A reader’s musings on safety
At the facility where I spent the bulk of my machining career, we had two components to the operation: the surface refinery where I worked and the underground portion where the ore was mined before being sent up to the refinery. The mine was 1,570 feet deep, so it wasn't just a simple jaunt when folks were in a bind. In addition, there were restrictions on who entered the mine, and the hazard training required for both the underground (MSHA) portion and the methane presence in the mine atmosphere. This mine generated about 2½ million cubic feet of methane on a daily basis.