Published in the March 2006 American Longwall Magazine
The refuge chambers are self contained and can be carried in a durable carry bag and placed in the working section and at strategic points.
When needed, the Portable Fresh Air Bay is connected to a compressed air source, breathing air bottle or convective oxygen regenerator and inflates in minutes.
A constant air flow forces out all noxious gases, making it safe for miners to enter and remain in the chamber until rescued. Depending on the size of the air source and equipment, the chamber would be safe for a minimum of 24 hours, Strata Products says.
The size of the chambers ranges from a 5-man to a 15-man unit, and Strata Products recommends the oxygen sources and chambers undergo maintenance annually.
The bay costs about $500 per person, with a total cost of about $1000/person. Strata Products is currently in discussion with MSHA to get the bay approved for underground coal mines.