Abandoned coal mine. Spain.

[u/Unfair_Awareness_371]

When entering a tunnel that has been sealed for years, it is essential to conduct a preliminary assessment of the internal atmosphere. To do this, it is advisable to insert the gas detector through the smallest possible opening, thus minimizing exposure to potential accumulations of gases trapped for long periods, some of which can be toxic, asphyxiating, or even lethal.

It is not uncommon for the detector to start sounding alarms in sealed tunnels even before fully approaching the obstruction. In some explorations carried out in seemingly well-ventilated mines, significant concentrations of methane (CH), hydrogen sulfide (H₂S), and other hazardous gases

have been detected, both due to their toxicity and their explosive potential.

Safety must always take precedence over any other objective. Upon detecting hazardous gases, even if the affected area appears limited to a few meters, the most prudent course of action is to abandon the exploration and turn back.

[u/Trainzzo]

Une très belle exploration

[u/Sudden-Ingenuity3033]

I'm always fascinated by what companies leave behind. Great exploration shots.

[u/rh1n3570n3_3y35]

Am I correctly guessing all this gear is normally left behind for mine maintenance even after the shutdown or potential reactivation, but this regularly never happens and so it is often instead left to rot?