engineering

[Image: A "Jeffrey Portable Blower," once billed as the "highest efficiency in mine ventilation, insuring [sic] a continuous and abundant supply of fresh air under every operating condition.” Image courtesy of Kentucky Coal Heritage].

I had never heard of a “Gorniczy Agregat Gasniczy” apparatus prior to the Pike River Mine disaster still unfolding in New Zealand, where one such device is about to be deployed.

The GAG, as it’s known, is “a jet engine inertisation unit developed for use in mines, controlling and suppressing coal seam fires,” Wikipedia explains—another way of saying that it is literally a jet engine that you plug into one end of a sealed mine in order to blow high-powered chemical winds (carbon dioxide, nitrogen, and water vapor) into the tunnels below. These gases then “lower the oxygen levels, suppressing fires and forcing methane out of the mine.”

[Image: A New Zealand Herald News].

There are only three operational GAG units in the world right now, apparently. Each operates by taking a “docking position” on the earth’s surface, attached to “intake ventilation headings” that lead, via boreholes, into the porous labyrinth of artificial caves below. The GAG then rapidly pumps a new atmosphere into the existing mineworks, as if generating artificial weather underground. In a paper on “jet engine inertisation techniques,” Stewart Bell points out that “a variation of this device was used, mounted on a remotely controlled tank, to extinguish the oil well fires in Kuwait following the Gulf War.”

As Jonathan Rennie, the person who originally pointed this machine out to me, added: “I wonder what alternative structures it could be plugged into and what alternative gases could be pumped.” Indeed. Weaponized jet-engine army battering rams used to clear enemy houses of hidden combatants. Emergency subway ventilation machines. Alcoholic mist-dissemination units for avant-garde cocktail parties. Underground deodorant guns.

As it happens, the specialty subfield of preventing and/or extinguishing underground mine fires comes with a wide range of spatial and material techniques. These include the controlled “injection” of instant gel-foam barriers (operated via “an underground-based mobile gel preparation and injection system”), in order to block airflow through the mines, and the installation of ventilation control devices (VCDs), or rapidly deployed explosive barriers.

Looking into this latter architectural form—if we can treat underground ventilation control devices as a form of spatial design—led me to something called the “TestSafe Explosions Gallery” in Queensland, Australia—a kind of experimental underground explosion lab that operates as “a full-scale pressure test facility for ventilation control devices (VCDs) within Australia.”

[Image: The CDC].

This “full-scale pressure test facility” joins another Aussie site, called the Lake Lynn Experimental Mine (LLEM), “a highly sophisticated underground and surface facility where large-scale explosion trials and mine fire research is conducted.”

Read more on Ventilating Mines with Repurposed Airplane Engines…