Fire Mission! Field Artillery in Vietnam Ron Griffin

From the first moment that cannons hurl stone projectiles at a fortress wall, military forces began to look at cannons and Artillery as a force to be reckoned.  Over the years, it has improved in technology, tactics, and effectiveness, and through the years, it has earned the title “King of Battle.” But like anything else, Field Artillery has limitations. In a low-intensity warfare environment like Vietnam, using Artillery to combat guerilla forces is something akin to using an elephant to stomp out ants in your kitchen. After all, it’s hard to win the “hearts and minds” of someone after you’ve blown up his house and killed his family from 10 miles away.

But if you talked to most infantry “Grunts” from the war, they will tell you a very different point of view. Many of them owe their very lives to the firepower of Artillery. That’s because there were two various wars fought in Vietnam. In the populated coastal plains, there was indeed a guerrilla war where Artillery could only be used in limited situations. But in the mountainous jungles the war was more like the jungle battles of WWII in such places like Burma and Guadalcanal. There the battles often involved Battalions, regiments, and even Divisional size forces with one side fighting from prepared defensive positions and both sides employing Artillery and occasionally armor, to overcome these fortifications.

When the war started, the standard artillery weapons in use were: a variant of a WWII era weapon, the M101 (towed) 105mm howitzer; the M108 Self Propelled (SP) 105mm; M109 (SP) 155mm; M114 (towed) 155mm, another obsolete WWII era model; the M110 – 8” (SP); and the M107 175mm (SP) Gun, the only non-howitzer weapon that fired the projectile in a straight flat line.  Towed weapons used a 2 ½ or 5-ton truck to move the howitzers into position while the self-propelled models were all tracked vehicles.

All of these weapons were designed for use in a European battlefield with a well-defined front line as opposed to Vietnam, where there was no front and Artillery would have to fire in all directions at any time, and all of the weapons had to be modified.  Because it was already considered obsolete, the M101, 105mm models were soon replaced by a new towed design, the M102, designed explicitly for Vietnam. Too heavy to be airlifted and with a shorter range and smaller shell, the M108 SP models saw only limited use. Because towed 155mm weapons were to be phased out of the US arsenal, new models were never designed, so the guns were modified to allow the gun to be more quickly turned in any direction. The M109 design had a turret that could be rotated 360 degrees while the 8” and 175mm gun SP’s would have to be physically turned to change the direction of fire.

 At the time, field artillery units were organized as battalions, usually consisting of 3 to 4 firing batteries with 4 to 6 howitzers or guns per Battery. They were supported by a Headquarters and Service Battery without guns. While not unique to the Vietnam War, the use of composite battalions made up of batteries of different caliber weapons were far more common in Vietnam than other theaters at the time. A good example of a composite force was the 1st Battalion 82nd artillery in the 23rd Infantry Division, which had 3 M114 towed 155mm batteries and one M110 8” Battery.  

Light (105mm) artillery units were designated as direct support with a battery being used to support a specified infantry or armor battalion with the same Brigade. Medium (155mm) and Heavy (8” and 175mm) artillery units were given the mission of general support/reinforcing fires under control of a Division level command and would be used wherever they were needed within the Division’s area of operations.

Vietnam was, of course, a helicopter war of constant moving of troops. The 105mm’s were lightweight and could be moved by helicopters to anywhere their assigned unit moved and often moved daily and sometimes moved multiple times in a day to fulfill their direct support missions. None of the self-propelled models were light enough to be airlifted and were restricted to moving on the few roads, so the Army, needing a more massive weapon than the 105mm that was still mobile, decided to use the M114 (towed). It was light enough to allow it to be airlifted by the Chinook helicopter, and if the larger Skyhook was used, the gun, its equipment, and a necessary load of ammunition could be moved in one lift.

All of the traditional tactics used by Artillery were used in Vietnam. Most missions required only minor variations for the jungle terrain. An example of this is the usual airburst artillery rounds were of little use in triple canopy jungle, so more contact fused rounds were used to get the round to explode closer to the ground.

While traditional tactics like “Preparation Fires” to soften up enemy defenses, along with “Final Protective fires” that protected US positions during ground attacks, were as crucial to Vietnam as any conflict, other missions more unique to Vietnam were used as well. Both the 105mm and 155mm guns could fire an illumination round containing parachute flairs, and while not unique to Vietnam these were much more commonly used in Vietnam. Often these were used when the artillery position itself was under night attack. A unique mission to Nam was the “Harassment and Interdiction” (H&I)  or “scheduled fires.” Firing a few rounds into areas where no friendly units or civilian populations were located limited the movements of guerrilla and main force units at night and was a typical mission used in more populated areas. Another unique purpose to jungle terrain like Vietnam was the use of Artillery to help lost grunts find their way in lush jungled terrain.

While it is undoubtedly true that the indiscriminate use of field artillery as well as airstrikes in populated areas, helped alienate many local villagers against the allied forces, it is also true that Artillery accounted for a significant percentage of enemy killed and helped save the lives of the countless US and allied forces and was a significant factor in almost every successful fight in Vietnam. Field Artillery continued to live up to its title as the “King of Battle.”