Central Mine Rescue Training in Idaho

Central Mine Rescue Training Exercise
North Idaho's Silver Valley
contributed by Floyd Varley, NIOSH

This exercise (Spring 2003) was in a cool & wet mine (50 to 55F), filled with smoke and a live fire. The exercise was a simulation of a borehole explosion with victims barricaded past a burning borehole and a wrecked drilling rig obstructing the drift.

The interesting result is that everyone heated up moderately at first, then maintained until about the one hour mark then began rapidly heating up again, some much more than others. We believe this may be a dehydration effect because the work rate and environment didn't change after the first hour.

We thought we might see a change when the team attacked the fire but they stayed far enough away to not be impacted by the local high heat. All of the people monitored were wearing BG-174A's. One person on each team wore the BG4. The ice pak on the BG4 was about 2/3 of it's original size at 90 minutes but only a walnut sized chunk was left for the rescuer who was under for 2 hours. This seems to indicated a significant change in heat loading during the second hour for that apparatus as well.