The Brown Water Navy in Vietnam


Robert H. Stoner, GMCM (SW)(Ret)

Part 3

 [Part 2 covered Operation GAME WARDEN.  In Part 3 we will look at the MOBILE RIVERINE FORCE.  This is operation took amphibious, combined-arms war into the Mekong River Delta, up the rivers and into the canals of South Vietnam.]


The naval war in South Vietnam during the years 1964 to 1975 was very dynamic.  For the Americans aiding the South Vietnamese, the effort was several fold: (1) build and equip a capable Vietnamese Navy; (2) teach the new VNN how to fight; (3) how to keep itself supplied; and (4) how to keep itself operational. 


At the same time, the United States Navy found itself embroiled in a war that was fought at first, off the coastal waters of South Vietnam, and then in the river deltas, smaller waterways and canals of the country.  To combat North Vietnamese infiltration of men and supplies by sea, three Task Forces were formed: TF-115 called Operation MARKET TIME; TF-116 called Operation GAME WARDEN; and TF-117 called the MOBILE RIVERINE FORCE (a joint amphibious Army-Navy riverine operation).




South Vietnam was divided into four Corps areas: I Corps was in the North, II Corps was the central highlands, III was the area around the capital city of Saigon, and IV Corps extended from the Mekong River Delta to the tip of the Ca Mau Peninsula.  The delta was a major population and food center, but there were no large parcels of land where a big military installation could be constructed without dislocating large numbers of people. Also, numerous rivers, streams and canals crisscrossed the delta and restricted ground movement.  American planners pondered how they could find a way to overcome the mobility problem.

In March 1966 a joint committee of Army and Navy personnel drew up tentative plans for the establishment of a Mekong Delta Mobile Afloat Force (MDMAF). On 1 September 1966, the first administrative unit of the new MDMAF was commissioned at Coronado, California. Shortly after this, the unit received the designation Task Force 117 (TF-117), and was named the MOBILE RIVERINE FORCE (MRF).


The purpose of the MRF was to support an infantry brigade and an artillery battalion using modified landing craft, support ships, and specially designed assault boats.  The strike unit would be a self-contained amphibious assault force with all support elements except aircraft [added later].  Because the Marines were heavily engaged in I Corps, a brigade from the Army’s 9th Infantry Division was chosen as the infantry component of the MRF.

The Navy’s component of TF-117 was a wide variety of ships and boats. The first unit, River Assault Flotilla One (RivFlotONE) was composed of River Assault Squadron 9 (RAS 9) and RAS 11.  Each of the RAS was broken into two River Assault Divisions: Divisions 91 and 92; Divisions 111 and 112.  The Divisions were distributed among two APBs (self-propelled barracks ships), an APL (non-self propelled barracks ship) with two YTB (fleet tugs), an ARL (landing craft repair ship), and an LST (tank landing ship).  Each RAS had a total of 26 ATCs (armored troop carriers), five Monitors, two CCBs (command and control boats), one Refueler ATC, and 16 ASPBs (assault support patrol boats) and an EOD (explosive ordnance detachment) team.

In 1967, Task Group 117.3 was composed of USS BENEWAH (APB-35), USS COLLETON (APB-36), APL-26 with USS KALISPELL (YTB-784) and USS WINNEMUCCA (YTB-785) attached, USS ASKARI (ARL-30) [later USS SPHINX (ARL-24)] , and a supporting LST (an LST-1156 class from Amphibious Ready Group BRAVO), plus other support and salvage craft as assigned.  The MRF was based at the Army-Navy base at Dong Tam on the My Tho River branch of the Mekong River Delta. 

Above: The headquarters for the MOBILE RIVERINE FORCE was the joint Army-Navy base located at Dong Tam, just up river from the city of My Tho on the way to Vinh Long. 

Below: A detail map of the Dong Tam base.  The boat turning basin is the square-shaped blue area just off the large canal that joins the My Tho River.  The city of Vinh Long is to the west and the city of My Tho is to the east on this map. 

Above: The Dong Tam base.  The Navy side is in the foreground with the boat turning basin.  The Army side is in the background.  [Photo: Jerry Laviviere]


The MRF continued to grow to full strength during 1968 with the addition of two more River Assault Squadrons (RAS 13 and RAS 15), two APBs (USS MERCER [APB-39] and USS NUECES [APB-40]), one APL (APL-30), another repair ship -- USS SATYR (ARL-23), and a supporting LST from ARG Bravo, plus other support and salvage craft as assigned.

Boats of the MRF

The main craft of the RAS was the ATC.  An ATC could carry a full infantry platoon.  Armed with three 20mm cannon or Mk 19 automatic grenade launcher and two 20mm cannon, up to two .50 caliber machine guns and four 7.62mm machine guns, two Mark 18 40mm grenade launchers, plus various small arms, the ATCs not only landed troops, but also re-supplied them and provided close-in fire support during operations.

All the riverine boat conversions were well protected with both conventional and “stand-off” armor. This “stand-off” or bar armor was a series of 1-inch concrete reinforcing steel rods set about 12 to 18 inches from the boat’s hull and superstructure.  The bar armor was designed to detonate an RPG (rocket propelled grenade) or recoilless rifle rounds before they hit the armor plate. “Stand-off armor” proved to be very effective against both hand held and crew served weapons used by the VC, and significantly reduced casualties and damage when an riverine craft was hit by enemy fire.

Some ATCs were modified with a helicopter flight deck counted over the troop wells (called Program 5). This was done initially to provide a platform for helicopters to land on for delivery of supplies and transfer of personnel. Almost immediately, helicopters were pressed into service for casualty evacuation since they were often the only place for a helicopter to land during operations in the Delta. Some of the ATCs with helicopter pads were designated ATC(H)s.  The ATC(H) was fitted as battalion aid station and carried a doctor and either Army medics or Navy corpsmen.  One ATC(H) also carried refrigerated whole blood and there was always a fully equipped operating table ready to perform emergency surgery.

Each river squadron had an ATC fitted-out as a refueler. The refueler ATC carried bladders of combat gasoline (mogas) or aviation fuel (avgas) under the flight deck to refuel the squadron’s boats, assault craft, and sometimes helicopters. The refuelers proved indispensable during prolonged operations and pumped huge quantities of fuel to keep the riverine forces on station.

The fire support vessel of the MRF was the Monitor. These had the same superstructure as the ATC, but were completely different forward.  The monitor had an open well deck, forward of the superstructure, that contained a Mk 2 Mod 0 Navy 81 mm mortar and two 7.62mm machine guns.  A rounded bow replaced the bow ramp of the ATC. The redesigned bow mounted a 40mm cannon (with a co-axial 50 caliber machine gun) enclosed in a turret. The 40mm was the main gun of the riverine forces and it provided a high volume of fire during landing operations. In addition, at least two Mark 18 grenade launchers were carried along with the individual weapons of the crewmen. Later, Program 5 Monitors replaced the 40mm turret with the 105mm turret of the Marine Corps LVT(H)-6 amphibious tractor (Amtrac).

Initially, an ATC was used to test an Army M132A1 flamethrower armored personnel carrier (APC) to burn out enemy bunkers along the shoreline.  This conversion was called the “Zippo” boat.  Another ATC (T-111-7) was converted to permanently mount two M10-8 flamethrower turrets and the associated fuel and compressed air to run them.  One Monitor, M-92-2 mounted two flame guns aft of the 40mm turret in where the mortar pit was located. Later, several Monitors were converted to Zippo boats by mounting the M10-8 flamethrower turrets on the bow and the napalm and compressed air cylinders in the space formerly occupied by the mortar pit.  Still later, several Program 5 Monitors were converted to Zippo boats.

Two Monitors in each squadron were also fitted out as Command Control Boats (CCBs). The only major difference between a regular Monitor and a CCB Monitor was the removal of the mortar pit aft of the 40mm turret. In its place a command and control shelter was fitted to serve as the command post for the battalion and task group commanders during an operation. The CCB Monitor was almost identical to a regular monitor and carried out much the same function.

The Assault Support Patrol Boat (ASPB) was specially constructed for use by the riverine forces. It was also designed to serve as a minesweeper and was fitted with a mine countermeasure chain drag. Lighter and faster than the Monitor, the ASPB was not as heavily armed or armored. It carried a single 20mm cannon and twin .50 caliber machine guns or 20mm cannon in two turrets, one in the bow, and one atop the superstructure. The 81mm mortar was mounted in the stern and a combination of 7.62mm machine guns or Mark 18 grenade launchers were also carried in place of the mortar. The ASPB had a unique underwater exhaust system that made it the quietest of the riverine boats.

The ASPB was employed for ambushes, patrols, special operations, reconnaissance, and escort missions. Later in the war, pairs of single .50 caliber machine guns replaced the 7.62mm machine guns on the stern while the forward gun turret received eight 3.5-inch rocket launchers (Mk 47) mounted on their sides. Linked to the machine guns the rocket launchers could be targeted by elevating or depressing the machine guns and traversing the turret.

Ships of the MRF

The MOBILE RIVERINE FORCE had a number of support ships and craft. The self-propelled barracks ships (APBs) were purpose-built on LST-542 class hulls to berth a battalion of troops.  Built in World War 2, they were modified for use in Vietnam. Each was APB was fitted with a flight deck and equipped with air conditioning. Both USS BENEWAH and USS COLLETON mounted a pair of 3”/50 dual purpose guns on the aft end of their flight decks.  [This became a major recognition feature because USS MERCER and USS NUECES did not have them.]  Each APB could accommodate about eight hundred troops and provide support for the riverboat crews.  Each APB was outfitted with an extensive communications system. The USS BENEWAH (APB-35) was equipped to serve as the brigade and flotilla flagship while the USS COLLETON (APB-36) had similar arrangements for battalion and squadron commanders.  In late 1967 the COLLETON also received hospital facilities for the care of wounded men.  Both MERCER and NUECES duplicated the facilities on BENEWAH and COLLETON.

However, since these barracks ships could not handle all the men of the infantry battalions, and artillery batteries, another non-self propelled barracks ship (APL) supplemented the APBs.  An APL could house 625 men, but without engines, it had to be towed from place to place. This hampered the MRF since its movement was relatively slow and created tactical problems for the Riverine forces.

To service and repair the various riverine boats and landing craft a repair ship was assigned to the support section of the task force. The job fell to the ARL or landing craft repair ship.  ARL-23, -24, and -30 were built on LST-542 class hulls.  Each was equipped as a complete repair facility for the riverine craft.  Cranes could lift boats out of the water and deposit them on Ammi pontoons moored alongside for dry-dock work. In addition, the ARL housed Army personnel who worked on weapons, radios, and engines. This ship provided indispensable service and without it the MRF would have been unable to keep its boats in service and carry out operations.

The last major support vessels of Task Force 117 were 1156-Class LSTs assigned to the flotilla from the 7th Fleet. These provided additional storage space that was unavailable on the APBs.  The LSTs housed supplemental supplies of ammunition, weapons, spare parts, and rations for the riverine forces during prolonged operations. The LSTs were equipped with a flight deck and carried the brigade’s helicopter detachment of four helicopters and one company of infantry. The LSTs also supported a River Assault Division.

The final components of the MRF were the artillery and helicopter barges developed by the Army.  The Army quickly discovered that the soggy terrain of the Mekong Delta was not suited to either artillery or helicopters.  An Army artillery officer had a fire support barge fabricated from sections of two Ammi pontoons that enabled a pair of 105 mm howitzers to fire while anchored next to the shoreline. These barges could also be beached if the tide went out.  Helicopters faced a similar problem because there were few areas for them to land. The ATC(H) provided a partial solution.  A helicopter barge was developed using sections of Ammi pontoons.  Each of these helicopter barges could accommodated three UH-1 helicopters and was equipped with a refueling system that carried 1,500 gallons of JP-4 aviation fuel.  Army LCM-8 landing craft were used to move the artillery and helicopter barges about and to supply the barges with fuel and ammunition. The MRF did not lack for artillery or helicopter support.

Ships of the MRF: APBs (4), ARL (2), LST (2); supporting ships and craft: AKL (2), YRBM (2), and YTB (2); riverine craft: ATCs, ATC(H)s, Monitors, CCBs, Zippos, Douche boat, and ASPBs.  Other craft: artillery support barges and helicopter support barges.

USS BENEWAH (APB-35) - class Self-Propelled Barracks Ship


Above: The 328-foot USS BENEWAH (ABP-35) was built on a World War 2 LST-542 class hull.  Like the riverine craft the APBs supported, the superstructures of these ships carried the same bar armor to protect them from rockets and recoilless rifle fire.  APBs USS BENEWAH and USS COLLETON carried two quad 40-mm guns, two 3”/50 dual purpose guns (aft of the helo deck; deleted on APBs USS MERCER and USS NUECES), eight .50 machine guns and eight 7.62mm machine guns. [Drawing: Windjammer Arts]


Below:  BT2 John Hardy stands next to his .50 machine gun on USS BENEWAH in 1968.  The arch-shaped tubes are limit stops for the machine gun.  Personal radios were common entertainment aboard ship.  [Photo: John Hardy]



Below: USS BENEWAH shown with her brood of riverine craft nested alongside the Ammi pontoons tied to her starboard side.  [Photo: John Hardy]




Above: A starboard side shot of USS NUECES (APB-40) entering Pearl Harbor in 1968.  USS MERCER (APB-39) and USS NUECES joined the MRF in 1968.  Note the lack of 3”/50 guns forward of the stack.  Nueces had a well-equipped hospital to provide aid to wounded soldiers or sailors.  [Photo: Norval Holley]


Below: USS NUECES (APL-40) – as a non-self propelled barracks ship -- is still used for berthing American sailors in Yokosuka, Japan.  NUECES is shown undergoing dry dock repairs at Yokosuka Naval Base.  Her appearance has changed dramatically from her Vietnam days.  The former helicopter landing pad has been replaced by additional berthing spaces.  Sister USS MERCER serves as APL-39 at Sasebo Naval Base, Japan.  [Photo: Bob Gregory]


APL – Non-Self Propelled Barracks Ship


Below: The APL was similar in concept to the APB, except that it did not have engines and relied on tugs (YTBs) to move it about.  The APL was very similar to, and easily confused with. the YRBM (Yard Repair, Berthing, and Messing barge).  Two YRBMs were attached to the MRF, but they were non-self propelled and stayed at or near Dong Tam as semi-permanent fixtures.  APL-26 is shown here with its YTB.  [Photo: Robert Kisko]




Above: KALISPELL (YTB-784) closest to camera, USS WINNEMUCCA (YTB-785) inboard of YTB-784, and a Light Salvage Lift Craft (YLCC-1) of Harbor Clearance Unit ONE alongside APL-26 in Dong Tam in 1967.  [Photo: Doug Lindsey]


Below: YRBM-17 (left) and APL-26 (right) at Dong Tam in 1967.  The YRBM has yet to be repainted in Riverine Green.  Note the similarities and differences between the two craft.  The large pole on the YRBM is its lift crane.  [Photo: Bob Gregory]




Above: A composite photo of USS ASKARI (ARL-30) that maintained the many craft of the MRF.  The ARL had the heavy lifting equipment to lift the various MRF boats out of the water so their sides and bottoms were accessible for maintenance.  [Photo montage: Gary Oliver]

Above: The ARL was key to keeping all the various boats of the MRF operational.  Based on an LST-542 class hull, the ARL was crammed with repair shops that could do just about anything with the boats entrusted to its care.  [Drawing: Windjammer Arts]


LST – Landing Ship Tank, LST-542 class, LST-1156 class


The ships that brought the supplies to the various ships of the MRF and acted as floating supply, fuel, and ammunition storage were the LSTs.  The MRF always had at least one LST-1156 class (and sometimes two) assigned to it from Amphibious Ready Group BRAVO.  The LST-1156 class ships were improvements over the LST-542 class World War 2 designs.  These later LSTs came into service towards the end of the Korean War and shortly thereafter.  They were quite different in appearance from their World War 2 cousins.


Below: USS KEMPER COUNTY (LST-854) off Vung Tau in 1967.  Most of the WW2 LSTs carried a crane on the top deck to assist with off-loading of supplies or lifting large, heavy objects aboard ship.  Like all LSTs, KEMPER COUNTY had a ramp that could be lowered to connect the main deck with the tank deck.  This ramp allowed the LST to carry vehicles on both the main deck and the tank deck.  USS KEMPER COUNTY was 328 feet long, 50 feet in beam, and drew 10 feet of water at the stern with a full load of 4,080 tons.  The main gun battery was two twin 40mm guns, four single 40mm guns under control of Mk 51 gun directors.  An APB of the Mobile Riverine Force [USS BENEWAH or USS COLLETON] is anchored directly in back of the ship.  The barge in the foreground is ferrying Australian Army vehicles.  [Photo: Dave Perham]



Above: USS WINDHAM COUNTY (LST-1170) off the coast of Vietnam in 1966.  This photo was taken from a sister LST, USS WASHOE COUNTY (LST-1165).  Note the double rails extending from the front of the superstructure forward.  These rails were used to mount floating causeways.  Four could be carried; two mounted on either side.  The causeways could be dropped overboard, floated around, linked together, one end attached to the front of the ship (bow doors open, ramp down) and the assembled causeway pushed ashore.  The causeways were used when the beach was unsuitable for the LST to beach itself on the shore.  Four causeways attached together were nearly twice as long as the LST.  The main battery of the LST-1156 class was three twin 3”/50 RF (rapid fire) guns with three Mk 56 gun directors.  USS WINDHAM COUNTY was 384 feet long, 55 feet in beam, and drew 17 feet of water at the stern with a full load of 5,800 tons.  [Photo: Rich Krebs]

AKL – Attack Cargo Light, Camano-class



Above: Two of the hardest working ships of the MRF were the USS BRULE (AKL-28), shown here, and the USS MARK (AKL-12).  Both were small Camano-class light freighters built for the US Army during World War 2 and transferred to the US Navy in 1950 and 1947 respectively.  On average, an AKL could carry 225 tons of cargo, 38,000 gallons of fresh water, and 20,000 gallons of diesel fuel or combat gasoline (mogas).  While serving at Vung Tau and An Thoi, USS BRULE served as a mother ship for Navy PCF patrol craft and US Coast Guard WPB cutters.  The AKL displaced 550 tons, was 180 feet long by 33 feet in beam and drew 10 feet at full load.  Crew was 42 officers and enlisted.  Speed was 12 knots.


ASPB – Assault Support Patrol Boat


The ASPB was designed for operations in Vietnam.  It was 50 feet long, 15 feet wide, had two 12V71 diesel engines and twin propellers.  The superstructure utilized spaced armor and bar armor was fitted later.  Crew was 5 men.  Early boats had a Navy 81mm mortar or two 7.62mm Mk 21 machine guns or .50 machine guns.  The turrets were designed for 20mm guns, .50 machine guns, 7.62mm machine guns, and a 40mm automatic grenade launcher.  The ASPB underwent several improvements in armor and armament during the years 1967 to 1971.


Above: A drawing of a typical ASPB as it appeared in 1967.  The Mk 48 Mod 2 turret on the bow carried two .50 machine guns, the Mk 48 Mod 0 turret aft of the coxswain’s station carried either a Mk 16 Mod 4 20mm gun and a Mk 21 Mod 0 7.62mm machine gun or a Mk 19 Mod 0 40mm grenade launcher. [Drawing: Windjammer Arts]


Below: A nest of Vietnamese ASPBs alongside YRBM-20 about 1970.  These boats are showing signs of a lot of hard use.  Note the muddy water.  [Photo: Kent Hawley]




Above: In late 1969 many ASPBs were fitted with eight (4x2) 3.5-inch rocket launchers Mk 47.  This boat has the Mk 48 Mod 2 turret with the twin .50 machine guns.  Rockets were either HEAT (high-explosive, anti-tank) or WP (white phosphorus).  [Photo: Tom Lefavour]


Below: The Mk 48 Mod 2 turret with Mk 47 3.5-inch rocket launch tubes.  The Gunner’s Mate holding a 3.5-inch rocket is explaining the new modifications to the boat crew.  The “lumps” on the back of the rocket launch tubes are the contactor latch groups.  Each one holds a rocket in the tube and provides a firing contact for the rocket motor.  [Photo: Tom Lefavour]


Below: A Mk 48 Mod 0 turret on the bow of an ASPB mounts a 20mm Mk 16 gun and a 7.62mm Mk 21 machine gun.  [Photo: Mike Gregory]




Above: The MSR (Minesweeper, River) was a conversion of the standard ASPB.  These were used as a command and control boat for the MSD (Minesweeping Drone).  The MSD was a 23-foot remote-controlled minesweeping boat powered by a 327 Chevrolet gasoline engine.  The MSR differed from the standard ASPB by the addition of specialist minesweeping gear and electronics.  Also the upper 20mm turret was replaced by two 7.62mm machine guns.  Mine Division 113 of Mine Squadron 11 used the MSR boats.   This boat is MSR-7.  [Photo: Jack T. Walker]


Below: Three MSDs of Mine Division 113.  The MSD was designed to sweep different types of river mines and not put a crew at risk.  It was designed to be run remotely from a control boat and was considered expendable.  The MSD was also capable of manual operation.  [Photo: Tom Lefavour]




Above: MSDs of Mine Division 113 operating in manual mode with crews.  Keeping the main waterways swept of mines was hot, dirty, tiring, tedious and punctuated with moments of sheer terror.  [Photo: Tom Lefavour]


Below: The MSD used a 327 Chevy engine and MerCruiser stern drive.  The circular tube is a propeller guard.  The hull of the MSD was non-magnetic.  [Photo: Tom Lefavour]



ATC – Armored Troop Carrier


The ATC was a modified LCM-6 landing craft.  It was 56 feet long by 14 feet wide and was powered by two diesel engines driving twin propellers.  All versions carried a chain minesweeping dragline for cutting cables of command-detonated mines in canals.  The ATC had an armored superstructure that had gun tubs for .50 machine guns, 20mm cannon, or 40mm automatic grenade launchers.  Early ATCs [Program 4] were called “rag tops” due to the fabric cover over the well deck of the boat.  Later boats replaced the soft top with a hard top [Program 5] capable of landing a UH-1 helicopter.  Called the ATC(H) for helicopter, some of these boats were pressed into service as a battalion aid station with doctors and medics to take care of wounded sailors and soldiers.


Each squadron had a refueling boat using an ATC boat.  Instead of troops, the well deck of the boat carried pumps and rubber fuel bladders with diesel fuel for boats or JP-4 for helicopters.  During long operations, these boats would help keep the boats of the squadron running and the helicopters flying.


Early on, two ATCs were modified to field flamethrowers.  The flamethrowers would burn away the dense foliage along the riverbanks to reveal enemy bunkers.  The Zippo was hated and feared by the VC.  The simplest conversion was the removal of the soft top on the ATC (T-91-8 and T-112-5) and an M132A1 APC [armored personnel carrier] with an M10-8 flame gun was backed onto the boat.  The APC contained the fuel and compressed air tanks to power the flame gun.  A purpose-built conversion of the ATC (T-111-7) followed soon after that installed the compressed air tanks and fuel in the well deck of the boat under armor and put two M10-8 flame guns on a modified bow. 


Another ATC conversion was the “Douche Boat” that was armed with two high-pressure water cannons.  The water cannons were used to wash away enemy bunkers and fortifications along the riverbanks.  The boat had an auxiliary diesel engine mounted in the well deck that drove the high-pressure water pump that fed the two water cannons.  A water induction tube was located on the left side of the boat with a pivoting pickup strainer head for river water.



Above: RAS 9 and RAS 11 extensively used The ATC “rag top”.  Each RAS had one ATC reserved as a refueler for the boats in the squadron.  The ATC could carry a fully equipped infantry platoon.  The refueler ATC was indistinguishable from a troop carrier. [Drawing: Windjammer Arts]


Below: “Irma La Douche” was a “rag top” ATC with two water cannons.  The tall, curving pipes just in back of the soft top are the water cannons. [Photo: Ray F. Longaker, Jr.]




Above: A test run of the converted Douche Boat.  The water inductor pipe is down (left corner of stern) and its right water cannon at full pressure.  In this photo, the soft top has been removed from above the well deck.  The water pressure from the cannon is actually causing the boat to list to port.  [Photo: Mike Harris]


Below:  A model of the Douche Boat shows the location of the third engine and water pump for the water cannons.  The inductor and its pipe are shown running along the top, portside of the hull.  The brown boxes behind the bar armor are C-ration cases.  [Model: Ray F. Longaker, Jr.]



Above: Tango T-91-8 is shown with an M132A1 flame APC sitting in the well deck.  The soldier without the shirt is sitting on top of the M10-8 flame gun turret.  [Photo: Bill Doolittle]


Below: A close-up of the M132A1 “flame track” APC as mounted in T-112-5.  The APC was heavy and made ATC steering difficult with the 12.5-ton vehicle aboard.  However, the flamethrower was a very nasty surprise for the VC.  It was also very effective in dealing with the heavy jungle along the riverbanks. [Photo: Al Moore]



Below: Another Tango boat, T-111-7, was converted to mount two M10-8 flame guns on top of a modified bow.  The fuel bladder for the liquid napalm and compressed air tanks were put under armor in the well deck.  This is the ATC conversion to a Zippo boat after its turnover to the Vietnamese.  The bar armor has been extended around the bow to protect the flame guns, the two are shown on the raised platform on the bow.  The deckhouse behind the flame guns is for the boat crew. [Photo: Tom Lefavour]



Above: Another Zippo was a conversion of a RAS 9 Monitor M-92-2 that put two M10-8 flame guns behind the 40mm gun turret in place of the 81mm mortar pit.  The terrifying efficiency of the M10-8 flame gun is well demonstrated here.  The VC feared and hated the Zippo boats.  [Photo: Mark Fontaine]


Below: A nest of ATC(H) boats.  The Program 5 boats were assigned to RAS 13 and RAS 15.  The hard top could land a UH-1 helicopter.  These are Vietnamese-manned, former RAS 13 craft nested next to YRBM-20.  Note the Red Cross flag on one of the boats that indicates it is fitted-out as an aid station. [Photo: Kent Hawley]




Above: An ATC(H) of RAS 15, Tango 53,  with a UH-1 helicopter on deck. [Photo: Dave Hazelett]


Below: A Program 5 ATC(H), Tango-152-1 of RAS 15.  One of the two access hatches to the well deck is open.  The well deck usually had two, sometimes three, machine guns per side.  The three gun tubs of T-152-1 are mounting 20mm Mk 16 guns. [Photo: Carl Hill]



Below: Another landing platform for helicopters was the helicopter barges of the Army’s 9th Division.  These were made from two Ammi pontoons.  Here is one of the division’s OH-23 Raven helicopters on one of those improvised landing platforms.  The barges were towed by Army LCM-8 landing craft.  [Photo: Larry Webb]




Above: Brigadier General William B. Fulton, 2nd Brigade, 9th Infantry Division, confers with one of his officers.  The starboard bow of the helicopter barge pusher LCM-8 is shown in the foreground with its bow ramp down.  The converted Ammi pontoon helicopter barges could land three helicopters and could provide 1,500 gallons of JP-4 to refuel them during action. [Photo: Larry Webb]


Below: Sometimes the helicopters couldn’t set down on the barges and pilots had to improvise.  Here a UH-1D medical evacuation helicopter (“Dustoff”) hovers above an Army LCM-8 pusher boat to pickup wounded troops.  [Photo: Lee Wahler]



Monitors, CCBs, and Zippo Boats

The first Monitors and Command and Control Boats (CCB) were very similar in construction.  The main recognition point was the 81mm mortar pit aft of the 40mm turret on the Monitor and a radio communications shelter in place of the mortar pit on the CCB.  Initially, two of these Program 4 Monitors were converted by replacing the mortar pit with two M10-8 flame guns to become Zippo boats.  Later, Program 5 Monitors were converted to Zippo boats by replacing the forward gun turret with two M10-8 flame guns.


As originally built, the Program 4 Monitors of RAS 9 and RAS 11 mounted a 40mm Bofors gun in a tall turret with a co-axial .50 machine gun.  There was an open mortar pit in back of the 40mm turret for a Navy Mk 2 Mod 0 81mm mortar and two Mk 21 7.62mm machine guns were installed on either side of the mortar pit.  RAS 13 and RAS 15 had Program 5 Monitors.  These later Monitors redesigned the superstructure of the boat and mounted a Mk 48 Mod 0 gun turret with a Mk 16 20mm gun and a 7.62mm co-axial machine gun or 40mm Mk 19 grenade launcher.  The mortar pit and 40mm gun turret of the Program 4 boats was replaced by a turret from a Marine Corps LVT(H)-6 Amtrac that mounted and M49 105mm howitzer. 


RAS 13 and 15 CCBs had the same superstructure as the ATCs, but had an enlarged and improved communications center and mounted a 20mm gun turret on the bow in place of the 40mm turret.  Other Program 5 Monitors were fitted with two M10-8 flame guns in their bows as Zippo boats.  As the war progressed, the Monitors made more and more use of bar armor around the gun turrets to protect them from rockets and recoilless rifle fire.



Above: Monitor M-92-1 in 1968 showing the lines of the first Program 4 Monitor boats.  The tube sticking up to the left of the standing sailor is the 81mm mortar.  A 7.62mm machine gun is under the gun cover to the rear of the mortar. [Photo: Ron McAbee]


Below: CCB C-91-1 in this 1967 photo shows the similarity to the Monitor.  The CCB had multiple radio antennas around the communications shelter that replaced the mortar pit on the Monitor.  CCB C-91-1 was a Program 4 boat and the first command and control boat delivered to the newly formed MRF.  Note the armored doors of both the turret and communications shelter are opened due to the oppressive heat and humidity. [Photo: Dan Dodd]




Above: The first of the Program 4 boats of the MRF were Monitor M-91-1 (left) and CCB C-91-1 (right).  This side-by-side shot shows both similarities and differences between the two kinds of craft. [Photo: Doug Lindsey]


Below: The Program 4 Monitor M-92-2 became a Zippo with the addition of two M10-8 flame guns behind the 40mm turret.  This series of photos shows the Zippo conversion clearing the shoreline growth to expose bunkers.  [Photos: Don Blankenship]







Above: RAS 13 Monitor M-132-1 was a Program 5 conversion showing its redesigned superstructure, additional bar armor, and 105mm gun turret.  These Program 5 Monitors mounted the heaviest guns of all the riverine craft.  [Photo: Doug Laney]


Below:  RAS 13 CCB C-132-1 was a Program 5 conversion.  This photo shows its forward 20mm turret, additional bar armor protection and redesigned communications shelter.  The crew has rigged an improvised sunshade over the roof of the communications shelter to act as an impromptu patio. [Photo: Steve Lovey]





Above: The aft Mk 48 Mod 0 turret on a Program 5 Monitor was surrounded by bar armor.  In the left photo, the crew has installed sandbags between the bar armor and armor plate to increase the armor protection.  The improvised sandbag armor was not particularly effective.  The right photo shows the business end of the 20mm Mk 16 gun and the co-axial 7.62mm machine gun.  As seen in the photos, some gunners took the cone-shaped flash hider off their guns (left), while others kept it on (right). [Photos: Steve Lovey (L), Dave Hazelett (R)]


Below: A good close-up bow shot of Monitor 2 at SEA FLOAT in early 1970.  Note the protective bar armor around the 105mm turret and the twin .50 machine guns mounted on top.  This was an uncommon field modification but very wise considering operational area. [Photo: Bill Patterson]




Above: A still closer look at the 105mm turret and twin .50 machine guns of Monitor 2.  This boat was turned over to the Vietnamese in November 1970. [Photo: Bill Patterson]


Below: The Program 5 Monitor and Zippo boats were very similar.  Here are two sitting side-by-side for comparison with the Zippo on the left (flame guns covered) and the Monitor on the right.  Kenner Ski Barges are in the foreground with their twin outboards. [Photo: Tom Byrnes]




Above: A close-up photo of Zippo Z-132-1 showing both M10-8 flame guns.  The flame tube is on the right and the co-axial 7.62mm machine gun is on the left of the flame tube [as seen from the front].  The Zippo could carry over 1,100 gallons of napalm. [Photo: Dewey Pollack]



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