From February through March, the 11th Marines with its 190 guns surpassed
the size of the 12th Marines. Reinforced not only by the 1st Field Artillery
Group and Army artillery in the Phu Bai sector, the regiment also obtained
operational control of the 2d Battalion, 13th Marines. The latter battalion
arrived with the 27th Marines as part of the February reinforcements
approved by President Johnson.15*
As the enemy Tet attacks gradually subsided, the U.S. forces prepared to take the offensive. Towards the end of March, the 11th Marines lost operational control of several of the Army artillery units and the 1st Battalion, 11th Marines to the 1st Air Cavalry Division in preparation for that division's Pegasus operations. At the same time, the artillery regiment at Da Nang in its own way took more aggressive actions. It continued to support the reconnaissance Stingray patrols and began to employ "Firecracker Munitions". On 7 April, for example, the 1st Platoon, 3d 8-inch Howitzer Battery fired three CoFraM rounds on about 80 VC in the open and killed over 50 of them according to the reconnaissance Marines who called in the mission. In another "Firecracker" mission, three weeks later, the 4th Battalion, 11th Marines claimed to have killed more than 60 enemy troops attempting to cross a river. Of the total 1,100 reported enemy dead in the 1st Marine Division area of operations for the month of April, the 11th Marines maintained that nearly half were the result of its artillery fire.16
By the end of the month, the 1st Marine Division supported by the 11th Marines prepared for extensive offensive operations which would require more forward firing positions. The division planned to conduct two multi-battalion spoiling operations in May. In Operation Allen Brook, the 27th Marines planned to penetrate the Go Noi Island sector, while the 7th Marines and later the 26th Marines were to conduct Operation Mameluke Thrust in the Vu Gia River Valley near the U.S. Special Forces camp at Thuong Duc, about 25 miles southwest of Da Nang.**
At the same time, American intelligence reported that North Vietnamese troops posed a threat to two other Special Forces camps Ngog Tavak and Kham Duc, about another 35 miles southwest of Thuong Duc. Situated near Laos in Quang Tin Province, the two outposts provided the allies the ability to monitor the North Vietnamese infiltration through the Ho Chi Minh Trail network across the border into South Vietnam. With the fall of Lang Vei near Khe Sanh earlier in the year, they remained the only Special Forces camps in I Corps near the trail.
With the increased likelihood that the North Vietnamese might attack, General Cushman, the III MAF commander and the senior I Corps advisor, decided to reinforce the bases. Army engineers had already started in early April to upgrade the runway at Kham Duc and to construct a radio navigation facility there. On 16 April, the 11th Marines alerted the 2d Battalion, 13th Marines to be prepared to send a 105mm howitzer detachment of two guns from Da Nang to Kham Duc. Thirteen days later, a fixed-wing transport ferried a platoon-sized detachment from Battery D of the battalion consisting of one officer and 43 enlisted men with two 105mm howitzers to the Kham Duc airfield. On 4 May, a Marine helicopter lifted the detachment together with its guns and equipment from Kham Duc to the satellite camp at Ngog Tavak, a distance of some five miles to the south. Sited on Hill 738 and within 10 miles of the Laotian border, the Marine artillerymen were in position to disrupt the movement of North Vietnamese troops along the nearby trails and avenues of approach.17
Besides the Marines, Ngog Tavak, with its defenses dating back from the days of the French war against the Viet Minh, was home to a 113-man CIDG Mobile Strike Force Company. Serving with the Vietnamese irregulars were eight U.S. Army Special Forces advisors and three members of an Australian Army training team. For a brief period, even with the arrival of the Marines, the North Vietnamese left the camp relatively unmolested. This all changed in the early morning hours of 10 May. At 0240, the Marine detachment reported that Ngog Tavak was under attack from four directions. By 0330, under cover of B-40 rockets, grenades, mortars, and small arms, North Vietnamese regulars had breached the wire of the outside defenses. According to reports, some of the CIDG troops manning the outposts turned their weapons upon their compatriots and Americans in the compound. The Marine artillery gunners lowered their howitzers and fired directly into the onrushing North Vietnamese. Other members of the detachment grabbed whatever weapons were available and continued to fend off the attackers as best they could.18
One Marine, Corporal Henry M. Schunck, rushed from the protective cover of his position near the command bunker to a more exposed, abandoned 4.2-inch mortar emplacement in the center of the compound.
* See Chapters 13 and 27 for the arrival of the 27th Marines.
** See Chapter 17 as well for discussion of Operation Mameluke Thrust.