Indeed, it looks like a most interesting find, and nice to get the postwar build confirmation in the woods.

Lot to take in too - wonder if they were originally as buried as they are now, or have been consumed, then there's the safety filling you suggested - pity.

The online imagery is getting better! It showed what was found, and looked odd because of the extras.

I've come across a few electric fences, but being a "trained electrical type" gave them all an extremely wide berth, preferring to slide under lower than a snake's dangly bits, as I wasn't carrying anything to check them with. I've been in too many hazardous places, and even lost colleagues, to get zapped voluntarily, even if supposedly "safe". Being stunned in a field in the middle of nowhere sounds like bad news, especially for anyone with a dicky heart.

I was zapped with a humble 3 volt flykiller last year, and it practically paralysed one of my fingers for a few minutes - lord knows what a sustained taser srtike is like.