This aims to be a complete rewrite of the old mod (https://forums.factorio.com/viewtopic.php?t=19178 by StanFear) to the new versions of Factorio. I'm using it's code and graphics but work on replacing everything from time to time. I appreciate contributions to this mod, especially for graphics. See todo.txt for already noted to-do's.
You can help me translate the mod on Crowdin: https://crowdin.com/project/factorio-mods-localization and search for "Factorio Subsurface"
Mod portal link: https://mods.factorio.com/mod/Subsurface