Machines that make tunnel under the Ground?
Ninety years ago these same machines were created for up to sixteen men to work within the rolling drum digging out the soil, rock, sand by hand and many were killed, either falling forward or back!
But today these boring machines are much bigger and longer, being automated, still crewed by with more safety at hand and they can with lasers work more accurately to also lay the framework of these tunnels with reinforced sections?
Eventually it is expected with A.I. that all types of machines with be robotic and serviced when out of operations, while all controls will come from a control room than the need for human intervention!
Currently the largest borers are building a underwater canal across China and other transport links, with motorways through mountain tunnels and bridges cutting time on land distant travel on winding roads and rail?