The HORRORS of the M18 Claymore Mine in Vietnam 

The HORRORS of the M18 Claymore Mine in Vietnam 

The United States Army wrote down exactly what this weapon does to a human being. It is printed in a field manual in plain language with numbers. 700 steel balls, a 60-degree fan, 2 m high and 50 m wide at a range of 50 m. Fragments still moderately effective at 100 m and still traveling at 250. That was the most dangerous object sitting in front of an American position after dark in Vietnam.

At least, that is what everyone thought. Because the same manual on the same page describes a second zone. It sits behind the mine. And it is the reason this story is not the one you have been told. But this story does not begin in Vietnam. It begins with a piece of physics that two men found independently on opposite sides of the Second World War.

The effect is named for both of them. József Misnay, a Hungarian officer,  and Hubert Shardin, a German physicist, were working on anti-tank mines when they noticed that a broad sheet of explosive backed by a heavy plate does not blast outward in all directions. It throws forward. Everything it is holding goes one way.

After Korea, where Chinese infantry attacked in numbers that overwhelmed defensive positions, the Canadian Army built a weapon around that effect. They called it the Phoenix. According to the technical record, it fired quarter-inch steel cubes out of 5 lb of composition B, and it was a failure. It was too big for a man to carry, and its maximum effective range was somewhere around 20 to 30 yd.

An American named Norman MacLeod, working at the Explosive Research Corporation, spent the early 1950s shrinking the idea. His design went through Picatinny Arsenal as the T48. He filed the patent in January of 1956. He named it after the Scottish claymore, the two-handed sword. And here’s the first thing almost every video on the subject gets wrong.

The weapon McCloud designed is the M18. It is not the weapon that defined Vietnam. Field Manual 23-23, the Army’s own document, lists both side by side.  And the difference is not small. The original M18 threw its fragments about 30 m wide at 30 m, and the manual rates them moderately effective out to 40.

Its replacement covers 50 m wide at 50 m and stays effective to 100. The Army standardized that replacement in 1960, and its designation is M18A1. Roughly 10,000 of the original were built. A handful reached Vietnam. Everything else you are about to hear is the A1. So, what is actually inside it? The Australian War Memorial holds a photograph of three of them staked out in front of the defensive positions at Fire Support Base Pat in Phuoc Tuy province, and the memorial’s own catalog description is one of the cleanest technical

summaries you will find. A curved plastic case, 650 g of plastic explosive pressed between a steel backing plate and 700 steel ball bearings, two detonator wells, a fixed plastic sight on top, the words molded into the convex face. The whole thing weighs about 3 and 1/2 lb. Each ball is an 8th of an inch across, which is roughly the size of birdshot.

When the C4 goes, those balls leave the case at something close to 1,200 m per second. Field Manual 23-23 is specific about where the operator is supposed to let that happen. It tells him to fire as the leading edge of the enemy reaches a point 20 to 30 m out, which the manual calls  the killing zone.

That is where the fan is tightest and the balls are still carrying nearly all their energy. Here’s the detail that gets missed at the time and still gets missed now. There is no reliable figure for how many people the Claymore killed in Vietnam. None. The number that circulates online that landmines caused 33% of American casualties and 28% of American deaths comes from Harry Hambrick and William Schneck in a paper presented at a Naval Postgraduate School Symposium in 1996.

Read what it actually covers. That is every mine and every booby trap in the war, the overwhelming majority of them enemy devices. It is not a Claymore statistic. Nobody has a Claymore statistic. Any video that gives you one is inventing it. What we do have is testimony from the men who fired them. >> And the image I’ll take to my grave is the NVA running at port arms towards us.

And we had to make it back to the LZ. So, we were doing a fire our rotations and then the Claymore mines put them down. Then we used the Claymore mines with a 5-second fuse as we continued to move back and then the the 20th SOS Air Force the [snorts] Green Hornets got there in time.

 With the gun runs, the 5 seconds on our Claymores, we got back and got out under the >> That is what the weapon was for. Now, here’s the part that does not make the highlight reels. Turn back to the same field manual to the section headed danger area  and read it as an American soldier would have read it in 1967. The danger from fragments, it says, is a 180° fan with a radius of 250 m centered on the direction of aim.

Not 60°. 180. The army assumed fragments would come off to the sides. Then, the backblast. Within 16 m to the rear and sides of the mine, the manual says backblast can cause injury by concussion, meaning ruptured eardrums, and create a secondary missile hazard. Friendly troops are prohibited inside that radius.

The minimum safe operating distance is 16 m. And even at 16 m, the man holding the firing device is supposed to be in a foxhole, behind cover, or lying flat in a depression. Every friendly soldier within 100 m is told to take cover because the blast will pick up whatever is lying behind the mine and throw it.

Sticks, stones, pebbles. I mean, think about that for a second. The document teaching a 19-year-old to use this weapon spends as much space telling him where he is not allowed to stand. The appendix covering the older M18 is even more revealing because it breaks the space behind the mine into bands.

0 to 8 m, friendly troops prohibited outright. 8 to 16 m, friendly troops must lie prone or be in foxholes. 16 to 50 m, and only if every loose stone within a meter of the mine has been cleared by hand, friendly troops need do nothing more than shut their eyes. Shut their eyes. That is the instruction.

Somebody sat down, worked out the arithmetic of blast and debris, and concluded that at a certain distance behind a Claymore, the remaining hazard to an American soldier was to his eyeballs. For a while on a well-run perimeter, that discipline held. It did not always hold. In December of 1969, the United States Mine Warfare Center published a bulletin called Mine Warfare Notes.

The language in it is not the language of a manual. A review of casualty reports, it said, “reveals an alarming number of incidents involving American troops being injured by the untimely detonations of M18A1 Claymores or the blasting caps.” It called for small unit leaders to put more emphasis on proper testing and handling to reduce unnecessary deaths and injuries.

That is the Army in 1969 saying its own men were being killed by their own Claymores often enough to write a bulletin about it. And sometimes the failure ran the other way. Captain Rick Woolard, who commanded a SEAL platoon on two Vietnam deployments and later chaired the board of the Navy SEAL Museum, described an ambush to Task and Purpose where the mine was the whole plan.

He gave the command. He heard the firing device click three times. Moisture had shorted it. Nothing happened. If you are finding this useful, subscribing genuinely helps this channel keep making documentaries that check the sources instead of repeating them. While all of that was going on at the perimeter wire, something else was quietly hollowing out the defense.

The M18A1 contains a pound and a half of composition C4. C4 burns clean and hot in the open air. And a soldier who wants coffee at 3:00 in the morning in a wet foxhole has a pound and a half of it  sitting 20 m away wired to his own firing device. Dave Elliott served with a reconnaissance platoon in Echo Company, 4th Battalion, 21st Infantry of the Americal Division.

In an oral history recorded for the Main Vietnam Veterans Project in 1999, he described what men actually did with those mines, which included cannibalizing them to get material out to heat water for instant coffee. The unit history of the 1st Battalion, 6th Infantry, records the same practice and adds the reason it spread in 1970.

Several defective lots had reached the Americal Division. The mines would not fire properly anyway. So, men cut them open. A perimeter that looks defended  and is not. That is the horror nobody puts in a thumbnail. Which brings us to the story that is in every thumbnail. You have heard it. Viet Cong sappers crawl through the wire at night, find the Claymores, turn them 180°, crawl back out, then fire a few rounds to make the Americans blow their own minds into their own positions.

The document that keeps getting cited for this is real  and it does not say what people think it says. The 27th Engineer Battalion in its operational report for the quarter ending the 31st of October, 1967, recorded that its soldiers were afraid to detonate Claymores because of numerous accidents that had been reported about mines turned around by the Viet Cong. Read that carefully.

[music] The report documents fear and it documents rumor. Accidents that had been reported. It is a record of what men in that battalion believed was happening to other units. Captain Dale Dye, a Marine Vietnam addressed this directly in the Armory Life. He wrote that he never actually saw it happen, but that he had heard enough accounts from other veterans to believe there was something behind the claims.

 That is an honest answer from a man who was there, and it is a very different thing from a documented event. The evidence that does exist points somewhere else. In April of 1967, the Third Brigade of the 25th Infantry Division reported that the enemy was a scavenger, prone to police up everything left behind, and listed found Claymores among the items collected.

In Phuoc Thai Province, Viet Cong units lifted thousands of mines out of an Australian barrier minefield and used them against the men who laid them. Theft is documented. Re-use is documented. Reversal, as a verified event rather than a fear, is not. And the Mine Warfare Center’s own bulletin, the one written specifically about Americans being hurt by Claymores, blames handling and untimely detonation.

It does not mention the enemy turning them around at all. The enemy did not need to. They built their own. American technical intelligence, in the manual on foreign mine warfare equipment, documented the DH-10 directional mine, supplied by China and used by both the Viet Cong and the North Vietnamese Army.

Roughly 450 half-inch fragments over cast TNT. The Australian War Memorial holds photographs of captured examples, and the memorial’s own description notes they work on the same principle as the American mine. The Chinese Type 66 went further and copied the M18A1 almost directly, down to the convex face with around 600 steel spheres inside.

There is one more claim worth killing because it is repeated constantly. The Claymore is not banned by the Ottawa Treaty. The Senate report accompanying the amended mines protocol spells it out. The Ottawa definition covers a mine designed to be exploded by the presence, proximity, or contact of a person. A Claymore fired by a man holding a firing device does not meet that definition, so it is not prohibited.

Rig it to a tripwire and it is. The United States never joined Ottawa and did ratify the amended protocol, which permits tripwired Claymores for unit protection. That distinction was not academic in Vietnam. Units did rig them. The 1st Battalion, 6th Infantry called them mechanical ambushes and its own history records that they could only be set during curfew hours, generally 6:00 in the evening to 7:00 in the morning  because Vietnamese civilians move through those areas the rest of the time, which returns us to the lettering, front toward enemy. The original M18 did not carry those words. They were molded onto the replacement in raised capitals, deep enough that a man can find them with his fingertips in total darkness because the Army understood that this mine would be emplaced at night in the rain by exhausted men who could not use a light.

It is usually quoted as a joke. It was designed as a warning aimed inward at the person carrying it. If you want the other half of this story, our video on Viet Cong mines and booby traps covers the war those men were defending against.