Two stories about demolitions.
John B in the comments of the earlier posts talks about routinely training on demolitions. It’s a perishable skill. Practice may not make perfect, but it DOES keep you from blowing yourself up.
In the run-up to Desert Storm, I was the only guy in my entire company that had ever done live demolitions before. Accordingly, I was tasked to “train the trainer” and teach representatives from each platoon in the company how to rig some simple non-electric charges for breaching minefields. We had plenty of demolitions equipment- C-4, det cord, time fuse, igniters, and what have you. But no training materiel. Given that, all our training was live fire. Still, it’s not rocket science. After setting up (and blowing) a few charges, the newly trained “Subject Matter Experts” went back to their own platoons, and began to teach them. I wandered from platoon to platoon to check up on them. Most of them caught on very quickly.
One platoon, however, had a misfire. They pulled the fuse igniter. They waited the appointed time. No boom. Not good. They waited the required interval to ensure it wasn’t just a delayed explosion. Still nothing. Getting engineers or EOD out (as normal range practice would require) wasn’t really an option in the desert. So I was nominated to begin OTJ training for EOD.
I very slowly walked up to their charges, thinking that it would be a damn shame if Mrs. Xbrad’s little boy was kilt, and by a US caused accident at that. Turns out, there was very little risk of that happening.
The charge was laid out almost exactly as if they had consulted the manual. They could have been justifiably proud of their handiwork. Except for one little problem.
The fuse igniter had worked as advertised. The reason it hadn’t ignited the fuse? Well, they apparently got confused somewhere, because they were using det cord for fuse. And everywhere they should have had det cord, they had time fuse.
The other incident took place back when I first received demo training in Hawaii. Det cord is often used to cut down trees and telephone poles. And sure enough, one of the “targets” on the demo range was a telephone pole. My battle buddy and I figured chopping it neatly in half would be pretty nifty. So we wrapped det cord around it. And wrapped and wrapped. I’d guess we probably put about 20 or 3o wraps around that thing.
The only problem? Nobody told us that cutting a telephone pole only takes about 2 wraps of det cord. PETN is pretty powerful stuff.
When we cranked the blasting machine, the top half of that pole went up like a Saturn V rocket. When you’re 300 meters from the blast, and it there’s a real possibility you might have to dodge half a telephone pole, you just might have used too much.