I saw a water powered coal cutting machine many years ago, this impressed me a lot, basically a pressure washer which blasted the coal off the face!!
Water can't be compressed so it gives a very strong jet under pressure.
It was ripping coal off as easily as a DECMT. (Double Ended Conveyor Mounted Trepanner). Super powerful machines.
Recently saw a similar thing, basically a pressure washer with silicone particles in the water, this was cutting through 3 inch steel with amazing accuracy. And quick. Computer controlled nozzle, amazing bit of kit. Would have liked one myself, just didn't have the 2 million quid in my pocket at the time...........
Now if it had been a couple of weeks later.......
