The Concept of a Riverine Force
- Chapter II:
In July 1965 the staff of the United States Military Assistance
Command, Vietnam (MACV), teas drafting the campaign plan for 1966, the purpose
of which was to help the government of South Vietnam establish control over
the people. The staff concluded that it was possible to secure government
control over the I, II, and III Corps Tactical Zones, a conclusion largely
based on the presence of American and other Free World Military Assistance
Forces in these corps areas. In the IV Corps Tactical Zone, however, where
there were no U.S. ground forces to bolster the efforts of the Vietnam armed
forces, the staff questioned whether the objective of the campaign plan could
be attained. The armed forces of Vietnam were considered capable of maintaining
their position in the IV Corps, but not of reducing Communist control over
significant portions of the population and terrain in the Mekong Delta. While
additional American and other Free World Military Assistance Forces were planned
for the other corps areas, none were planned for the IV Corps area. In the
opinion of the staff, there could be no substantial progress in the IV Corps
Tactical Zone unless U.S. ground forces were introduced.
As a preliminary step in studying the possibility of sending U.S. forces
into the delta, Brigadier General William E. DePuy, J-3 (assistant chief of
staff for military operations) of the MACV staff, directed his planners to
survey the delta for land suitable for basing ground troops. A team dispatched
to examine My Tho, Vinh Long, Sa Dec, and Can Tho concluded that all land
suitable for large tactical units was either heavily populated or occupied
by Republic of Vietnam armed forces. If U.S. units were based in the delta,
they would have to share already crowded areas or displace a portion of the
population. Since neither of these courses was acceptable, the planning staff
then searched for other means of basing troops. Obtaining river sand as fill
material and building up an area to accommodate a division base was considered.
U.S. Military Assistance Command engineers estimated that with the dredge
equipment at hand seventeen and a half dredge-years
would be necessary to fill an area large enough to base a division. Since
adequate dredge equipment was not available in Southeast Asia, immediate steps
were taken to procure additional dredges from the United States, but these
were not expected to arrive until late 1966. Although not entirely satisfied
with this solution, the planning staff believed the building of a base area
by dredging operations to be a sound choice.
In addition to a land base, other means of operating in the delta were needed,
and the planning staff turned to the experience of the French in Indochina
for answers. The French had used small landing craft extensively to exploit
the net of waterways from land bases. The American staff planned to use not
only small craft but also a group of larger landing craft that would house
and support a riverine force. These ships, the planners believed, might also
be able to move along the coastline and major rivers and serve as mobile bases.
It was known that during World War II the Navy had converted LST's (landing
ships, tank) into barracks ships, and the planners believed that such ships
could provide a base for a brigade force afloat. As the concept of an American
river flotilla took form, the planners concluded that the LST barracks ships
could be altered to furnish a helicopter flight deck and that barges could
be provided on which helicopters would be able to land for maintenance. The
ships could also be equipped with weapons for defense.
In their initial survey to find anchorage sites in the delta, the planners
of the Military Assistance Command suggested seven that might serve. An LST
could resupply the river force by traveling from Vung Tau across a stretch
of the South China Sea into the selected anchorage sites on the Mekong and
Captain David F. Welch of the U.S. Navy, who headed the Plans and Requirements
Division of J-3, the Operations Directorate, U.S. Military Assistance Command,
Vietnam, believed that the afloat force concept merited full study and suggested
that a task force be set up under a U.S. Navy commander. He discussed the
matter with Rear Admiral Norvell G. Ward, Commander, U.S. Naval Forces, Vietnam,
who agreed that the idea had possibilities and that some naval ships could
be made available.
In early December of 1965, during the monthly Commander's Meeting of the
Military Assistance Command, Vietnam, General DePuy briefed General William
C. Westmoreland and his commanders on the concept of a Mekong Delta riverine
force that would employ an Army brigade with a comparable Navy organiza-
LST WITH ARMORED TROOP CARRIERS AND MONITORS
tion, and that would operate from various anchorages within the delta. The
plan called for the development of two land bases, one for an infantry division
headquarters and one brigade, and another for one brigade to be located in
the northern part of the delta, probably in Long An Province. A third brigade
would be based on the water. With the use of a mobile floating base, the mingling
of U.S. troops with the Vietnamese population could be reduced-a prime consideration
in view of the reluctance of the Vietnamese to accept U.S. ground forces within
the delta. General Westmoreland declared the idea of a floating base "most
imaginative," and directed that a team be sent to brief Headquarters,
Pacific Command, and solicit its support.
When General Westmoreland had accepted the idea, reconnaissance was conducted
to find a land base for a division headquarters and one brigade. General DePuy
and Colonel Sidney B. Berry, Jr., Senior Advisor, 7th Division, Army of Vietnam,
selected a base site approximately eight kilometers west of the town of My
Tho, where the Kinh Xang Canal enters the My Tho branch of the Mekong River.
According to French hydrographic maps, adequate sand deposits for fill material
existed nearby. A request was then sent to the joint Chiefs of Staff in Washington
additional infantry division to employ in the IV Corps area. For planning
purposes the unit was designated Z Division.
During the latter part of December a MACV team headed by General DePuy
met with the Pacific Command staff and outlined a general plan for the riverine
force. After a period of discussion, the Pacific Command staff accepted the
feasibility of the proposal. I In the discussion the concept that the river
force operating within the Mekong Delta would be a joint Army-Navy task force
was emphasized. It was felt that barracks ships, then in storage, could be
utilized to house part of the force, and that these barracks ships could.
be supported by small landing craft, patrol boats, and helicopters. Such support
would enable the river force to conduct operations within a defined radius
of the floating base. In addition, the mobility of the small craft would help
to protect the floating base.
Upon acceptance by the Commander in Chief, Pacific, of the feasibility of
a riverine force, the joint Chiefs of Staff tentatively approved the employment
of an Army division in the Mekong Delta to put the plan in operation. The
force was to be provided barracks ships and LCM-8's. The matter of land bases
was left unanswered in the joint staff action of the Commander in Chief, Pacific.
In Washington the Vice Chief of Naval Operations, Admiral Horacio Rivero,
Jr., supported the concept of a riverine force and approved a proposal to
send a planning group to Saigon to work with the MACV staff. The group was
asked to develop a complete plan and to specify the means to support it. Headed
by Captain David Bill, U.S. Navy, Office of the Chief of Naval Operations,
and consisting of representatives of the Bureau of Ships, the Marine Corps,
and the Amphibious Command, Pacific, the planning group arrived in Vietnam
in January of 1966. Together the MACV staff and the Navy group studied in
detail the experience of the French and Vietnamese with river assault forces
in order to establish a similar American force, but one with greater capabilities.
Under the leadership of Captain Welsh and Captain Bill, requirements were
drawn up for self-propelled barracks ships (APB's), LST's, large covered lighters
(YFNB's), large harbor tugs (YTB's), landing craft repair ships (ARL's), and
a mine countermeasures support ship (MCS) ; all were to carry appropriate
armament for the area of operations. The LCM-6 would be used instead of the
LCM-8, which was in limited supply.
In a message of 19 February, the Commander in Chief, Pacific,
SELF-PROPELLED BARRACKS SHIP WITH AMMI BARGE MOORED ALONGSIDE
requested that the Commander, U.S. Military Assistance Command, Vietnam,
develop and submit a detailed plan of operations and logistical support for
the employment of a Mekong Delta Mobile Afloat Force. The plan was to cover
force composition and phasing, tasks to be executed, methods of execution,
navigable areas, operating areas, afloat force locations, afloat force base,
provisions for U.S. Air Force, Navy gunfire, and helicopter support, and command
relationships. The Commander in Chief, Pacific, Admiral Ulysses S. Grant Sharp,
Jr., also asked for amplification of the logistics involved: depots and ports
from which support would be provided, additional facilities required at the
logistic support base, requirements for additional lighterage, and specification
of other resources needed to support operations. Representatives of Admiral
Sharp would meet with the MACV staff to "assist in the development of
the foregoing and to facilitate subsequent evaluation and review." The
MACV-Navy group continued to plan, following the guidance of the Commander
in Chief, Pacific.
The planning culminated in a MACV study, Mekong Delta Mobile Afloat Force
Concept and Requirements, dated 7 March 1966, which was forwarded on 15 March
1966 to the Commander in Chief, Pacific, for approval. The study articulated
fully for the
first time the concept for the Army-Navy force afloat. It later proved
to be a far-sighted and comprehensive blueprint for the preparation of both
Army and Navy components and the conduct of operations. Most of the planned
features of the force as stated in this document later materialized in the
The study recommended that the force contain a U.S. Army reinforced brigade
consisting of three infantry battalions, an artillery battalion, and other
combat and combat service support. The force would be based aboard U.S. Navy
ships that would include 5 self-propelled barracks ships, 2 LST's, 2 large
harbor tugs, and 2 landing craft repair ships. In addition, two U.S. Navy
river assault groups would provide tactical water mobility. Each assault group
would be capable of lifting the combat elements of one reinforced infantry
battalion. A small salvage craft would be necessary to recover damaged ships
or craft. The reinforced brigade would be organized under the current standard
ROAD (Reorganization Objective Army Divisions) tables of organization and
equipment, with limited augmentation. Certain equipment specified in the tables,
such as tents, mess facilities, 106-mm. recoilless rifles, antitank wire-guided
missiles, and all wheeled vehicles except artillery prime movers were to be
deleted from the force requirements. The number of 90-mm. recoilless rifles
in each rifle company was to be reduced from six to three to improve the mobility
of the weapons squads. The 4.2-inch mortars would accompany the force and
be moved by water or air to field positions as necessary. Radios would be
either ship-mounted or man-portable. Coxswains of plastic assault boats were
to he designated in the proposed tables and trained upon arrival in Vietnam.
Enough troops from each of the units afloat would be left at a land base to
maintain equipment left in storage. The plan provided for an augmentation
of three counter-mortar radar sections, each manned by nine men, to operate
and maintain ship-mounted counter-mortar radars. A mobile Army surgical hospital
team, U.S. Air Force tactical air control parties which included forward air
controllers, Vietnam Army liaison troops, and additional ANPRC-25 radios were
to be furnished from sources outside the parent division of the brigade.
Each river assault group, later designated river assault squadron, was to
consist of the following: 52 LCM-6's to serve as armored troop carriers, 5
LCM-6's to serve as command and communication boats, 10 LCM-6's to serve as
monitors, 32 assault support patrol boats, and 2 LCM-6's to serve as refuelers.
A salvage force would include: 2 2,000-ton heavy lift craft, 2 YTB's for salvage,
ARMORED TROOP CARRIER
(landing craft, utility), and 3 100-ton floating dry docks. The Mobile Afloat
Force concept stated the specific tasks the force was to accomplish: secure
U.S. base areas and lines of communication required for U.S. operations; conduct
offensive operations against Viet Cong forces and base areas that posed a
threat both to the national and to the IV Corps Tactical Zone priority areas
for rural construction in co-ordination with Republic of Vietnam armed forces
and other U.S. forces; isolate the most heavily populated and key food-producing
areas from Viet Cong base areas; interdict Viet Cong supply routes; and in
co-ordination with the Vietnam armed forces provide reserve and reaction forces
in the IV Corps Tactical Zone.
Because the Viet Cong forces were dispersed throughout the Mekong Delta,
the river force would be required to operate in many locations. Initial operations
would be conducted in the provinces to the north of the Mekong River-Go Cong,
Dinh Tuong, Kien Phong, Kien Tuong, and as far north as the Plain of Reeds.
(See Map 5.) Once the Viet Cong main force units were neutralized in
these areas, with the U.S. Navy GAME WARDEN forces con-
COMMAND AND COMMUNICATIONS BOAT
trolling Viet Cong cross-river movements, the center of gravity of U.S. operations
would shift south into the provinces between the Mekong and the Bassac and
eventually south of the Bassac River.
It was decided to use a brigade for initial operations because the experience
of U.S. forces in Vietnam indicated that the brigade was the smallest U.S.
unit that could be safely and economically kept in the delta. It was large
enough to defend its base against heavy enemy attack and at the same time
to have forces available for offensive operations.
The formal plan of the Military Assistance Command required the construction
of a land base by dredging. Since land reclamation would be expensive and
time-consuming, however, the plan also recommended the creation of a water
base as well in order to use American forces most effectively. The plan indicated
that the land base near My Tho could be made available at the end of 1966
or in early 1967.
Criteria for the selection of anchorages for the floating base were established.
The base was to be reasonably near an airfield;
be within or contiguous to a relatively secure area; have access to a land
line of communications; have enough room to anchor the entire force; and have
a river bank that would permit debarking of artillery to provide fire support
to the force. Sites that met most of the above criteria were found in the
vicinity of My Tho, Vinh Long, Cao Lanh, Tra Vinh, Can Tho, Long Xuyen, and
Dai Ngai, which was in the vicinity of Soc Trang.
Recognizing that the My Tho land base would not be large enough to accommodate
a division headquarters until early in 1968, the plan called for the Z Division
to go initially to Ba Ria, which lies north of Vung Tau. The division base
was to include a division headquarters, a support command, one brigade, and
a storage area for the heavy equipment and rolling stock of the two brigades
sent into the delta-one to be land-based near My Tho rather than in Long An
Province, and a second to be the Army component of the Mobile Afloat Force.
Vung Tau was to be the port for staging and resupplying the Mobile Afloat
Force. Minimum security measures would be needed for the force when it was
at Vung Tau and when it was traveling from there to the Mekong River. During
navigation of the major rivers, however, continuous security measures would
be necessary. Such movements were to be considered ventures through hostile
territory and were to be handled much the same way as running a tactical land
The plan provided for continuous air cover, both by fixed-wing tactical aircraft
and armed helicopters. Advance, flank, and rear security on the rivers was
to be provided by U.S. Navy river assault groups. GAME WARDEN forces would
provide intelligence to assist in reconnoitering the route. The mine countermeasures
were to be chain drags pulled along either side of the channel to cut command
detonation wires of river mines, and mine-hunting sonar. Canals terminating
in the main river might harbor hostile boats and were therefore to be reconnoitered
by both boat and air. Armed helicopters, in conjunction with the Navy assault
groups, were to cover the banks of the rivers and search out possible ambush
sites. The major ships were to be at a condition of highest watertight integrity
during transit, and fixed weapons were to be manned to counter enemy attack.
Major ships of the force were to be moved in daylight hours.
At the anchorage of the afloat base, an area security plan would be in effect,
with Army security forces on shore and reinforced by artillery. Outposts including
foot and boat patrols would be used. The barracks ships would be moored near
the center of the river
and their countermortar radars could provide coverage of the surrounding
area. All weapons would be manned, with an Army-Navy reaction force standing
by while the ships were at anchor.
The plan recognized three principal enemy threats. The first was infiltration
by small mortar or recoilless rifle teams which would attempt to penetrate
the infantry perimeter ashore. These teams would probably fire several rounds
quickly and then withdraw rapidly. The second threat was that of a large-scale,
overt attack. The third and possibly the most critical threat to the floating
base would come from the water-floating mines, swimmer saboteurs, and suicide
boats. Measures to counter the threats were left to the commanders immediately
The Mobile Afloat Force concept provided for a variety of tactical operations.
The force would remain in an enemy base area as long as operations could be
profitably conducted-about four to six weeks. Ground operations would last
four to five days, after which troops would be allowed a rest of two or three
days to dry out and to repair equipment. It was believed that the force could
conduct four operations a month. A brigade would be deployed in the delta
for as long as six months, with the possibility of rotation with either the
brigade at My Tho or that at Ba Ria. The force would obtain intelligence and
develop plans prior to its arrival in a base area, and operations would commence
as soon as the floating base arrived at its anchorage. The brigade would rely
heavily on local Vietnamese intelligence organizations.
To acquire knowledge of the area in which the force was operating, elements
of the brigade, embarked in Navy assault group boats, helicopters, and plastic
assault boats, would be employed to gather data on stream and canal depths,
height of banks, areas for beaching, possible artillery positions, helicopter
landing zones, the local population, and the enemy.
Full-scale operations would be conducted by deploying the force into the
combat area by water, land, and air. Security for the floating base would
require from a company to as much as a battalion in the immediate base area.
Operations could range up to fifty kilometers from the floating base and,
in exceptional cases, beyond. Security measures similar to those for relocation
of the major ships would be taken for the movement of the assault craft formations
during operations. Tactical air and armed helicopters were to fly cover, and
artillery would displace by echelon as required to provide continuous fire
support. The assault support patrol boats were to furnish forward, flank,
and rear security, and to sweep for shore-
ASSAULT SUPPORT PATROL BOAT. A high-speed armored boat used for waterway interdiction,
escort, mine-sweeping, and fire support.
commanded mines. Preparatory fire could be delivered by the armament of the
Navy assault groups, by artillery, and by air. Landing of the force would
be in accordance with the tactical plan and the armored troop carriers would
then withdraw to rendezvous points or return to the afloat base for resupply.
At least one armored troop carrier would be designated as a floating aid station
located at a prearranged point in the operational area of the battalion that
it was supporting. Some elements of the force could deploy by water or air
beyond the immediate landing areas to cut off withdrawing enemy troops and
some could be held afloat as a reserve. The river force would prevent the
enemy from withdrawing across the major rivers. Assault support patrol boats
and monitors not required to protect the troop carriers would be used to provide
flank and rear security, close-in fire support, and forward command post protection.
Command and control would be exercised through the use of command and communications
boats, which were to provide space and communications for battalion and brigade
command groups. Command helicopters could also be used to control operations.
Helicopters would be used to deploy a portion of the ground force, to position
artillery, and to deliver reserves for the purpose of blocking the enemy or
exploiting success. Armed helicopters would be employed for escort and fire
support. Large Viet Cong forces encountered in these operations were to be
neutralized or destroyed by fire and land maneuver. Should no large enemy
force be encountered, the Mobile Afloat Force would be redeployed to another
area of operations or the area would be systematically searched and enemy
resources captured or destroyed. It was estimated that a battalion could conduct
an operation throughout an area of forty square kilometers in four to six
days. After troops had closed in on the final objective they would be met
and withdrawn by the Navy assault group boats or possibly by helicopters.
The withdrawal phase was considered critical because of the possibility of
ambush and mines. Alternate routes and decoys would be used, but the basic
concept for withdrawal would be the same as that of the movement to contact.
Mine-clearing devices and air cover would be used. (Diagram 3)
All available means of fire support would be employed by the force, using
the air and ground operations system common throughout Vietnam. Sorties would
be allocated upon planned requests; emergency requests would be honored in
accordance with priorities. The Direct Air Support Center at IV Corps Tactical
Zone headquarters in Can Tho would be responsible for the allocation of
Diagram 3. Riverine operation and base defense.
tactical air support with airborne forward air controllers utilized to the
maximum. Artillery support would be furnished in the traditional manner, providing
fire support to all echelons of the force. Gunfire support would also be supplied
by assault support patrol boats and monitors. Army helicopter gunships would
be requested and allocated by the division in the same manner as for other
The Vung Tau Area Support Command would provide common items of supply and
logistic support peculiar to the Army; the Navy would furnish items peculiar
to the Navy. A small Navy
support facility at Vung Tau would probably be necessary. Two LST's from
Vung Tau would take care of all resupply except Class III. Each would be capable
of carrying ten days' dry cargo for all elements of the force. One LST would
remain on station with the force for seven days as a floating supply point.
At the end of the seven days, the LST on station would be relieved by the
second ship carrying ten days of supply, and would return to Vung Tau for
Self-propelled barracks ships would be stocked with thirty days of frozen
and chilled components of Class I and thirty days of dry components prior
to deployment. Resupply of Class I would be scheduled to draw on the initial
provisioning to a fifteen-day level by the time an APB returned to Vung Tau.
The Navy would be responsible for operating all messes aboard ships, utilizing
both Army and Navy mess personnel.
Resupply of petroleum products would be accomplished by having the craft
of the Navy assault groups refuel from the APB's and the supply LST. The supply
LST would refuel the APB's and other ships of the flotilla as required. Gasoline
for the assault boats and vehicles would be supplied from two LCM-6 tankers,
each with a capacity of 10,000 gallons. The LST would be refilled by commercial
barge at ten-day intervals. Fuel for helicopter companies would be provided
to the base by commercial contractor. U.S. Army, Vietnam, would supply what
the commercial contractors could not.
The LST supply ships would carry that portion of the Class V basic load not
carried on the APB's and ATC's. Army Class V carried aboard an APB would be
limited to that portion of the basic load carried by the individual soldier
and ten days' supply for Army weapons mounted on the ship. A normal allowance
would be carried for the Navy weapons. The Army element of the force would
prepare loading plans for that portion of the basic load to be carried on
the ATC's. An operating allowance of Class V would be carried on the Navy
assault group craft for all mounted weapons, with a ten-day resupply for these
weapons on the supply ship.
Resupply of forces operating away from the Mobile Afloat Force anchorage
would be tailored to the specific operation and would vary with the size of
the force, duration of the operation, and distance from the anchorage. Resupply
would be accomplished primarily by ATC and helicopter. Airlift and other means
of transportation could be called upon to augment the capacity of the organic
force for resupply as warranted by the area and nature of
operations. Matériel to be evacuated to Vung Tau or to the division base
at Ba Ria would be carried by the resupply ships on their return to Vung Tau.
Aircraft would be used for evacuation and for the replacement of urgently
needed materiel between supply ship turnarounds. The Army and Navy components
would retain maintenance responsibility for organic materiel, including parts
supply for service-peculiar items. Each component would provide repair stores
and load lists accordingly.
Army responsibility for maintenance would be limited to organizational maintenance
of all materiel and direct support maintenance of weapons, vehicles, signal
equipment,. and assault boats and motors. Shops on the APB's would be used
by unit armorers and maintenance men to perform organizational maintenance.
Billeting space for a maintenance detachment of one officer, three warrant
officers, and twenty-seven enlisted men, and shop space of approximately 1,500
square feet would be required on the ARL's to meet the Army direct support
All Navy ships and smaller craft were to arrive in Vietnam in operational
condition. Maximum operational time would be available prior to regular overhaul.
Two ARL's constituted the major repair arid maintenance assets for the force
and would normally remain with the force to function as advanced tenders.
ARL shop spaces and equipment would be designed for a broad range of repair
and maintenance of all craft and ships of the force and for overhaul of all
assault craft. In addition, shop spaces were to be manned by the Army to provide
for repair and maintenance of Army equipment.
Medical care would remain a service responsibility aboard ship. The Army
would provide medical service for all elements of the force when they were
away from the flotilla on an operation. Two medical evacuation helicopters
would be stationed at the airfield closest to the area of operations to evacuate
patients from battalion aid stations located on ATC's or from the battlefield
to a mobile Army surgical hospital or an APB. Further evacuation to hospitals
in the Saigon or Vung Tau area would be by helicopter or fixed wing aircraft.
Hospitalization would be in the Saigon, Bien Hoa, and Vung Tau areas. A mobile
Army surgical hospital located at the land base near My Tho, in conjunction
with the brigade to be based there, and a surgical team located on an APB,
would provide surgery and medical treatment necessary to prepare critically
injured or ill patients for evacuation to hospitals. A helicopter pad, sixteen-bed
dispensary, and surgical suites with equipment neces-
nary for one surgical team would be provided on each APB.
Communications would be provided by the permanently installed Army and Navy
radio equipment aboard each ship and assault craft. This equipment would provide
command, tactical, and logistical communication links to higher and subordinate
headquarters. Tactical communications ashore would be by man-packed radios
and by airborne relay when required.
General command arrangements had been set forth previously by General Westmoreland.
The plan indicated that they would be further developed by study. The command
relationships of the force were to be a major topic of discussion for many
months after the publication of the Mobile Afloat Force concept.
Page created 29 May 2001
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