men on the ambush patrol could say for sure.  One of the ambushed NVA was also carrying 75,000 South Vietnamese Piaster – over $70,000, quite a tidy sum in those days.  He was also carrying a lot of receipts, both from Vietnam and from Cambodia, the sort of things one would carry if they were in the business of procuring food, building materials, and medicine to stock a jungle bunker complex. 

But the real prize of the 5 August ambush – other than the fact that there were no friendly casualties – were two documents taken from the NVA dead.  First, there was a book that contained a detailed list of undercover VC agent numbers and reports since October 1970.  In his official report, the Squadron S-2 wrote “Very hot item” behind this entry.  The CRIS also discovered a secret code book, which the S-2 characterized as “of extreme importance.”

These documents were quickly scanned at squadron-level and then forwarded to the “highest commands.”  Although there is no hint in later 2/11 records what happened to these documents, they were clearly extremely valuable.  They gave information about who the VC agents were, what they were says, and provided a key to the codes that were being used by these agents and NVA headquarters.

The 5 August ambush proved the value of the Combat Reconnaissance Intelligence Squad.  The theory was right, the training was appropriate, and the Eaglehorse was more than up to the challenge.  Like their Air Cav Long Range Reconnaissance Platoon (LRRP) predecessors, the CRIP became part of the Blackhorse’s ability to find the bastards and pile on.



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