The MN-3 is a mining and excavation automaton — a heavy tracked platform the size of a small truck with a rotating bore head, material collection system, and reinforced chassis rated for operation in tunnel environments. Arcturus originally designed it for military tunneling — creating fortified underground positions — but the civilian mining variant has become the primary revenue generator. The MN-3 bores through rock, soil, and concrete, processes extracted material for valuable minerals, and deposits waste in compacted blocks behind it as it advances.

The MN-3 operates in environments that would kill human miners within hours — collapsed sections, flooded tunnels, atmospheres laden with toxic gas or explosive particulates. It does not need air, does not need light, and does not panic when the ceiling drops. Its chassis is rated for pressure loads that would crush a human body, and its bore head can chew through materials ranging from soft clay to granite. GLMZ's extensive tunnel network — the infrastructure beneath the megacity — was largely excavated by MN-3 units and their predecessors.

The MN-3's dual military-civilian heritage means that many units operating in mining capacities retain capabilities that have nothing to do with extracting minerals. The military variant's hardened communications system, seismic sensor array, and reinforced armor are present in civilian units — technically deactivated, trivially reactivated. A mining MN-3 is fifteen firmware modifications away from being a military tunneling platform. Arcturus considers this a feature, not a bug.