Parachute-type Stoppings - USBM Develops Different Designs for Day- to-day and Emergency Ventilation Control.
Eng and Min J 1979 Feb; :91-94
A parachute-type stopping intended for changing the course of mine ventilation air during mine emergencies has been designed and tested. Some production uses are also visualized for metal mines. Preliminary tests in the laboratory and underground indicate that the parachute stopping is a workable concept, but further developmental research is required.
Eng. and Min. J., February 1979, PP. 91-94