|FIRE PATTERNS||FUSES & AMMO|
|FIRE SUPPORT BASES||OBSERVATION|
|FIRE TYPES||ARTILLERY TO&E'S|
Artillery was seen as being so central to US operations in RVN that 70 battalions of it served there alongside some 81 Infantry Battalions. This allowed for massive firepower to be placed rapidly over a large area and under all or any conditions of visibility, weather and terrain.
One particular innovation in Vietnam, prompted by the fluidity of the area battlefield was the system of interlocking Fire Support Bases and improved Night Defensive Positions which were developed to provide continuous all-around defense.
Major emphasis was put on fire support. Artillery was positioned so that any point in an AO could be reached by fire from at least one (usually two) batteries. The batteries were themselves mutually supporting so that they could fire in support of one another in case of attack.
In particular, the great range of the 175mm guns made it possible to deliver heavy and accurate fire to positions and patrols within 20 miles of the gun position, regardless of weather.
The Division Artillery in RVN contained a division artillery HQ and HQ battery, one 155mm towed / 8-inch self-propelled howitzer battalion (general support), and three 105mm towed battalions (direct support). There were originally 18 105's in a battalion, assigned to 3 batteries of 6 guns a piece. However, after '68 an additional 105mm battery was frequently assigned to each battalion. In addition, each separate Infantry Brigade had it's own 105mm battalion present (except 1st Brigade, 5th Infantry Division which had it's own 155mm self-propelled M109 howitzers).
Divisional artillery usually also had it's own aviation contingent.
1967 INFANTRY DIVISIONAL ARTILLERY
|28 Warrant Officers|
|18 x 155mm (towed)|
|4 x 8-inch (self-propelled)|
|54 x 105mm (towed)|
|9 x OH-6A|
|2 x UH-1B|
M101 / M102 105mm Towed Howitzer
The 105mm towed howitzer most often served in the direct fire support role. Light, dependable and with a high rate of fire this was an ideal weapon for moving with light infantry forces and responding quickly with high volumes of close-in fire.
Initially, units were equipped with the M101A1 howitzer, virtually the same weapon as used in WWII. Weighing 2,220-kg and with a maximum range of 11,200-meters the M101A1 could fire HE, HEAT, SMOKE, WP, CHEM and ILLUM munitions at a ROF of 8 rounds/minute.
In 1966 the new M102's started to replace the older M101A1 versions. This weapon was nearly 1-ton lighter and fully air-portable at 1,470-kg. It had an improved range of 14,000-meters as a result of having a longer barrel length. It was also capable of using the 'Beehive' flechette round.
See 105mm towed Howitzer Battalion TO&E.
M108 105mm Self-Propelled Howitzer
This weapon was obsolescent but still in the army inventory. It was too heavy at 22,452-kg to be lifted by helicopter and so it's support of highly mobile forces was restricted.
However, it was employed effectively in area support roles and, if the terrain permitted, in support of ground operations. Only two of these battalions went to RVN.
M114A1 Towed / M109 Self-Propelled 155mm Howitzer
Both weapons normally provided area coverage or augmented direct support artillery.
The M114A1, like the M108, was considered obsolescent for a war in Europe against a highly mobile armoured enemy. In Vietnam however, the M114A1 proved invaluable since at 5,800-kg it was light enough to be heli-lifted and so could provide medium fire support to infantry forces at ranges up to 14,600-meters. It could sustain a ROF of 2 rounds/minute and fire HE, SMOKE, WP, ILLUM and CHEM/GAS rounds.
With a range 3000 meters greater than the 105mm and a shell three times the weight of a 105mm, these howitzers provided additional punch to existing direct support weapons.
The M109 was used in a direct support role with 1st Brigade, 5th Infantry Division (Mechanized). Weighing 20,500-kg it had to move into position by road.
See 155mm towed Howitzer Battalion TO&E
See 155mm towed / 8" SP Howitzer Battalion
M107 175mm Self-Propelled Gun & M110 8-inch Self-Propelled Howitzer
These weapons were mounted on the same gun carriage but used different tubes. The M-107 175mm Gun fired a 174-pound projectile out to almost 33 kilometers (32,700-meters) and proved of great value in providing an umbrella of protection over a wide area. Also used in support of incursions into Laos and Cambodia where it could strike deep inland from the RVN border.
The M-110 8-inch Howitzer fired a 200-pound projectile out to almost 17 kilometers (16,800-meters) and was the most accurate weapon in the field artillery.
Since the weapons had an identical gun carriage it was common practice to install the tubes best suited to the current tactical mission, so that one day a battery may be all 175mm Guns and a few days later it may be half 175mm and half 8-inch.
See 175mm SP Gun / 8-inch SP Howitzer Battalion TO&E
Vietnam Order of Battle, Shelby Stanton, US News Books, ISBN 0-89193-700-5
The US Army in Vietnam, Leroy Thompson, David & Charles Publishers, ISBN 0-7153-9219-0