It is method of extracting minerals from great depth. According to this method, a shaft is used to drill vertically, after which mining process is started
This section sets forth requirements for tunnel and shaft construction. It covers
the following specific areas:
• General Requirements
• Emergency Provisions
• Ventilation
• Air Quality
• Dust Control
• Internal Combustion Engines
• Noise Control
• Fire Prevention and Control
• Excavation Operations
• Ground Support
• Transportation and Haulage
• Shafts
• Tunneling in Soil
• Compressed Air Work
23.1 General Requirements for Tunnel and Shaft Construction
In addition to complying with the safety requirements set forth in this section and
other parts of these standards, comply with applicable provisions of the contract
when excavating and constructing tunnels and shafts. Begin underground-related
work only after an acceptable safety program or a detailed supplementary
submittal specific to underground operations has covered all aspects of the
operation.
23.1.1 Employee Identification. Entrances to all underground facilities must
have a check-in and checkout system that provides the contractor with an
accurate record of each person underground. The system must be able to
identify each individual and general location. General locations include
heading, train crew, track crew, maintenance area, storage area, survey
stations, etc. Additionally, when underground, all employees must carry or
wear a positive means of identification, such as a metal disk or tag.
23.1.2 Illumination. Underground lighting and illumination intensities must
adhere to the current ANSI/IES RP-7, "Recommended Practice for Industrial
Lighting" and UL 924, "Emergency Lighting and Power Equipment." Use
nonmetallic light fixtures and support lighting conductors on insulators
located on the side of the tunnel or shaft opposite the firing line. Use
acceptable portable lighting equipment within 50 feet of any underground
heading during explosives handling.