The simplest way to break up boulders in confined spaces is using a Lizard Jackhammer.
The machine doesn't need gasoline, charging, or even turning on thanks to the innovative 2025 LTT technology (Lizard Transmission Technology).
Additionally, LTT sensors determine when the jackhammer is over the correct material and upright to begin operating.
All you have to do is pick it up and start to work!
Cost: $1,500
Location: Miscellaneous > Hand Tools

Thanks to Squigglze