Jees, doesn't anyone watch national geographic or discovery around here? Theres always some programme on about these massive mining machines, I remember seeing one about THIS one in particular. Said channels start at 520 on Sky. Look for programmes called mega machines, massive machines etc. And that "blade" is like a wheel of buckets that rotates and kicks the much back onto a conveyor which carries the muck to lorries. The machine is generally stationery, with the upper part of it swinging back and forth, so moving the bucket wheel left to right and gradually making forward progress. Cool eh?