CHAPTER V

The Hot War (1968-October 1969)

The Viet Cong and the North Vietnamese Army in late 1967 launched several costly attacks. On 29 October the Viet Cong attacked the South Vietnamese district capital of Loc Ninh, ran up the flag of the National Liberation Front, and tried to hold the city. United States and South Vietnamese forces responded with massive air and artillery bombardment, but the enemy continued to press the attack despite heavy losses. Similarly, in early November four North Vietnamese Army regiments fought U.S. and South Vietnamese troops near Dak To. The U.S. command deployed the equivalent of a full division from the heavily populated coastal lowlands to the battle area. Again, as at Loc Ninh, the enemy sustained heavy casualties. A captured enemy document listed four objectives for the 1967 campaigns. These included encouraging units to improve, in combat, the technique of concentrated attacks to annihilate relatively large enemy units and effecting close coordination with various battle areas throughout South Vietnam to achieve timely unity. The activity of late 1967 was a prelude to Tet 1968. A high-level prisoner later revealed that the assault on Loc Ninh had been ordered to test mass formations and previously inexperienced troops in preparation for the 1968 offensive.

Tet, the festival of the Asian lunar new year, usually was the occasion for a formal cease fire. In 1968, however, the North Vietnamese Army and the Viet Cong, using reserve forces and the larger supporting weapons, launched a series of massive coordinated attacks in what became known as the Tet offensive. As revealed by captured enemy sources, the strategy for the offensive was based on the belief that the war would culminate in 1968 and that large-scale continuous attacks, in conjunction with a general uprising of the people, would precipitate the withdrawal from Vietnam of U.S. forces and the collapse of the South Vietnamese government, which would then be forced to accept a coalition government dominated by the National Liberation Front.

Tet 1968

Political and military targets of the Tet offensive included pro-

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vincial and district capitals, the government in Saigon and its agencies such as the Regional Development Cadres and the National Police, and the Republic of Vietnam Armed Forces. The enemy believed that if widespread attacks were successful, the inability of the government to protect the people would become obvious and the credibility of that government would be undermined. Installations and facilities that were essential to the conduct of the war and that were difficult to defend became tactical targets. (Map 10) In preparation for the Tet offensive, the enemy went to unprecedented lengths to assemble supplies and weapons and to infiltrate the cities. In Saigon, funeral processions concealed the movement of arms and ammunition. In Hue and Saigon, enemy troops in civilian dress escaped detection. In provincial centers such as Quang Tri, Da Nang, Nha Trang, Quin Nhon, Kontum city, Ban Me Thuot, My Tho, Can Tho, and Ben Tri, the enemy infiltrated in strength.

The offensive began at 0015 on 30 January at Nha Trang. The same night eleven other cities in I and II Corps zones, as well as several military installations and airfields, came under attack. Enemy documents later revealed that these attacks were premature; the forces operating in these areas had not received the order for a one-day postponement of the offensive. The main attack took place on the following night, 30-31 January, when enemy forces hit eighteen cities throughout the country. The allies cleared most of the cities within hours. However, in a few cities, particularly Saigon and Hue, the fighting continued for days.

The attack on Hue commenced at 0340 on 31 January. (Map 11) Elements of the 800th, 802d, and 806th Battalions, 6th North Vietnamese Army Regiment, and the 804th Battalion, 4th North Vietnamese Army Regiment, initiated a rocket, mortar, and ground assault on the city. Forces of the 4th Regiment soon occupied all of southern Hue except the Military Assistance Command compound. Meanwhile, to the north, two battalions of the 6th Regiment moved into the citadel, an old French fortress near the center of the city. By morning the flag of the National Liberation Front had been mounted on the flag pole of the citadel and the enemy controlled all of the fortress but the South Vietnamese Army 1st Division headquarters.

The allies acted immediately to relieve the pressure on the Military Assistance Command and South Vietnamese Army compounds. While U.S. and Vietnamese marines along with the 1st Division bore down on the enemy forces to the south and within the city itself, the 3d Brigade, 1st Cavalry Division, sealed off Hue to the north and west. Each of the maneuver forces fought exceptionally well, but the actions of the 3d Brigade, 1st Cavalry Division,

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Map 10

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Map 11

were the most significant from a fire support aspect. The 3d Brigade blocking force was comprised of the 2d Battalion, 12th Cavalry, and the 5th Battalion, 7th Cavalry. The 1st Battalion, 7th Cavalry, 3d Brigade, was committed to base camp defense and did not join the rest of the brigade until 19 February. On that day the 2d Battalion, 501st Airborne, of the 101st Airborne Division, newly arrived from III Corps, also joined the 3d Brigade. The 3d Brigade direct support battalion, the 1st Battalion, 21st Artillery, established a fire support base at a South Vietnamese Army compound northwest of Hue.

On 3 February the 2d Battalion, 12th Cavalry, detected a large North Vietnamese force positioned near Que Chu, west of Hue.

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Map 12

The battalion, supported by indirect artillery fire, aerial rocket artillery, and helicopter gunships, attacked the well-fortified enemy position. By 5 February the 2d Battalion controlled the high ground in the Que Chu area overlooking the surrounding plains and, with precise artillery fire, was able virtually to stop all enemy movement.

Beginning on 9 February, while the 5th Battalion, 7th Cavalry, maintained the blocking position, the 2d Battalion, 12th Cavalry, entered the village of Bon Tri to the south of Que Chu and encountered a well-dug-in regimental-size enemy complex. For three days U.S. artillery, air strikes, and naval gunfire pummeled the positions. On 12 February the 2d Battalion had to break contact without any substantial change in the situation. The 5th Battalion took over the assault, but it too was unable to dislodge the enemy.

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It remained for the 2d Battalion again to pick up the assault on 21 February and finally secure the village.

Meanwhile the remainder of the 3d Brigade, joined by the 1st Battalion, 7th Cavalry, and the 2d Battalion, 501st Airborne, had begun its move toward Hue from the northwest. On the morning of 21 February the brigade crashed into a strong enemy defensive position in the Ti Ti woods, approximately five kilometers northwest of the city. Tube artillery, along with naval gunfire and aerial rocket artillery, enabled the brigade to breach the enemy positions.

The advance of the 3d Brigade toward Hue necessitated close fire support coordination. Elements of the 1st Battalion, 30th Artillery (155-mm.), and 1st Battalion, 83d Artillery (8-inch, self­propelled), had been situated at Landing Zone NOLE since 20 February. From that position these elements had been supporting the Vietnamese and Marine units in and around Hue. With the approach of the 3d Brigade, coordination. requirements became more exacting to avoid shelling refugees and friendly forces. On 21 February the South Vietnamese 1st Division commander requested a field artillery liaison party from the 1st Cavalry Division to assist in the coordination. of fire support. The liaison party, which was dispatched the next morning, contributed to the success of the operation.

At 0730 on 24 February, U.S. and South Vietnamese forces breached the southwest wall of the citadel and met only light resistance. An intense artillery preparation the night before had killed 161 enemy. The citadel secured, the battle of Hue was officially over. (Map 12) The National Liberation Front flag which had flown from the citadel tower since 1 February came down. The recapture of Hue had involved four U.S. Army battalions, three U.S. Marine Corps battalions, and eleven South Vietnamese battalions. Ten Viet Cong and North Vietnamese Army battalions had been committed in an attempt to hold the city.

Colonel Richard M. Winfield, Jr., 1st Cavalry Division Artillery commander, in summarizing the actions and problems of the artillery, emphasized the conventional quality of the operation and concluded with a description of clearance activities and the consequences:

In the battle for Hue, the brigade was operating four battalions in the most conventional type of conflict that this division had ever been faced with. The brigade had their normal supporting artillery-three direct support batteries, a medium battery, and, during the latter periods of the attack, an 8-inch battery. Those units, from the 3d to the 26th of February, fired 52,000 rounds. In addition, 7,670 rounds of 5-inch to 8-inch naval ammunition, and 600 tons of Air Force-delivered munitions were expended in the area. In the last stages of the operation, the di-

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vision commander and I went into Hue and worked with the commanding officer of the 1st ARVN forces. We took whoever was needed for fire control and clearance so that we wouldn't have any major accidents against US Army, ARVN, or Marine unit or civilian, who were all converging on Hue. This required tight and rigid fire control, which was exercised by both the GS battalion commanders, by myself, and by the senior officer whom I had placed in Hue to control those fires. We had 11 fire support agencies in Hue. Now, this of course, had an effect on our infantry units, which are used to operating when they want to shoot-they call for fire and the fire is there. When we have all these clearance requirements and you have to have minimum safe distances all around you, the fire becomes slow because of the clearance and becomes restricted both in the caliber of weapons and in the number of rounds you can fire. I would say that the fire support was adequate. It was tough to get, but it was certainly adequate.

U.S. plans in the III Corps Tactical Zone for early 1968 envisioned only fourteen allied battalions remaining within a 29-mile radius of Saigon. Since early December 1967, defense of the capital itself had been the responsibility of the South Vietnamese command. The 5th Ranger Group, with a U.S. 105-mm. howitzer battalion (2d Battalion, 13th Artillery) in direct support, was responsible for providing the necessary security. U.S. forces thus released from the defense of Saigon were incorporated into plans for assaults on enemy base camps in the Cambodian border region. Thirty-nine battalions were to operate against these camps.

As the U.S. plans were set in motion, however, General Weyand, commanding II Field Force, became concerned over the results. Enemy resistance along the Cambodian border was weak. This weakness, coupled with the large volume of enemy radio transmissions near Saigon, convinced him of the necessity for redeployment. He conveyed his conclusions to General Westmoreland. The result was a shifting of forces. By the time of the Tet attacks in the III Corps area, twenty-seven U.S. maneuver battalions were in the capital area and the remaining twenty-five outside.

The operational plan of the enemy in the III Corps Tactical Zone included:

1. Seizing the Bien Hoa-Long Binh complex. Key targets: Bien Hoa Air Base, II Field Force headquarters, III Corps headquarters, prisoner-of-war camp between Bien Hoa and Long Binh, Long Binh ammunition storage area.

2. Attacking targets in the Hoc Mon area northwest of Saigon while blocking allied reaction by interdicting Route 1 between Saigon and Cu Chi; maintaining readiness to exploit successes in the northern Saigon area.

3. Blocking any attempted reaction by the U.S. 25th Infantry Division from the Cu Chi-Dau Tieng region.

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Map 13

4. Attacking district and government installations in Thu Duc and destroying the Newport bridge over the Saigon River between Saigon and Long Binh.

5. Containing the 1st Infantry Division in the Lai Khe area and cutting off Highway 13 at An Loc.

6. Seizing Tan Son Nhut Air Base and possibly the adjacent vice-presidential palace; taking over the presidential palace along with the U.S. and Philippine embassies; holding or destroying installations of the government of Vietnam such as the National Police stations and power plants. Success here would cause the government and the United States to lose face and would propel a move to the conference table, where the National Liberation Front would negotiate from a position of strength.

7. Controlling Cu Chi, Duc Hoa (including the South Viet-

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namese 25th Division headquarters), Ba Ria, Xuan Loc (18th Division headquarters), My Tho, Ben Tre, and Phu Loi-Phu Chang.

In the III Corps area the Tet offensive began at 0300 on 31 January in the Long Binh-Bien Hoa complex with a rocket and mortar attack on headquarters of the 199th Infantry Brigade and II Field Force. (Map 13) By 0321 Saigon and Tan Son Nhut were also receiving heavy fire. In order to control combat units in the Capital Military District (Gia Dinh Province), General Weyand ordered his deputy commander, Major General Keith Ware, and a small staff to Saigon to take operational control of all U.S. units. Task Force WARE, the operational headquarters, situated at Capital Military District headquarters, was operational by 1100 that same day and remained so until 18 February.

At the outset of the Tet offensive, only one U.S. infantry battalion and four 105-mm. howitzer batteries operated in Gia Dinh Province. Three of these batteries were in direct support of the South Vietnamese 5th Ranger Group. General Westmoreland, for political and psychological reasons, had refrained from maintaining U.S. maneuver units in Saigon and several other large cities. Once the Tet attacks began and American maneuver battalions arrived in the Capital Military District, division and field force artillery units relocated and supported the relief of the district.

Fire support for American units in the Capital Military District, particularly in Saigon, posed serious problems for the artillery. Numerous homes and shops and heavy concentrations of people within the city limited the area where artillery could be fired. When artillery could be employed, it was slow to respond because of difficulties in obtaining clearance to fire. Vietnamese military units in the city and the city government had not been placed under a single control headquarters. As a result, no centralized clearance activity was established. Artillery liaison officers were required to obtain clearance locally from the national police station in their area of operations. The situation was corrected in June 1968 when the Army of the Republic of Vietnam established a single military governor in the Capital Military District. Artillery support was further limited in Saigon because buildings and other structures restricted the view of forward observers. Gunships and tactical air proved more adept at providing support because the pilots had a better view of the target area. As a result specific enemy locations could be pinpointed and damage held to a minimum. For these reasons most of the major field artillery engagements in the Capital Military District during the Tet offensive and counteroffensive occurred in the outer edges of Saigon and in other areas of the zone.

Particularly impressive during Tet was the fire support pro-

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vided to the 1st Infantry Division in III Corps Tactical Zone. The division killed over 1,000 enemy troops. The Big Red One estimated that artillery and air strikes accounted for 70 percent of these enemy losses. The volume of field artillery fire increased substantially during the Tet offensive. The 1st Infantry Division recorded the following:

The most significant engagement during Tet for units of the 1st Infantry Division Artillery and the 23d Artillery Group began on 1 February. The division had shifted its artillery south along Highway 13 in order to meet increased enemy activity between Lai Khe and Saigon. On the morning of 1 February, elements of the division engaged units of the 273d Viet Cong Regiment at An My, approximately 4,000 meters north of Phu Loi. The artillery began by providing blocking fires. Then at 1330 the artillery placed destructive fires upon enemy forces entrenched in the village. Throughout the day 3,493 rounds hit the northern half of the village and caused approximately 20 secondary explosions. A survey of the area before dark confirmed 201 enemy killed and evidence supporting estimates of more than twice that number. Once darkness set in, the artillery again provided blocking fires. The next morning, the 1st Infantry Division found the remainder of the 273d Regiment still entrenched in An My. The action resumed at 1030 with the artillery continuing to provide blocking fires. When rounds were fired on the village, numerous secondary explosions again resulted. After several hours of bombardment, friendly elements swept and secured An My and found 123 Viet Cong killed. Prisoner reports later confirmed the import of the encounter. The 273d Regiment was moving south when it met the 1st Infantry Division at An My; the ensuing battle rendered the 273d ineffective before it could reach its assigned objective and contribute to the Tet offensive.

The performance of the field artillery in III Corps Tactical Zone during Tet caused General Weyand to observe that the field artillery was instrumental in blunting or defeating many of the assaults in the zone: "Timely response, especially in the moments of

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fluid uncertainty during the initial phase of the attacks, and in spite of clearance handicaps, contributed to the successes of the infantry and armored units."

Numerous smaller but significant field artillery actions occurred throughout Vietnam during Tet. For example, the 25th Infantry Division was plagued by enemy bunkers near the highway between Cu Chi and Saigon. Fires from the bunkers prevented free movement between the two locations. Numerous attempts to reduce the bunkers with artillery, air strikes, and infantry assaults were unsuccessful. An 8-inch howitzer delivering assault fire finally eliminated the bunkers. Also noteworthy were the actions of units of the 54th Artillery Group which prevented the collapse of the Xuan Loc base camp. On 2 February Xuan Loc came under heavy attack. The quick and devastating fire of Battery C, 1st Battalion, 83d Artillery, saved the post. Battery C fired thirty-five 8-inch rounds and killed 80 of the attackers. During the period 1-18 February similar missions supported the defense of Xuan Loc. The 2d Battalion, 40th Artillery, the direct support battalion of the 199th Light Infantry Brigade, was one of the first artillery units to respond to enemy attacks in III Corps. An observer detected the enemy launching rockets on II Field Force headquarters and shifted fire onto the launching sites. Several of the firing points were neutralized before the enemy had fired all his rounds. The enemy suffered more than 50 killed.

In IV Corps Tactical Zone the enemy offensive included attacks against My Tho and Vinh Long. On 31 January 1968, the Mobile Riverine Force was placed under operational control of the senior adviser in IV Corps. The riverine force initially was moved to the vicinity of My Tho, and two of its battalions conducted a three-day operation north of the My Tho River in response to a multibattalion Viet Cong attack on the provincial capital. Then, on 4 February, the riverine force moved to the provincial capital of Vinh Long and engaged three enemy battalions that were trying to seize the city. The 3d Battalion, 34th Artillery (105-mm., towed), was in direct support of the Mobile Riverine Brigade. One battery was equipped with airmobile firing platforms and two batteries were mounted on barges. The artillery battalion effectively delivered 8,158 rounds in support of the My Tho campaign. At one point a barge-mounted battery was required to make an airmobile deployment. The battery was provided a 1/4-ton jeep and a 3/4-ton trailer for a fire direction center. The barges were beached and the pickup was made directly from them. This type of movement opened possibilities for deeper penetration into the Mekong Delta.

Finally, in I Corps area on 12 February 1968, Battery C, 1st

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Battalion, 40th Artillery (105-mm.), while in support of a South Vietnamese unit, became the first U.S. Army artillery unit to fire improved conventional munitions in combat. The target was 40-50 North Vietnamese troops in the open. The battery fired 54 rounds of the new ammunition, resulting in 14 enemy killed. The round was a controlled, fragmentation-type ammunition similar to the Air Force cluster bomb unit. FIRE CRACKER became the code word used when a forward observer wanted improved conventional munitions.

Khe Sanh

The 66-day battle of Khe Sanh, which began in January 1968, became a classic defensive operation for U.S. forces It tested American concepts of defense and demonstrated that good fire support could effectively neutralize a superior force.

Khe Sanh sits atop a plateau in the shadow of the Dang Tri Mountains and overlooks a tributary of the Quang Tri River. Surrounding it on all sides are hills from which the North Vietnamese could shell the base. If controlled by the Marines, however, the hills would form a ring of protection for the base and afford good vantage points for detecting enemy movement. American involvement at Khe Sanh had begun in 1962, when Special Forces elements established a Civilian Irregular Defense Group camp at the site that was later known as the Khe Sanh combat base. Its purpose was to counter enemy infiltration through the area and provide a base for surveillance and intelligence-gathering operations in the western part of northern I Corps. Marine units occupied the base in late 1966 and the Special Forces moved southwest to the village of Lang Vai.

Between late 1966 and late 1967, activity around the base fluctuated from heavy contact to none at all. Then in December 1967 a surge of enemy activity began. Reconnaissance teams reported large groups of North Vietnamese moving into the area. The movement in itself was not irregular, but now the forces were staying, not passing through. The enemy was building up men and equipment in preparation for a siege. The enemy initiated major offensive action around Khe Sanh early in January 1968, when he shifted his emphasis from reconnaissance and harassment to actual probes of friendly positions.

On the night of 2 January an outpost at the western end of the base reported six unidentified figures walking around outside the wire. When challenged, they made no reply and were taken under fire. Five of the six were killed. Later investigation disclosed that the dead included a North Vietnamese regimental commander and

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Map 14

his operations and communications officers. The commitment of these key men to such a dangerous reconnaissance mission was a clear indication that something big was about to happen. (Map 14 and Map 15)

In the predawn of 21 January, the enemy began his anticipated move against Khe Sanh. Just after midnight rockets and artillery shells began impacting on Hill 861 to the northwest of the city. A full-scale ground attack followed, only to be repulsed after several hours of fighting. At 0530 another intense barrage of 82-mm. shells and 122-mm. rockets hit Khe Sanh. Damage was substantial-a major ammunition dump and a fuel storage area were destroyed. When news of the attack reached the United States, many questioned the feasibility of defending Khe Sanh. The base was isolated and, with Route 9 interdicted, would have to be resupplied by air. Fearing that Khe Sanh would become an American Dien Bien Phu, critics favored a pullout.

The problem, therefore; was not merely how to defend the base but whether the base should be defended at all. General Westmoreland and General Cushman, commander of III Marine Am-

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Map 15

phibious Force, decided to defend Khe Sanh. The base and adjacent outposts commanded the plateau and the main avenue of approach into eastern Quang Tri Province. Although these installations did not stop infiltration, they blocked motorized supply from the west. Another advantage to holding the base was the possibility of engaging and destroying a heretofore elusive foe. At Khe Sanh, the enemy showed no desire to hit and run but rather chose to stand and fight. The marines could fix him in position around the base while air and artillery barrages closed in. Finally, two crack North Vietnamese divisions, which might otherwise have participated in attacks in other areas of South Vietnam, were tied down by one reinforced Marine regiment. The decision made, all that remained was to complete the buildup of men and materiel required to hold the base.

Air power and artillery played an important role at Khe Sanh and were given the highest priority. The Khe Sanh defenders had three batteries of 105-mm. howitzers, one battery of 4.2-inch mortars, and one battery of 155-mm. howitzers; all five batteries were Marine artillery. In addition, they were supported by four batteries of Army 175-mm. guns, one at the "Rockpile," north of the base,

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and three at Camp Carroll, to the east. These artillery pieces, 46 in all, were supplemented by 90-mm. tank guns, 106-mm. recoilless rifles, and tactical air support. The fire support coordination. center, the 1st Battalion, 13th Marines (Artillery), located at Khe Sanh, controlled all supporting arms fire. Once the fighting began, the battalion commander, Lieutenant Colonel Lownds, said that the side which kept its artillery intact would win the battle. Only three American artillery pieces were destroyed during the entire siege.

Since the enemy maneuvered mainly under cover of darkness, the Marine and Army batteries were most active during these hours. Preplanned artillery fires included combined time-on-target fires from nine batteries, separate battalion time-on-target missions, battery multiple-volley individual missions, and battery harassment and interdiction missions. Fire support coordination. progressed to the point that artillery was seldom check fired while tactical aircraft were operating in the area. Throughout the battle 158,981 rounds of various calibers of artillery were directed against enemy locations around the base.

During the siege, air-delivered fire support reached unprecedented levels. A daily average of 45 B-52 sorties and 300 tactical air sorties struck targets near the base. Eighteen hundred tons of ordnance a day laid waste wide swaths of jungle terrain and caused hundreds of secondary explosions. In seventy days of air operation, 96,000 tons of bombs, nearly twice what the Army Air Corps delivered in the Pacific during 1942 and 1943, pulverized the battle area.

In addition to volume, reaction time was a key factor. Relatively easy clearance procedures meant immediate response-unless friendly aircraft were in the target area-regardless of the weather. Artillery rounds were usually on the target area within forty seconds after the call for fire. This instant artillery impaired enemy movements within the tactical area of responsibility and helped to break up numerous attacks.

Protective fires were carefully planned in advance. The fires of the artillery batteries planned by the fire support coordination. center prevented the enemy assault forces from reaching the perimeter wire. Because the North Vietnamese usually attacked with their battalions in column, the center also planned fires to isolate the assault elements from the reserves. When the enemy launched his attack, the center placed a three-sided artillery box around the lead enemy battalion. Three batteries of the 1st Battalion, 13th Marines, executed this mission. The fourth battery then closed the remaining side, which faced the friendly positions, with a barrage that

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Diagram 8

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rolled from one end of the box to the other much like a piston within a cylinder. The enemy force in the box could neither escape nor avoid the rolling barrage. Those North Vietnamese who spilled out of the open end of the box came under the final protective fires of the marines along the perimeter. At the same time, the fire support coordination. center placed a secondary box around the North Vietnamese backup units. The four U.S. Army 175-mm. batteries were responsible for two sides, which were about 500 meters outside the primary box. On order, the gunners rolled their barrage in toward the sides of the primary box and back out again. The third side was sealed by continuous flights of aircraft under the control of radar. Whenever B-52's were available or could be diverted in time, arc light strikes saturated the approach routes to the battle area.

The manner in which the center coordinated its air and artillery support was another critical element in the defense of Khe Sanh. The mini arc light, devised by the assistant fire support coordinator, was used against area targets. The mini arc light was similar to a B-52 strike but could be organized and employed more rapidly. When intelligence reports indicated that enemy units were in a certain region, the fire support coordination. center plotted a 500- by 1,000-meter block in the suspected area or across a likely route of march. Then the center called two Intruder tactical aircraft, each armed with twenty-eight 500-pound bombs, for a radar bomb run. Meanwhile the batteries at Khe Sanh, Camp Carroll, and the Rockpile were alerted for a fire mission. Thirty seconds before the bombs were dropped, the 175-mm. batteries, concentrating their fires on one-half of the block, salvoed the first of approximately 60 rounds. When the aircraft rippled their loads down the middle of the block, the Marine artillery batteries opened up on the second half with about 200 155-mm., 105-mm., and 4.2-inch rounds. The trajectory and flight times of all ordnance were computed so that the bombs and initial artillery rounds hit at the same instant. The saturation of the target area all but insured that any enemy soldier caught in the zone during the bombardment would be a casualty.

The micro arc light, developed and executed in the manner of the mini arc, used less ordnance and covered a 500- by 500-meter target block. The advantage of the micro arc light was that it could be in effect within ten minutes whereas the mini arc light required roughly 45 minutes. On an average night the fire support coordination center executed three to four mini arc lights and six to eight micro arc lights.

Artillery also functioned extensively in the direct fire role

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against targets of opportunity. The three Marine 105-mm. howitzers on Hill 881S demonstrated the effectiveness of this technique. An alert machine gunner on the hill spotted a twenty-man column of North Vietnamese slowly climbing Hill 758, due south of 881S. They were carrying what appeared to be several mortar tubes. The marines from a range of 1,200 meters managed to hit several of the enemy. Instead of scattering, the remaining soldiers clustered around their fallen comrades. The Marine gunners pushed aside their parapet, depressed the tube for a downhill shot, and slammed a dozen rounds into the midst of the tightly packed enemy group. All 20 were killed.

While supporting air and artillery whittled away the strength of the enemy, the defensive posture of the Khe Sanh combat base grew more formidable. A full-scale ground attack would be costly. However, the North Vietnamese forces remained determined and, during the last ten days in February, launched several attacks. The most significant attack occurred 29 February-1 March.

Early in the evening of 29 February, intelligence showed the enemy moving toward the eastern perimeter of the camp. The fire support coordination. center called for saturation of the enemy route of march. Massed artillery, tactical air, and mini and micro arc lights were targeted in blocks to the east, southeast, and south. B-52 strikes added to the carnage in the area. The enemy attempted three ground assaults during the night at 2130, 2330, and 0315. All were stopped short of the perimeter by intense ground fire and air and artillery barrages. Later in the morning of 1 March, 78 enemy bodies were found, some still in their assault trenches, peppered with holes from the artillery airbursts. Although the exact number of enemy killed was never accurately determined, Montagnard tribesmen inhabiting the surrounding hill reported finding 200-500 bodies at a time stacked in rows along the trails and woods leading to the base. The North Vietnamese forces apparently had been caught while on the march and had been mangled by air raids and piston-like artillery concentrations.

Beginning in mid-March, U.S. intelligence personnel noted an exodus of major North Vietnamese units from the battle area. Most of one division pulled back into Laos. As the enemy settled into a wait-and-see strategy, heavy incoming fires and limited ground probes nevertheless continued to plague the marines. But this waiting game proved disastrous because clear skies dominated the area for all but five days in March and the air strikes were stepped up considerably. The observers had unrestricted visibility and were able to ferret out artillery positions and bunker complexes. The clear skies and accurate supporting fires formed a potent combina-

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tion, and the number of confirmed enemy dead recorded in March increased approximately 80 percent over the number recorded in February.

On 31 March, the 1st Cavalry Division took control of the 26th Marine Regiment, signalling the start of PEGASUS, a fifteen-day air assault operation that ended the battle of Khe Sanh. The 1st Cavalry Division, along with the 1st Marine Regiment and the South Vietnamese 3d Airborne Task Force, began a push from Ca Lu, located east of Khe Sanh, to reopen Route 9 and relieve the pressure on Khe Sanh. The siege, in effect, was over.

The basic plan of Operation PEGASUS called for the 1st Marine Regiment, with two battalions, to attack west toward Khe Sanh while the 1st Cavalry Division air assaulted onto the high ground on either side of Route 9 and moved constantly west toward the base. On D plus 1 and D plus 2, all elements would continue to attack west toward Khe Sanh. Then on the following day the 2d Brigade of the 1st Cavalry Division would land three battalions southeast of Khe Sanh and attack northwest. The 26th Marine Regiment, holding Khe Sanh, would attack south to secure Hill 471. The linkup was planned for the end of the seventh day.

Fire support involved a multitude of units, requiring detailed planning and coordination. for the two phases of the operation­reconnaissance and attack. The objective of the reconnaissance phase was the destruction of the enemy antiaircraft resources between Ca Lu and Khe Sanh and the selection of landing zones for use by the advancing airmobile assault force. The 1st Squadron, 9th Air Cavalry, assumed this mission and was supported by an abundance of air and artillery. Additional artillery was moved into the area during the reconnaissance phase and automatically came under the control of a forward division artillery fire direction center located at Landing Zone STUD and manned by personnel of the 1st Battalion, 30th Artillery. The additional artillery included one Marine 4.2-inch mortar battery at Ca Lu and two 105-mm. batteries (one Marine and one Army) at the Rockpile. On 25 March an 8-inch battery and a 105-mm. battery moved from Quang Tri to Ca Lu and STUD, respectively. This move brought the total to 15 batteries available to support the 1st Squadron, 9th Air Cavalry, in its reconnaissance. All batteries in the area began answering calls for fire from the 1st Squadron, 9th Cavalry, on D minus 6 and commenced attacking planned targets that night. Prior coordination. between the 3d Marine Division; the 108th Artillery Group; and the 1st Battalion, 13th Marines (Artillery), insured that all available target information would be in the hands of the forward fire direction center and that lateral communication would be estab-

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lished. Throughout this phase, air and artillery fire destroyed enemy automatic weapons, mortars, and troop positions. The attack phase consisted of the preparation of landing zones, suppression of enemy fires, and on-call support of committed ground forces. For this phase, ten 105-mm. howitzer batteries, four 155-mm. howitzer batteries, one 8-inch howitzer battery, and one 4.2-inch mortar battery joined the already overwhelming artillery force. Each cavalry battalion drew support from the battery with which it was habitually associated. Each cavalry brigade had reinforcing fire from a medium battery, and the 1st Marine Regiment could count on support from two 105-mm. batteries, one 155-mm. battery, and one 4.2-inch battery. The additional heavy battery with the mission of general support of the 1st Air Cavalry Division moved from Camp Evans to Landing Zone STUD. Thirty-one batteries supported the relief of Khe Sanh-the largest array of artillery ever to support a single operation in Vietnam to that time.

Counterbattery fire contributed significantly to the success of Operation PEGASUS. For some time, North Vietnamese forces had been able to shell Khe Sanh at will with 152-mm. and 130-mm. artillery plus rockets and mortars positioned to the southwest and northwest of the base. When the 1st Cavalry Division Artillery came within range of the enemy guns, rapid and massive counterbattery fires achieved superiority. From that point enemy artillery ceased to be a serious deterrent to maneuver.

On 6 April at 1350, six days after Operation PEGASUS had begun, the initial relief of Khe Sanh took place. A lead company of the South Vietnamese 3d Airborne Task Force airlifted into Khe Sanh and linked up with the South Vietnamese 37th Rangers. Two days later the 2d Battalion, 7th Cavalry, had completed its sweep along Route 9 and the official relief took place. The command post of the 3d Brigade, 1st Cavalry, airlifted to the base at 0800 and became its new landlord. By the evening of 8 April, all elements of the PEGASUS task force were in position on the Khe Sanh plateau. The North Vietnamese 304th Division faced entrapment and destruction as a great vise closed about the enemy daily. American and South Vietnamese units soon uncovered grisly evidence of how badly the North Vietnamese had been beaten. They found hundreds of North Vietnamese bodies in shallow graves and hundreds more that lay where they had fallen. The allies destroyed or captured 557 individual weapons, 207 crew-served weapons, and two antiaircraft pieces. In addition, they confiscated 17 vehicles ranging from PT76 tanks to motor scooters, tons of ammunition and food, and numerous radios and items of individual equipment. The mountain of captured or abandoned enemy stores indicated either

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that PEGASUS had caught the enemy flatfooted or that the remnants of the enemy divisions had been unable to cart off their equipment and supplies.

On the morning of 14 April, PEGASUS officially ended. The operation was successful, Route 9 opened, the enemy routed, and the base itself relieved. The North Vietnamese lost 1,394 killed and 21 captured. The battle of Khe Sanh established that, with sufficient fire power, an encircled position could be successfully held and the enemy devastated.

A Shau

With the exception of the defense of Khe Sanh, post-Tet operations were similar to past counterguerrilla actions. The enemy, badly shaken, again eluded massed allied forces. It was necessary to hunt him in search and destroy operations conducted over large land areas. The two largest of such operations took place in the III Corps area and were known as QUYET TONG (Resolve To Win) and TOAN THANG (Complete Victory). Both took place in and around Saigon and were aimed at destroying enemy forces that had participated in the Tet attacks and were hiding in the area. Operation TOAN THANG involved 42 U.S. and 37 Vietnamese maneuver battalions and was the largest operation of the Vietnamese war. Artillery support was provided by 81 batteries of U.S. artillery and all Vietnamese artillery in the area.

Though not the largest, perhaps the most significant operation of the period immediately following Tet was DELAWARE-LAM SON 216. This operation, in April 1968, took friendly forces into the A Shau Valley, which had been controlled by the enemy since 1966. The operation, like PEGASUS, was preceded by intelligence acquisition by the 9th Cavalry. Antiaircraft weapons were pinpointed and destroyed by artillery, tactical air, and B-52 strikes. Two battalions of the 3d Brigade air assaulted into the northern portion of the A Shau Valley on 19 April. Hampered by extremely bad weather in the objective area, the brigade did not close until 23 April. On 24 and 25 April the 1st Brigade was deployed in the central portion of the valley. On 29 April, one battalion of the South Vietnamese 3d Regiment was airlifted into the southern part of the valley and, by the end of the month, most elements of the regiment were operating­ing in the south central portion.

Artillery support for Operation DELAWARE-LAM SON 216 was provided by two organic battalions of the 1st Cavalry Division Artillery-the 2d Battalion, 19th Artillery, and the 1st Battalion, 21st Artillery. In addition, two batteries of the attached 1st Bat-

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Map 16

talion, 30th Artillery (155, towed), reinforced the two direct support battalions, and the 2d Battalion, 20th Artillery (Aerial Field Artillery), were in general support. Heavy artillery was provided by six 175-mm. guns of the 1st Battalion, 83d Artillery, and 8th Battalion, 4th Artillery. One battery of the 1st Battalion, 21st Artillery, moved into the valley on 19 April 1968. Plans called for moving another battery; however, hazardous flying conditions prevented the move. No additional artillery was moved into the valley until 23 April. By 29 April, however, all the supporting artillery was in position. (Map 16)

Movement into the A Shau Valley was much slower than planned because of enemy antiaircraft fire. The enemy air defense

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was composed of relatively sophisticated weapons and fire distribution means, served by well-trained and disciplined crews, and an effective communication system. Despite attacks by tactical aircraft and artillery, the air defense weapons took a heavy toll of U.S. aircraft on the first day of the operation.

The entire operation by the 1st Cavalry Division was conducted by air. Positioning and supporting the artillery were hampered not only by enemy antiaircraft fires but also by difficult weather conditions. The operation was successful only because of feats of airmanship performed under instrument flight rule conditions by aviators of the 11th Aviation Group, the 9th Cavalry Squadron, and the 2d Battalion, 20th Artillery. Despite their efforts, however, careful management of ammunition and supplies by all supporting artillery units was necessary. On one occasion, water to swab the tubes of the 155-mm. howitzers was even in short supply.

The success of Operation DELAWARE can be measured principally by the amount of supplies and equipment captured, not by the number of enemy killed:

Later in the year, another operation was conducted into the A Shau Valley. Intelligence indicated that the enemy had rebuilt his defenses in the valley following the withdrawal of the 1st Air Cavalry Division. The enemy was actively clearing and improving access to and along Route 548 while moving large amounts of supplies and replacements in Thua Thien Province and southern

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I Corps Tactical Zone. Accordingly the 101st Airborne Division was directed to conduct a follow-up operation into the valley and, during the period 19-26 July 1968, built bases to support the operation. Before D-day, eight batteries of field artillery were moved into the bases. Each 105-mm. battery stockpiled 3,000 rounds of ammunition; each 155-mm. battery, 2,000 rounds. Two 175-mm. batteries were within supporting range.

The amounts and types of preparatory fires were impressive. Fourteen B-52 strikes were directed against the hard targets. Eleven of the strikes were within twenty-four hours of H-hour, the last at 0850 on D-day. Following the strikes, a tactical preparation of four flights dropped Daisy Cutter bombs to neutralize any enemy in the landing zones. When the last aircraft cleared the landing zones, the artillery preparation began. Each 105-mm. battery fired 1,000 rounds, each 155-mm. battery fired 600 rounds, and each 175-mm. battery fired 200 rounds on two landing zones. Approximately 8,000 rounds of artillery were fired before H-hour by the ten batteries supporting the operation.

Enemy resistance was light on one landing zone and moderate to heavy on the other. Four gunships were damaged or destroyed during the initial phase of the operation, but no troop-carrying ships were lost.

By 6 August, all elements of the 101st and the Vietnamese task force had been moved into the A Shau Valley and were conducting reconnaissance-in-force (RIF) operations in their assigned areas, with very light contact. Withdrawal of the forces began on 17 August 1968 and was completed on 19 August. Results of the operation were 181 enemy killed and 4 captured, 45 individual weapons and 13 crew-served weapons seized, and the following miscellaneous enemy equipment captured or destroyed:

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Actions at Fire Bases and Lessons Learned

Fire bases throughout Vietnam sustained numerous attacks in this period of maximum U.S. troop commitment. The fire base concept surpassed the most optimistic expectations. Occasionally the enemy was able to penetrate the defenses and take a heavy toll of personnel and equipment, but he never was able to take an American fire base. At the same time, lessons learned in countering enemy attacks during this period suggested further refinements of procedures for establishing and defending a fire base. For instance, actions at Fire Support Bases MAURY I and PIKE VI provided valuable insights on the proper positioning of artillery when several batteries occupied the same fire base.

Batteries B and C (105-mm.), 7th Battalion, 11th Artillery, and Battery A (155-mm.), 3d Battalion, 13th Artillery, were occupying MAURY I, a 25th Infantry Division Artillery fire base. Although the base was located in what was probably the best available area, bamboo thickets and wood lines surrounded the clearing. The three field artillery batteries had been arranged within the perimeter in a triangle, with one battery at each point. The 155-mm. battery was to the west and the 105-mm. batteries to the northeast and southeast.

On the night of 9 May, MAURY I came under heavy attack. (Map 17) The enemy began his attack at 0200 with an intense mortar and RPG (Russian-made antitank grenade) barrage. He launched a diversionary attack against the northeastern and southwestern portions of the perimeter followed by the main attack directed against the western portion of the triangle, where the 155-mm. battery was located less than 200 meters from the tree line.

The 155-mm. battery, between the two 105-mm. batteries and the attacking enemy, took the brunt of the attack. The RPG fire had a devastating effect on the 155-mm. howitzers. At 0330 an attempt was made to move two 105-mm. howitzers to the southwestern side of the perimeter to aid the medium battery. By this time, only one of the 155-mm. howitzers was serviceable; of the others, three had been completely destroyed, as had two M548 ammunition trucks. Flareships and gunships arrived by 0330 and Air Force fighter aircraft by 0500. At 0530 a relief element of the 4th Battalion, 23d Infantry (Mechanized), arrived and battered its way into the beleaguered base. The attack was finally repulsed.

All Beehive ammunition had been expended but, because of the speed and accuracy of the assault against the medium battery, less than 10 rounds of 155-mm. ammunition had been fired before

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Map 17

the destruction of the howitzers. Eighteen Viet Cong were confirmed dead, and friendly losses numbered 10 killed and 66 wounded. Four men died of wounds received in battle. These, along with 7 others killed and 39 wounded, were artillerymen. Five M109 howitzers were destroyed; one serviceable howitzer was later pieced together from two damaged howitzers. Two M548 trucks were destroyed, and one 5-ton truck was severely damaged. Fourteen M16 rifles were either lost or destroyed.

The defenders had been aggressive and determined in withstanding a heavy enemy attack. Despite their success, as with any actions, there were lessons to be learned. An analysis of the battle suggested techniques that might reduce American losses and increase enemy casualties in a similar situation. No bulldozer had been available to construct berms around the howitzers; ammunition was protected on the sides only; the medium battery situated at the point of the triangle should have been more centrally located within the perimeter and away from a tree line; and poor fields of

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fire reduced the effectiveness of the Beehive rounds. Positions that would have allowed maximum use of the Beehive round should have been chosen early in the occupation of the fire support base.

On the morning of 11 May, Fire Support Base PIKE VI was occupied by Battery B, 6th Battalion, 77th Artillery (105-mm.); Battery A, 1st Battalion, 8th Artillery (105-mm.); and Battery C, 3d Battalion, 13th Artillery (155-mm., self-propelled). (Map 18) The commander set up the base using the valuable experience gained from the attack on MAURY I. The batteries entered the fire support base early in the afternoon, and a bulldozer began constructing berms for the 155-mm. howitzers immediately. By nightfall only the turrets of the howitzers were exposed. The 105-mm. batteries had been carefully positioned to allow maximum use of Beehive, and two 105-mm. howitzers, one from each battery, had been placed at strategic points along the perimeter some distance from the rest of the battery positions. Although the terrain was much the same as that at MAURY I, the nearby wood lines were covered by two attached Dusters. The light batteries enjoyed excellent fields of fire. The medium battery was positioned between the two light batteries and thus was able to support equally well in all directions.

At 0130 on 12 May 1968 the enemy attacked with a mortar barrage of approximately 400 rounds, all falling within 30-60 minutes. Once again, the enemy began a diversionary attack from the south. The Duster position on the southern tip of the base took 60-70 Viet Cong under fire with its M60 machine gun and 40-mm cannon. The crew managed to fire only 12 rounds of 40-mm. ammunition, however, before the Duster was silenced by an RPG round. Leaving 16 enemy bodies in their wake, the crew fell back to a 105-mm. howitzer pit directly to their rear. The enemy managed to reach the Duster, but small arms and a few well-placed Beehive rounds from the 105-mm. turned him back.

As the main attack was starting from the west, artillery shells from adjacent units were already impacting around the perimeter. Support was called for and received from 155-mm. howitzers of Battery B, 3d Battalion, 13th Artillery, near Saigon. The entire western approach was covered by a 105-mm. battery which fired round after round of Beehive and time rounds, all with a very short fuze setting, into the attacking enemy. The defense was entirely successful and the attack ended just two and one-half hours after it began. Mop-up operations in daylight produced a body count of 110. Friendly force losses amounted to 5 killed and 30 wounded, of which 1 killed and 5 wounded were artillerymen. No equipment was lost. The damaged Duster was easily repaired, and two vehicles sustained minor damage.

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Map 18

Actions MAURY I and PIKE VI offered an excellent example of how techniques could be improved by observing lessons learned. The Killer Junior technique, for instance, was developed during this period and used profitably in defense of fire bases. The technique was expanded to include projectiles of improved conventional munitions as well as high explosive projectiles. Killer Junior

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was employed in the defense of PIKE VI as well as on numerous later occasions. The following are a few instances when the technique proved particularly effective:

1. On 13 September 1968, Battery C, 2d Battalion, 13th Artillery, expended 1,305 rounds in defense of Fire Support Base BUELL and killed 76 enemy.

2. On 25 September 1968, a platoon of Battery C, 6th Battalion, 15th Artillery, expended 288 rounds in defense of Katum and killed 47 enemy.

3. On 25 September 1968, a platoon of Battery B, 6th Battalion, 15th Artillery, expended 220 rounds in defense of a position at Thien Ngon and killed 142 enemy.

The 25th Infantry Division conducted an appraisal of its fire support bases in late 1968, after many of the bases in the Tay Ninh area had been attacked, and made two major recommendations. First, commanders were to insure that insofar as possible fire bases be constructed in a circle and small enough for one rifle company to defend. Both these recommendations were in accord with what were already considered correct procedures. Apparently there were sufficient deviations from correct practice to warrant further emphasis. The circular shape permitted equal fire power in all directions and allowed for faster emplacement. The reduction in construction time became essential because the enemy began to deviate from his normal two- or three-day reconnaissance and to attack bases on the first or second night after the base was occupied. The smaller size of the bases also freed more companies for night ambushes and mobile patrols and reduced the number of enemy shells that landed in the area. These modifications proved highly successful in a series of engagements fought along the Cambodian border in early 1969. Each base was manned by one rifle company and one howitzer platoon. The apparent vulnerability of these small positions was tempting, and the enemy seized the opportunity to try to destroy them. But his forces ran into a storm of carefully preplanned fire power, which not only broke the assault but also shifted to attack the enemy and his supporting weapons as he retreated.

The second major recommendation was that the activities of fire bases be viewed as offensive operations. The base was considered the anvil and the maneuver force the hammer. Fire support or "offensive fires" were planned for the entire battle area. Enemy troops, attack positions, supporting weapon positions, and command centers were struck simultaneously, and then when activity declined, the routes of withdrawal and likely assembly areas were attacked. This system of deep, simultaneous, and continuous fires was em-

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ployed at Fire Support Base CROOK on the night of 5-6 June and served to test the validity of the fire support base evaluation.

Perhaps the best example of the damage that could be inflicted on the enemy by the determined defenders of a well established fire support base occurred in late 1968 during Operation FISH HOOK. The operation, along the Cambodian border; was in an area astride a primary infiltration route running through War Zone C into the Saigon complex. Two fire support bases, RITA and DOT, and one night defensive position were established to obstruct and interdict enemy movement south from Cambodia. They were so located that each fire support base could mutually support the other with artillery fire and both could support the infantry position.

Headquarters and Battery B of the 1st Battalion, 5th Artillery (105-mm., towed), commanded by Lieutenant Colonel Charles C. Rogers, and Battery C, 8th Battalion, 6th Artillery (155-mm., self­propelled), were located at Fire Support Base RITA. This base, with two batteries and the artillery tactical operations center (TOC), was the key position. The base was also occupied by one cavalry squadron and one infantry company. Battery D, 1st Battalion, 5th Artillery, was at Fire Support Base DOT. During the period 25-30 October, there were enemy mortar and ground attacks on all three bases. Artillery support called in on all these attacks resulted in a Viet Cong body count of 105.

On 1 November 1968 at 0330, the west-northwest perimeter of Fire Support Base RITA was attacked by a North Vietnamese Army force of an estimated 800 men. (See Map 13.) The attack immediately followed a "mad minute" reconnaissance by fire by the friendly forces. The enemy, initially surprising the friendly forces with the intensity of his attack, penetrated the defensive perimeter and was inside the position of the 155-mm. howitzer battery. A counterattack was mounted and the bunkers were retaken. A second attack and penetration was made at 0515 by the enemy against the southwest perimeter. Again, the enemy was beaten back by an aggressive counterattack and the defensive positions were reestablished. When the enemy attempted to regain the initiative by attacking the northern perimeter with a third charge, the 105-mm. howitzers were swung to the north and lethal barrages, were fired into the massed assaulting enemy.

During the battle, the U.S. forces suffered 12 men killed and wounded. The enemy body count could not be obtained, but it was estimated that at least 200 bodies lay in the woods around the fire support base. The ferocious intensity of the battle, which raged from 0330 until 0645, with frequent concentrations of mortars impacting the fire support base until 0800, was attested to by the

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massive quantity of ammunition expended by friendly forces. The field artillery fired 1,300 rounds in direct fire and 800 rounds in indirect fire. In addition, the defense was supported by air strikes and innumerable strikes by helicopter gunships and fire teams from the 1st Infantry Division. Colonel Rogers directed the defense of the base with such heroism as to be awarded the Medal of Honor.

Peak Strength and Beginning of Redeployment

On 4 May the enemy launched another wave of nationwide attacks against 109 cities and military installations, including 21 airfields. These attacks lacked the intensity and coordination. of the Tet offensive. Bien Hoa Air Base was the hardest hit installation; strong attacks occurred in Binh Duong and Hou Nghia Provinces. The enemy also tried to seize the Saigon-Bien Hoa highway bridge near Saigon. Heavy fighting continued near Dong Ha in northern I Corps on 6 May, and moderate to heavy fighting persisted around Saigon. Because of the attacks on Saigon, another task force was formed to control U.S. units in the Capital Military District. The task force was commanded by Major General John H. Hay, Jr., deputy commander of II Field Force, Vietnam.

The buildup of U.S. forces continued through most of 1968. Between February and July, four additional artillery battalions arrived. Two were 155-mm. towed battalions, which were assigned to the 41st Artillery Group and the 54th Artillery Group. One was a 105-mm. towed battalion which was assigned to the 108th Artillery Group. The fourth was a 155-mm. towed and 8-inch self­propelled battalion which was assigned to the Americal Division as its general support battalion. During July the 1st Brigade of the 5th Mechanized Division arrived with its 155-mm. self-propelled direct support battalion. The 1st Brigade was the last major U.S. army maneuver unit to be deployed to Vietnam.

Later in the year, two additional artillery battalions arrived together with more support units and infantry battalions. These were National Guard units, the first to be deployed to Vietnam. The two artillery battalions were the 3d Battalion, 197th Artillery, from New Hampshire, and the 2d Battalion, 138th Artillery, from Kentucky. They were assigned to the 23d Artillery Group and the Provisional Corps, Vietnam, respectively. The 4th Battalion, 77th Artillery (Aerial Rocket Artillery), arrived in December 1968 and was assigned to the 101st Airborne Division (Airmobile). With its arrival, the field artillery was at its maximum strength of the war.

During the latter part of 1968, some major troop realignments took place. In September the 1st Brigade, 101st Airborne Division,

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moved to I Corps to rejoin the rest of the division, and the 3d Brigade, 82d Airborne Division, moved to III Corps from I Corps. In October, over the objections of the Commanding General, XXIV Corps, and Commanding General, III Marine Amphibious Force, the 1st Cavalry Division began the move from I Corps to III Corps. The move was completed in November 1968 and the division began to operate in III and IV Corps areas. With these operations the 1st Cavalry added another first to its list, that of being the first division­size unit to operate in all four corps tactical zones.

On 8 June 1969, President Richard M. Nixon announced plans for returning 25,000 U.S. troops from Vietnam. One month later, a C-141 Starlifter jet left Bien Hoa Air Base with members of the 3d Battalion, 60th Infantry. On 12 June the 9th Infantry Division received notification of its selection as the first major U.S. Army unit to leave the Republic of Vietnam. The first field artillery unit to redeploy was the 3d Battalion, 34th Artillery, which left Vietnam on 26 July 1969. It was followed in mid-August by the 1st Battalion, 11th Artillery; 1st Battalion, 84th Artillery; and the 9th Infantry Division Artillery. Since the 3d Brigade, 9th Division, was remaining in Vietnam, the 2d Battalion, 4th Artillery, also remained as its direct support battalion. The next redeployment of artillery units took place in September and October, when the 3d Battalion, 197th Artillery, and the 2d Battalion, 138th Artillery, the two National Guard units, were returned to the United States. The 2d Battalion, 12th Artillery, and 1st Battalion, 39th Artillery, were activated in Vietnam as replacements.

The enemy Tet offensive and the allied counteroffensive propelled the artillery toward increased sophistication. During the period, the artillery was exposed to essentially three types of major operations, each with its own peculiar demands. Because of the proximity of friendly forces and civilians, solving clearance problems was crucial in Hue and Saigon. The defense and relief of Khe Sanh resembled a conventional situation with requirements for large volumes of supporting fires concentrated in a relatively small area. Operations into A Shau were highlighted by movement and supply by air and by support of dispersed ground forces. The period thus offers an interesting study of the actions taken by field artillerymen to optimize the effectiveness of supporting fires in all situations.

Artillery Organizations

Various organizations were adopted for the field artillery in Vietnam during this period to meet both the peculiarities of certain

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short-term operational requirements and long term needs. Artillery commanders at all levels were flexible and innovative in organizing their subordinate units to provide the best possible support.

At the start of the Tet offensive 34 U.S. Army artillery battalions were in Vietnam. They were organized for the most part to provide dedicated support to divisions or separate brigades or to provide area coverage. (Chart 2) Units in I and II Field Force Artilleries served primarily in the latter role. I Field Force Artillery, with two artillery groups-the 41st and the 52d-and two separate battalions, provided force artillery in the II Corps areas. II Field Force Artillery, with two groups-the 23d and 54th-­provided force artillery for both III and IV corps areas. The 108th Artillery Group was not assigned to either field force. Before Tet it had been placed under the operational control of III Marine Amphibious Force to provide artillery support in the I Corps area. The group was reinforced with the 1st Battalion, 83d Artillery (8-inch and 175-mm.), from the 54th Artillery Group.

This organization served U.S. maneuver forces and augmented South Vietnamese artillery when needed during Tet; however, some reorganization took place thereafter. During the first half of 1968, General Westmoreland created two new headquarters to coordinate­ordinate the actions of U.S. forces in I Corps and in the Capital Military District. In March the Provisional Corps, Vietnam (later changed to XXIV Corps), succeeded Military Assistance Command Forward, which had been operational since 9 February; and in June, the Capital Military Assistance Command reestablished the coordination. which existed during the brief existence of Task Forces WARE and HAY. The command paralleled that of the newly established Military Governor of the Capital Military District, who controlled all South Vietnamese Army forces, National Police, Regional and Popular Forces, and General Reserve in the district. This reorganization prompted, in turn, a reorganization of artillery. (Chart 3) In I Corps a provisional Corps Artillery, Vietnam, was formed. No separate U.S. artillery command was formed to serve the needs of the Capital Military Assistance Command, but artillery units around Saigon could look to a single centralized clearance and coordination. activity.

Despite the amount of artillery in Vietnam, the old cry that there were not enough artillery units to support the maneuver elements was heard again and again. The creation of a fourth firing battery in some artillery battalions, particularly with the division artillery direct support battalions, dramatized the requirements and response. There were generally two reasons for the extra battery. First, in a brigade, it was not uncommon to have a fourth maneuver

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element resulting from the use of the divisional armored cavalry squadron as a separate maneuver force. A fourth firing battery was essential to insure the timely delivery of fire to this fourth maneuver element. Second, the large areas of operations assigned to division were often difficult to cover by division or field force

          CHART 2-FIELD ARTILLERY TASK ORGANIZATION, JANUARY 1968

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CHART 3-FIELD ARTILLERY TASK ORGANIZATION, JULY 1969

1. Arrived Oct 68, redesignated 1st Bn, 39th Arty, Oct 69.
2. Arrived Sep 68, redesignated 2d Bn, 12th Arty, Sep 69.
3. OPCON Senior Adviser, IV Corps.

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artillery under conventional organization. A fourth firing battery alleviated this condition. Otherwise, the desire to keep maneuver elements within the range of a 105-mm. battery restricted operations.

The requirement for additional firing batteries could be satisfied in a number of ways. In one instance Headquarters, U.S. Army, Vietnam, authorized a fourth battery for the 3d Battalion, 319th Artillery, 173d Airborne Brigade. The battalion in this case supported five maneuver elements and badly needed the additional artillery. Additional firing batteries in all other cases were organized from existing assets. Typical was the artillery reorganization in the Americal Division. Each of the division's direct support battalions was reorganized into two five-tube and two four-tube batteries. The 1st Infantry Division had a more unusual solution. One or two 4.2-inch mortar platoons were attached to each of the division's direct support artillery battalions and designated Batteries D and E. Although attached to the headquarters battery for administration, these platoons functioned tactically as separate fire units. The range of the mortars limited their employment in the direct support role. Consequently, they defended base camps or covered fire support bases that were out of range of other field artillery. The particular situation of many artillery battalions did not require the formation of a fourth battery. Even so, contingency plans were often developed to permit the reorganization on a moment's notice if the situation were to change. II Field Force Artillery, for instance, required all light and medium battalions to have contingency plans for forming a fourth battery from organic assets. None of these reorganizations made the support rendered less effective. The nature and size of targets most frequently encountered in Vietnam (six or less personnel) could be effectively engaged with four howitzers rather than six per battery. In fact, four-tube batteries were frequently more compatible with the small position areas available.

One of the most interesting organizations was that of Battery D, 2d Battalion, 13th Artillery. This was a composite 105- and 155-mm. battery which was formed temporarily on two occasions for a specific purpose. Battery A, 2d Battalion, 13th Artillery, provided three 105-mm. tubes and Battery B, 3d Battalion, 197th Artillery, provided three 155-mm. towed weapons toward the formation of the battery. The regular gun crews were transferred along with weapons. Other battery personnel and equipment requirements to flesh out Battery D were filled by both contributing batteries. The unit capitalized on the advantages of both calibers for jungle operations. Whereas the 155-mm. howitzer was more effective for

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firing in the triple-canopy jungle, the 105-mm. was more effective for close-in defense and for delivering fire at high rates. Battery D, known as the jungle Battery, operated in direct support of the 3d Mobile Strike Force, a joint U.S.-Vietnamese Special Forces command during operations in War Zone D.

Safety

Artillery units at all levels took every reasonable precaution to insure the safety of allied forces and noncombatants. The requirement that artillery units obtain both political and military clearance was but one of many rules that the artillery was required to observe in engaging the enemy. The rules were published in a directive entitled MACV Rules of Engagement, cited below. They are evidence of the unusual care that was required of all soldiers and commanders to insure that friendly casualties were held to an absolute minimum:

1. UNINHABITED AREAS.

a. Fire may be directed against VC/NVA forces in contact in accordance with normal artillery procedures.

b. Unobserved fire may be directed at targets and target areas, other than VC/NVA forces in contact, only after approval by Province Chief, District Chief, Sector Commander, or Subsector Commander and US/FWMAF Military Commander, as appropriate, has been granted.

c. Observed fire may be directed against targets of opportunity which are clearly identified as hostile without obtaining Province Chief, District Chief, Sector Commander, or Subsector Commander and US/FWMAF Military Commander's approval.

d. Approval by Province Chief, District Chief, Sector Commander, or Subsector Commander and US/FWMAF Military Commander, as appropriate, is required, before directing fire on targets of opportunity not clearly identified as hostile.

2. VILLAGES AND HAMLETS.

a. Fire missions directed against known or suspected VC/NVA targets in villages and hamlets occupied by noncombatants will be conducted as follows:

(1) All such fire missions will be controlled by an observer and will be executed only after approval is obtained from the Province Chief or District Chief, as appropriate. The decision to conduct such fire missions will also be approved by the attacking force battalion or task force commander, or higher.

(2) Villages and hamlets not associated with maneuver of

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ground forces will not be fired upon without warning by leaflets and/or speaker system or by other appropriate means, even though fire is received from them.

(3) Villages and hamlets may be attacked without prior warning if the attack is in conjunction with a ground operation involving maneuver of ground forces through the area, and if in the judgment of the ground commander, his mission would be jeopardized by such warning.

b. The use of incendiary type ammunition will be avoided unless absolutely necessary in the accomplishment of the commander's mission or for preservation of the force.

3. URBAN AREAS.

a. Fire missions directed against known or suspected VC/NVA targets in urban areas must preclude unnecessary destruction of civilian property and must by nature require greater restrictions than the rules of engagement for less populated areas.

b. When time is of the essence and supporting weapons must be employed to accomplish the mission or to reduce friendly casualties, fire missions will be conducted as follows:

(1) All fire missions will be controlled by an observer and will be executed only after GVN/RVNAF/US approval. The decision to conduct fire missions in urban areas will be retained at corps/field force or NAVFORV level. Approval must be obtained from both the corps commander and the US field force level commander. This approval is required for the employment of any US supporting weapons in urban areas to include those US weapons in support of RVNAF.

(2) Prior to firing in urban areas, leaflets and loudspeakers and other appropriate means will be utilized to warn and to secure the cooperation and support of the civilian populace even though fire is received from these areas.

(3) Supporting weapons will be used only on positively located enemy targets. When time permits, damage to buildings will be minimized.

(4) The use of incendiary type munitions will be avoided unless destruction of the area is unavoidable and then only when friendly survival is at stake.

(5) Riot control agents will be employed to the maximum extent possible. CS agents can be effectively employed in urban area operations to flush enemy personnel from buildings and fortified positions, thus increasing the enemy's vulnerability to allied firepower while reducing the likelihood of destroying civilian property. Commanders must plan ahead and be prepared to use CS agents whenever the opportunity presents itself.

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4. THE ABOVE STATED PROCEDURES WILL NOT BE VIOLATED OR DEVIATED FROM EXCEPT, WHEN IN THE OPINION OF THE RESPONSIBLE COMMANDER, THE SITUATION DEMANDS SUCH IMMEDIATE ACTION THAT THESE PROCEDURES CANNOT BE FOLLOWED. SUCH SITUATIONS INCLUDE PRESERVATION OF THE FORCE OR THE RIGHT OF SELF-DEFENSE.

5. RVN/CAMBODIAN BORDER AREA.

a. Fire missions within 2000 meters of the RVN/Cambodian border will be observed, except under circumstances where fires are in defense of friendly forces and observation of such fires is not possible. These requirements are in addition to applicable control procedures stated elsewhere in this directive.

b. Fire missions with intended target areas more than 2000 meters from the RVN/Cambodian border may be unobserved, subject to applicable control procedures stated elsewhere in this directive.

c. Fire missions will not be conducted where dispersion could result in fire being placed on or over the RVN/Cambodian border.

d. Commanders will review and comply with the provisions of MACV Rules of Engagement-Cambodian when planning for operations near the Cambodian/RVN border.

Major commands subordinate to Military Assistance Command frequently published directives that interpreted the MACV rules, expanded them in greater detail, and often added qualifications which made them even more restrictive.

Field artillery units adopted the following procedures in the employment of their weapons to insure accuracy and preclude friendly casualties:

1. Firing a smoke shell set for a 200-meter height of burst as the first round for most observed missions. Smoke was relatively safe; thus, if the target location was improperly reported, supported ground troops would not be hurt. The forward observer made any correction necessary to insure that subsequent high explosive rounds fell in the intended locations.

2. Double-checking or triple-checking all data at each echelon from the forward observer to the howitzer. This procedure created a problem for some units because of personnel requirements. In many cases, especially in force artillery units, a battalion did not control its batteries. When the battalion controlled the batteries and retained a technical fire direction center either the battery or the battalion computed the mission and the other checked the data. When the batteries operated separately, each battery center had to be augmented so that it would have two shifts or two com-

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1ST BATTALION, 8TH FIELD ARTILLERY, FIRE DIRECTION CENTER. Note Primary plotting chart with check chart.

puters and two chart operators for the double-check system. Data sent from the fire direction center by one computer were monitored by the other computer. The executive officer post received the data and read them back. Data then were passed to the guns through the executive officer post. One practice called for placing an AN /GRA­39 remote radio set at each gun. This permitted all members of the section to hear the data being transmitted to the guns. One section then read back the data received.

3. Conducting periodic gunner (firing) inspections and drills for subordinate units.

4. Separating and segregating, by lot, projectiles and powder for separate-loading ammunition.

5. Insuring that howitzers were boresighted at least twice daily and that batteries registered twice weekly.

6. Conducting frequent staff inspections of subordinate units to see that safety policies were being complied with.

Friendly casualties resulting from misplaced artillery fires were thoroughly investigated whenever the combat situation permitted. Often the mistake was unavoidable, and, for that reason, investigation first determined whether the mistake was an accident or an

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FADAC COMPUTER WITH BACKUP CHART AND RADIO COMMUNICATIONS

incident. A firing accident was defined as an occurrence not caused by human error or neglect. Malfunction of ammunition or equipment, civilian casualties in previously cleared areas, and personnel hit by debris or secondary fragments were classified as accidents. A firing incident, on the other hand, resulted from human error or neglect. Plotting errors by the forward observer or fire direction center, crew errors in setting quadrant elevation or deflection, and errors in transmitting unit locations or firing data, in obtaining proper clearance, in following the rules of engagement, or in identifying friendly units contributed toward firing incidents. If the firing error resulted in an incident, its precise cause was determined and necessary action was taken at all levels to prevent similar errors in the future.

The investigation of artillery accidents brought to light a problem in illumination missions. The impact point of the baseplate and the projectile body could not be accurately determined because of the erratic trajectory after fuze function. Consequently, it became necessary to establish a buffer zone around the grids of illumination and impact. Clearance to fire into these buffer areas was required before illumination could be fired.

A study conducted in 1969 by U.S. Army, Vietnam, into the causes of artillery, mortar, and aviation incidents and accidents set out to determine if incidents and accidents followed any discernable patterns so that commanders might be forewarned to give

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careful attention to certain specific areas. The study showed that a majority of the accidents and incidents involved direct support units firing observed fire. The following chart outlines the incident and accident profile developed in the study as well as recommended corrective action:

Section I
Incident/ Accident Profile

Section II

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Artillery units were concerned not only with the safety of friendly forces and noncombatants on the ground but also with that of aircraft. Aircraft safety was assured by the establishment of aircraft warning centers. These centers normally were set up and operated by field artillery liaison sections at maneuver battalion and brigade. The liaison section was notified by artillery units in the area before firing and given the direction of fire, the maximum ordinate of the trajectory, and the point of impact of the projectile. Aircraft entering the area could then be advised of artillery firings and provided with recommended safe routes through the area.

In most cases Army control of air space over the battle area was not contested by the Air Force. Where it was contested, local agreements were made between representatives of both services. The most common agreement was that air space below 5,000 feet would be controlled by the Army and that above 5,000 feet by the Air Force. In certain areas such as Bien Hoa, Tan Son Nhut, and DA Nang, where the activity of the Air Force aircraft was the greatest, the Air Force controlled all air space.

Target Acquisition

Targets must be found and their location pinpointed if field artillery is to be effective. In Vietnam, as in past wars, forward observers augmented by aerial observers were the principal means to identify artillery targets. Despite the development and improvement of other target acquisition means, observers were, and promise to be for some time to come, more reliable, flexible, and responsive than any other system. This does not say that other target acquisition means are not valuable. Radars, sound and flash ranging, and sensors were all employed profitably in Vietnam.

Three target acquisition batteries were deployed to Vietnam. They were Battery F, 2d Target Acquisition Battalion, 26th Artillery, and the headquarters batteries of the 8th Target Acquisition Battalion, 26th Artillery, and the 8th Target Acquisition Battalion, 25th Artillery. Each of the headquarters batteries was assigned to a field force headquarters to coordinate field force level target acquisition activities. Battery F established sound and flash bases in the XXIV Corps area to monitor the Demilitarized Zone. This was

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the only sound ranging equipment employed, and though the equipment failed to detect a large number of targets, all sound located targets that were engaged resulted in secondary explosions.

Two field artillery radars-the AN/MPQ-4 countermortar radar and the AN/TPS-25 ground surveillance radar-were deployed throughout the country. The AN/MPQ-4 was assigned to every direct support battalion and the AN/TPS-25 was assigned to every division artillery. Both radars were also assigned to field force radar detachments.

Most units believed that the AN/TPS-25 did a good job and was a valuable piece of equipment. The AN/MPQ-4, however, caused mixed reaction. Units identified two major shortcomings: the radar had a small sector of scan, and it could not locate low­trajectory weapons, specifically rockets. The first shortcoming could be significantly alleviated where several radars were available to provide mutual and overlapping coverage. The second could not be corrected because the radar had been designed solely to detect high­trajectory weapons.

An evaluation of the effectiveness of the AN/MPQ-4 was conducted in 1969. The study revealed that in 1,759 attacks over a six­month period the radar determined only 342 confirmed launch locations for an over-all effectiveness average of 19.44 percent. For the months of May and June, the study singled out the limited sector of scan as the foremost disadvantage. The set could scan only a 445-mil sector at a time, which accounted for many nonsightings. Of 537 attacks by fire during these two months, 253 occurred out of sector, 56 during normal off time for the crews, and 20 while the set was down because of mechanical failure. In the remaining 208 attacks in which sightings were possible, 89 sightings were made, for an over-all operator efficiency of 42.8 percent. The enemy, aware of these limitations, initiated mortar and rocket attacks from positions outside the scan of the radar. He first noted the orientation of the radar and then selected the axis of his attack. In order to cope with this handicap, U.S. troops employed a screen to conceal the direction in which the radar was oriented.

As with any sophisticated equipment, the value of the Q-4 was directly related to the degree its use was emphasized by commanders. When careful consideration was given to its positioning and employment to realize its maximum effectiveness, command interest aroused in radar crews a feeling that their work was important. They, in turn, strove to obtain maximum effectiveness from their radars. On the other hand, lack of command interest often resulted in a radar being positioned on the corner of some installation where it was ignored, its crews bored and indifferent.

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