It's possible they're digging
with industrial MACHINERY.
Money Heist Season 3, Episode 8
Westworld Season 3, Episode 8
They are working with heavy MACHINERY.
Indeed, they’re building a tunnel.
Money Heist Season 1, Episode 11
And doesn't require outside MACHINERY
to be built to access it.
The Big Bang Theory Season 8, Episode 21
...and you don't want someone like that
operating heavy MACHINERY.
The Big Bang Theory Season 3, Episode 11