Riverine Operations
1966 - 1969
Plans and Operational Procedures for the Mobile Riverine Force
While the Army elements were being moved aboard the ships
of River Assault Flotilla One, the staffs of the flotilla and brigade completed
the planning for initial tactical operations. Lacking the unity of organization
for planning that is present in a joint staff, the brigade and flotilla
commanders informally agreed upon the planning roles of each staff.
Colonel Fulton and Captain Wells decided that Mobile Riverine Force operations would be planned and conducted on the basis of intelligence collected from areas in which major enemy forces were most likely to be met and in which the abilities of a river force could be best used. Once an enemy force and area had been agreed upon as a target by the two component commanders, the brigade S-2 and flotilla N-2, working together closely, would collect intelligence to support further planning. The N-2 would concentrate on the navigability of waterways and threats to the Navy ships and assault craft. The S-2 would gather intelligence information necessary to conduct land operations. Both the S-2 and the N-2 would be highly dependent upon the intelligence disseminated by other U.S. and Vietnamese headquarters because the Mobile Riverine Force had a large area of interest and would need to move considerable distances from one location to another.
Since the S-2 and N-2 could not supply all the information needed by the riverine force, intelligence was obtained from several agencies. A seven-man Mobile Intelligence Civil Affairs Team was formed by the brigade to co-ordinate with these agencies. This team was formed from the brigade S-2 and S-5 sections, the prisoner of war interrogation team, the psychological operations team, and military police platoons. It moved into the operational areas of the force to collect intelligence from Vietnamese political officials and from intelligence officers of military units. Working close
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to the intelligence centers of Vietnamese organizations, the team aided in the exchange of tactical intelligence as well as in the coordination of a limited number of civil affairs activities. The Mobile Intelligence Civil Affairs Team was not usually moved into an area during the planning phase of an operation for fear of detection by enemy counterintelligence, but was moved in at the beginning of an operation.
Another means of intelligence collection for the riverine force was the riverine survey team. Controlled by Task Force 117, the team accompanied the task force on missions and recorded depth soundings and clearance measurements, thus providing reliable navigation data for subsequent operations. Under the direction of the 9th Infantry Division engineer, Vietnamese Regional and Popular Forces also collected information on bridges so that the riverine force could be sure of vertical and horizontal bridge clearance on a waterway.
While they were collecting information, the S-2 and N-2
briefed the brigade and flotilla commanders and the planners on the area of the
impending operation, and this intelligence along with other information was
incorporated in planning guidance provided by the commanders. It was at the
point of the formulation of planning guidance that - the command relationships
of the Mobile Riverine Force received one of its greatest tests. By close
co-operation, Colonel Fulton and Captain Wells decided upon the guidance to be
issued to their staffs for each operation, and these agreements in time came to
be accepted as an informal set of standing operating procedures. They were,
however, subject to change at any time by either commander and were not reduced
to a written, formally approved document. Task Force 117 published a standing
order that contained the results of considerable Army and Navy planning but was
not jointly approved.
The brigade commander or a higher echelon Army commander usually selected the enemy target and area of operations. The two commanders then agreed upon the general task organization, the tentative duration and timing of the operation, and the location of the mobile riverine base to support the operation. The planning often included great detail in order to insure that major issues were resolved early, permitting the two staffs to plan efficiently.
From the outset, Colonel Fulton and Captain Wells recognized
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the need to plan for future efforts while operations were in progress. Colonel Turner, who lead been designated riverine adviser, acted as the planning coordinator, with the assistant N-3 (plans) , the assistant S-3 (plans) , the N-2, and the S-2 forming the planning staff. The planning for operations to take place ten days hence, the planning for the next operation, three to five days hence, and the execution of the current operation were accomplished at the same time, with the S-3 and N-3 dealing with the current operation.
The planning staff, using the commanders' guidance, began by outlining the scheme of maneuver in the objective area. From there the planners worked backwards, covering in turn the landing or assault, water movement, and loading phases. In preparing operations orders they took into consideration factors peculiar to riverine operations such as tides, water depth, water obstructions, bridge clearance, distance of the mobile riverine base from beaches, availability of waterway routes into the area of operations, suitability of river banks for landing sites, and mooring for barge-mounted artillery. Operation orders followed the format of the standard, five-paragraph field order, and were authenticated by the S-3 and the N-3. The bulk of the information peculiar to riverine operations was in the annexes, which included intelligence, operations overlay, fire support plan, naval support plan, signal arrangements, logistics, civil affairs, and psychological operations information. The intelligence annex supplied information on terrain, weather, and the enemy situation. Waterway intelligence was usually provided in an appendix that covered hydrography and the enemy threat to assault craft. A map of the waterways to be used was furnished, showing tides, widths and depths of streams, obstacles of various types, bridges, shoals, mud banks, and other navigation data. The enemy threat to assault craft was covered in descriptions of recent enemy action along the waterways, location of enemy bunkers, kinds of enemy weapons likely to be used in harassing action and ambushes, and water mine and swimmer danger to the small boats. The operations overlay annex showed schematically the area of operations, plan of maneuver, and control measures such as checkpoints. The naval support plan annex contained the naval task organization and referred to the operations order for information concerning the situation, mission, and concept of operations. It assigned specific support tasks to subordinate naval elements together with the necessary coordinating instructions. An appendix to the naval support plan provided waterway data.
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Battalion orders for operations in a riverine area followed the format used in the brigade orders and were authenticated by the battalion S-3. The supporting river assault squadron water movement plan was prepared by the river assault squadron operations officer in co-ordination with the battalion S-3. It was, in effect, the river assault squadron operations order. This plan did not become a formal part of the battalion operations order but was attached to it. The water movement plan contained the task organization, mission, schedule of events, boat utilization plan, command and communications instruction, and coordinating instructions. The schedule of events paragraph listed events critical to the operation and the time they were to take place, for example, where and when each unit was to load, and its scheduled time of arrival at critical water checkpoints. The boat utilization paragraph included numerical designations of boats and the companies to embark on these boats. The coordinating instructions paragraph included information on submission of reports, radio silence, recognition lights, reconnaissance by fire, and the use of protective masks.
Once approved, both the brigade and battalion operations orders became the authority for fulfilling the intent of the scheme of maneuver and for providing combat and combat service support. Prior to each operation, a briefing was conducted on the flagship of the Mobile Riverine Force; it included presentation of the plan of each battalion and squadron, as well as the latest S-2 and N-2 intelligence. Briefings seldom required decisions by the flotilla or brigade commander because problems had been resolved between the Army and Navy elements at each subordinate echelon and between echelons during planning. Beginning in June of 1967, plans and orders were in far greater detail than the Army brigade and battalion commanders believed was needed or even optimum for routine land warfare. The detailed nature of the plan, however, included agreements at the Mobile Riverine Force command level; the Navy commander desired to define clearly the tasks to be performed by each service. For the Navy commanders and staffs, the detailed plan was less objectionable, being similar to the planning associated with amphibious, ship-to-shore operations. After June of 1967 as time passed both Army and Navy commanders realized that matters such as the loading of a battalion from a barracks ship onto the assault craft of a river assault squadron and the configuration of a battalion river assault squadron convoy were standing operating procedure. The Mobile Riverine' Force was nevertheless to rely heavily on detailed operations orders
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MOBILE RIVERINE FORCE BRIEFING
ABOARD USS BENEWAH
rather than a formal, written standing operating procedure
for many months of its operations.
Operational
Concept and Procedures
The initial operations of the Mobile Riverine Force during the period 1 June to 26 July 1967 were designated Operation CORONADO I. From 3 June through 10 June operations were conducted in the vicinity of Dong Tam, and were designed to make the land base more secure and to test the operational procedures of the force. A tactical operations center manned jointly by the Army and Navy provided a focal point for communications and for monitoring operations and could fulfill the needs of the riverine brigade and flotilla commanders separately.
At the levels of maneuver battalion and river assault squadron, the staffs operated independently but maintained close, harmonious relationships. The maneuver battalion staff Outranked and outnumbered the river assault squadron staff. Because of a limited staff, the naval river assault squadron was unable to perform staff functions which corresponded to those of the infantry battalion it
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supported. This limitation contributed to the centralization of planning at the flotilla level. The two boat divisions organic to the river assault squadrons also were limited in their planning. The rifle company commanders transacted their business with naval enlisted men, who did not have .the authority to make decisions. Time could be lost at the company and boat division level in situations requiring quick decision.
Operations consisted of coordinated airmobile, ground, and waterborne attacks, supported by air and naval forces. The ground and naval combat elements traveled to the area of operations by river assault squadron craft, helicopter; or a combination of these means. While the boats would serve as a block and could transport troops in the early stages of an operation, once the troops had engaged the enemy more speed was necessary and air transportation of forces was generally more satisfactory.
The basic offensive maneuvers used by the Mobile Riverine Force were to drive the enemy against a blocking force, with the open flanks covered by Army helicopter gunships, or to encircle him. These maneuvers were based on the estimate that the enemy would choose to fight only when he thought he could inflict heavy casualties or when he was surprised and forced to fight. If he chose not to fight, he might attempt to take advantage of the concealment afforded by the numerous tree-lined waterways by dispersing into small groups and leaving the area of operations under the protection of small delaying and harassing fire teams. It was necessary for U.S. forces to establish blocking positions quickly and to be able to deploy troops rapidly. Several maneuver battalions were needed, but the Mobile Riverine Force had usually only two battalions, a situation that provided further incentive for coordinating operations with Vietnamese or other U.S. units.
Control of the riverine forces was aided by reliable and versatile parallel Army and Navy communications systems, by operations conducted over flat terrain by units within mutually supporting distances, and by command helicopters used at the brigade and battalion levels. Troop movements were controlled and coordinated from the flagship. The focal point for control was the joint tactical operations center, the Army element of which was under the supervision of the brigade executive officer. Staff representation came from the S-3, S-2, N-3, air liaison, Army aviation, and artillery fire support sections, and the center was operational at all times.
During operations the brigade employed a forward command group, usually located at the fire support base, and composed of the
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TROOPS PREPARE TO EMBARK FROM AMMI
BARGES
brigade commander, the brigade S-3, the brigade assistant fire support co-ordinator, and the air liaison officer. The brigade command group was generally aloft in- a command helicopter in daylight hours. The battalion command post was fragmented into a forward and a rear tactical operations center. The forward post was located in a command boat that accompanied the troops during their waterborne movement and normally consisted of the battalion commander, S-3, assistant S-3, artillery liaison officer, an operations sergeant, an intelligence sergeant, and two radio telephone operators. The river assault squadron commander and his operations officer were aboard the same command boat. The rear command post was located aboard ship at the mobile riverine base and usually consisted of the battalion executive officer, S-1, S-2, S-3, S-4, an operations sergeant, and two radio telephone operators. When a command and control helicopter, usually an observation type, was available, the battalion commander and his artillery liaison officer controlled the operation from the air.
After the briefing that took place before each operation, battalion commanders and supporting river assault squadron com-
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MONITORS AND ASSAULT PATROL BOATS HEAD IN
TO SHORE
manders issued final instructions to their staffs and subordinate commanders. These confirmed or modified previously issued orders. Each rifle company was allocated three armored troop carriers, and arrangements were made to load bulk cargo and ammunition prior to troop embarkation. At the designated loading time for a particular company, three armored troop carriers were tied alongside the Ammi barges moored to the ship and three platoons of a company embarked simultaneously. In most instances, the loading of a complete company was restricted to twenty minutes. The Navy stationed expert swimmers on the barges prepared to rescue men who might fall overboard. Once a company was loaded, the ATC's proceeded to a rendezvous where they waited for the remainder of the battalion to load. Upon completion of the battalion loading, the ATC's moved at a specified time across a starting point and thence to the area of operation. Army elements observed radio silence; the naval radio was used only for essential traffic control.
The boats moved across the starting point in column formation, the leading assault support boats providing minesweeping and fire support. Each minesweeper was equipped with a drag hook that
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ASSAULT CRAFT GOING IN TO LAND TROOPS
was tethered with a steel cable to a high-speed winch. Two of the leading minesweepers preceding on the flanks of the column dragged these hooks along the bottom of the waterway in an effort to cut electrical wires rigged to underwater mines. The river assault squadron commander traveled aboard the leading command and control boat. The battalion commander was either in the control boat or in a helicopter aloft. Each supporting river division was
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divided into three sections, each section consisting of a monitor and three ATC's supporting the one rifle company. These sections were in such order in the column as to maintain infantry company integrity and to place units on the beach in the order specified by the battalion commander. While underway, the river assault squadron commander exercised command and control of the boats. The rifle company commanders monitored the Navy command and control and the battalion command net in order to stay abreast of developing situations. Radar was the principal navigational aid during the hours of darkness.
Water checkpoints were designated along the routes as a means of control, and as march units passed these a report was made to the- joint tactical operations center. Whether on large rivers or small streams, river assault units were faced with the threat of hostile attack. However, when the boats left the large rivers for the smaller waterways the danger from recoilless rifles, rocket fire, and mines increased. The waterways negotiated by the boats varied from a width of 100 meters where the smaller waterways joined the river to widths of 15 to 25 meters. The formation that the boats assumed was similar to that used on the main river except that the leading minesweepers moved to positions nearer the column. While the column proceeded along the small waterways, suspected areas of ambush (if in an area cleared by the Vietnamese government) were often reconnoitered by fire from the small boats and by artillery.
When the lead boats of the formation were approximately 500 meters from the beach landing sites, artillery beach preparations were lifted or shifted. The leading minesweepers and monitors then moved into position to fire on the beaches on both sides of the waterway. This fire continued until masked by the beaching ATC. If no preparatory fire was employed, the boats landed at assigned beaches in sections of three, thus maintaining rifle company integrity. Boats within a section were about 5 to 10 meters apart, and a distance of 150 to 300 meters (depending on the beach landing sites selected for each company) separated each boat section or assault rifle company. After the units had disembarked, the boats remained at the beaching site until released by the battalion commander. Upon release, the river assault squadron craft either moved to provide fire support to the infantry platoons or moved to interdiction stations and rendezvous points. Subsequent missions for the boats included independent interdiction, resupply, and extraction of troops.
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TROOPS GO ASHORE FROM ARMORED TROOP CARRIER
After landing the troops secured initial platoon and company objectives and moved forward in whatever formation the terrain and mission required. (Diagram 6) When contact with the enemy was made, commanders immediately acted to cut off possible enemy escape routes. The most frequently used tactic was to move units to blocking positions to the flanks and rear of the enemy and direct extensive artillery fire, helicopter gunship fire, and air strikes into the enemy positions. After this softening up process, troops swept the area.
The Mobile Riverine Force had little trouble finding suitable helicopter landing and pickup zones. Pickup zones used to mount airmobile operations were normally located in the vicinity of the fire support base or on terrain adjacent to the waterways. When there were not enough aircraft to move an entire company at one time, platoons were shuttled into the area of operations. The brigade standing operating procedure called for helicopter gunships to escort each serial, and for an airborne forward air controller to operate along the route of aerial movement.
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Diagram 6. Typical company landing formation.
During each day plans were made to arrive at a night defensive position before dark unless troops were engaged with or pursuing the enemy. After resupply, the night defensive position was organized against possible enemy attack.
The fourth rifle company of each battalion was usually employed at the fire support base under operational control of the base commander; for mobile riverine base security it was under direct control of the Mobile Riverine Base commander.
When the river-assault craft remained overnight on the small waterways in the operational area, the brigade and battalion commanders planned for security of the boats, which were usually kept near infantry elements ashore. The boat fire was integrated with the fire of other units.
Withdrawal of riverine forces from the area of operations was accomplished chiefly by boat. When units operated far inland from navigable waterways, however, they were extracted by helicopter and taken to a landing zone near a navigable waterway. They were then transported by boat to the Mobile Riverine Base or to another area of operations. Sites designated for picking up troops were often on streams lined with dense banana groves, coconut groves, or nipa palm that made it difficult for both the ground unit
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commander and the river assault squadron commander to spot. Ground and water movement to the site was therefore controlled and coordinated from the battalion commander's helicopter. The commander marked specific beach and unit locations with colored smoke and directed the Army and Navy elements to them by radio.
The same boat that was used to put an Army element ashore was also used to bring it out. Each boat carried an identifying number and flew a distinctive colored pennant from the mast that could be recognized by troops who were behind dikes and vegetation. Each boat also carried three running lights tiered near the top of the mast. Through the use of varying color combinations in the top, center, and bottom running lights, the boat designated for each boarding element could be readily identified.
Tides, draft, and maneuver room were primary considerations when boats were scheduled to rendezvous with Army forces for pickup because tides not only affected the water depth in canals, but caused significant changes in current velocity and direction. Traveling a distance of thirty kilometers upstream could take up to six hours against an ebbing tide, whereas the same route might be covered in four and a half hours on an incoming tide.
The threat of ambush during troop removal was considered as great as during movement to landings. When possible, an alternate to the route used for entering an area was selected for picking up troops. Beaching of the boats was usually accomplished with little difficulty because the infantrymen on shore had reconnoitered the banks for obstacles. Army security elements were placed 100 to 150 meters inland from the extraction site. After the troops were aboard, the boats resumed tactical formation and moved along the canal or stream and into the major waterway where the Mobile Riverine Base was anchored.
During offensive operations, the commander of the Army element of the Mobile Riverine Force in his position as base commander for all joint Army and Navy bases was also responsible for the defense of the Mobile Riverine Base. The Navy provided its appropriate share of forces, which included those for gunfire support and protection against waterborne threats. Defense of the base also involved arrangements for curfew and other restrictions for water craft with appropriate Vietnamese civilian and military officials in the immediate vicinity.
River assault divisions were assigned the responsibility for waterborne defense on a rotating basis. They conducted patrols to control river traffic, enforce curfews, and deter attack by water;
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swept the vicinity of the Mobile Riverine Base for water mines; sent demolition teams to inspect underwater anchor chains, hulls of ships, and pontoons for limpet mines; and dropped random explosive charges in the anchorage area to deter enemy swimmers.
One rifle company under the base commander was responsible for shore defense of the Mobile Riverine Base. Normally the company employed one platoon on each bank of the river and held the remainder of the company in reserve. Since anchorage space was 2,000 to 2,500 meters in length, it was impossible to conduct a closely knit defense with the relatively small number of troops committed. Platoon ambush sites were established on the banks opposite the flotilla flagship and during daylight hours security patrols were dispatched to provide early warning of enemy attack. The security troops were reinforced as needed by elements of the company defending the fire support base. Artillery and 4.2-inch and 81-mm. mortar fire as well as fire from the boats was planned in support of the defense of the base. The flat trajectory of naval weapons fire required careful planning for both shore and waterborne defense.
The planning and operational procedures initially used by the Mobile Riverine Force were refined as the staff and the force gained experience. The first significant test of these procedures came during operations in Long An Province in the III Corps Tactical Zone.
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