Vietnam Tables of Organisation and Equipment
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Armor Battalion
Organized HQ and HQ Company [3 tanks], three tank companies [17 tanks each] and Service Coy.
Personnel: 592
M48 tanks: 54, M106 APC with 4.2" mortar: 4, M113 APC: 14
Divisional Armored Cavalry Squadron
Organized in HQ and HQ Troop, three armored cavalry troops, air cavalry troop
HQ and HQ Troop: 264 personnel, 10 M113 APCs, 4 M132 Flamethrower Carriers
Ground Troop: 197 personnel, 9 M48 tanks, 3 M125 APC with 81mm mortar, 21 M113 APC
Air Troop: 194 personnel, 9 AH-1G, 9 OH-6A, 2 UH-1B, 6 UH-1D
Aggregate: 1049 personnel, 27 M48 tanks, 9 M125 APC with 81mm mortars, 73 M113 APCs, 4 M132 Flamethrower Carriers, 9 AH-1G, 9 OH-6A, 2 UH-1B, 6 UH-1D. Both here and in the armored cavalry regiment the M577 ACV has been ignored and is not included in the M113 count.
In 1965, the TOE included M114 vehicles, which were not well regarded. Squadrons replaced them with M113�s before deployment. However, they were also prevented from taking their tanks, as MACV and other high-level Army headquarters were opposed to armor in Vietnam. If the tanks were shipped, they were not allowed to be used. Thus, the 1st Infantry Division�s squadron had their M48 tanks withdrawn and held at base camp for six months after arrival in Vietnam before the division commander could convince Westmoreland to allow their use. The tanks were back in use by 1966.
The Air Troop was also somewhat different in 1965. A TOE from then or somewhat earlier showed a unit of 141 personnel, with an aero scout platoon (9 LOH and four UH), an aero weapons section (4 UH armed with rockets), and the aero rifle platoon (four squads carried in 5 UH). Other aircraft at headquarters included 1 LOH and 4 UH.
In Jan 1969 3rd Sqn 4th Cavalry began to receive the M551 Sheridan, which replaced M48 tanks one for one. By 1970, the other divisional squadrons were re-equipped with Sheridans.
Note that a divisional air cavalry squadron (e.g., in 1st Cavalry Division) had the opposite organization: one ground troop and three air troops. It probably had some variations in the HQ and HQ Troop as well.
Armored Cavalry Regiment
The regiment had a HQ and HQ Troop, Air Cavalry Troop, and three squadrons. HQ and HQ Troop included 2 light observation and 8 utility helicopters. The Air Cavalry Troop was essentially the same as that in the divisional squadron. The three squadrons were organized into HQ and HQ Troop (281 personnel, 5 M113 APCs, 3 AVLBs, 2 light observation and 2 utility helicopters); three armored cavalry troops (each 170 personnel, 9 M48 tanks, 3 M106 APC with 4.2" mortars, 22 M113 APCs), Tank Troop (102 personnel, 17 M48 tanks, 3 M113 APCs), and Artillery Battery (143 personnel, 6 M109 155mm SP howitzers). A squadron thus had 44 M48 tanks, 9 M106 APC with 4.2" mortars, 6 SP 155mm howitzers, and a number of M113 APCs.
In 1965, as with divisional units, the TOE had included M114 reconnaissance vehicles. M113�s were substituted for them, and for the M48 tanks in the cavalry troops (giving each squadron another 27 M113�s and no 48�s). While the design had existed earlier, the designation of ACAV (armored cavalry assault vehicle) for a modified M113 (.50 caliber machine-gun with shield in front, two M60 machine-guns with shields in the rear) was coined by the 11th. Even though divisional squadrons had their tanks restored in armored cavalry troops during 1966, the 11th shipped without them. The tank troops were allowed to ship their vehicles.
In Jan 1969, 1st Sqn 11th Armored Cavalry began to receive M551 Sheridans, receiving three Sheridans for each two ACAVs in the troops. By 1970 the remainder of the regiment was re-equipped with Sheridans.
Airmobile/Assault Helicopter Company
258 personnel, 23 UH-1D [door-mounted MG], 8 UH-1C [6 with 2.75" rockets and MG, 2 with 40mm GL]
Medium Helicopter/Assault Support Helicopter Company
269 personnel, 16 CH-47, 2 OH-6A
Division Aviation Battalion
These were originally organized with a HQ and HQ Company, Light Airmobile Company (24 utility helicopters) and GS Aviation Company (6 utility helicopters, 16 light observation helicopters, and 4 observation aircraft).
105mm Towed Howitzer Battalion
HQ and Service Battery and four batteries (each with 6 105mm howitzers)
These originally had three batteries
641 personnel
General Support Battalion [towed 155mm and SP 8" howitzers]
HQ and Service Battery, three towed batteries (each 6 155mmhowitzers), one SP battery (4 8" howitzers)
These were found in the infantry divisions
616 personnel
155mm Towed Howitzer Battalion
HQ and HQ Battery, three batteries (each 6 155mm howitzers), service battery
598 personnel
175mm Gun/8" Howitzer Battalion
HQ and HQ Battery, three firing batteries (each 2 175mm SP guns and 2 8" SP howitzers), Service Battery
565 personnel
All of the original 175mm gun or 8" howitzer battalions were reorganized by 1969 as composite units; both weapons were mounted on the same carriage.
Aerial Rocket Battalion
39 helicopters with 2.75" rockets
Quad M55 Battery
142 personnel with 24 trailer-mounted M55 quad .50 MGs
Infantry Battalion
HQ and HQ Company, four rifle companies, Combat Support Company
HQ and HQ Company had 166 personnel
Each rifle company had 164 personnel (HQ: 12, three rifle platoons: 42 each, mortar platoon: 26 [3 81mm mortars])
Combat Support Company had 100 personnel with 4 4.2" mortars
Each rifle company had 3 90mm recoilless rifles on TOE, but these were usually left at base camp
Battalion aggregate: 922 personnel. The battalion had 33 jeeps and 17 trucks (8 �-ton and 9 2 �-ton)
At the time of the initial commitment, 1965-66, there were variations in infantry battalions. A normal infantry battalion had HQ and HQ Company (290 personnel, 4 4.2"mortars and 2 106mm recoilless rifles); three rifle companies (180 personnel, with 2 3.5" rocket launchers at company HQ, 3 81mm mortars, 2 106mm recoilless rifles and 1 3.5" in the weapons platoon, and 2 MG and 2 90mm recoilless rifles in each of three rifle platoons). The battalion totaled 830 personnel.
An airmobile battalion had HQ and HQ Company (134 personnel), three rifle companies (170 personnel, with 3 81mm mortars in the weapons platoon and 2 MG and 2 90mm recoilless rifles in each of three rifle platoons) and a Combat Support Company (123 personnel, 4 81mm mortars and 8 106mm recoilless rifles). This unit totaled 767 personnel.
Gradually the Army standardized infantry on the model light infantry battalion given at first. Actual strength, of course, would have been well below the nominal 900-plus personnel.
Infantry Battalion (Mechanized)
HQ and HQ Company, three mechanized rifle companies
HQ and HQ Company had 304 personnel
Each mechanized rifle company had 199 personnel, with heavy weapons probably similar to 1965 infantry battalion
The strengths shown above are from 1963. By Nov 1970 a mechanized rifle company had 170 or 172 personnel, with three platoons, each in 4 M113 APCs, and a weapons platoon (3 M125A1 with 81mm mortars and 2 M113 with TOW). The company had a total of 15 M113 APCs. By Nov 1970 there was also a Combat Support Company, which included a scout platoon (10 M113), a mortar platoon (4 M106 with 4.2" mortars), and AT platoon (6 M113 with TOW). The Combat Support Company pulled units from the old HQ and HQ Company. Battalions in Vietnam did not, as far as I know, ever receive the M113 with TOW.
Ranger Infantry Company
118 personnel (two platoons, each eight 6-man patrols and 2-man HQ)
Armament was restricted to rifles and 40mm GL; the company had 9 jeeps