Mortars and Howitzers used to support the 1st Battalion 6th Infantry, Vietnam, 1967-71

(1) 81 mm Mortar.

On left, an 81mm mortar, M29 with mount M23A3 -- total weight of 93.5 lbs. A muzzle loaded,
drop fire weapon, capable of  a maximum rate of fire of 12 rounds per minute (charge 8) for two
minutes; or a sustained rate of fire of 3 round per minute (charge 8).  Maximum effective range of
3,650 meters.  Approximate bursting area in meters of 25 x 20.  Each round weighed 7 to 12 pounds.
Photo from Don Kaiser (A/1-6 Inf 1967-68).  If you recognize these men, contact
An 81mm mortar mount with M34A2 sight.  The traverse mechanism allowed for 95 mils traverse in
either direction. (equivalent to a 5.34 degree shift, or about 105 m. at a range of 1,000 m.)  One turn
on the mechanism in traverse and elevation equaled to approximately 10 mils or about 12 m. at a
range of 1,000 m. [A "mil" is a unit of angular measurement in military terminology = 1/6400 of a 360
degree circle.].  Photo at left at Dai Loc from Wayne Johnston (1-6 Inf 1970-71).  An ammo report
from Dai Loc in November, 1970, showed that they had 145 rds HE, 29 rds WP, and 72 rds of
Ill on hand.  In the photo of Hill 270 (above right) from Rob Cook, (G/55th Arty Quad 50), note
that the bipod legs were intentionally not pressed into the ground, and that ammo was next to the
tube ready for use.

Three types of rounds were used with the 81mm mortar:

(a) M374 HE (high explosive); 9 lb; color OD w/yellow band; 4,737 m. max range and 72 m. minimum
range; available with charge 0 to charge 9; bursting diameter of 34 m.  Equipped with super quick fuze
to burst on impact, delay fuse of .05 sec to allow 18" penetration, and proximity fuse for 1 to 6 m.
burst up in the air.

(b) M375 WP (white phosphorous); color light green w/red marking and yellow band; 20 m. bursting
diameter; an incendiary round used to ignite the target and cloak the target area in smoke and haze.

(3)  M301A3 Illumination; 10 lb.; color white w/black marking; bursts at 600 m. with parachute flare
illuminating a 1,100 m. diameter area; fired with charge 2 for illumination; mechanically timed fuse

(2)  M30 4.2 in. Mortar

US 4.2-inch mortar, M30 w/ mount M24A1.  This fire support weapon was operated by soldiers in
Co. E, 1st Bn 6th Inf, while at the small fire support bases--Nui Pho Tinh (BS 648 936), OP Shaw
(BS 670 874), Hill 270 (BS 421 047), etc.  It could fire High Explosive (HE), White Phosphorous
(WP), and Illumination(Ill) rounds (shown in bunker next to tube and ready for use).  Each round of
ammunition weighed 26-29lbs.  An ammunition report from Nui Pho Tinh in November, 1970,
showed the fire base had 179 rds of HE, 75 of WP, 116 of ILL, and 88 rds of CS gas on hand.

Officially called a muzzle load, drop fire weapon, it could be fired at
six rounds per minute for two minutes, or two rounds per minute for longer periods of time.  The
maximum effective range was 5,650 m. with a 40 m. casualty radius for HE rounds.  Note the chain l
ink fence--used to detonate RPG rounds fired by the Viet Cong.  Scan of US Army official
photograph CC70742 at the National Archives II, College Park, MD.

(3) 105 mm Howitzer M101A1 or M102.

US Howitzer 105mm towed M101A1 or M102.  Weight 3,000 or 4,988 lbs with 11,000 m. range.
Both FSB Nui Pho Tinh and FSB Chippewa had two tubes of 105mm howitzer like the one above.
The tubes at FSB Nui Pho Tinh were moved back to LZ Dottie on 8 Nov 70, because they could
provide adequate fire support from there most of the time.  These weapons from the D Btry. 1st Bn
14th Arty at LZ Dottie could be airlifted to temporary firing positions to provide artillery support.
Scan of official US Army photograph CC70743 at the National Archives II, College Park, MD.

105mm howitzers were capable of firing a "Beehive" round in the direct fire role as part of the final
protective fires from artillery positions.  Used against troops in the open, the howitzers fired in a
swath across the ground like a giant shotgun.  Thousands of one inch long steel darts or "flechettes"
like those above pierced everything in their path.  To minimize the danger to friendly forces, a signal
flare would be fired to warn soldiers to take cover.  These flechettes were retrieved from the area
of operations near LZ Dottie in 1970.   Scan provided by Wayne Johnston (1/6 Inf '70-71).

The gun pit for howitzer #4 (A Btry, 1st Bn 14th Artillery) at LZ Dottie was particularly well located
for firing Beehive rounds as final protective parallel to the east side of the LZ Dottie perimeter. Photo

The 105mm howitzer also could fire ICMs (Improved Conventional Munitions) known as the
"Firecracker" round.  This specialized artillery shell consisted of dozens of smaller munitions that were
scattered by an air burst.  They exploded on contact with the ground and were effective against enemy
troops in the open.  Unfortunately, the smaller bomblets sometimes did not explode when they landed
in rice paddies.  They would explode later, however, when kicked by someone wading through the
flooded field.

The various types of ammo were stored in the gun pit for ease of use.  Note the categories listed
behind this 105mm howitzer at Artillery Hill a Chu Lai:  "Beehive, Fire Cracker, Fuzes, Small Arms,
Section Chief, and HE-X [high explosive]"  Note also just to the left of  the tube the wood lawn chair
constructed from used ammo crates.  Photo provided by Earl Pogue, A/1-14 Arty.

(4) 155 Howitzer

Howitzer, 155mm towed, M14A1, with 14,600 meter range. Max rate of fire of 12 rounds for
three minutes or one round per minute indefinitely.  Bursting area in meters 30 x 50.  Soldiers from
the 1st Bn 6th Inf received fire support from these weapons located at most of the fire support
bases adjacent to their area of operations.

Link here to Ron Griffin's web site for the 1st Battalion 82nd Artillery.  Ron (shown talking on the
phone in the above photo from the August 27, 1971 edition of the Southern Cross) served as the
Section Chief of Gun #5 at LZ Dottie and also at LZ Fat City with D/1-82FA in 1970-71.

Select additional photos from the index at left or link to the 1st Bn 6th Inf  Home Page