In the mining and excavation industries, bolders and crap just get in the way and need to be sized down for better management. The Steam Rubble Hammer only goes so far but the Rubble Grinder turns rocks nearly to sand.
Side view: Furnace and tank
Side view: Control
Stage 1. The forward motion of the vehicle sends rubble up the ramp to Stage 2.
Stage 2. Saw blades cut rubble into smaller pieces. First is the line of horizontal blades, then 2 verticle blades.
Stage 3. A very heavy cylinder compresses and crushes the remaining rubble.