I really have to come in on this.
If a mine is permanently grilled it means that access is denied.
To gain access one has a choice of 2 completely different methodologies.
Option 1. Ben's way, Fairly simple but not permanent and possibly leading to police action and the courts and certainly throwing mine exploration into disrepute.
Option 2 My way. Quite complicated and requiring specialist knowledge of legal matters relative to company law etc, protracted negotiations, very untimely, and possibly expensive. But permanent and with many peripheral benefits.
In a funny way its a bit like a dig. You can stick a few pieces of plywood in for support and burrow away to have it all come down on your head.
Or plan it carefully, go to the expense of good steel support work etc and you have a permanent road.
My avatar is a poor likeness.