Hey I asked last bread but it was kinda towards the end. I'm just looking for some info or articles or videos on the underground tunnels or the DUMBs. So far I've got the following, but not too much on like an underground high speed railway system or anything. Any leads are appreciated. Love you anons!
Just an intro on Tunnel Boring Machines - Meet Crossrail's giant tunnelling machines - https://www.youtube.com/watch?v=z38JIqGDZVU
Army Is Spending Half a Billion to Train Soldiers to Fight Underground - https://www.military.com/daily-news/2018/06/24/army-spending-half-billion-train-troops-fight-underground.html - http://archive.is/wzfpb
Abstract performance to celebrate Switzerland's rail opening - https://www.youtube.com/watch?v=CbOldRsITpQ