https://www.darpa.mil/program/underminer https://www.darpa.mil/program/underminer Concept art suggest tunnels networks a few inches wide, not for moving bodies

https://www.darpa.mil/program/underminer https://www.darpa.mil/program/underminer Concept art suggest tunnels networks a few inches wide, not for moving bodies but for resupply in urban environments. Looks like horizontal directional drilling rigs for wells, which takes weeks.