1997-04-30_GENERAL DOCUMENTS - C1981013

• Permit No: C1981013
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Date: 4/30/1997
• Doc Name: Letter Enclosing Information on Vent Shaft and Mine Progress
• From: DMG
• To: John Toupal
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY PFV7,
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Department of Natural Resources
1313 Sherman St.,Room 215
Denver,Colorado 80203
Phone:[phone] V011A
FAX:[phone]
DEPARTMENT OF
NATURAL
RESOURCES
April 30, 1997 Roy Romer
Governor
James S.Lochhead
Executive Director
Mr. John Toupal Michael B.Long
14900 Highway 12 Division Director
Weston, CO 81091
RE: Ventilation Airshaft and Mine Progress Request
Golden Eagle Mine, #C-81-013
Dear Mr. Toupal:
Enclosed please find information on file with the Division of Minerals and Geology with regard
to the Third North Ventilation shaft and mine progress at the Golden Eagle mine.
I reviewed Technical Revision# 8 (TR-08), Technical Revision#14(TR-14), Technical Revision
#30 (TR-30), Mine Plan Map 3 (revised 3/24/93), and the Subsidence Monitoring file containing
subsidence monitoring data. The results of this review are as follows:
1. The Third North Intake shaft was constructed to provide an opening where fresh
air could enter the mine workings. Intake fans bring air into the mine, as opposed
to exhaust fans, which blow mine air to the atmosphere. The Third North Intake
fan was also a point of emergency exit for the miners. This makes sense, as an
emergency escapeway needs to be a corridor where fresh air would always be
available, rather than exhaust air which could contain smoke and other toxic gases.
Intake fans openings are also normally larger, as evidenced by this shaft and it's
16 foot, finished diameter.
To construct a mine opening of this diameter, a small diameter (typically 12 inch)
hole is drilled to penetrate existing mine workings below. Then, a large reamer
bit is attached from within the mine workings and the bit is raised toward the
surface, with the excavated material falling into the workings, where it is removed
and stored underground or brought to the surface to a mine waste pile. The point
of this discussion is that in order to conduct this activity, underground mine
workings must be established below the point on the surface where the intake fan
will be placed. The activity to drill this large shaft was approved by the Division