What was the average number of people fighting in platoons in Vietnam?

Answer 1

Mainly the US Army & US Marines used platoons. Air Force, Navy, and Coast Guard most likely used other designations.

A platoon (Army or Marines) was the LOWEST unit led by an officer (2nd or 1st Lieutenant). Notice the word used was "led" and not commanded. Captains commanded companies (or Troops in the Cavalry or Batteries in the Artillery). And the captain had Lieutenants leading his platoons. Consequently, there were about 4 platoons per company; 1st, 2nd, 3rd, and Headquarters Platoon. 1st, 2nd, and 3rd platoon were led by a LT, and the XO (Executive Officer, a 1st Lieutenant) was in charge of Headquarters Platoon. The captain commanded the whole outfit.

In Vietnam (the army's changed since then) a US Army tank platoon had 5 Patton tanks. Each Patton tank was manned (by TO & E) four crewmen. Therefore, a tank platoon in Vietnam had 20 men.

A US Army Infantry Company (called a Rifle Company) might have 186 men (or rounded off, about 200 men). They might even have a 4th Rifle Platoon; but the average was supposed to be about 40 infantrymen per platoon. The largest amount of men was almost always in HEADQUARTERS platoon, and HEADQUARTERS Company withing the battalion. Headquarters company had what GIs termed, all the "ash and trash" which was slang for "everything else." Everything else was: Mess section (food); Supply section; Scout section (reconnaissance); Medical section (they rationed out the medics to the line platoons); Radar section (GSR-Ground Surveillance Radar); Mortar section; Maintenance section (mechanics); Administrative section (men have to get paid ya know); etc. You can see why headquarters held the most men.