The business end of a modern drilling unit. This DKK one has a multimelta on a spar in the gap. IRL ones do not have this. Yet.
In our mundane world, what tends to happen with things like this at the end of the project is that despite the expense of building and running one of these, is that they are driven into a right angle from the thing they have tunnelled and then just walled in; the expense of getting them out of the tunnels, dismantling, transporting and reusing them is greater than the cost of buying a new one each time. There are loads of tunnelling machines buried all over the world.
This one is intended to be reused many times by the DKK Engineers. In my experience, they never survive their deep strike, let alone any round of combat. Sort of art reflecting life, then.