I was assuming if no sharp practices were occurring, then it might be a similar situation to what we've found in the other pipes/caves nearby, and that the ore was 'loose' or bound up within sediment infill of natural caverns, requiring little in the way of blasting. Certainly reminds me strongly of another site not too far away, at least in a structural sense.
Funnily enough, I only have a few of JH - various scattered shots of the cartgate and the base of Leviathan. Oh, and a birthday party in a side-chamber in The Workshop, but hadn't wanted to upset anyone! This was tea, cake and candles though, rather than booze, research chemicals and fireworks 😉