Interesting guy.
Hard (for me) to believe but I did that back in the 70s. Not the physical knocking down part though.
I went up the old Tetley Walker chimney which was 300 feet. Straight ladder, no hoops, no harness, no hard hat.
I climbed over the top section as you see Fred doing.........that part was fine, it was climbing back over to get back on the ladder I found a bit scary.