And this special NPC type 'Dirthauler' can just be set to idle when you are in the Command Room of the same mine he is in.
In the 'Facility Management' screen push --> ACTION --> MINING/FARM --> ADD NPC
Then use the checkboxes to change the status of your NPC.
I have not tried that yet, but since the NPC must be owned by the mining faction, it might be possible to make them over to someone else. Accordingly to the RULES they probably quit working then.
Edited By: Vip Fortuna on Year 9 Day 81 1:53 ____________