He was talking to someone that said drilling tunnels is hard. He responded with something like, it's just a hole in the ground, how hard could it be. Within a year or so he designed and built a tunneling rig and completed a tunnel. I believe it was in LA. There is a show with Jay Leno where they took a Cyberyruck through it. The tunnel controlled the truck and they were hauling ass under all the traffic above. I'll look for a link to it.