In the summer of 1967, it was decided to increase the number of M-113s in ARVN units from three to five, and the total number per squadron from 15 to 22 without increasing the number of soldiers. Among other approved proposals was one to disband armoured car squadrons and to issue M-125A1 81mm mortar carriers. Regimental headquarters retained their armored car platoons with the V-100s. An M-113 hydraulically operated vehicle-launched bridge and an M-113 dozer blade kit was also added to the ARVN armor's table of organization.
The newly reorganized units fought several conclusive battles. During Operation "Cuu Long 15" in March 1966, the 6th ACR encircled a Viet Cong battalion at Moc Hoa and killed 200 of the guerrillas. On 16 September 1967, the 4th ACR repulsed an important night assault against the city of Quang Ngai. But it was during the infamous Tet Offensive, launched on 29 January 1968, that ARVN armor played a decisive role. Along with American armored units, ARVN armored cavalry regiments counterattacked to recapture the lost cities in bitter house-to-house fighting. The 3rd ACR broke up an attack against Quang Ngai in a two-day battle. The same unit later moved to Pleiku to withstand Viet Cong assaults for five days. At Ban Me Thout, the 8th ACR fought a three-day street battle. Encountering ambushes on the way, the 1st ACR travelled 100 kilometres (62 miles) in eleven hours to relieve the city of Phan Thiet.
At Saigon, the 10th, 5th and 1st ACRs fought various battles around Long Binh, Bien Hoa, Ho Nai and Due Hoa. At Thu Duc, a cavalry task force of students and faculty from the ARVN Armor School defeated the enemy in bitter street fighting. Inside the capital itself, ARVN M-41A3 tanks and M-113 APCs fought tenaciously with the help of Rangers to clear out the Communist occupied sections of town.
In the Mekong Delta, the provincial capital of My Tho was reoccupied after a three-day battle. The 6th ACR, along with ARVN and US Army infantry, killed 800 enemy troops. The 2nd ACR fought its way fifteen kilometres (nine miles) from their base camp to the city of Phu Vinh. Using massive firepower and without the aid of infantry, the cavalrymen destroyed the enemy resistance in the city in less than twenty-four hours. Later the regiment was redirected to retake Vinh Long after five long days of urban fighting.
Along the Demilitarised Zone (DMZ) that separated the two Vietnams, at Dong Ha and Chu Lai, the 4th and 7th ACRs fought with US Marine Corps armor battalions to clear out many ambushes set up by the PAVN along the main roads leading to Da Nang and Hue. At Hue, the old Imperial Capital, ARVN and US Marines fought the longest battle of Tet, which lasted twenty-six days. The 17th ACR, reinforced by elements from the 4th and 7th ACRS, supported the infantry assaults in a thickly populated area. Tank crews were so shaken by multiple hits from rocket-propelled grenades (RPG) - as many as fifteen on some tanks - that crews were changed at least once a day. Armored units were in constant demand and often expended their vehicle ammunition loads in a few hours.
The Tet Offensive improved the confidence of the ARVN troops in the very fighting that was designed to persuade them to desert to the enemy. The ARVN Armor Command proved its value in combat and was further expanded. Seven more armored cavalry regiments were set up during the 1968-1969 period. The first one was the 11th ACR at Dong Ha, followed by the 12th ACR at Can Tho, the 17th ACR at Hoi An, the 14th ACR at Kontum, the 15th and 18th ACR at Bien Hoa, and the 16th ACR at Long Xuyen.
Only the fighting elements are
indicated. The Regiments in the Delta (2nd, 6th, 9th, 10th and 16th)
In 1969, the various armored cavalry regiments deployed within a Military Region (the new name of the Corps Tactical Zone) were regrouped within an armor brigade. This brigade would be placed under the control of the Military Region commander as a mobile reserve. The 4th Armor Brigade was the first then created at Can Tho and was attached to Military Region 4. It was followed by the 1st Armor Brigade at Da Nang in Military Region 1. The year 1970 saw the creation of the 3rd Armor Brigade at Bien Hoa in Military Region 3. Finally, the 2nd Armor Brigade was set up at Pleiku in 1971 in Military Region 2.
During 1969, the ARVN armored regiments continued to support pacification operations, often operating with the regional and popular forces. In February 1970, the 1st Armored Brigade conducted mobile independent operations along the sea in the northern part of Military Region 1. Controlling up to two armored cavalry regiments, Rangers, and territorial forces, the brigade roamed over the area for two months and succeeded in destroying three enemy battalions. Almost 900 Viet Cong and PAVN were killed or captured, while the brigade lost sixty-eight men. For success in its first large-scale operation, the ARVN 1st Armored Brigade was awarded a US Presidential Unit Citation.
With the gradual withdrawal of US forces, under the policy of "Vietnamization", the ARVN armored units were destined to play the main role in future combat. On 14 April 1970, the ARVN 3rd Armored Brigade launched Operation "Toan Thang 41", a three-day operation into the so-called Angel's Wings, an area in Cambodia long used by the PAVN. This led to the capture of several logistical bases and the killing of 378 enemy troops.
On 20 April 1970, it was 4th Armored Brigade's turn, along with three armored cavalry regiments and three Ranger battalions, to attack into the Crow's Nest. Large quantities of equipment and weapons were seized. On 28 April, the 2nd and 6th ACRs attacked again into the Crow's Nest and diverted enemy attention from the larger attacks in Military Region 3.
The major attack into Cambodia was a series of operations jointly planned and conducted by South Vietnamese and American units. When it began, Operation "Toan Thang 42", the ARVN portion, was probably the best planned South Vietnamese operation to date. The operation was planned so that US and ARVN forces were separated by well-defined boundaries, although they attacked simultaneously with the ARVN forces forming most of the eastern pincer.
Operation "Toan Thang 42" began on 29 April when the three task forces entered the Cambodian Svay Rieng province. All the units from the 3rd Armored Brigade were committed, and they reopened Route 1. On 2 May 1970, the 4th Armored Brigade also attacked into the Parrot's Beak to support an encirclement of the area by the 3rd Armored Brigade. The object was to trap the enemy with elements of nine armored cavalry regiments. The advance of the 4th Armored Brigade encountered heavy resistance during the afternoon. The vehicles from the 2nd, 6th, 9th, 12th and 16th ACRS, some 250 M-113s, lined up abreast at 25-meter (27-yard) intervals and, with infantry support, attacked on a 6-kilometer (3.7-mile) front on flat terrain. The breadth of the attack overwhelmed all resistance. The two ARVN forces linked up early in the afternoon of 4 May. Over 400 of the enemy were killed, and tons of ammunition and weapons were captured.
The ARVN task forces then sped north and secured Kompong Trach. On 17 May, ARVN M-41A3s and M-113s reached Route 15, halfway to the besieged town of Kompong Cham. In the meantime, the 11th ACR attacked the rubber plantation of Memot and captured 21 American-made 2 1/2-ton trucks of World War II vintage. The 11th ACR continued to advance in the Fishhook area in late May.
On 23 May 1970, the two ARVN armored brigades attacked toward Kompong Cham to relieve the siege laid by the 9th PAVN Division. The 5th, 15th and 18th ACRs inflicted a severe beating on the 9th PAVN Division in the rubber plantations of Chup. In mid-June, the PAVN 271st Regiment re-entered the Chup plantation and cut Route 15. For three days, repeated attacks were launched by the 15th and 18th ACRS, which finally cleared the road.
The ARVN forces of Military Region 3 periodically returned to Cambodia during the next eighteen months. Most of their operations were hit and run and had limited objectives. One operation, "Thoan Thang 01 -71 ", which started on 4 February 1971, ended in failure. Superior enemy forces on Route 13 quickly surrounded the ARVN task force. The 3rd Armored Brigade was ordered north to link up with the isolated task force, which attacked south hoping to pass trough the enemy positions. This ordinary withdrawal quickly turned into a rout, with the ARVN losing a dozen M41A3s and M-113s. The collapse of command under stress was to plague the ARVN forces up to the end of the war.
Vietnam Tracks, Armor in Battle 1945-75, Simon
Dunstan, Osprey Publishing Ltd., 1982, ISBN 0-85045-472-7