"Smoke grenades in Vietnam" Topic

After a bit of research, I've found numerous references to American troops carrying smoke grenades into combat in Vietnam---though this is something often left out of combat accounts.

Was their use in combat normal---to mask a rush between areas of cover, or to mask a retreat from one position to another?

I mean concealing smoke here, not the colored marking smoke---I don't imagine that would create enough material to mask or block enemy fire?

Both put out a lot of smoke, so could be used to hide.

Smoke doesn't "block enemy fire", but it does make targeting opponents difficult, since you can't see through it.

I imagine every soldier was issued with at least one smoke grenade (perhaps more), for self-protection, in order to be able to use that as an aid to breaking contact, and/or to obscure their movements when assaulting enemy positions, if desired.

They had illumination grenades, too.

Could it have been used for dropping in tunnel networks?

I'm always interested in grenade policies in the infantry. There must have been a practical limit as to how many and what kind were carried or issued. How was this managed in the field?

In games, everyone naturally wants an unlimited number of explosives, but in real life this wouldn't have worked. I'm reminded of D&D games especially, where unless the DM puts a lid on things, everyone in a party is walking around stuffed with molotov cocktails and flasks of oil.

When calling in air strikes , they would pop a color of smoke to denote where the friendly lines were to prevent fratricide. The NVA and VC would listen on the same frequencies and pop the same colored smoke to prevent them from getting targeted. In order to stop this, the FAO would call in "I'm popping purple smoke. The enemy would pop a purple smoke grenade. The FAO would ask, "Do you see my smoke". When acknowledged by the pilot, the FAO would say, "I didn't pop! Thats the enemy location….pour it on!"

…It took a lot of different colored smoke grenades sometimes….

Smoke grenades were issued to squad leaders, platoon sgts and plt leaders. Generally three or four of different colors were issued to each leader. The colors I recall were red, yellow, green, purple and white. Green was seldom used because it would get lost in the vegetation. Oddly enough it was excellent for getting rid of stinging hornets and bees.
Uses were to mark LZs, mark friendly positions for aircraft or other friendly units and to mark NVA/ VC locations. As to screening NVA or VC units there was little point in screening them if you could see them well enough to kill them. During the fighting in Hue when smoke was used to "obscure" USMC movement during street crossings etc the NVA would fire into it since what we were trying to do was obvious. For good accounts of small unit combat including the use of smoke read any of Keith Nolans books.
link

How long would grenade smoke linger in its area before dissipating?

Depends on the wind, humidity and the undergrowth but around three to five minutes.

IIRC when I was in during the 90's, they taught us to pop the smoke grenade, the supporting aircraft would then call the color they saw, and the guy on the ground would confirm if this was correct or not. I was not a FAC so I could be imagining this.

Several ways to skin the cat. I suspect we do not have near enough emphasis on preventing friendly fire in our 20th century + games.

@Tin Man – you are correct that was and still is pretty much SOP.

M79 and later M203 grenade launchers even had non-colored smoke rounds with them.
The M551 Sheridan had six smoke launchers, three to each side of the turret.
Smoke was a constant item. Normally the platoon Sgt and the Platoon Leader carried colored smoke.
Copters refused to to fly into and land in non-colored smoke as they did not know if it was CS or not. The smoke and CS canisters were similar.
With my mortar platoon, we had WP but also had non-colored smoke rounds. i never used a color round with mortars.
Like passwords, colors of smoke changed from day to day in regards to their meaning.
This kept the enemy from laying traps for copters by popping smoke for a fake emergency LZ.

I never issued any colored smoke other than to section/Sqd Sgts and they kept them in the track. Individual soldiers NEVER got colored smoke. They would only get smoke for a specific imediate use situation.
The Plt Sgt got colored smoke but other smoke for his section was with the M551.

So, how many grenades did the troops get?

I'm guessing each with at least one, white smoke grenade (perhaps two?).

Probably two regular grenades per soldier, with options for more during planned assaults, or when manning defensive positions?

We used them in RVN to identify location to supporting air or resupply/transport. Yeah, sometimes Charles had 'em too <lol>

As many have already posted. Smoke Grenades can be use to cover movement e.g. falling back. And they were use to mark LZs/DZs or ID locations of Friendies as CAS is coming in. To show where you are. Or even if you use a GL, etc., to mark an enemy location. In either situation to make sure the CAS hits them and not you.

They also could be used to ID a friendly location by asking the color of Smoke that was popped. So the choppers, etc., would know they were not landing in an ambush, etc. As noted the VC/NVA used them too …

As far as issue to the troops. They could be liberally give out in various colors based on SOPs, mission, etc.

In all of the reading and interviews I have done over the years about Vietnam, I know of only 3 instances where hand-thrown colored smoke was used to mask movements; 2 USMC and 1 US Army. However, I know of at least a dozen instances where WP grenades were used to cover a movement (mostly by SOG, usually thrown AT the enemy to shock them before friendlies moved back) though it was not common due to the problem of throwing the heavy beasts far enough to be outside of the cascade radius of the embers when it goes off.

And sometimes the foliage is too thick to get much distance for a smoke grenade. I learned that the hard way in Panama …

And yes, WP will make a great smoke screen. If you can throw the "SOB" far enough not to add yourself to the casualty list.
Great for spiking FA, vehicles, etc. or even starting a fire too.

WP screening smoke is good for causing casualties and its instant, you could use signalling smoke to screen, but it would take a few and it takes a bit to build up.

The other thing about smoke was the code words used to ID the colors.

"Popping smoke"

"Roger, I see grape."

"Confirmed. Grape is your LZ."

or

"Who wants cool aid?"

"I like lime."

"Negative, Charles likes lime."

"Aborting"

As if the VC couldn't figure it out after a couple of iterations…

Of course black smoke always meant the same thing: "The target is marked by the burning scout"

Of course black smoke always meant the same thing: "The target is marked by the burning scout"

That's why one of my objective markers for Flames of Nam is a downed/burning OH6.

As far as smoke for marking tunnels, I'd just as soon use CS than colored smoke…

As a Vietnam era veteran and in the Army in the 1970s, I never saw black smoke. Many other colors but not black.
As I said, individual soldiers did not get colored smoke WP/Gray and CS but not colder.
I did read about reports that CS was used in tunnel searches

I think they meant the black smoke was from the burning chopper. So yeah, I too never saw a black colored smoke grenade. Don't think they were made.

And I too have heard about CS used for tunnels. If anyone was ever hit with CS in training or otherwise. It's not a pleasant thing. And in the cramped space inside a tunnel or cave with no wind, etc. It could be very effect.

I also saw a training file about pumping some type of propane into the tunnel(s) then igniting it.