What are “damps”?
Let’s talk about what miners call “bad air”; the “damps”—the different gases which are formed in and emitted from a coal seam. Though each “damp” is generally associated with a specific singular gas, they are each a dangerous mixture of several different gases which may require different devices and means to detect or measure.
“Damps” are good to know as they can also emit from modern HVAC systems and accumulate in unventilated spaces, like your own home. This is why it is important to open those windows and get some breathable “good air” into the space every so often. I recommend checking out the new “Canairi” device to learn more about detecting and diluting the “bad air” in your own home.
“Fire damp”
A dangerous mixture of natural gases, containing mostly methane. Then and now, this term is used exclusively for methane and the two are, basically, interchangeable. Whether you are learning from sources of the early 20th century or those of now, this term will come up and it is safe to directly associate it with the presence of methane in dangerous amounts.
Methane is colorless, odorless, highly noxious, and highly explosive. It “weighs less” than “breathable air” and collects in the ceilings or highest points of underground workings.
Methane is not combustible until it makes up 4% or more of the atmosphere in the space and it is at around 9% that it hits a *sweet spot* for severe explosiveness. Methane can also displace oxygen and asphyxiate in a relatively short period of time.
“There is fire damp generated in every mine—no matter how harmless it may be—at least one half of one per cent, and you cannot detect that much with a safety lamp. You cannot detect 2% with a safety lamp, and it takes 5% to make an explosive combination and 9% or 10% is the condition when these great explosions occur. When there is fourteen times the amount of air to one of gas there cannot be an explosion.” – Andew Roy to the Joint Legislative Committee, 1908 (Inquiry, pg 601)
“Black Damp”
A dangerous mixture of natural gases, containing mostly carbon dioxide. Carbon dioxide “weighs more” than “breathable air” and collects at the lower areas of the workings while also blending with and dispersing oxygen in the air.
Carbon dioxide will emit naturally from the coal of the mine’s infrastructure once the coal comes in contact with oxygen. Though it is colorless, it does give a slight acidic smell when present in abundance.
Carbon dioxide can also asphyxiate. The process can begin with less than 3% in the air, causing symptoms which are easy to confuse with general fatigue or even a slight cold. Should the carbon dioxide levels get to as much as 18% of the available air in the space, they can be fatal in a matter of seconds.
Today, the formal chemical name “carbon dioxide” is preferred over the older “Black Damp” since most places have some sort of ventilation system (the HVAC system in your own home, for instance) which can cause a build-up of carbon dioxide or monoxide.
“White Damp” / “Afterdamp”
A dangerous mixture of natural gases, containing mostly carbon monoxide. Carbon monoxide is colorless, odorless, and tasteless often being branded as “the silent killer”.
Carbon monoxide in mines is typically what follows fires or major explosions as it is a result of partially combusted coal. It is highly flammable and explosive as well as extremely toxic to the human system, needing as little as 0.2 — 0.5% in the air to take a life in less than an hour in some cases.
Today, the formal chemical name “carbon monoxide” is preferred over the older “white damp” or “afterdamp” terms as modern ventilation systems expose everyone, be they above or below ground, to the build up of the “silent killer”. Most areas have laws requiring carbon monoxide detectors in for residential and commercial spaces.
There is also “Stinkdamp”, but this was not known to ever be detected or suspected in any of the Monongah mines even in the direct aftermath of the explosion as far as I have found in my research. “Stinkdamp” is Hydrogen Sulfide, it is highly explosive and is easily detected by its characteristically potent “rotten egg” smell. It is possible with all the destruction & devastation all over both mines that any stinkdamp which was stirred up was very, very small amounts and the smell of this gas was simply not enough to override the smell of mass death.
In 1907, these gases, their mixtures and the levels at which they were considered safe or dangerous were *known*, but there was still much debate and disagreement on what exactly would cause them to light, ignite, or explode. Formal scientific testing was still in its infancy in Europe and hadn’t begun at all in the United States outside of individuals within the industry, like Andrew Roy, who had taken upon himself to test gases and dusts from various mines he had worked at over the decades.
“…there should be a chemist provided for by law, who is competent to make an analysis of coal dust and fire damp, and combinations of it, and also to make an analysis of air that is inflammable, or is contaminated by inflammable gas—black damp is what miners call it; carbonic acid gas is what it is; or white damp or carbonic oxide. That experiment should be made. I confess with all the experience I have had that there are some things I don‘t know and do not think anybody knows and chemistry would be the best thing to bring in…” – Andrew Roy to the Joint Legislative Committee, 1908 (Report of Hearings…, pg 593)
Recommended by Author
For more:
- “Damps”
- “Mine gas“
- Andrew Roy’s Testimony – Report of Hearings before the Joint Select Committee of the Legislature of West Virginia, pages 587-594
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