Riverine Operations
1966 - 1969
Chapter
IV:
Initial
Delta Operations
When the 3d Battalion, 60th Infantry, was sent to Dong Tam in January 1967, the Headquarters, 3d Brigade, U.S. 9th Infantry Division, also went to Dong Tam to direct construction of the base and to conduct operations in Dinh Tuong Province. The 5th Battalion, 60th Infantry (Mechanized), was stationed at Tan Hiep, an airstrip about eight kilometers northeast of My Tho along Highway 4. The 3d Brigade conducted the first of a series of operations in late February 1967; these operations were usually limited to one battalion and one or two companies of another battalion because so many troops were needed to protect the construction work at Dong Tam Base.
Implementing earlier planning, General Westmoreland decided to move Headquarters, 2d Brigade, to Dong Tam so that it would become operational at that location on 10 March. The 3d Brigade was moved north to Tan An, the capital of Long An Province, with the mission of conducting a consolidation operation to assist the pacification program in the southern portion of the III Corps Tactical Zone. With the arrival of Headquarters, 2d Brigade, at Dong Tam, the brigade began a demanding 90-day period of performing four separate but related tasks: the defense and construction of the Dong Tam Base; limited offensive operations in Dinh Tuong and Kien Hoa Provinces; operations in the Rung Sat Special Zone to protect the shipping channel; and planning with Task Force 117 to move aboard the Navy ships.
Conducting operations in Dinh Tuong Province was to prove as important in the seasoning of the battalions of 2d Brigade as was the riverine training in the Rung Sat Special Zone. The threat posed to Dong Tam by the Viet Cong 514th Provincial Battalion, the 263d Main Force Battalion, and local force sapper and infantry companies and guerrillas demanded a varied offensive campaign to protect the base as well as to reduce the Viet Cong influence.
Although Dinh Tuong Province was bordered on the south by
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the My Tho River, the limited navigability of smaller streams greatly limited boat movement within the province. Most canals were blocked by the debris of destroyed bridges or by earthen dams erected by the Viet Cong to prevent their use by civilians or military forces. Therefore, although the brigade was scheduled for a riverine role, it was to carry on between March and June a variety of operations common to all U.S. infantry units in Vietnam. These included throwing a cordon around hamlets and searching them in the hope of capturing members of the local Viet Cong political organization and guerrilla squads and platoons; brigade and battalion reconnaissance in force operations; and extensive patrolling. Troops moved by helicopter, boat, wheeled and tracked vehicles, or on foot. During the wet season the brigade operated in the Dong Tam area by boat and helicopter chiefly. When aircraft were not available, wheeled vehicles could carry troops on Highway 4 to find the enemy near suspected Viet Cong bases. The troops then moved on foot into the operational areas to the north and south of the road.
During March and April the brigade commander and staff, assisted by the senior U.S. adviser of the 7th Vietnam Army Division, Colonel Lance, assembled good intelligence covering Dinh Tuong and Kien Hoa Provinces. In addition, through the U.S. senior adviser to IV Corps, General Desobry, arrangements were made for periodic briefings of the brigade staff by the G-2, IV Corps advisory staff. This information was used in a series of cooperative operations undertaken by the 2d Brigade with the 7th Vietnam Army Division. These were to provide beneficial combat experience for the brigade before it embarked as the Army component of the Mobile Riverine Force.
The diverse tasks of the brigade seldom permitted more than two infantry battalions to be used in offensive operations. Thus in covering large base areas without exact intelligence of enemy locations, participation of additional forces was coordinated with the 7th Vietnam Army Division to search thoroughly and to block escape routes. The Commanding General, 7th Vietnam Army Division, approved of such operations because they permitted him to deploy small forces into Viet Cong base areas, for which he would otherwise have been obliged to use more Vietnamese troops than he could spare from their security missions. Throughout the experience of the Mobile Riverine Force, it was to prove necessary to obtain additional troops, whether they were other U.S. units, Vietnam Army units, or Vietnamese marines, to augment the two
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battalions routinely operating within the Mobile Riverine Force.
During the period 15 February-10 May, the 2d Brigade,
although physically based at Dong Tam, conducted infantry operations with the 3d
and 4th Battalions, 47th Infantry, in the Rung Sat Special Zone and southern
Bien Hoa Province. While the 3d Battalion, 47th Infantry, was located in the
Rung Sat during February and March, the 4th Battalion, 47th Infantry, was used
in the southern portion of Bien Hoa Province, south of Bearcat and bordering the
Rung Sat. The boats of the Navy's River Assault Squadron 9 supported Army
operations in the Rung Sat during this period.
Final
Mobile Riverine Force Preparations
At the same time active co-ordination and planning for the Mobile Afloat Force was begun by the 2d Brigade staff with the advance staff of River Assault Flotilla One. General Eckhardt assigned Lieutenant Colonel John R. Witherell, who had been the Combat Developments Command liaison officer to the G-3 Section, U.S. Army, Vietnam, to 2d Brigade. As a major, Colonel Witherell had initiated the first outline draft of the riverine doctrine manual. He was made the deputy for riverine planning for the 2d Brigade, augmenting the brigade staff. At this time, Lieutenant Colonel James S. G. Turner, U.S. Marine Corps, was placed on duty with Headquarters, 9th Division, by the Commandant of the Marine Corps as an observer and liaison officer for riverine operations. At the request of the brigade commander, Colonel Turner was placed on special duty with the brigade staff. Colonels Witherell and Turner proved to be valuable additions because the brigade staff was involved in planning for and conducting daily operations of the two maneuver battalions, including Dong Tam Base defense operations, as well as in formulating plans to establish the brigade at Dong Tam. In the early draft plans prepared by Colonel Witherell, the term Mekong Delta Mobile Afloat Force was dropped and the title Mobile Riverine Force was formally adopted.
As of mid-January, two APB's, Colleton and Benewah, were scheduled to arrive in Vietnam during May or June 1967. The two ships would provide only 1,600 berthing spaces for Army troops. When troop space for artillery support, base security forces, and the brigade staff was subtracted, there would remain spaces for a combat force of approximately one reinforced battalion. It was considered essential to increase the combat strength of the brigade to at least two battalions. Since only two APB's were available, it
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NON-SELF-PROPELLED BARRACKS SHIP
was recommended by the 2d Brigade that a towed barracks ship, an APL, with a berthing capacity for 660 troops be made available. This recommendation was forwarded through division to the commander of II Field Force, who, in turn, requested the commander of the naval force in Vietnam to make the APL available. He proposed that if the APL was diverted, Navy men be provided to operate and maintain only the equipment peculiar to the Navy and that Army troops be required to perform all other support functions such as cleaning, preventive maintenance, messing, laundry service, and security. This proposal was satisfactory to the Army and APL-26 was diverted to Dong Tam in May, along with two sea-going tugs to move the barracks ship. An additional 175 berths were provided by building hunks on the top side of the APL under a canvas canopy.
Frequent co-ordination meetings were field with Captain Wells aboard his flagship at Vung Tait. During the last two weeks of March Colonels Witherell and Turner moved aboard the flagship to participate with the Navy staff in the development of a Mobile Riverine Force standing order. The brigade operations officer, Major Clyde J. Tate, continued to concentrate on the current
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brigade operations. Colonel Fulton felt that the Mobile Afloat Force plan had not provided effective artillery support for the Mobile Riverine Force operations. The armored troop carriers were to lift the 105-mm. howitzers and their prime movers. The artillery battalion, after being moved by water, would debark at a suitable place along the river and establish firing positions. Terrain reconnaissance conducted during his October 1966 visit had convinced Colonel Fulton that the off-loading of the prime movers from an ATC as provided for in the plan would greatly restrict operations because of the varying tides of four to thirteen feet and the steepness of the river banks. Consequently, the Commanding Officer, 3d Battalion, 34th Artillery, Lieutenant Colonel Carroll S. Meek, began to experiment with barge-mounted artillery. He placed a 105-mm. howitzer on an Ammi barge, using cleats and segments of telephone poles against which the trails of the howitzer rested. Successful firing demonstrated the feasibility of this method. By use of aiming stakes placed ashore routine fire support could be provided from the barges anchored securely against the river bank.
During these experiments, the Deputy Commanding General,
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Diagram 5. Artillery barge towing position.
U.S. Army, Vietnam, Lieutenant General Jean E. Engler, placed a liaison officer from the G-4 Section on temporary duty with the brigade. This officer's sole mission was to procure special equip ment requested by the brigade, thus eliminating the procedure of requesting items through normal channels and greatly facilitating the acquisition of equipment. After Colonel Meek's initial firing experience with the barge-mounted artillery, the liaison officer was asked to arrange fabrication of an experimental artillery barge. The work was done in a few weeks at Cam Ranh Bay, where small pontoons were welded together into an artillery barge. The barge was then towed down the coast and brought up the Mekong River to Dong Tam by a commercial ocean-going tug. Further firing experiments proved the barge unsatisfactory in that the high bow of the ponton was nearly perpendicular to the surface of the water, making it hard to maneuver and tow, especially against the current, tide, or prevailing wind. The barge was redesigned so that it floated lower in the water and had a sloped bow, and the design was forwarded by the G-4 liaison officer to Cam Ranh Bay. As a result of successful experiments with the new design, six barges were fabricated, each barge to accommodate two tubes of 105-mm. howitzer, M102. (Diagram 5) Each barge was to be towed by an LCM-8 throughout the areas in which the Navy assault craft supported Army forces. The decision to develop the artillery barges was the most important equipment decision made by the Army for the
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ARTILLERY FIRES FROM BARGES ANCHORED ON
RIVER BANK
Mobile Riverine Force because the barges provided effective artillery support at all times. Had General Engler not had the foresight to furnish liaison and to make special arrangements to obtain unique equipment, the initial effectiveness of the Mobile Riverine Force would have been greatly impaired.
Also during the March-April period, Colonel Fulton decided that there was not enough helicopter landing space aboard the ships of the river force. Each APB had one helicopter landing pad, and the LST could accommodate the landing of one helicopter. Through the same expedited development process used for the artillery barges, a helicopter landing barge was provided that could accommodate three UH-1 helicopters and would have a refueling capacity for the helicopters of 1,500 gallons of JP-4. This barge would be towed by an LCM-8 of the Army transportation boat company.
As more U.S. Navy craft arrived in Vietnam and the initial training was completed, River Assault Flotilla One elements were sent from the Vung Tau-Rung Sat Special Zone training area into Dinh Tuong Province. On 10 April the first river assault division
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moved to Dong Tam with 18 ATC's, 1 CCB, and 2 monitors and immediately began waterborne operations with the 3d Battalion, 47th Infantry, which had also left Rung Sat Special Zone for Dong Tam. Although these operations on the Mekong River were small in scale during the month of April, the men soon learned that unlike the rivers of the Rung Sat Special Zone, where obstacles were few, the delta waterways had many man-made obstructions such as low bridges, fish traps, and earthen blocks on canals.
During April a small staff group of River Assault Flotilla One went to Dong Tam to work closely with the 2d Brigade staff in developing the final plans for Mobile Riverine Force operations, which were to begin on 2 June. The first embarkation was to include the brigade headquarters and staff; 3d Battalion, 34th Artillery; Company C, 15th Engineers; and the division support elements. In the final planning phase for this embarkation it was decided that a larger supply LST would be needed to provide an additional 375 U.S. Army berthing spaces. Originally two class 542 LST's were scheduled as the logistics support ships to rotate between Vung Tau and the riverine base. Since the 542 class is
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much smaller and provides less billeting space, a request was made to River Assault Flotilla One for one of the larger 1152 class LST's. Again, the Navy accommodated the Army request. Acquisition of the larger LST was to prove very advantageous in that the entire brigade aviation section, which included four OH-23 helicopters, and the maintenance section were placed aboard the LST and were operated from the flight deck. Limited air resources were now available for combat operations regardless of the remoteness of the location of the mobile riverine base from 9th Division support.
Both the brigade headquarters and the infantry battalions
were internally reorganized so that all equipment not necessary for riverine
operations could be left at the Dong Tam base under the control of unit rear
detachments. Spaces for jobs not needed by the Riverine Force, such as for
drivers and mechanics, were converted to spaces with shipboard and combat
duties. The combat support company of each battalion was reconstituted into a
reconnaissance and surveillance company. Men assigned to spaces whose function
was not required in the Mobile Riverine Force were placed in these two companies
and thus two additional rifle platoons were created in each of the two
battalions. When these two platoons were added to the reconnaissance platoon
normally found in the combat support company, a fourth rifle company for each
battalion was organized. This arrangement was to prove most satisfactory because
it provided for base defense and other security missions and at the same time
left three companies for battalion tactical operations.
While planning of the riverine organization of the infantry battalions was taking place, in April and May the battalions were actually conducting land operations. The 3d Battalion, 47th Infantry, and 3d Battalion, 60th Infantry, were increasing their proficiency in airmobile operations and learning to work with the officials of Dinh Tuong Province and Army of Vietnam division forces.
On 1 April 2d Brigade forces made a raid into northern Kien Hoa Province on the My Tho River south of Dong Tam, using barge-mounted artillery. During darkness, one battery was moved west on the river from the land base, followed closely by infantry mounted in ATC's. Once opposite a manned station of a Viet Cong communications liaison route, the artillery poured surprise, direct fire into the target area. To protect a Ham Long District company, which had occupied a blocking position south of the target, time
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fuzes were used. Immediately after the artillery fire, infantry troops landed and swept through the station. The artillery then anchored against the north bank of the river and prepared to provide indirect fire support. The raiders captured enemy ammunition and a portion of the labor force of the enemy communication-liaison platoon.
On 2 May the 3d Battalion, 47th Infantry, and 3d Battalion, 60th Infantry, participated in the 2d Brigade's heaviest fighting to date. The target of the brigade assault was the 514th Local Force Battalion in the Ap Bac 2 area, which had been identified by the commanding general of the 7th Vietnam Army Division as a normal operating area for the Viet Cong. (Map 4) The ground over which the battle would take place was alternately rice paddy and thick patches of vegetation with heavy foliage along the streams and canals. The brigade plan was to conduct an airmobile operation in
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co-operation with the 7th Vietnam Army Division. On the morning of the operation, however, shortly after the scheduled time for the airlift of the first company, the brigade was notified that no airmobile company was available. The brigade commander decided to send the unit by truck, a move requiring approximately two hours. At the same time the brigade forward command post elements moved north by ATC's on the Kinh Xang Canal to set up a post at Long Binh. The 3d Battalion, 60th Infantry, truck convoy was followed by the 3d Battalion, 47th Infantry, on the same route. The companies of both battalions were off-loaded facing north from Highway 4.
By 0830 both battalions were moving north to their first objectives. Elements of the 3d Battalion, 60th Infantry, on the west met no resistance. Units of the 3d Battalion, 47th Infantry, moved forward cautiously during the morning, covering about 1,500 meters and receiving light sniper fire. At approximately 1250 both Companies A and B, 3d Battalion, 47th Infantry, encountered the enemy. Company A came under heavy automatic weapons fire immediately after emerging from a wood line; it deployed in an attempt to move against the enemy position, but was hampered by heavy undergrowth that made it difficult to see the enemy firing positions. The company sought to improve its position, and called in fire support, including artillery fire, gunships, and eventually three air strikes on the enemy position.
About 1300, Company B, 3d Battalion, 60th Infantry, was placed under operational control of the commander of 3d Battalion, 47th Infantry, and directed to establish a blocking position north of the enemy location. At the same time Company A, 3d Battalion. 60th Infantry, and Company C, 5th Battalion, 60th Infantry, were ordered to close enemy escape routes on the west. Companies B and C, 3d Battalion, 47th Infantry, were ordered to block northeast of the position of Company A, 3d Battalion, 47th Infantry.
Company C, 5th Battalion, 60th Infantry, a mechanized company, using full-tracked armored personnel carriers, moved through inundated areas which had been thought impassable to occupy a position west of the enemy. Company C, 5th Battalion, 60th Infantry, and Company A, 3d Battalion, 60th Infantry, then made the final assault from the west into the enemy position. Company C, 5th Battalion, 60th Infantry, greatly enhanced the firepower of the assault by employing the .50-caliber fire of its full-tracked armored carriers in the assault line. The organic infantry attacked on foot alongside the carriers. The enemy resisted with heavy rifle
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and automatic weapons fire. Company A, 3d Battalion, 60th Infantry, on the right flank of the assault, charged into the southern line of bunkers, and finally overran it. Seeing that their line was broken, many Viet Cong tried to escape to the east but were killed or wounded as both attacking companies made their final assault into the bunker line. By 1820 enemy resistance was overcome.
Although not a riverine operation, the action at Ap Bac contributed to the brigade tactical experience which was later carried into riverine operations. In developing operational plans, the brigade staff recognized that tactical control measures have to provide for maximum flexibility in controlling the maneuver of units. If the original plan cannot be executed, there must be sufficient latitude to redirect the effort of the participating units according to the control measures previously issued. Check points, a series of intermediate objectives, and an area grid system provide flexibility for redirection of units and shifting of boundaries and fire coordination lines.
The Ap Bac operation included in the words of an infantryman "finding, fixing, fighting, and finishing" the enemy. Through the use of simple control measures, units of the two battalions were moved into blocking positions to cut off enemy routes of withdrawal, and other units were maneuvered into assault positions. When this maneuver was combined with use of both air and artillery supporting force, the enemy had to remain in his position or expose himself in an attempt to withdraw.
The operation made it clear that units must be prepared to bring in artillery and air support as close as possible to the front lines. Each battalion commander used an observation helicopter to co-ordinate fire in close support of his unit. The infantry units, once having found the enemy, had to be prepared through fire and maneuver to conduct a coordinated assault against the enemy positions. In this engagement, by the use of close supporting artillery fire; the infantry units were able to launch a coordinated attack which overcame the enemy.
Mechanized infantry was used most successfully at Ap Bac. The unit commander had to search for routes through very swampy and marshy areas. Once his armored personnel carriers (APC's) were deployed, he dismounted his infantry and moved APC's and infantry in a forward rapid assault on the enemy. The volume of fire delivered by the APC's into the bunker -line, along with high explosive and white phosphorous rounds of artillery, enabled the infantry to overcome the enemy in bunkers and foxholes. Once
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fire superiority had been established, the assault was executed with few American casualties.
General Thanh, commanding the 7th Vietnam Army Division, monitored the course of the 2 May battle with interest. By midnight the intelligence staffs of the brigade and 7th Vietnam Division had estimated that the enemy consisted of the 514th Local Force Battalion with two companies and its heavy weapons. An enemy attack launched at dusk of 2 May on the command post of the 3d Battalion, 60th Infantry, just south of Highway 4, appeared to be the rest of the 514th Local Force Battalion trying to relieve pressure on its units north of Highway 4. On the strength of this estimate, General Thanh sent a Ranger battalion on 3 May into the area which he
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ARMORED TROOP CARRIERS IN CONVOY BATTLE
LINE
considered the most probable location to which the enemy would flee. His Rangers encountered and attacked an estimated company of the 514th Local Force Battalion during the afternoon. The casualties inflicted upon the 514th by the U.S. 2d Brigade and the 7th Vietnam Army Division severely reduced its combat effectiveness. Reports received later suggested that the 263d Main Force Battalion was forced to undertake training of new recruits and operational tasks of the 514th Battalion because of the losses in men and weapons.
On 13 May the 4th Battalion, 47th Infantry, completed operations in the Rung Sat Special Zone and joined the brigade at Dong Tam. Colonel Tutwiler's battalion participated in its first major riverine operation in the Dona Tam area on 15 May as the 2d Brigade conducted the first of several operations in the Cam Son Secret Zone. (Map 5) The Cam Son area was considered one of four major Viet Cong bases in Dinh Tuong Province by the intelligence staffs of both the province and 7th Vietnam Army Division. The operation of 15 May relied entirely on intelligence provided by these Vietnamese organizations.
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The brigade plan was to search the southern area of Cam Son along the Rach Ba Rai and Rach Tra Tan streams and to capture or destroy the Viet Cong, their supplies, and their equipment. A forward brigade command post was established approximately two kilometers north of Cai Be, and a barge-mounted artillery base was established on the southern bank of the My Tho River, five kilometers southeast of the mouth of the Rach Ba Rai. The two infantry battalions were supported by 22 ATC's, 2 monitors, and 2 CCB's of River Assault Flotilla One. Commander Charles H. Black, the operations officer of River Assault Flotilla One, joined the brigade command group and coordinated the support of the Navy assault craft.
The operation began at 0815 when the 3d Battalion, 47th Infantry, landed from assault craft at the mouth of the Rach Ba Rai and began to search northeast along the stream. At 0830 the 4th Battalion, 47th Infantry, landed two companies from assault craft on the north bank of the My Tho River approximately halfway between the mouths of the Rach Ba Rai and the Rach Tra Tan. At 1200 Company A, 4th Battalion, 47th Infantry, was airlifted from Dong Tam, where it had been in readiness as a reserve, and was landed three kilometers north of the river on the west side of the Rach Tra Tan to act as a blocking force against any enemy encountered. After landing the Army troops, the boats of the Navy task force proceeded to blocking stations along the waterways.
At 1400 Companies B and C of the 4th Battalion, 47th Infantry, met a Viet Cong force equipped with small arms, light machine guns, and rocket launchers. Company A maneuvered south and met the enemy within two kilometers of the My Tho river. Although Companies B and C made little progress in moving against the enemy fire, artillery and close air support maintained pressure on the Viet Cong.
In an effort to move more troops to the northeast and rear of the Viet Cong force, the Reconnaissance Platoon, 3d Battalion, 47th Infantry, was moved by ATC into the Rach Tra Tan. When the low tide and enemy antitank rockets prevented the assault craft from penetrating upriver beyond enemy positions on the banks, the platoon was withdrawn.
By 1630 it became apparent that some enemy forces were escaping by moving to the northeast, away from both Companies B and C, which were moving from the south, and from Company A, which was moving from the northwest. At this point Colonel Fulton directed Colonel Bolduc to move one of his companies by helicopter
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to establish a blocking position northeast of the battle. This was accomplished by 1700, but the company failed to find the enemy, and by 2000 all contact with the Viet Cong was lost.
This fight called attention to the limitations imposed upon maneuver or assault craft during low tide and the importance of artillery and close air support against an enemy in well-prepared bunkers and firing positions. Although most American casualties did not require evacuation because their wounds were superficial, both Army and Navy were concerned -by the vulnerability of men aboard the assault craft to rocket fragments. The Mobile Riverine Force was to find vulnerability of troops aboard assault craft one of its continuing problems.
On 18 and 19 May the 2d Brigade moved a forward command post by motor convoy north of Cai Be in western Dinh Tuong Province to control the operations of 3d Battalion, 47th Infantry, and 3d Battalion, Goth Infantry. To reduce the distance the supporting helicopters would have to fly, River Assault Flotilla One assault craft moved both battalions by water thirty-six kilometers west of Dong Tam to landing sites on the north bank of the My Tho River. With the infantry battalions positioned within seven kilometers of the center of the target area, one airmobile company was able to insert each battalion rapidly into the area. In the event of substantial fighting the helicopters could turn around quickly in building up forces.
During this operation the battalions of the 2d Brigade met few of the Viet Cong, but the brigade command post was attacked by mortar, recoilless rifle, and machine gun fire during the early hours of 19 May. A ground attack was thwarted when the Reconnaissance Platoon, 3d Battalion, 47th Infantry, led by Second Lieutenant Howard C. Kirk III intercepted enemy movement toward the western perimeter of the position; assisted by artillery, gunships, and an armed illumination aircraft, the reconnaissance platoon broke up the attack.
Throughout the month of May, a maximum effort was made to establish procedures for close co-operation between Army and Navy elements. Colonel Fulton and Commander Black agreed that the helicopter was invaluable for command and control of riverine operations. Finding important terrain features is a very difficult task for the commander on the surface, but a simpler task for the airborne commander. Foot troop and assault craft maneuver were facilitated by information furnished by the airborne command group. During darkness and in marginal flying weather, the com-
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mand and communications boats were valuable to brigade and battalion commanders in their forward positions. The combined use of command helicopters and command boats by brigade and battalion commanders permitted close supervision and control of the Mobile Riverine Force in combat.
The operations of the 2d Brigade in Dinh Tuong Province from March through May had already provided invaluable operational experience. All of the brigade's units had met and withstood the enemy; thus a feeling of confidence had been engendered in commanders and men. Of even greater importance, however, was the displacement of Viet Cong units from the Dong Tam area to the western portion of Dinh Tuong Province, from which the enemy could not readily launch a large ground attack on the base. The 2d Brigade had become operational at Dong Tam on 10 March, only seventy-two hours after an engagement involving a platoon of the 3d Brigade and a larger Viet Cong unit less than eight kilometers from the base, and forty-eight hours after the enemy launched an attack on Dong Tam with recoilless rifles and mortars.
In the next ninety days the enemy made one successful sapper attack that damaged a construction vehicle outside the camp and an American patrol ambushed an enemy force of platoon size three kilometers west of the base. To prevent enemy fire and ground attack on the base, a patrolling system was executed by the base defense battalion, using division artillery radar. Patrols were made on foot, by tracked and wheeled vehicles, by boat, and by helicopter, and were sent out by day and by night.
Offensive operations came to be guided by knowledge of the habits of the Viet Cong, who made use of certain areas and routes for bases and for communication, liaison, and supply. Although information provided by the Vietnam Army division and province intelligence agencies seldom arrived in time to serve as the basis for an attack, it was useful in tracking the enemy's routes, bases, and length of stay in bases. It permitted a rough guess as to when a Viet Cong battalion would be in any one of the four major Dinh Tuong base areas at a given time. Operations could be conducted against one or more bases on a priority basis. By co-operation with the Vietnam Army and using economy of force, the brigade could enter the first priority base area with most of two battalions, the Vietnamese forces could enter the second priority area, and the brigade would use a small force to reconnoiter a third base area. Helicopter transport was essential and air cavalry support highly desirable. It was not, however, until May that a portion of Troop
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D, 3d Squadron, 5th Cavalry, was used by the 2d Brigade.
By the end of May, the brigade had found the enemy in three
of the four Dinh Tuong base areas on many occasions and had contributed to a
period of relative security for the men attempting to complete construction of
the Dong Tam Base as well as for the province itself.
Mobile
Riverine Force Campaign Plan
During early April it had become apparent that the Navy's concept of the employment of the Mobile Riverine Force differed slightly from the original Mobile Afloat Force concept. Captain Wells contended that the force should act as a separate force, divorced from 9th U.S. Division operations and control, with deployments deep into the delta. A period of intensive discussions between the component commanders ensued. Differences were not resolved until the preparation of a wet and dry season campaign plan for the Mobile River Force as well as a draft letter of instruction from the 9th U.S. Division commander to the brigade commander. This letter was prepared by the brigade staff and carried to the commander of the 9th Infantry Division, General Eckhardt, with the recommendation that it be issued by Headquarters, 9th U.S. Division, to the Mobile Riverine Force Army component commander.
General Eckhardt accepted the draft letter and draft campaign plan and personally took them to Captain Wells, who, as the commander of River Assault Flotilla One and Task Force 117, the operational designation of the Navy component of the riverine force, accepted both. These two documents adhered to the original Mobile Afloat Force plan for operation of the river force in conjunction with the other 9th U.S. Division elements in the southern III Corps Tactical Zone and in the northern portion of the IV Corps Tactical Zone north of the Mekong River.
The opinion of the Navy component commander that operations should be conducted exclusively in IV Corps was not supported by Headquarters, MACV, Planning Directive Number 12-66, dated 10 December 1966, entitled Command Relations for Riverine Operations in South Vietnam. Essentially, this document placed Army forces conducting riverine operations in III and IV Corps Tactical Zones under the operational control of the Commanding General, II Field Force, with a stipulation that he might exercise operational control through designated subordinate U.S. Army headquarters. The commander of U.S. Army, Vietnam,
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would exercise command, less operational control, of all U.S. Army units engaged in riverine operations. Similarly. Navy riverine forces were placed under the operational control of the commander of Naval Forces, Vietnam, and under the command, less operational control, of Commander in Chief, Pacific Fleet.
The planning directive recognized the unique command arrangements peculiar to the Mobile Afloat Force concept. This was not to be a joint task force and the specific command relationships had not been planned under the original concept. The planning directive took note of the fact that "the conduct of riverine operations by Army and Navy forces is a new concept which will require the utmost coordination and cooperation by all concerned. As operations are conducted and lessons learned, command relations will be revised as necessary to insure effective and workable arrangements." There was to be no single commander of the Mobile Riverine Force.
The MACV document stipulated that the base commander for all bases, whether ashore or afloat, would be the senior Army commander assigned. It further stipulated that the relation between the Army and Navy units stationed on both Army and Navy bases would be one of co-ordination and mutual support, with the Navy providing its appropriate share of forces for local base defense, including naval gunfire support and protection against waterborne threats. Operational control of Navy units in these circumstances was to be exercised by the base commander through the Navy chain of command.
Command relationships for riverine operations were further defined as commencing when troops began embarking on assault craft to leave the base and ending when troops had debarked from the boats upon return to the base. During riverine operations, the Army commander would control all participating Army forces and the Navy commander would control all participating Navy forces. The Navy would provide close support to the Army during these operations according to the definition by the joint Chiefs of Staff:
When, either by direction of higher authority or by agreement between the commanders concerned, a force is assigned the primary mission of close support of a designated force, the commander of the supported force will exercise general direction of the supporting effort within the limits permitted by accepted tactical practices of the service of the supporting force. Such direction includes designation of targets or objectives, timing, duration of the supporting action, and other instructions necessary for coordination and for efficiency.
Command relationships between the Army and Navy elements
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or components during the operational planning phase would be one of co-ordination. This particular aspect of the planning directive posed a basic dilemma in that co-ordination meant agreement at the lowest possible level as to where the force would deploy and how it would fight. If the agreement could not be obtained during the planning phase, the planning directive made provision for the following:
It is the responsibility of commanders at all levels through liaison, cooperation, coordination, and good judgment to make every effort possible to solve all command relationship problems in the most expeditious and workable manner consistent with the problem. Problems which cannot be solved satisfactorily will not be forwarded to the next higher headquarters until the commanders concerned have made every effort to reach agreement.
In the event that agreement could not be reached, the division of component authority meant that each of the component commanders would proceed up his respective chain of operational control to obtain a solution. A solution would require co-ordination between the headquarters of the parallel Army and Navy echelons. For example, in the event that there was a disagreement between the Navy component commander and the Army component commander of the Mobile Riverine Force, the Army commander would have to pass the problem to the commander of the 9th U.S. Division. It is notable that there was no Navy echelon equivalent to the 9th Infantry Division under the Navy chain of operational control. The commander of the 9th Infantry Division would then have to pass the matter to the commander of II Field Force, who, in turn, would co-ordinate with the parallel Navy commander. (Chart 2)
The command relationships had complicated planning of the location of initial operations, and prompted Captain Wells to challenge the role of the 2d Brigade as an integral part of the 9th U.S. Division's over-all operations. This initial disagreement was resolved by Captain Wells' acceptance of the 9th Division letter of instruction. Determination of the mission and area of operation of the Mobile River Force in relation to the 9th Infantry Division, however, was a continuous source of friction between the brigade and flotilla commanders. Generally the commander of River Assault Flotilla One agreed to the joint Chiefs of Staff provision that the supported force would direct operations: "Such direction includes designation of targets or objectives, timing, duration of the supporting action, and other instructions necessary for the co-ordination and for efficiency."
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Chart 2 - Mobile Riverine Force Command Structure
Brigadier General George G. O'Connor, Assistant Commander, 9th U.S. Infantry Division, was responsible to the division commander for the division operations in IV Corps. He provided broad guidance and considerable latitude to the brigade commander in dealing with the command relationships and operational procedures of the Mobile Riverine Force. Without this degree of flexibility, it is unlikely that the brigade and flotilla commanders could have resolved as they did many fundamental issues without recourse to their respective superiors.
Based on the fundamental issues agreed upon and the campaign plan outline of where and how the river force was going to fight, planning continued as the 2d Brigade and its subordinate units began to board the Navy ships of the Mobile Riverine Force at Dong Tam on 31 May.
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