>>German soldiers in WW2 had to dig foxholes using explosives; shovels just bounced off the ground.

Related to this (but not so much your article), my dad was in France in WWII. He was the 'explosives' guy (and cook - and driver of their M8) in his reconnaissance unit. He mentioned that the infantry guys were very glad to see him as he could string out some detcord, and boom - instant foxholes.

And, yeah, I learned to cook (and that cooking was a 'guy' thing) from him. He also insisted I learn to 'drift' a car before I could go to driver's ed. I still miss the guy.