How to:

• Dig into underground by placing a drill. As soon it has finished you can type Enter to step down.
• Place item elevators, liquid elevators and heat elevators above and underground to handle your logistics. Connect wires to the player elevator.
• Expand your underground place by digging walls, throwing cliff explosives or using AAI Vehicles: Miner in combination with AAI Programmable Vehicles to automate boring.
• Place active or passive air vents to handle pollution.
• Use wooden supports instead of electric poles

Automatic digging with AAI Miners and Programmable Vehicles:

Once you placed an AI miner vehicle in a subsurface you can select a path for it when holding the unit remote item. This path must be created using the path remote item. Turned-on vehicles will then start moving along this path.
Note that the path angle at waypoints should not be less than 90 degrees in either direction, otherwise the vehicle will end up with 'no path' due to its pathfinding logic. If a destination waypoint is located at an already exposed point, the vehicle will not dig through walls.
Miners with full inventory don't move until they are cleared.
If vehicles won't move, just select them using the unit remote and order them to move.

Contribution and modding

I need help creating graphics, balancing stuff, feature suggestions and localization.
I welcome remote interface suggestions to interact with this mod!

This mod is a remake of the old mod (Subsurface by StanFear) for recent Factorio versions.