The Boom Boom Chronicles, Part III.
The Big Bang Theory!

Copyright 2002: Ray Sarlin. All rights reserved. (copy permission at bottom)

Webmaster's Introduction
The Boom Boom Chronicles shed a little light on life in the field for combat infantrymen. Many of our days involved arduous physical labor, either humping the boonies, crashing through jungle, searching vacant bunker complexes, digging in, filling sandbags (with dirt or rice), and other physical tasks. But some tasks were fun for some people, and demolitions could brighten your day.

On one extended mission in 1970 when Charlie Company was patrolling deep in the mountains, we occasionally passed perfectly round ponds in the middle of nowhere. The ponds had seemed like geological anomalies until we realized that sometime in the past B52s had deposited their 70,000 pounds of cargo there to quell some perceived threats.

B52 cargo came in different sizes and shapes. A systematic description of all of the types of aerial munitions would be difficult because they fall under so many different headings. They can be referred to as free drop, free drop with guidance, cluster units, projectiles, self-propelled projectiles, and guided rockets. Or they can be grouped by their blast effects - their fragmentmentation, projectile, incendiary or chemical actions. Munitions can also be identified by their intended targets, whether fixed or mobile targets, point or area targets, hard or soft targets, personnel or materiel targets, or flammable, nonflammable or explosive targets. Bombs also be clustered by their fuzing into categories like detonation on impact, penetration, advanced detonation, time delay or external stimulus (mines).

But the greatest number of aerial munitions used in Vietnam were called low drag general purpose (LDGP) high explosive bombs, also known as "iron bombs" or "dumb bombs". They were delivered by free-fall and weighed from 100 pounds to 3,000 pounds, with nearly 50 percent of their weight comprised of explosive. The bombs primarily worked by blast effect, with the shrapnel from the casing also an important factor. The crater from a 500 pound MK82 bomb with impact fuze was typically about 30 feet in diameter and 15 feet deep, depending upon the terrain. The shrapnel range was about 200 feet in diameter for the same bomb on the ground or over 2,000 feet in the air.

These few facts show two items of relevance to this particular war story. Firstly, judging from the craters that we saw as we hiked through the mountains, the majority of bombs dropped by the B-52s in no-man's land seemed to be the 500 pound MK82s, but some were bigger or smaller. Secondly, any discussion of bombs in Vietnam can be highly confusing to the average infantryman.

But as the other stories in this series tend to show, SSG Koch was not your average infantryman, certainly not where demolitions were concerned. Armed with his trusty graphic training aids GTA 5-10-28 (Demolitions), GTA 5-10-31 (U.S. Firing Devices, Booby Traps and Expedients), GTA 5-10-33 (Demolition) and GTA 5-11-15 (Cratering), no force could stand in his way. And somewhere, on one of his GTA cards, he had the demolition of USAF bombs covered - how to prepare them, how to blow them, how far away to hide... the whole enchilada about bomb disposal. Or so he thought, until his platoon came across an unexploded B52-dropped bomb midway through an extended Charlie Company patrol high up in the remote mountains. It was a whopper!

My knowledge of what happened next was largely due to radio messages as the platoon wrestled with its find. Suffice it to say that we soldiers often wrestled with our finds during the Vietnam War, even when A Company found the $150,000 in greenbacks before I arrived in Vietnam. And a bomb, even a very big bomb, was worth a lot less money in those days, selling for about $1.50 per pound.

The first calls were very excited - sort of like when the monkeys discovered the monolith in 2001 A Space Odyssey. And the calm voice of SSG Koch assured us that he, and his trusty GTAs, had the situation well in hand as he proceeded to prepare the munition for disposal. The platoon was even, we were assured, carrying enough explosives to do the job properly. And so minutes passed.

And then a radio call from Charlie 25 indicated that the bomb wasn't quite the same as the largest bomb on his GTA, a 250 pound MK 81 LDGP. Oh, it was a dead ringer in shape and had the same number of fins, it just seemed bigger somehow. Much bigger! Just how much bigger was soon to become apparent.

For the record, a MK81 LDGP bomb weighs 260 pounds (118 kg). It is 6 feet 2 inches (1.88 m) long and 9 inches (228 mm) in diameter. The MK81 packs quite a punch. But these dimensions weren't recorded on the GTA, because it was assumed, quite wrongly as it turned out, that whoever was using the card could positively identify the bomb. After all, can you tell if a bomb is a MK81without reading the numbers; I sure can't!

So then another radio call came in from Charlie 25, "The bomb is just over 10 feet long and about a foot and a half in diameter. It looks to be about twice the size of the 250 pounder on my card, so I'll double everything. We'll double the MSD (minimum safe distance) as well, just to be on the safe side. What do you think?"

Well, have you ever been asked a question where you absolutely don't have a clue? I had no real idea what they saw or what GTA he had or what it said. I only had confidence in SSG Koch. Even though I trusted him a lot, visions of accidental self-destruction flew through my brain. About all I could say was something worthless like, "Be careful. Don't do anything that you're not sure of. We'll radio the TOC and see if we can get some help."

"Roger that, but we should be okay." And more minutes passed.

"Charlie 6, this is Charlie 25, over."

"Charlie 6, over."

"Charlie 25. Uhhh, it's wired and ready to blow, but, uhhh, I'm just not sure."

"Charlie 6, Roger. EOD (explosive ordnance disposal) says that they can send out a team. Can you find an LZ for insertion?"

As it turned out, because of the thick canopy of jungle foliage, the insertion had to be made in the middle of a river, standing in a foot or so of water on gravel wash on the inside of a bend. Two EOD NCOs from the 191st Ordnance Battalion were winched in with their gear. Unfortunately, we would not again be near a LZ where they could be extracted for another two days, but both were thoroughly pumped about being "combat infantrymen" for awhile. Little did they know what that meant - endless humping of the worst kind.

And they were pretty disappointed when they learned about the 30-day qualification period for a Combat Infantryman's Badge. But they were there to do a job, and they had no option but to get stuck into it so that Charlie Company could start moving closer to their extraction LZ. Both men were experienced senior NCOs. By my recollection, one was a MSG E-8 and the other an E-7 SFC. They were interesting and funny and despite not being Infantrymen, they both did okay on the march, but they definitely didn't like it. Of course, we didn't much like it, either. Liking it wasn't in our job description.

But back to our bomb. Our platoon had met them and escorted them to the unexploded bomb, and SSG Koch explained how they'd found it, what steps had been taken, and how at the last minute he'd stopped despite adopting a conservative approach. He pointed out the rock where he had placed the plunger outside the identified danger zone.

The two EOD sergeants looked somberly at each other, looked back at the bomb, looked at the rock, looked at our grunts, and started laughing. "Boys," they said, "you'll never know how lucky you are that Bill has good instincts. That's a 2,000 pound MK84 bomb there, the biggest thing we've worked on so far. You ain't talking about a 500 pound bomb, you're looking at 945 pounds of Tritonal explosive alone, and that rock that you were going to hide behind is about to become dust!"

As a postscript to this story, I understand that SSG Koch talked the two EOD guys into leaving him with their somewhat more complete set of GTA cards - but fortunately, we never encountered another 2,000 pound bomb while I was in the field with Charlie Company.

Copyright 2002 Ray Sarlin,

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