Napalm canisters

I watched a nice (and long) documentary called “Vietnam in HD”, I never saw most of this footage. A plane was shown dropping Napalm canisters and it appeared to me that the outside of the canister was in flames shortly after it left the plane. Is this correct? If not, how was Napalm activated?

Vlad–The Napalm canisters had an approximate 4 inch diameter container of white phosphorous in each end. When the canisters hit the ground these phosphorous containers burst open and ignite the Napalm. There is no way for the napalm to be ignited until it hits the ground. There is no fuse to malfunction or any source of ignition.

Vlad, can you give us the time? The video is 44 mins.

It’s sort of toward the end, but I did not get the time. I think it is sunlight reflecting off the canister as it falls.

At 35.05 it is a refelction as the fire bombs were of unpainted aluminum.

The Argentine M-2 Napalm bombs dropped in 1982 used a omnidirectional fuze with mechanical delay.

Alex is right, it is a reflection off the bomb, my old eyes are playing tricks on me.

Fede–That is quite different than the Naplam the U.S. used in Vietnam. I prepared and loaded hundreds of them on F-4 Phantoms. No fuses, just the phosphorous igniters. If you see any film footage of the Naplan hitting the ground you will see the white smoke from the phosphorous.

Ron, those I had seen (maybe even those you loaded!) had allways fuzes on the WP boosters. Maybe you mean something else?

EOD–As they say, the truth is in the details. Technically the BLU 1/B Naplam Fire Bomb did have a fuze, but not in the sense that I think of a fuze as in a time fuse for artillery or GP bombs. It used what we called an FMU-7B Initiator. This Initiator came to the flight line already installed in the M123A1 White Phosphorous Igniter. We then screwed the Igniter in both ends of the BLU 1/B.

Here are some illustrations to explain this. I hope this clears some of this up.

This is a breakdown of the complete unit.

This is the M123A1 White Phosphorous Igniter. It is shown with the older FMU-60/B Fuze rather than the FMU-7B, but they look very similar.

Here is a complete descripation of how the FMU-7B worked. Note that this unit is entirely electrical.

Ron, so we are on the same thing.

Ron, is that your fingerprints on that thing I photographed in Laos?

EOD–Could be. I was at Camn Ranh Bay AFB from Aug-1968 to Aug. 1969 and we sent a lot of Naplam to Laos. What you show is, of course, the M123A1 White Phosphorous Igniter with the FMU-7/B Initiator.

Too bad we are so far apart, I probably had a million questions for you…

EOD–Go ahead and ask. But I would suggest you use email as I doubt many people will be interested in my remembrances from the Vietnam era.

Not so Ron. I love to hear war stories and sea tales. A lot more interesting than talking about 9mms or 7.62x39, IMHO. ;-)


Ron, I would not even know where to start. I have no catalog of questuions or thelike but when looking at certain items or images from that time there will be doozens of questions immediately on many different subjects. Merely the whole SEA issue will be a whole question (and so many other subjects). Often I realize it is not the best choice to be interested in everything but I can not refrain from trying…

Ray, nothing wrong with 7.62x39 !!! :)

I would like to clear up a little confusion if I may. I, too, was a 462 in Vietnam for one year, and then in Thailand two years later, on the F4C/D/E.
As far as the FMU-7/B fuze goes, you are quite correct that it was not a timed fuzed, but nevertheless, a fuze it was. It was not called an initiator. Total time as a USAF 462 was 7 yrs.

Rather, there was indeed a single initiator that was seated in a well in the top of the BLU-1B between the suspension lugs, and had a lanyard that engaged the TER/MER or MAU-12 bomb rack’s arming solenoids. The initiator’s lanyard, upon release from the bomb rack, was yanked out if the solenoid was energized. This started a chemical reaction inside the initiator that produced an electrical current which was passed through coaxial cables connected to the fuzes at each end of the bomb. The current armed the fuze and caused a long, slender indicator pin to protrude from a foil-covered hole centered in the end of the fuze. Upon impact, an arming pin set off the explosive charge built into the fuze. This, in turn, burst open the WP igniter/s whereupon the WP, when contacting the air, burned intensely and thereby ignited the burst canister’s spreading napalm gel. (All of which appears in the diagram and page of text.)

The photo in this thread shows an FMU-7B fuze still in the intact WP igniter. You can see the cable connector still attached the fuze. Since there is no pin visibly protruding, it was not armed for any number of possible reasons. (Jettisoned?) We put hundreds of these together on the flightline in Vietnam. They were not delivered to us prepped from the bomb dump like they were in Thailand. Never did a pre-load until Thailand. We fuzed everything just after loading.

You are quite right that they were not timed, but then many of our fuzes were not “timed”; but, instead, were armed by an air-driven vane and activated by impact. (ie, the M904 nose and the M905/M906 tail fuzes) .

Welcome home, Brother!

Welcome aboard Pops! Always good to have more knowledge around.