NVA HILL TRAP MANEUVERS

In or around 1966, the NVA began to develop a new maneuver, which was called the 'Hill Trap' maneuver. This maneuver sought to exploit the known battle habits of US troops by drawing them into a mountainous killing ground where a defence in depth, combined with standoff bombardments and rear attacks, would likely annihilate them.

Hills and mountains in each of South Vietnam's four Corps areas were prepared as battlefields. Conscripted labourers prepared mountain strongholds where they dug tunnel complexes, bunkers and trench lines. Most of this work was concentrated in I Corps in and around the strategic A Shau/Da Krong War Zone, west of Hue, and in the strategic Triborder/Chu Pong War Zones, west of Dak To, in II Corps.

To ensure that these preparations were not impeded, NVA troops occupied the A Shau valley in early 1966 and established strong anti-recon screens to the west. The same procedure was followed between the Triborder Zone and Dak To.

DAK TO

Map of the Dak To battleEarly in '66, allied intelligence indicated a strong build-up in the Triborder area where two NVA Infantry Divisions (1st and 10th) were supposedly preparing for action. The US 4th Infantry Division began scouting the staging area in early 1967.

The US 4th Infantry Division had already been engaged in skirmishes with the NVA further south along the Cambodian border, near the Ia Drang River where, in May 1967, the K4 and K5 Battalions of the 32nd NVA Regiment had been encountered.

NVA attacks began to flare up near the Cambodian border. In June '67, the NVA initiated rocket attacks against Pleiku. In July '67, elements of the 66th NVA Regiment severely mauled the US 1st Battalion, 12th Infantry, near Duc Co.

The 6th Battalion, 24th NVA Regiment, appeared near Dak To on June 22nd, 1967. The Regiment had recently been engaged with the US 1st Brigade, 101st Airborne and, in a bloody battle, the 6th Battalion had destroyed Alpha Company of the US 2nd Battalion, 503rd Airborne, Bob Fleming wrote,

I know, because I had arrived in Vietnam on that very day and was a assigned as a replacement to it.  It lost around 70-80 men in a short period.

In August '67, ARVN troops fought the 2nd Battalion, 174th NVA Infantry Regiment near Dak To while in early November the US 4th Battalion, 503rd Airborne suffered severe casualties when it assaulted an NVA bunker line near Dak To.

NVA battlefield preparations were extensive. In mid 1966, the 24th NVA Infantry Regiment moved into the mountainous area twenty miles north-east of Dak To and began to occupy fortified positions centred on Hill 1416. This position directly threatened the Route 14/Route 512 road junction West of Dak To.

Ten miles to the South of Dak To, the 32nd NVA Infantry Regiment carried out similar deployments, occupying a series of fortified mountain redoubts. Primary defensive areas were concentrated around Hill 1262 and Hill 1338. Fortifications had also been established along the 32nd's intended line of retreat, following a watercourse southwestward toward the Cambodian border. Forming the hinge of that escape route was fortified Hill 823.

Ten miles west of the Triborder Zone (less than ten miles south of Ben Het) was another fortified area occupied by the 66th NVA Infantry Regiment accompanied by the 40th NVA Artillery Regiment. These two regiments were well dug-in along a fortified mountain front, which centered on Hill 823.

Only five miles south of Hill 823 was the prepared battlefield of the 174th NVA Infantry Regiment, it's own defensive area being centered on Hill 875, just five miles due west of the Cambodian border.

General Peers, Commander of the US 4th Infantry Division, later commented, "The enemy had prepared the battlefield well. Nearly every key terrain feature was fortified with elaborate bunker and trench complexes. He had moved vast quantities of supplies and ammunition into the area. He was prepared to stay..."

NVA B-3 FRONT

The B-3 Front, which controlled the Triborder and Chiu Pong War Zones launched it's 1967/68 Winter-Spring Campaign in II Corps with the following objectives in mind;

  • to draw allied troops into the Triborder Area where some of their elements could be annihilated.
  • if the campaign went badly, to withdraw rapidly into the Cambodian/Laotian sanctuaries
  • to practice the 'Hill Trap maneuver' in the prepared battlefields

For the campaign around Dak To, the B-3 Front assigned a formidable collection of units to the NVA 1st Infantry Division;

  • 32nd NVA Infantry Regt
  • 66th NVA Infantry Regt
  • 24th NVA Infantry Regt
  • 174th NVA Infantry Regt
  • 40th NVA Artillery Regt.

The Division controlled approximately 7,000 combatants, or the equivalent of seven USMC Battalions. It was, however, spread quite thinly over a vast area of some 900 square miles of jungled terrain with fortified mountain redoubts too far apart to mutually support each other.

In early November, 1967, the US 4th Battalion, 503rd Airborne, fought small elements of the 66th NVA Infantry Regiment on Hill 823.

In mid-November, 1967, the 2nd Battalion, 503rd Airborne, was informed that the 174th NVA Infantry Regiment was being used to cover the withdrawal of the 'beaten' NVA 32nd and 66th Infantry Regiments and that the 174th was dug-in on Hill 875, five klicks from the Cambodian border.

HILL 875

An M79 Grenadier fires at enemy positionsHill 875 was thick with vegetation and tall trees. Its steep slopes were covered with mixed bamboo and scrub brush. Arriving at the foot of the hill, two rifle companies (Delta and Charlie) of the 2nd Battalion, 503rd Airborne, lined up abreast facing the objective area. They intended to advance up the gradual, 100-meter wide ridgeline leading to the top of the hill and, if the enemy were there, they would use Tac Air and artillery to attack him.

Although the two assault companies were fighting side-by-side, they were fighting independently since there was no overall commander on the ground with them. When the three companies of the battalion jumped off in their assault, the battalion commander was not present.

It was expected that when the enemy was encountered, the US troops would form into a defensive perimeter and watch as air and artillery decimated the enemy. Then the US troops would simply occupy the positions.

As the two assaulting rifle companies advanced, they were soon pinned down by an enemy bunker line which was defended by NVA from 2nd Battalion, 174th Infantry Regiment who not only pinned the US troops, but also left their fortified lines in an effort to close assault the US companies.

Behind the front line, the US reserve Company (Alpha) chopped an LZ and set up outposts covering the rear of the assault. Two platoons from this Company then began ferrying wounded from the front line back to the LZ.

Observing the US Company around the LZ were the two other battalions of the 174th NVA Infantry Regiment who were preparing to execute a Hill Trap Maneuver. In all likelihood, the maneuver was to be prosecuted by the 174th NVA Infantry Regiment in the following manner;

  • pin the US assault force on Hill 875 in front of the defences of 2/174th, causing as many casualties as possible such that, after several hours, the US reserve company would be spread very thinly carrying casualties and protecting the rear
  • at the right moment, bombard the US reserve company with a deployed mortar platoon and then hit it with the 1st Battalion, 174th NVA Infantry Regiment. The 1st Battalion, 174th, would then drive through the US reserve company and into the rear of the US assault forces pinned on Hill 875.
  • as the enemy reeled from this blow, the 3rd Battalion, 174th, which was deployed behind a nearby hill, would also be committed to attack the enemy perimeter from another direction.

Four hours after the battle began, the NVA 1/174th Battalion struck the US rear guard Company, charging through the position with such force that two US platoons were destroyed. Split, and under fierce assault, the US Battalion reserve was in immediate danger of being overrun. Most of the paratroopers were already dead or wounded when the six-man command group was wiped out in hand-to-hand combat.

The force of the NVA assault drove the remnants of the reserve Company up the hill and into the rear of the two assaulting Companies. The battered US battalion formed a perimeter and was attacked relentlessly for the next 24-hours. Whilst supporting fires rained down onto the attacking NVA the US perimeter barely survived. During the course of this period an unfortunate friendly fire incident resulted in a US pilot accidentally dropping a 250-lb bomb into the US perimeter on Hill 875 which killed forty-two and wounded a further forty-five, in effect, destroying one whole Company of the US 2nd Battalion, 503rd Airborne.

Troopers taking cover from withering NVA fireThe US 4th Battalion, 503rd Airborne, attempted to relieve the beleaguered 2nd Battalion and tried to attack up the hill, towards its surrounded comrades. As they did so they were met with volley-fired RPGs and machine gun fire at point blank ranges. NVA mortar shells impacted all over and around the US positions as the NVA constantly struck at the flanks and rear of the battalion. Massive artillery and air support saved the US 4th Battalion as it reeled back down the mountain.

That night, while two decimated US paratroop battalions littered the slopes of Hill 875, the NVA 174th Infantry Regiment slipped away and crossed into Cambodia without further losses.

Despite the losses inflicted on the two US battalions, losses which left them as skeleton commands with Companies of only twenty or more effectives and platoons reduced to six or seven men, the NVA were not able to successfully complete the Hill Trap Maneuver all the way to annihilation of the US force. Nonetheless, they had managed to gut the 173rd Airborne Brigade, which was never again deployed as a complete combat unit.


Read Bob Fleming's recollection of events on Hill 875

 

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