Changes

==Safety==

==Safety==

Dangerous gases such as [[methane]] can accumulate in mines and can explode if ignited, and the inhalation of dusts is also a health issue, so underground mines must be ventilated, typically with large fans located above ground which keep air circulating through the mine.  Another hazard in underground mines is blackdamp, which refers to an accumulation of gases such as [[carbon dioxide]] and [[nitrogen]] with the [[oxygen]] level too low to sustain life.  Blackdamp can be detected using a safety lamp, the flame of which will diminish or extinguish in the presence of blackdamp, or in modern use an electronic air quality detector is used.  In earlier times a [[canary]] might have been used to detect both blackdamp and methane as the bird would be quite dead by the time the gases reached levels dangerous to miners.

Dangerous gases such as [[methane]] can accumulate in mines and can explode if ignited, and the inhalation of dusts is also a health issue, so underground mines must be ventilated, typically with large fans located above ground which keep air circulating through the mine.  Another hazard in underground mines is blackdamp, which refers to an accumulation of gases such as [[carbon dioxide]] and [[nitrogen]] with the [[oxygen]] level too low to sustain life.  Blackdamp can be detected using a safety lamp, the flame of which will flare up in the presence of methane and diminish or extinguish in the presence of blackdamp, or in modern use an electronic air quality detector is used.  In earlier times a [[canary]] might have been used to detect both blackdamp and methane as the bird would be quite dead by the time the gases reached levels dangerous to miners.

In addition, mines must be inspected for unstable conditions which might result in a cave-in, and other hazardous conditions.

In addition, mines must be inspected for unstable conditions which might result in a cave-in, and other hazardous conditions.  Timber framing is installed inside underground mines, but contrary to popular misconception this is not to reinforce the mine and prevent collapse, as no timber framing can support the vast tonnage above the mine passage.  Rather, it is to warn of unstable conditions and an imminent collapse and give miners advance notice to escape.  If the timber framing breaks or starts making loud creaking noises, this is a warning that a cave-in is likely.

==Notes & References==

==Notes & References==