Be able to create a mine in the underground (tunnel network)

For now we only have opencast mining.
I would be great when we have underground mining.
Mechanics:
- No available at start (requires energy to lift stuff e.g. Steam)
- When underground tunnel network is to width in size and not supported by concrete walls. it can collapse.
- the player has to plan how the underground network should be, otherwise he is not able to maximize its gain.
- after time better maschines get researched.
- groundwater in these deps has to be pumped out constantly (constant requirement of energy) otherwise the mine will flood.

Maybe more areas or levels similar to how they work in Factorio would be good.