Robotic hydro-excavation devices

A hydro-excavation device configured to be operatively connected to a pressurized water supply and to excavate a tunnel, the hydro-excavation device comprising:

• a housing comprising a plurality of housing segments comprising a forward-most housing segment;
• a nozzle supported by the forward-most housing segment, wherein the nozzle is configured to be operatively connected to the pressurized water supply and to eject water forward of the hydro-excavation device to excavate the tunnel;
• and
• a locomotion system operatively supported by the housing, wherein the locomotion system is configured to propel the hydro-excavation device through the tunnel, wherein the locomotion system comprises:
• at least one tunnel-engagement structure;
• and
• at least one actuator, wherein the at least one actuator is configured to translate the at least one tunnel-engagement structure radially away from and toward the housing between an expanded position and a contracted position, and linearly forward and rearward relative to the housing to move the hydro-excavation device through the tunnel.