It was a walk behind industrial machine.The great thing is that it doesn't smash the soil up but turns it over leaving quite a course finish but on a second pass you could bring the soil down to a fine tilth to a depth of about 2 to 2.5 feet.
5 feet is from memory but being a man it could have been nearer 4.
Before we bought this machine we used to use a Honda twin 6 rotovator but switched simply because of the damage repair work we had to do to maintain soil condition.