I high speed rock that came flying while using the hydraulic breaker to bust up oversize ore. It managed to aim itself perfectly through the steel screen and exploded my windshield.
You are supposed to have Lexan windshields for this application, but guys don't like them because they get scratched and discolor, then they are really hard to see through.
So what we did now is I got one of the maintenance guys to cut me a few sheets of lexan (so I have spares) and put hooks on the tops. So now I can just hang one over the steel screen when I'm breaking, then take it off when I'm excavating and need clear vision.