75.221—Roof control plan information.
(ii)
Identify the type and show the thickness of each stratum up to and including the main roof above the coalbed and for distance of at least 10 feet below the coalbed; and
(5)
A description and drawings of the sequence of installation and spacing of supports for each method of mining used.
(6)
When an ATRS system is used, the maximum distance that an ATRS system is to be set beyond the last row of permanent support.
(7)
When tunnel liners or arches are to be used for roof support, specifications and installation procedures for the liners or arches.
(8)
Drawings indicating the planned width of openings, size of pillars, method of pillar recovery, and the sequence of mining pillars.
(9)
A list of all support materials required to be used in the roof, face and rib control system, including, if roof bolts are to be installed—
(10)
When mechanically anchored tensioned roof bolts are used, the intervals at which test holes will be drilled.
(b)
Each drawing submitted with a roof control plan shall contain a legend explaining all symbols used and shall specify the scale of the drawing which shall not be less than 5 feet to the inch or more than 20 feet to the inch.
(c)
All roof control plan information, including drawings, shall be submitted on 8 1/2 by 11 inch paper, or paper folded to this size.