30 CFR § 75.213
Roof support removal.
(a)(1) All persons who perform the work of removing permanent roof
supports shall be supervised by a management person experienced in removing
roof supports.
(2) Only persons with at least one year of underground
mining experience shall perform permanent roof support removal work.
(b) Prior to the removal of permanent roof supports, the person
supervising roof support removal in accordance with paragraph (a)(1) of this
section shall examine the roof conditions in the area where the supports are
to be removed and designate each support to be removed.
(c)(1) Except as provided in paragraph (g) of this section, prior to the
removal of permanent supports, a row of temporary supports on no more than
5-foot centers or equivalent support shall be installed across the opening
within 4 feet of the supports being removed. Additional supports shall be
installed where necessary to assure safe removal.
(2) Prior to the removal of roof bolts, temporary support
shall be installed as close as practicable to each roof bolt being
removed.
(d) Temporary supports installed in accordance with this section
shall not be removed unless--
(1) Removal is done by persons who are in a remote
location under supported roof; and
(2) At least two rows of temporary supports, set across
the opening on no more than 5-foot centers, are maintained between the miners
and the unsupported area.
(e) Each entrance to an area where supports have been removed shall
be posted with a readily visible warning or a physical barrier shall be
installed to impede travel into the area.
(f) Except as provided in paragraph (g) of this section, permanent
support shall not be removed where--
(1) Roof bolt torque or tension measurements or the
condition of conventional support indicate excessive loading;
(2) Roof fractures are present;
(3) There is any other indication that the roof is
structurally weak; or
(4) Pillar recovery has been conducted.
(g) Permanent supports may be removed provided that:
(1) Removal is done by persons who are in a remote
location under supported roof; and
(2) At least two rows of temporary supports, set across
the opening on no more than 5-foot centers, are maintained between the miners
and the unsupported area.
(h) The provisions of this section do not apply to removal of
conventional supports for starting crosscuts and pillar splits or lifts
except that prior to the removal of these supports an examination of the roof
conditions shall be made.
[55 FR 4595, Feb. 8, 1990]