Armor in the South Vietnamese Army
 
As modest as the armored forces were in the South Vietnamese Army, they had been in existence almost five years before the first U.S. advisers arrived. Under French tutelage, the Vietnamese Armor Corps was founded in 1950 by the simultaneous establishment of an armor training section in the Vietnamese Military Academy at Dalat and a Vietnamese reconnaissance company manned by French officers and Vietnamese enlisted men.
 
By late 1955, after the division of Vietnam under the Geneva Accords, the armored force in the south had an armored regiment deployed in each of the four military regions. Each regiment had a headquarters company and three reconnaissance companies that were equipped with M8 armored cars, M3 half-tracks, M3 scout cars, and towed M8 howitzers. From the French the armor troops had inherited old equipment, black berets, and concepts of employing armored units that would take years to change. Tactics stressed defense, reaction rather than action, piecemeal commitment of armored vehicles and units, the use of armored vehicles as mobile pillboxes, and the movement of armored units almost exclusively along roads.
 
Late in 1952 an armor course was established at the Thu Duc Reserve Officer's School. In 1955, when the officer's school became the Thu Duc Military School Center, the armor branch became a separate school. Eventually the Armor School became an independent entity under the Armor Command. The first class of the basic armor officer course was graduated in May 1955, and in June Lieutenant Colonel Walter J. Landry became the first U.S. adviser to the school. In 1956 for the first time Vietnamese officers attended the U.S. Army Armor School at Fort Knox, Kentucky, to supplement their armor training in Vietnam. Between 1956 and 1973, 712 Vietnamese officers attended courses at Fort Knox.
 
To oversee armor training and the development of armor tactics for the South Vietnamese Army, the Vietnamese Armor Command, which also served as the office of the Chief of Armor, was established on 1 April 1955. The Chief of Armor, a general staff officer, theoretically had no tactical authority but advised the Vietnamese high command on armor matters, particularly training. He also supervised the armor school, armor doctrine, force structure, and equipment changes. In the early years the Chief of Armor became very powerful and even gave orders to field units, but this abuse of the chain of command ceased in the mid-1960's.
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SOUTH VIETNAMESE ARMORED RECONNAISSANCE UNIT stands inspection in 1952 at Thu Duc Officers School. 
The vehicle is a 1939 French Panhard armored car. (description)
 
With the creation of the Republic of Vietnam in October 1955 the Vietnamese Armor Corps became a part of the Army of the Republic of Vietnam, and by early 1956, when the U.S. advisers appeared it was already fairly well organized both for training and operations in the field. The existing South Vietnamese armored units were reorganized under U.S. influence as armored cavalry regiments consisting of two reconnaissance squadrons, each equipped with M8 armored cars, M3 half-tracks and M3 scout cars, and one squadron of M24 tanks. The Armor School, swept along in the reorganization, was patterned after the U.S. Army Armor School at Fort Knox. Instruction emphasized the hands-on method that characterized the American school, lesson plans and manuals were adapted from those prepared at Fort Knox, and courses like those at Fort Knox were undertaken to cover the full range of armor training.
In the years from 1957 to 1959 the U.S. adviser group with the armored force was small; sixteen armor officers were assigned to the Military Assistance Advisory Group, Vietnam. Only four armor officers were assigned to armored field units, and these assignments were not made until 1959. Not only were field advisers restricted from participating in combat operations, but before 1962 all returning military advisory officers were obliged to sign a certificate binding them to secrecy on the subject of advisory operations in Vietnam. This policy limited discussion and the publication of articles and hampered the U.S. Army in' its own preparations for Vietnam. It is no wonder then, considering the little armor there was in South Vietnam, the few American advisers, and the seal of secrecy, that the experiences of Vietnamese armored units were ignored by the U.S. military, even during U.S. troop deployments in 1965 and 1966. Yet this experience was gained in the hardest school of all, combat against an enemy. Ultimately, the impression of Vietnamese armored forces that filtered through the screen of secrecy was one of a force that had played a minor role in warfare in Vietnam. True or not, the impression was created, at least in part by the U.S. advisers.
 
U.S. Advisers
 
In early 1962, with the formation of the U.S. Military Assistance Command, Vietnam (MACV), the number of American advisers grew. In the fall of 1962, ten more armor officers arrived: four replaced armored cavalry regimental advisers, the others were assigned to six newly activated squadrons. The armor advisers who came to teach Vietnamese armor commanders and soldiers also learned, largely through trial and error, about the land, the war, and the enemy. By 1965 the regimental advisory detachment was authorized a major as regimental adviser, a captain as staff adviser, and a company grade officer and two noncommissioned officers for each squadron. As the armored force expanded, each new regiment and squadron was assigned an advisory detachment. These detachments preceded U.S. units into Vietnam and remained behind them until January 1973.
 
Advisers formed an exclusive group of officers and noncommissioned officers who were chosen by the Department of the Army strictly because they were available for reassignment and advisers were needed in Vietnam. There was no special schooling for advisers until early 1962 when a six-week course was established at Fort Bragg, North Carolina. This advisers' course, under the auspices of the U.S. Army Special Forces School, was basically infantry oriented and no armor training was provided. Language
instruction was not included and was offered only at formal language schools. As a result, most advisers had no knowledge of the Vietnamese language-a deficiency that continued as long as the war lasted. No adviser was really prepared for the cultural, climatic, and professional shock that awaited him when he joined a South Vietnamese Army unit. Patience, perseverance, and common sense were the most important assets a man could have for the job.
 
Once in Saigon, armor advisers were assigned to Vietnamese units by the armor adviser on the staff of the Military Assistance Advisory Group. Later, these assignments were made by the senior U.S. adviser to the South Vietnamese Armor Command. Each new adviser was given a short briefing on South Vietnamese armor and on the unit he was to advise before he left by helicopter or jeep to join his unit. Because squadrons were widely separated until mid-1966, the adviser rarely saw his boss, the regimental adviser, and seldom operated with other squadrons of the regiment. Dependent for supplies, food, ammunition, and his very existence on his South Vietnamese unit, he had to establish himself quickly as a team member.
 
The duty of an adviser can best be described as frustrating; it was complicated by serious differences in culture and combat experience between adviser and advised and the fact that the adviser could not speak the language of those he advised. As a representative of the U.S. Army, the adviser had access to communication and firepower support vastly superior to that of the Vietnamese unit commander. Although this advantage sometimes helped to establish the necessary working relationship, the adviser achieved a good relationship by working all day, seven days a week, mostly in the company of the unit commander. Although not expected to fight, on operations the adviser went with the Vietnamese commander, providing advice and American assistance with fire support, communications, and medical evacuation.
 
Until mid-1965 advisers were the main source of information for the American military on armor operations in Vietnam. When American troops finally joined the fighting, the adviser's position often became more difficult, particularly in the early years of the American troop buildup when the Army of the Republic of. Vietnam was generally regarded by U.S. units as inferior and a security risk. Frequently, the adviser himself was also treated like a poor country cousin. Many advisers declared bitterly that American armored units often ignored the experience and knowledge of enemy and terrain offered by the Vietnamese armor officers and the advisers. As a result of this attitude American units made fre-
quent mistakes that Vietnamese armor avoided as a matter of course. Eventually, time, improvement in the Vietnamese Army, and repeated tours by U.S. soldiers altered the situation. In the later stages of the war, many Vietnamese and American armored units established joint training, operational, and social programs that were helpful to units of both armed forces.
 
Most armor advisers were impressed by the technical proficiency of their Vietnamese units. In the maintenance of weapons and equipment, the Vietnamese armor crewman was outstanding; his innovations often extended to making repairs to his equipment with chewing gum, bailing wire, and even banana stalks. In tactics and the coordination of fire support, South Vietnamese armored units had much to learn in the early years from American advisers. The exchange of information between adviser and unit gave the adviser a better understanding of Vietnam's particular problems and was indirectly useful in helping to prepare American units for service in Vietnam.
 
Perhaps the contribution of armor advisers can best be summarized by saying that they created an atmosphere in which change, innovation, and development could take place. They were in a sense responsible for the spirit of aggressiveness and confidence that grew in Vietnamese armored units, and eventually led to the successes of Vietnamese armor during Tet 1968 and the enemy offensive of 1972.
 
M113's in the Mekong Delta
 
Despite the efforts of U.S. advisers, South Vietnamese Army tactics remained French for some time and reflected Vietnamese political pressures that put a premium on holding down casualties in men and equipment. Armor was used principally in defense; its primary missions were escorting convoys, defending positions, clearing roads, and acting as relief forces. Vietnamese equipment had been used in the French war and age had aggravated its shortcomings.
 
In an effort to introduce more recent equipment, in late 1961 the Military Assistance Advisory Group studied the possibility of using the M113 armored personnel carrier (APC) in Vietnamese Army units in the Mekong Delta. On the basis of recommendations growing out of this study, two M113 companies were organized in April 1962 and assigned to the Vietnamese 7th and 21st Infantry Divisions. The original plan had been to issue the armored personnel carriers to two well-trained rifle companies, then instruct the troops in mechanized operations. The newly organized units were
not well trained; one company was a hodgepodge of troops selected at random. Most key command positions were filled with men from the South Vietnamese Armor Command who had little combat experience, and it was necessary to extend the six-week training program to nine weeks. The companies were joined by U.S. advisers Captain James W. Bricker and Captain Stanley E. Holtom, recent graduates of the first advisers' course at Fort Bragg. Originally called mechanized rifle companies, the new units were modeled after American mechanized rifle companies. Each company was organized into three rifle platoons with three APC's in each platoon; a support platoon with four APC's, three 60-mm. mortars, and three 3.5-inch rocket launchers; and a company headquarters section with two APC's. All carriers were equipped with a .50caliber machine gun, and eighteen .30-caliber Browning automatic rifles were distributed throughout the company.
 
As with almost any new organization, the units' first engagements reflected their lack of experience. Because of the limited knowledge of armored tactics at higher commands, the units were also handicapped with improper assignments or missions that led them into impassable terrain. These early operations provoked a great deal of unfavorable comment that was directed chiefly at the alleged inadequacies of the M113. The situation improved, however, when the units acquired experience. Between 11 June and 30 September 1962, the two companies killed 502 of the Viet Cong and took 184 prisoners at a cost to themselves of 4 dead and 9 wounded.
 
The first real success with the new mechanized forces came about in a Vietnamese 7th Infantry Division operation in September 1962 in the Plain of Reeds. After studying the South Vietnamese plan, which involved several regiments under division control, Captain Bricker, the mechanized unit adviser, recommended that because of the terrain the mechanized company not be used. But since the division commander had personally developed the scheme of maneuver no changes were made and the operation was launched as scheduled.
 
Although aerial reconnaissance had confirmed the terrain difficulties, the mechanized company moved out early on 25 September with nine armored personnel carriers. For a time all went smoothly and movement was rapid. The company was ordered to bypass its first objective, continue to the second, and block the Viet Cong escape route along a four-kilometer segment of a canal. Shortly thereafter it was ordered to cross the canal and attack a group of sixty Viet Cong.
PICTURE - ARMORED PERSONNEL CARRIER, M113, firing .50-caliber machine gun during South Vietnamese training exercise. Barrel of side-mounted .30-caliber machine gun can be seen on far side of M113.
ARMORED PERSONNEL CARRIER, M113, firing .50-caliber machine gun during South Vietnamese training exercise. Barrel of side-mounted .30-caliber machine gun can be seen on far side of M113. (description)
 
The company reached the canal about 1045 and the lead elements, after a delay in finding a suitable site, began to cross. When one platoon had reached the other side, an observation post spotted fourteen enemy soldiers and the South Vietnamese company commander, Captain Ly Tong Ba, decided to attack. Although Captain Bricker had urged that the armored carriers be used t0 maneuver to the enemy flank, the APC's charged straight ahead through the flooded paddies toward the point where the Viet Cong had last been seen. Suddenly, enemy soldiers appeared all around the APC's, some firing automatic weapons and rifles and others running wildly in an attempt to evade the armored vehicles. As the APC's scattered the enemy, the South Vietnamese soldiers fired in all directions from the open hatches, with the .50-caliber machine guns dominating the fight.
 
After much discussion, Captain Bricker persuaded Captain Ba to order his troops to dismount, but this move proved to be a serious mistake. As long as the troops were mounted and moving the Viet Cong had been unable to fire well-aimed shots. Dismounted, the soldiers not only lost the advantages of movement,
cover, and observation aforded by their APC's but they also found themselves bogged down in water that was knee-deep. No sooner were the armor troops immobilized than accurate enemy fire found them out; the Viet Cong, knowing the terrain, had moved to the higher ground of an underwater knoll. As squad control disintegrated, casualties increased and the operation became disorganized.
 
The fighting subsided after an hour and South Vietnamese troops remounted their vehicles and moved west. Almost at once the company was engaged by heavy small arms fire from isolated groups of the enemy. As the APC's attacked, enemy soldiers hiding in the reeds were flushed from their concealment and overrun. It was mid-afternoon before the enemy began to withdraw. When South Vietnamese troops cleared the battlefield they found more than 150 of the Viet Cong dead. They had also captured thirty-eight men and seized twenty-seven weapons, including an American .50-caliber machine gun and two Browning automatic rifles.
 
Despite difficult terrain and poor tactical decisions this mechanized operation achieved success. Generally the unit performed well, showing that it had made great progress since completing its training in June. Its failure to maneuver, however, prevented the rapid destruction of the enemy, and, combined with confusion as to whether to conduct the attack mounted or dismounted, demonstrated that both the Vietnamese armor soldier and his adviser still had much to learn. The application of what was then American doctrine, which called for mechanized troops to dismount and assault the objective on foot, caused the attack to falter. Because of this experience, attacks in the future were conducted with troops fighting from the carriers. The M113 quickly became a combat vehicle, used almost as a light tank. Eventually, American units adopted this doctrine and fought mounted.
 
Reorganization and Retrenchment
 
The success of the first two South Vietnamese mechanized companies demonstrated the value of highly maneuverable, lightly armored vehicles in Vietnam. To supplement these two companies, the newly developed M 114 reconnaissance vehicle and additional M113's were shipped to Vietnam. The first two M113 companies were redesignated the 4th and 5th Mechanized Rifle Squadrons of the 2d Armored Cavalry Regiment and assigned to the IV Corps Tactical Zone in the Mekong Delta. The armored cavalry regiments
supporting each of the four tactical zones were reorganized in late 1962 with the addition of one armored reconnaissance squadron and two mechanized rifle squadrons. M 113's for the new squadrons arrived in late 1962 and the squadrons became operational as they completed training at the South Vietnamese Armor School. By May 1963 each of the four regiments had one squadron each of M24 tanks, M8 armored cars, and M114's, and two mechanized rifle squadrons with M113's.
 
Mechanized rifle squadrons were organized like their predecessors, the mechanized rifle companies, except for the supporting weapons. During 1962 the 3.5-inch rocket launcher and the 60-mm. mortar were judged unsatisfactory because of their limited range. Each newly organized squadron was equipped therefore with three 81-mm. mortars and a 57-mm. recoilless rifle, all transported by armored personnel carriers.
 
Unit reorganization and new equipment alone were not enough to bring about a change in the war. New tactics, better leadership, and improved training were needed to complement the increased firepower. When training lagged, overconfidence and poor leadership combined to teach some costly lessons. Advisers were often frustrated in their attempts to persuade Vietnamese armor leaders to use the new APC's properly and aggressively.
 
The battle of Ap Bac, sixty-five kilometers southwest of Saigon in the Mekong Delta in January 1963, illustrates the problem. The month before, Vietnamese Army intelligence had reported a reinforced Viet Cong company in Ap Tan Thoi, 1,500 meters northwest of Ap Bac. (Map 4) The Vietnamese 7th Division planned an operation to trap the Viet Cong by landing the 11th Infantry Regiment to the north by helicopter while a provisional regiment of two battalion-size task forces of Civil Guards (later named Regional Forces) moved in from the south. The 4th Mechanized Rifle Squadron, 2d Armored Cavalry, commanded by Captain Ba, was attached to the provisional regiment and was to attack from the southwest. Three Vietnamese Ranger and infantry companies were in reserve, with artillery and air support on call.
 
In contrast to the intelligence estimate, the enemy force actually consisted of three main force companies, reinforced with machine guns, 60-mm. mortars, and several local guerrilla units. The Viet Cong after action report subsequently captured revealed that the enemy knew a battle was imminent and had carefully prepared defensive positions along the Cong Luong Canal from Ap Tan Thoi to Ap Bac. The canal, bordered with vegetation, offered concealment and unobstructed fields of fire across the open rice paddies.
MAP 4
On the morning of 2 January 1963 the Civil Guard task forces started north, while in three uneventful trips helicopters lifted the Vietnamese 11th Infantry Regiment into position. About 0730 Task Force A encountered the southern flank of the Viet Cong positions along the Cong Luong Canal. During the first moments of battle, the task force commander was wounded and a company commander killed. Major Lam Quang Tho, commander of the 2d Armored Cavalry Regiment and also province chief, refused to allow the provincial forces to advance, and changed their mission to one of occupying blocking positions. Colonel Bui Dinh Dam, 7th Division commander, decided to commit a reserve force to the west side of the canal that runs through Ap Bac. At 1020 as the helicopters came in for their fourth lift, the Viet Cong antiaircraft crews hidden along the canal opened fire. Of the 15 helicopters bringing in the reserve, 14 were hit, and by noon 5 had been shot down.
 
Lieutenant Colonel John P. Vann, division adviser, radioed Captain James B. Scanlon, senior adviser to the 2d Armored Cavalry Regiment, that the helicopters were down about 1,500 meters to the southeast of the regiment. After considerable argument with Captain Scanlon, Captain Ba finally agreed to move across the Cong Ba Ky Canal and secure the helicopters. Three hours later, as the first of the APC's approached the helicopters, enemy fire suddenly raked the two leading vehicles and their dismounted infantrymen. The APC's began backing up, abandoning the wounded. A few minutes later they advanced again, firing their .50-caliber machine guns, and again they were hit by enemy fire. Exposed from the waist up, the machine gunners were particularly vulnerable; fourteen of them died before the day was over.
 
Captain Scanlon ran to the aid of the wounded helicopter crews, and with the help of Sergeant Bowers, another adviser, carried them to the APC's. By now more APC's had crossed the canal and they too tried to maneuver forward, but without success. Because there was no unified effort, the Viet Cong was able to concentrate fire on each vehicle in turn as it ventured forward.
 
By midafternoon when it was apparent that the enemy could not be overrun, the South Vietnamese Army commanders and the advisers decided to request reinforcement by an airborne battalion. Despite the vehement objections of both Colonel Vann and Colonel Daniel B. Porter, who was the IV Corps Tactical Zone adviser, the corps commander decided to drop the South Vietnamese airborne battalion to the west, behind the mechanized squadron, rather than east of the canal, where it would have completed the encirclement. At dusk the 8th Airborne Battalion parachuted into the rice paddies. -
The night was quiet save for artillery fire and the pop of flares over the enemy positions. Taking advantage of the open eastern side, the Viet Cong withdrew during the night and were gone by daylight. Early in the morning dismounted troops from the APC squadron crossed the canal, passed the empty enemy positions, and swept through most of Ap Bac before being ordered to hold. The airborne battalion was still organizing and collecting parachutes and was not ready to attack. Finally, at noon the force staged an attack that was really nothing more than a walk-through.
 
Because of the large number of South Vietnamese troops involved, and especially because of the number of U.S. helicopters downed early on the first day, the battle of Ap Bac drew much attention. Although estimates of the results of Ap Bac varied, Colonel Vann considered the operation a failure. Several days later he stated: "There were three main criticisms .... First, the failure of South Force to move. Second, failure of the APC's to move. Third, the parachute force. They were dropped on the wrong side of the river. It was a decision that I opposed. They wanted to reinforce defeat rather than ensure victory."
 
The fighting at Ap Bac and more specifically the employment of the mechanized rifle squadron, illustrates many of the problems faced by advisers. Poor coordination and planning were apparent at all levels in the South Vietnamese command; the airborne forces were not correctly employed and there was no unity of command on the ground. Politics also played a part. The South Vietnamese cavalry commander was the political leader of the province, and because his political and military future depended on his keeping casualties in the Civil Guard and armored cavalry to a minimum, he was reluctant to have these forces attack. Finally, strained relations between the advisers and the South Vietnamese unit commanders materially contributed to the lack of cohesion. Politically, the battle was reported as a victory, but for the armored forces it was much less. Only when the crews had had further training and experience and when improvements had been made on the equipment would the APC's be employed to better advantage.
 
While the lessons of Ap Bac were still. fresh, the South Vietnamese armored force undertook a series of expansions. In December 1963 two regimental-size armored units were activated. The 5th Armor Group, later redesignated the 5th Armored Cavalry Regiment, and the 6th Mechanized Battle Group, later redesignated the 6th Armored Cavalry Regiment, were both assigned to the Vietnamese high command as a general reserve. Formed from the tank squadrons of other units, the 5th Armor Group was in effect
the first South Vietnamese Army tank regiment. Later, in March 1964, two more mechanized rifle squadrons were formed at the Armor School and completed their training in October. These additions made a total of fourteen operational mechanized rifle squadrons.
 
Even with additional forces and equipment, however, the combat record of South Vietnamese armored forces in 1964 was still uneven. One battle in the Plain of Reeds on 3 and 4 March 1964 ended in a resounding victory for the South Vietnamese and the capture of over 300 of the Viet Cong. In contrast, on 28 December 1964 the 9th Viet Cong Division seized the town of Binh Gia, sixty-five kilometers east of Saigon. During a battle that lasted several days, South Vietnamese Ranger and Marine battalions were severely beaten. As the fighting continued into the first few days of 1965, South Vietnamese armored relief forces were ambushed and they too suffered heavy casualties. This battle was significant to both sides since it marked the beginning of Mao Tse-tung's classic and final "mobile" phase of the war. For the first time a Viet Cong division was committed as a whole; the battle itself was unusual in that the enemy unit remained on the battlefield for several days instead of resorting to the customary Viet Cong hit-and-run tactics.
 
Almost at the same time that the Viet Cong began to appear in larger units, American forces began deploying in Vietnam. Probably the most publicized campaign of 1965 was that of the U.S. 1st Cavalry Division in the Ia Drang valley west of Pleiku in the II Corps Tactical Zone. Little publicity, however, was given to the actions which led up to the 1st Cavalry battles in the la Drang valley.
 
From 19 to 27 October a South Vietnamese armored task force of tanks and APC's with Rangers battled through to the relief of the Plei Me Special Forces camp southwest of Pleiku. Although ambushed en route by a North Vietnamese regiment, the task force, with U.S. air and artillery support, reached the camp, established a perimeter, and stood off a heavy attack. It then counterattacked, killing 148 of the enemy and capturing 5. It was during this campaign that enough intelligence information was collected to warrant sending the 1st Cavalry Division into the Ia Drang valley.
 
The fight to save the Plei Me Special Forces Camp allowed American advisers to observe the Vietnamese armored task force in action. Gunnery was poor in the tank units, which were now equipped with M41 tanks. There was no effort to place accurate main gun fire; instead, the Vietnamese tankers "shot from the hip"
in the enemy's general direction and kept firing as fast as possible. Tanks bunched up, and troops demonstrated little aggressiveness, content to stand and fight as if they were in pillboxes. Security was poor-the unit was ambushed on the very first day. Coordinated action between tanks, armored personnel carriers, and Rangers was almost nonexistent. Leadership and control were still a long way from acceptable standards. Maintenance continued to be a bright spot in the performance of Vietnamese armored troops; all fifteen tanks returned from the fight.
 
Expansion of Armor in the Smith Vietnamese Army
 
In February 1965 Major Lloyd J. Brown, training adviser to the Vietnamese Armor Command proposed that the armored force be increased by seven mechanized rifle squadrons, and that the first squadron begin training almost immediately. A parallel plan sought to increase manpower authorizations and thus provide one armored cavalry regiment for each Vietnamese division, retain a task force headquarters, and greatly improve the efficiency of administrative and logistical support to the squadrons. Subsequently approved by the Vietnamese Joint General Staff and completed by mid-1966, the expansion helped solve some of the problems caused by wide dispersion of units.
 
Reorganization of South Vietnamese armored units in mid1965 brought about a change in the U.S. advisory organization. In the early 1960's there was no advisory detachment at the Armor Command; an officer assigned to the organization and training division of the Military Assistance Advisory Group also advised the Vietnamese Chief of Armor. At first described as senior adviser to the Armor Command, he became training adviser when the advisory group was supplanted by the Military Assistance Command, Vietnam, and the position came under the Training Directorate of that command. In July 1965 when the Military Assistance Command, Vietnam, established an Armor Command Advisory Detachment, Major Brown, the training adviser, became the senior adviser of the Armor Command.
 
Plans for the Vietnamese armored force for 1965 called for one V-100 armored car squadron and ten separate armored car troops to be formed, trained, and deployed to replace units equipped with the M8 and older obsolete vehicles. Three of these troops completed training in May, but structural flaws found in the V-100
armored cars delayed their use for six months. The faults were corrected by the Vietnamese Army 80th Ordnance Depot. When these units assumed route security missions the M113 units would be free for expanded combat operations.
 
In the midst of the expansion, the Armor Command was exploring alternatives for further increases. In late March 1966 Lieutenant Colonel Raymond Battreall, senior adviser to the Armor Command, directed Major James Madole, G-3 adviser, to study ways of enlarging the armored force. After accompanying each of the ten Vietnamese cavalry regiments on combat operations, Major Madole recommended that armored regiments be increased from ten to sixteen. Two of the new regiments would be placed in the two divisions scheduled to be added to the Vietnamese Army. Each of the other four would be placed under control of a corps tactical zone commander as a mobile reserve. Although the recommendations were not adopted at the time, the study influenced subsequent decisions to enlarge the Vietnamese armored forces.
 
A parallel study of Vietnamese armored cavalry was published in February 1966 by the U.S. Army Concept Team in Vietnam. This study evaluated organization, equipment, support needs, and the best ways to use armored units. After observing the six existing cavalry regiments from February to May 1965, the authors of the study recommended that each division be assigned an armored cavalry regiment consisting of a headquarters and at least two mechanized rifle squadrons. Commenting on the study, the director of the joint Research and Test Activity in Vietnam, Brigadier General John K. Boles, Jr., agreed that additional armor units were needed. However, he considered the need to be so urgent that he suggested the deployment of U.S. or other free world armored units. Thus, indirectly, Vietnamese armor influenced the deployment of U.S. armor.
 
Cuu Long 15
 
All Free World Military Assistance Forces in Vietnam faced the problem of forcing the Viet Cong into an engagement at a time of the allies' choosing. The allies' well-laid plans, based on what appeared to be sound intelligence reports, frequently led to so-called walks in the sun-because the enemy managed to avoid combat. The following is an account of one attempt to overcome this problem.
 
In March 1966 Vietnamese Army forces planned to conduct a search and destroy operation near Moc Hoa in the delta using the 6th Armored Cavalry Regiment and infantry elements of the 7th
Infantry Division. To reach the Moc Hoa area and be in position to attack on 21 March without alerting the enemy, armored forces moved a day earlier to Ap Bac, twenty-five kilometers south of Moc Hoa. Reaching Ap Bac on the afternoon of 20 March 1966, the 6th Armored Cavalry Regiment moved into a previously used assembly area, resupplied, and obstensibly prepared to stay the night. To an observer, the cavalry action resembled any number of earlier operations that had swept eastward from Ap Bac along the major canal net to Tuyen Nhon. Under the cover of darkness, however, the 6th left Ap Bac and marched to Moc Hoa, arriving there at dawn.
 
At first light on 21 March the 6th Armored Cavalry Regiment and supporting infantry elements moved across the major canal north of Moc Hoa and began a sweep to the northeast. Simultaneously, Vietnamese infantry elements were lifted by helicopter to blocking positions between the canal and the Cambodian border. Once across the canal, the regiment deployed its squadrons on line, with the lead troop of each formation in a wedge formation and the two following troops in column. At 0900 the 1st Squadron, commanded by a Captain Tien encountered a few Viet Cong eight kilometers northeast of Moc Hoa. Captain Tien immediately deployed his squadron on line and, firing rapidly, his men moved toward the enemy. High grass, however, limited visibility and the Viet Cong slipped away. At about noon the squadron began receiving small arms fire as it moved along a canal fourteen kilometers east of Moc Hoa. Again the squadron deployed on line and pressed rapidly toward the enemy positions. Pushing their way through the tall grass, the cavalry attempted to force the enemy into the open with machine gun fire. This time, however, the enemy had moved to well-prepared fighting emplacements from which they fought back with recoilless rifle, mortar, and small arms fire.
 
The high grass provided the enemy with good concealment and hampered coordination among the Vietnamese units. The 1st Squadron, 6th Cavalry Regiment, and the supporting infantry mounted on armored personnel carriers found themselves heavily engaged, flanked on both sides, and receiving fire from all directions. One APC was struck on the gunshield by recoilless rifle fire that killed the gunner and wounded three U.S. advisers riding in the vehicle. The cavalry laid down a barrage and withdrew to regroup and evacuate the wounded. While Captain Jerrell E. Hamby, the U.S. adviser, directed the medical helicopters, the troopers set fire to the tall grass, burning off the vegetation and exposing the enemy fighting positions.
Again the cavalrymen and their supporting dismounted infantry deployed on line and attacked; this time with the grass burned away they were able to pinpoint and destroy the enemy with machine gun fire. A running gun battle lasted until nightfall as the combined force moved slowly eastward along the canal. More than 200 of the enemy were killed, 17 were taken prisoner, and 89 weapons were captured. The operation demonstrated that with proper planning an armored unit could operate effectively as a strike force, even against elusive insurgents. In this instance a combined arms force, aggressively led, had proved to have sufficient organic combat power to overcome a well-armed and well-entrenched foe.
 
Time for Corrective Analysis
 
Actions like Cuu Long 15 were the exception, however, for the misuse of armor continued to be a problem through 1967. Many senior Vietnamese commanders either ignored or did not understand the capabilities of an armored force. Part of the misuse was due to the complex Vietnamese concept of unit of command. In part it also reflected the persistent palace guard syndrome that caused Vietnamese commanders to parcel out their armored forces among several province, district, or other headquarters as security elements. Consequently, armored units were unable either to take the fight to the enemy or to maintain an acceptable state of combat readiness. For example, at Ban Me Thuot in II Corps Tactical Zone the 1st Squadron (tank), 8th Armored Cavalry Regiment, served as the province headquarters guard force in 1967. The squadron had not fought since early 1966. Soon after assuming his duties, the unit's senior adviser, Captain Joseph Snow, discovered that over 60 percent of the troops had never been in combat. An extensive crew training program was immediately begun.
 
Although not all South Vietnamese armored squadrons were as inexperienced as the 1st Squadron, 8th Cavalry Regiment, similar situations were frequently encountered by other U.S. advisers as they tried to improve unit performance. A detailed discussion of the problems involved in the use of armor took place during an armor advisers' conference in March 1967. The advisers reviewed events of the past year and presented their consolidated recommendations to the Vietnamese Chief of Armor. Subjects covered the entire range of armor employment and included doctrine, training, organization, equipment, weapons, and combat vehicles.
 
The advisers' recommendations strongly echoed those set forth in the 1967 U.S. Army study, and included the suggestions that
1. Army of the Republic of Vietnam Field Manual 3-1, Armor Operations in Vietnam, be approved and distributed to all commanders, service schools, and training centers;
 
2. An M 113 hydraulically operated vehicle-launched bridge, an M 113 dozer blade kit, and the M 125A1 81-mm. mortar carrier be added to the Vietnamese armor's table of organization and equipment;
 
3. Modern weapons including the M16 rifle be issued and an automatic 40-mm. grenade launcher be evaluated;
 
4. Infrared equipment (M8 binoculars and xenon searchlights) be authorized and training conducted to improve night operations and the use of night sighting devices.
 
The advisers also supported an Armor Command proposal that the number of M 113's per troop be increased from three to five, and the remaining M8 armored car squadrons be replaced with M113 squadrons.
 
With most formal unit training and the acquisition of equipment completed and with a temporary freeze on force levels imposed, advisers began to put more stress on improving the quality of operations. They determined that there were several reasons for the poor use of Vietnamese armored forces. Supervision of subordinate elements by regimental headquarters, for example, was difficult because squadrons were widely dispersed. In addition, the tendency to employ the squadrons piecemeal frequently left regimental headquarters as unemployed control elements during combat operations. Inexperienced senior commanders often assigned unsuitable missions to armored units. Armored commanders were often given only the barest instructions for an operation-an objective and a direction of attack. Too many units were poorly led by ineffective but politically influential commanders.
 
Advisers were finally obliged to bring pressure against the Vietnamese high command to improve leadership. In April 1967, for example, they suggested that U.S. equipment support funds be withdrawn from the 5th Armored Cavalry Regiment, and in August another cavalry regiment was singled out for the same purpose. The South Vietnamese high command was moved to take corrective action. As a follow-up, advisers at all levels continued to emphasize the proper use of armored forces, including the exercise of unity of command and aggressive leadership.
 
In operations the South Vietnamese armored units continued to improve upon existing doctrinal guidelines. When ambushed, Vietnamese cavalrymen always attacked the ambushers directly. South Vietnamese operations were always much shorter in duration
than U.S. operations and the M113 units always had an infantry unit attached to fight on foot if necessary. A squadron usually operated on one radio channel so that all vehicle commanders were in constant communication and could hear the unit leader. Combat orders were oral and frequently modified to suit the developing situation. The line formation was the favorite method of movement, although enemy mining later changed this tactic. Superstition even modified doctrine since Vietnamese units seldom took eleven or thirteen APC's on an operation because these were considered unlucky numbers.
 
In the summer of 1967 General Creighton W. Abrams, deputy commander of the Military Assistance Command, Vietnam, approved the U.S. funding for several proposals made on behalf of the South Vietnamese high command by the Armor Command senior adviser, Colonel Battreall. Foremost was a plan to increase the number of M113's in a Vietnamese cavalry troop (platoon) from 3 to 5, and the total number per squadron (troop) from 15 to 22 without increasing the number of soldiers. Before this time APC squadrons had been organized along the lines of U.S. mechanized infantry companies, even though Vietnamese squadron tactics as they developed were not those of an infantry unit, but rather those of a tank company in mounted combat. The increase in the number of vehicles was accompanied by cutting the number of crewmen to a vehicle to seven men. Crew positions thus saved were then used to fill crews on additional vehicles. Among other approved proposals was one to disband armored car squadrons and issue M125AI 81-mm. mortar carriers. Regimental headquarters retained their armored car platoons, which had been issued V-100 armored cars in 1967. The M125AI mortar carrier replaced the field expedient of mounting 81-mm. mortars on the M113.
 
The advisers' emphasis on training slowly began to produce results. The 4th Armored Cavalry Regiment in I Corps Tactical Zone was an example of a unit which performed well in combat. The 4th developed an effective technique for occupying and defending a night position. Preferring to engage the enemy in the open rather than in fortified positions, the cavalrymen set up the night location whenever possible in a large open area. Vehicles moved into the area at dusk and occupied positions separated from each other by thirty-five to forty meters, the bursting radius of an enemy mortar round. The squadron was usually reinforced with an infantry battalion, dug in on line with the front of the vehicles. Barbed wire or claymore mines were placed only on wooded approaches, leaving the rest of the area free for vehicles to maneuver
during the defense. The short range of the enemy mortar and the distinctive thump produced by firing enabled the squadron to determine a compass azimuth to the mortar position. Fire from $1-mm. mortars was then walked up and down that azimuth, usually with good effect. If the perimeter received fire from long-range direct fire weapons, the squadron employed artillery and mortars rather than fire from the APC's, thus concealing the vehicles' positions.
 
To counter a ground attack, the tracked vehicles waited until the enemy was in the open before turning on their headlights and making a mounted assault with all weapons firing. Supported by fire from the infantrymen in foxholes and the squadron's mortars, this tactic usually disrupted the enemy attack. After suffering heavy casualties in several assaults against the 4th Cavalry, the Viet Cong and North Vietnamese in the area avoided night attacks on the unit's positions, preferring to attack fixed installations and less adept relief forces. Cavalry squadron commanders learned to move after dark to night locations, with squads of infantry riding the personnel carriers. The M 113's changed direction several times during the move, making it virtually impossible for the enemy to determine their destination. Thus unable to locate the unit exactly, the enemy could not attack.
 
The tactics just described paid off for the South Vietnamese 4th Cavalry on 16 September 1967, when the 3d Squadron, stationed at Tam Ky, was alerted to move south to Quang Ngai. (By late afternoon the move was canceled, and the unit remained in its compound.) Subsequent information revealed that the Viet Cong had planned a night attack by six companies to seize the provincial headquarters and a major bridge on Route 1 south of Tam Ky and to occupy Tam Ky itself. Learning that the 3d Squadron had been ordered to Quang Ngai, the Viet Cong considered the moment opportune and scheduled their attack for that night.
 
The attack began at 0200 with mortar fire, which was followed by a massive infantry assault on the provincial headquarters and the bridge. The 3d Squadron at the armor compound, two kilometers distant, also began to receive enemy mortar fire. It was normal for the squadron to leave some troops at the compound when it was on an operation, and it was these troops that the mortar attack was intended to hit. Notified of the heavy ground assault and realizing the urgency of the situation, crew members, dressed in steel helmets, flack vests, underwear and slippers, took only twenty minutes to get their fifteen tracked vehicles out of the compound and on the road. The squadron, in radio contact with the pro-
vincial headquarters, was informed that the forces at the bridge were holding their own but that the headquarters was in imminent danger of being overrun.
 
The armor vehicles turned left on Route 1 and headed north toward the sound of battle. Reaching the entrance to the headquarters, they wheeled hard left, with APC's coming on line and mortar tracks setting up to the rear. The entire line assaulted, machine guns opening fire simultaneously and headlights turned on as the APC's swept forward. The Viet Cong attack disintegrated, and those who survived fled from the onrushing vehicles. The cavalrymen scoured the battlefield for prisoners and enemy equipment. The night counterattack by the cavalry had been devastating; over two hundred of the enemy were killed; three members of the squadron were slightly wounded.
 
The 4th Armored Cavalry, one of the original South Vietnamese armored units formed in the early fifties, was by 1967 well trained and aggressively led. In addition, it operated in an area where U.S. forces had not been introduced. However, in other parts of Vietnam, with the buildup of U.S. and free world forces reaching 545,000 by December 1967, Vietnamese units were assigned the mission of supporting revolutionary development-the 1967 term for pacification. To carry out this difficult task the South Vietnamese forces were usually stationed in or near populated areas. Since U.S. forces were in the field seeking the large Viet Cong and North Vietnamese units, South Vietnamese troops, including armor, assumed primarily a defensive role; reaction to enemy initiatives was their only source of action. The result was predictable; Vietnamese armor became static and its contacts with the enemy infrequent. Armored forces lost the aggressiveness they had begun to cultivate, and advisers found it hard to get armor troops into action. The battles of 1968 would eventually change this situation.
 
Improvements in Equipment
 
Paralleling organizational changes in the armored force of the South Vietnamese Army were important changes in materiel. Improvements were sometimes made in the United States and the equipment was sent to Vietnam for testing; more often, however, the ideas originated and the work was done in Vietnam to meet a specific need. The M113 was a success but some other armored vehicles were tried out and eventually discarded. The best example of the latter was the M 114 armored reconnaissance vehicle, which was introduced into the U.S. Army in 1961 and 1962.
A U.S. Army team conducted staff briefings, driver training classes, maintenance courses, and demonstrations of the M114 for South Vietnamese soldiers. Graduates of these courses then organized and conducted classes in their own units and at the South Vietnamese Armor School. A total of eighty M114 reconnaissance vehicles were used to equip four newly organized armored cavalry reconnaissance squadrons. Others were issued to the Armor School and technical service installations for instructional and logistical purposes.
 
For a year the Army Concept Team in Vietnam evaluated the combat actions of the armored cavalry reconnaissance squadrons equipped with the M114. Although the squadrons had a few organizational and logistical problems, their critical problem was that the M114 could not move cross-country and had difficulty entering and leaving waterways. Since these defects limited the usefulness of M114's in Vietnam, the armored reconnaissance vehicles were replaced by M113's. Most Vietnamese reconnaissance squadrons. began transition training with the M113 in April and finished by November 1964. Unfortunately for the service, the M114's lackluster Vietnam performance was ignored by U.S. Army decision makers and the vehicle with all its inadequacies became standard issue for the Army everywhere but in Vietnam. It was not until 1973 that General Abrams, then the U.S. Army Chief of Staff, branded the vehicle a failure and ordered it retired from the Army.
 
The M 113, on the other hand, was the best land vehicle developed by the United States. With the aid of the M113, armored units could abandon the French tactic of sticking to the roads. An influx of enthusiastic U.S. advisers provided the spark needed for innovation. No armored vehicle is invulnerable, but the M113 proved to be as tough and reliable as any. It could absorb hits and continue operating. Only about one out of seven APC's penetrated by enemy fire was destroyed, and crew casualties were few. Successful as it was, however, the M113 did have limitations; to cut down on these and to provide new, more effective ways to use the vehicle, a number of modifications were tested.
 
The most necessary early modification was the provision of a gunshield for the APC's .50-caliber machine gun. The deaths of at least fourteen machine gunners at Ap Bac in early 1963 provided the incentive for the 2d Armored Cavalry, which fabricated the first two-gunners' shields, made of soft steel plating from the hull of a sunken ship. Later, when it was discovered that these could be penetrated, the Armor Command, the Advanced Research Projects Agency, and the Army Concept Team collaborated to make
Diagram 1. Capstan and anchor recovery
 
 
Diagram 2. Push-bar extraction. M113 employs a prefabricated bar to assist mired vehicles or improvises a push-bar from 4 x 4-inch timbers.
 
Diagram 3. Cable and log extraction is used to recover a vehicle from a canal with steep banks. The cable over vehicle 1 exerts an upward pull on the towed vehicle. Vehicles 2 and 3 exert forward pull. When the bow of the towed vehicle has been raised sufficiently, vehicle 1 moves forward. The logs on vehicle 1 serve as bearings.
Diagram 4. Block and tackle.
 
gunshields from the armorplate of salvaged vehicles. These worked well, and with the assistance of the 80th Ordnance Depot in Saigon forty-six shields were distributed to mechanized rifle squadrons during the summer of 1963. After 1964 all APC's for the Vietnamese forces were fitted with these shields before being issued. The French had used similar gunshields on armored vehicles in Vietnam ten years before. Later, many armored personnel carriers were
 
Diagram 5. Tow cables, a variation of the "daisy chain," used to extract an M113 mired in mud are 50 to 100 feet long. The yoke connections at the front of each vehicle are made from 10-foot cables issued with each M113. Poor traction near mired vehicle may require multiple tows as illustrated.
 
fitted with turrets mounting twin .30-caliber machine guns in place of the .50-caliber machine gun. Even 20-mm. guns were tried but were eventually discarded because of their mechanical unreliability.
 
Although the APC could travel across country, it did have trouble crossing the numerous canals, streams, and rivers in the delta. Of the several modifications devised, the capstan and anchor method of self-recovery proved to be one of the most successful techniques for getting an APC out of a steep-banked canal. Mechanized rifle squadrons operating in the delta devised several field expedients for canal crossing and vehicle recovery, among them the use of the push-bar, demolition, brush fill, 100-foot cable, and block and tackle. Even more rudimentary was the method known as the daisy-chain. A series of APC's were hitched together with cables and all the vehicles then pulled together. Muddy rice paddies were often crossed with as many as fifteen APC's chained together in parallel columns.
 
The average time a squadron took to cross a stream, however, was still considered excessive. Regimental commanders and advisers wanted to be able to begin crossing in five minutes or less after arrival. Although it did not meet the five-minute requirement, an aluminum balk bridge that could be placed over a thirty-foot gap by an M113 was developed in the latter half of 1965. With two additional balks, the bridge could be used by the M41 tank. Production of twenty-four M113 balk bridges was undertaken by the South Vietnamese Army engineers.
 
Originally, the M113, or APC, was intended merely as a troop carrier-a means of transport. Doctrine stated that the infantry were to dismount and engage the enemy. It soon became apparent
PICTURE - BALK BRIDGE CARRIED BY M113 is demonstrated by troops of South Vietnamese Armor School.
BALK BRIDGE CARRIED BY M113 is demonstrated by troops of South Vietnamese Armor School.
 
that the firepower of the .50-caliber machine gun, coupled with the vehicle's armor protection and mobility, produced a shock effect on the enemy. Some advisers and commanders realized that since the Viet Cong had no effective weapons to fight armor the M113 could be used as a mounted armored fighting vehicle. Consequently, Vietnamese troop commanders and U.S. advisers expressed a need for still more armament. At first, more machine guns were mounted on the sides of the vehicle by tying ground-mount tripods to the tops of APC's, then various fabricated mounts were tested and evaluated. In late 1963 it was common to see personnel carriers armed with side-mounted machine guns equipped with shields. In late 1964, even 2.75-inch rocket pods were attached to the sides of the carriers, but this scheme was abandoned because the fire was inaccurate. By 1965 the majority of the South Vietnamese cavalry squadrons used their vehicles in this manner, rarely dismounting, and then only when forced to do so by the enemy or the terrain. The APC's thus functioned as armored fighting vehicles, more like tanks than troop carriers.
 
When the enemy began to use weapons that were more effective against armor, the Americans and the South Vietnamese attempted to reduce the M 113's vulnerability to penetration. Ammunition boxes, sand bags, and track blocks were hung on sides of
vehicles. In 1966 closely spaced steel bars were installed on M 113's of the 10th Armored Cavalry Regiment, and the Army Concept Team was slated to evaluate their use. Since no significant engagement took place during the observation period, however, no conclusions could be drawn as to whether the bar armor offered protection against antitank rockets and grenades. It was, however, easily damaged when struck by brush and other obstacles. It also slowed the vehicle down, and made it less maneuverable. The Army Concept Team decided the bar armor was inadequate and the program to install it was terminated.
 
To improve the troop protection of the M113, firing observation port kits were designed for M113's, and six modified vehicles were assigned to the 2d Armored Cavalry Regiment at Vinh Long in IV Corps Tactical Zone. Each M 113 had a total of ten firing ports, four on each side and two in the rear. Above each firing port was an observation vision block. During the two-month evaluation made by the Army Concept Team no significant materiel deficiencies were noted. Because of Vietnam's consistently hot days, the absence of an enemy air threat, and the possibility of mines, South Vietnamese troops preferred to ride on top of the vehicle rather than inside. When the enemy was sighted troops jumped inside and fought, using chiefly machine guns atop the M113. After the test was completed in October 1966 the evaluators concluded that the modifications did not handicap the M113, but since the Vietnamese usually fought from the top with the hatches open there was no need for firing ports.
 
The test results were obviously biased by the fact that the team that evaluated the vehicles operated mainly with troops who fought on the top of the M 113's. Controversy over the proper positioning of M113 crews and squads continued throughout the Vietnam War. Several units, mostly American, required crews to ride inside their M 113's; others, pointing out the danger from mine explosions, did not. The differences of opinion remained unreconciled.
 
With the early success of the M113 mechanized rifle squadrons, it was only a matter of time until the M113 was modified for other roles. As early as August 1962, a flamethrower was installed in an M 113, but it was used only four times in combat in a year. In December 1964, two M132 flamethrower vehicles were sent to the 1st Armored Cavalry where they were used aggressively in daily operations. After an evaluation the Army Concept Team recommended that four M132's plus two M113 service units be issued to each regiment.
 
The 81-mm. ground-mounted mortar was made organic to the
 
M41 IN SOUTH VIETNAMESE TRAINING OPERATION. Tank has 76-mm. gun, light armor, two machine guns, and crew of four.
 
armored cavalry regiment during the reorganization of November and December 1962. For the first few months of 1963 the use of the mortar was limited because the enemy fled when faced by M113's. As the Viet Cong learned how to deal with armor and began to engage the armored personnel carriers, mortar sections had more opportunities to support the troops. The need for a mounted mortar was soon apparent as units found it difficult to fire mortars from soft ground during the rainy season. Setting up ground mortars was also too time-consuming.
 
After evaluating the 81-mm. mortar section of the mechanized rifle squadron, the Army Concept Team recommended that an armored carrier such as the M 106 with a 4.2-inch mortar be substituted. This recommendation was based on the need for the greater range and bursting radius that the 4.2-inch shell afforded. In May 1965, four M106 mortar carriers were permanently assigned to the 2d Armored Cavalry Regiment as a mortar troop. Evaluating this organization, the team concluded that although certain improvements were needed the weapon would provide excellent fire support and that one troop should be assigned to each regiment.
 
Tanks were also a problem, for by 1964 most of the M24 tanks left by the French had deteriorated into maintenance headaches. Repair parts, no longer in the U.S. supply system, were difficult to obtain. Engines, for example, were sent to Japan for rebuilding, but even this repair was uneconomical. The mechanical problems,
coupled with the M24's inability to move cross-country, helped make South Vietnamese tank squadrons ineffective.
 
In mid-1964 the M41A3 tank was chosen to replace the M24, and the first M41's arrived in January 1965. Instructor training by a mobile training team from the U.S. 25th Division in Hawaii was completed on 17 April. Five squadrons were equipped and trained by the end of 1965. Although the first plan was to turn in the old M24's, the relics became pillboxes at installations throughout South Vietnam, except for a few under control of the Vietnamese Air Force at Tan Son Nhut.
 
The singularly outstanding and most consistently praised characteristic of South Vietnamese armored troops was their ability to perform individual and unit maintenance on vehicles and weapons; advisers commended them for keeping equipment operational with very limited support. Without recovery vehicles, armored units became extremely inventive. Since the supply system in the South Vietnamese Army was universally poor, both advisers and troopers became adept at "scrounging" replacement parts. Squadron and regimental mechanics performed such tasks as internal repair of starters, generators, radiators, and carburetors-maintenance normally accomplished by ordnance units. Deprived of aluminum welding, troops repaired holes and cracks in the hulls of APC's with wooden pegs and cement. Banana stalks and ponchos were used to mend radiators in water-cooled vehicles, and roadwheels were changed by putting the damaged wheel over a hole to relieve the ground pressure.
 
With an inadequate supply system, no turret or support unit mechanics, and the only replacement vehicles in Saigon, units still managed to field consistently over 90 percent of their equipment. Combat unit maintenance remained at a high level throughout the conflict.
 
Enemy Reaction to Armored Vehicles
 
Perhaps the best way to judge the success of the M113 is to examine the enemy reaction to it. The Viet Cong were not prepared for M113's when the South Vietnamese first used them in mid-1962, as the following passage from a captured document indicates: "The enemy APC's appeared while we were weak and our antitank weapons were still rare and rudimentary. We had no experience in attacking the APC. Therefore, the enemy's M113 APC's were effective and caused us many difficulties at first." When confronted by armored vehicles, the Viet Cong usually fled rather than fight; at first there were few attempts, if any, to engage mech-
M113 AFTER HITS BY VIET CONG 57-mm. RECOILLESS RIFLE
anized units in open combat. Recognizing that they would have to adjust their tactics, the Viet Cong began to train to attack mechanized vehicles. The Viet Cong doctrine stressed occupation of dug-in positions in the face of APC assaults, and enemy soldiers were soon learning crude methods of destroying the M113. Holes the size of an APC, nicknamed tiger traps by advisers, were soon found in delta roads. Observing the difficulties that APC units had in crossing canals, the Viet Cong used canals as obstacles in their positions, and frequently they mined possible crossing sites.
 
In 1965 the Viet Cong published a comprehensive and fairly accurate training document entitled Attack on M113 APC. This document listed characteristics of the APC; organization, equipment, and strength of mechanized units; tactics used by APC units; methods of attacking an APC; and some training techniques. Included were instructions for using the new antitank weapons. In the spring of 1963 the Viet Cong had begun to use recoilless rifles with 57-mm. high explosive, antitank rounds, and the number of hits on M113's had increased dramatically by the fall of 1963. Although the rounds often penetrated, they did not usually destroy the M113. Late in that year, armor-piercing .30-caliber ammunition along with a large number of automatic weapons was found in a Viet Cong cache in the delta. The extent of the Viet Cong antiarmor equipment became apparent when, in August 1963, an armor-piercing grenade was discovered. The first 75-mm. recoilless rifle was captured in September, and in December the first M113 was damaged by a 75-mm. round. This arms buildup continued into 1964, when a variety of mines, both pressure and electrically detonated, accounted for the majority of damaged and destroyed vehicles.
 
By 1965 the Viet Cong was using armor-defeating weapons as low as company level among regular and provincial units. Newly organized weapons platoons, companies, and battalions armed with 57-mm. and 75-mm. recoilless rifles and .50-caliber machine guns were issued the rocket propelled antitank grenade, RPG2. For several years this weapon with its B40 warhead was the principal enemy weapon against armor. Eventually, the RPG2 was replaced by the RPG7, an improved antitank grenade with a more lethal warhead, greater range, and a better sight. This weapon and the antivehicular mine were the enemy's most successful antiarmor devices and were a constant and persistent problem for South Vietnamese and allied armor throughout the conflict. Although many measures to defeat these weapons were tried, no adequate means was ever found.
"Coup Troops"
 
Any discussion of the armored forces of the Republic of Vietnam in the early 1960's would be incomplete without some reference to the effect of politics on armored units. Political-military relationships in Vietnam had always been highly complex, but during 1963 the South Vietnamese armored units emerged as an important factor in the political-military equation. Since armor had been used to suppress at least three attempted coups d'etat, it was believed that armored forces had the power to uphold or depose any government. The 1st Armored Cavalry Regiment in Saigon and the 2d Armored Cavalry in My Tho, about sixty kilometers to the south, could be combined on short notice to support or suppress an attempt to overthrow the government.
 
President Ngo Dinh Diem took steps early to insure the loyalty of his armor leaders. Only the most trustworthy armor officers were assigned to the greater Saigon area. Diem also severely limited fuel allocations, so that most armored units could not reach Saigon without additional fuel. Under this system extended armor operations against the enemy were impossible. Before the November 1963 coup, President Diem and his brother Nhu developed elaborate means of monitoring troop movements. For example, Captain Ly Tong Ba, commander of an armored unit in My Tho, had to telephone the palace frequently to report his location.
 
In spite of President Diem's vigilance, on 1 November 1963 armored units from all over South Vietnam, including units from the Armor School, converged on the presidential palace to reinforce the demand that Diem resign. Early the next morning, tanks and infantry assaulted the palace, which was defended by tanks of the presidential guard brigade. The guards resisted valiantly until, hopelessly outnumbered and with several of their tanks in flames, they surrendered. Diem, meanwhile, escaped but was captured in the Cholon section of Saigon. While en route to Army headquarters, he and his brother were assassinated in an M113 of the 4th Squadron, 4th Cavalry.
 
Many armored officers were praised for their participation in the coup and rewarded with promotions. The tanks, APC's, and armored cars that participated in the coup proved the power of armored units as supporters of a political group. After the Diem downfall, the political situation was unstable, and subsequent governments kept a close account of key units that could support or defeat a new coup.
 As early as 30 January 1964, tanks participated in General Khanh's seizure of power.
 
In September, after an abortive coup attempt, there was a command reorganization that resulted in a number of officer reassignments and the imposition of restrictions on the movement of armored vehicles and units. After several South Vietnamese Armor School officers were accused of involvement in another abortive coup on 19 February 1965 the school was ordered to move. Leaving the advisers at Thu Duc, the school departed for Van Kiep on 25 February. The Vietnamese high command soon reversed its decision, and two weeks later the school returned to Thu Duc. For some time thereafter the number of forces located at the Armor School was closely scrutinized.
 
Political appointees as commanders were a fact of life until the mid-1960's and had a disastrous effect on the development and use of armor. These commanders were not always the best leaders, and often were completely lacking in initiative. Since many of these men were concerned only with their own careers, the training and combat operations of armored units suffered accordingly. If a unit had too many casualties and lost too many vehicles, particularly during Diem's rule, the commander was likely to be relieved. As a result, commanders, even the good ones, were reluctant to fight the enemy for fear of losing their jobs. Because of the necessity to protect political regimes, armored units, particularly tank squadrons, were seldom allowed far from the ruling headquarters. Thus, even down to the province level, the term palace guard was applied to many armored units. While the coups were being planned, armored units were not fighting the enemy. Only when political stability became a reality in 1968 were armored units finally able to shed this stigma of palace guard.