Mine Safety and Health Administration (MSHA) - Report of ...

elocated to crosscut 119 between the No. 1 and No. 2 entries. A fresh air base was established
at crosscut 119. A pager phone was connected between the clean-up area and the FAB. A
person was stationed at the FAB at all times to maintain communication with the clean-up area
and the command center on the surface.
The approved site specific plan also addressed the roof support system to be installed in the
clean-up area. As clean-up advanced in the No. 1 entry, additional roof and rib control measures
were implemented. The roof support portion of the plan required:
(A) As cleanup progresses roof support will be installed on 2.5' centers using rock props
[sic] or 8"x8" square sets on both sides of the entry. The square sets will be capped
with Jack Pots for active support.
(B) Screen mesh will be installed between the rib and the entry to confine rib roll and
protect employees and roadway.
(C) As each crosscut is completed 5/8" cable will be wrapped around these props to
secure them from pushing out.
Since 6 x 8-inch hard wood timbers were stronger and more immediately available than the
8 x 8-inch pine square sets specified in the plan, Item A was modified to include them at
1:05 p.m. on August 8, as follows:
(A) As cleanup progresses roof support will be installed on 2.5' centers using rock props
[sic] or 8"x8"pine square sets or, 6X8 hard wood with 8" dimension perpendicular to
the rib, on both sides of the entry. The square sets and the 6X8 hard wood will be
capped with Jack Pots for active support.
In addition to the items required for equipment setup, the initial plan listed several special
precautions:
(A) The continuous miner operator will be protected by a 4'x8' sheet of ½" thick Lexan
secured at top and bottom. Conveyer belting may be used in place of Lexan until
Lexan arrives.
(B) All unnecessary persons will be kept outby the fresh air base located at x-cut 119.
(C) Life Line will be maintained in the entry up to the continuous miner operator
location. Additional reflective tape will be added to life line.
(D) If mining conditions change significantly, mining will stop and the plan will be reevaluated
before mining resumes.
(E) Additional SCSRs will be stored at the fresh air base at x-cut 119; so that every
person inby x-cut 115 will have access to two SCSRs.
The roof had deteriorated between the No. 1 and No. 2 entries at crosscut 120. This area
extended from the No. 1 entry to the location of the feeder breaker in No. 2 entry and required
additional roof bolting before the area could be safely traveled. Thus additional mining
equipment, including a twin boom roof-bolting machine, had to be moved into the area.
As specified in the plan, pressurized roof-to-floor standing supports were installed along pillar
ribs for protection from pillar bursts. On August 8, 6 x 8-inch hardwood wood posts were
installed on both sides of the No. 1 entry beginning at crosscut 118, narrowing the roadway to
14 feet. These posts were capped with Jackpots to actively preload each support between the
roof and floor (see Figure 5). The wood posts were installed in the No. 1 entry to midway
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