You need the Platinum Expansion, and then you use the hydraulic hammer. You do need to own the land.
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I have the Platinum Expansion, Dynamically Crushable Rock is not working and none of the hydraulic crushers. I can throw rocks in a rock crusher....nothing. I can dump them in a trailer and again nothing happens. Its not working. Maybe an idea to write a small storyboard. Because now i have no idea what should workon the map and what not.