Current through Register Vol. 43, No. 02, November 27, 2024
(1)
Construction of Ladders - Except in the case of
swinging or extension ladders used for shaft sinking, all ladders and
ladderways shall be built of clear lumber free of knots or other imperfections
as prescribed below:
(a) The stringers of
ladders shall be built of not less than two by four (2 x 4) inch sound lumber
or its equivalent.
(b) The distance
between the centers of the rungs of a ladder shall not exceed twelve (12)
inches and shall not vary more than one (1) inch in any one ladderway. The
length of the ladder rungs (width of ladder) shall not be less than ten (10)
inches between stringers.
(c) The
back side of the rungs of a ladder shall in no case be less than six and
one-half (6 1/2) inches from any obstruction.
(2) Wooden ladder rungs shall be set in one
of the following ways:
(a) Flush with the
outer surface of the stringers.
(b)
Nailed on top of the stringer. If this is done, there shall be filler pieces
between the ends of the rungs. These filler pieces shall be the same width as
the stringer and the thickness of the rungs.
(c) Stringers bored through and round rungs
inserted and wedged.
(3)
Installation of Ladders - Platforms Required Every
main ladderway, such as those used in shafts, winzes, raises and those used in
second exits, having an inclination of more than 70^ from the horizontal, and
where the distance between the top and bottom of the ladderway is more than
thirty (30) feet, shall have substantial platforms at intervals of not more
than thirty (30) feet. If possible, the sections of the ladders shall be
staggered at each platform so that no section shall be directly in line with
the section above or below it.
(a) The
opening in any such platform shall be approximately twenty-four by twenty-four
(24 x 24) inches or larger, but no opening shall be of such size or dimension
as to retard the passing through thereof of rescue men equipped with oxygen
breathing apparatus.
(b) Ladders
shall project at least three and one-half (3 1/2) feet above every platform in
the ladderway and at least three and one-half (3 1/2) feet above the collar of
a shaft, winze or raise, unless convenient and secure hand holds are fixed at
such places.
(c) In ladderways,
other than main ladderways, the ladders may be fixed vertically, provided
platforms are installed at least every thirty (30) feet.
(d) All ladders shall be securely
fastened.
(e) Under no
circumstances shall any ladder inclining backward from the vertical be
installed or used.
(f) Ladderways
shall be maintained in safe condition, kept clear of loose rock and
obstructions and shall be inspected regularly to ascertain that such condition
exists.
(g) Ladders of metal or a
combination of metal and wood, of equivalent strength, installed in a safe
manner shall be satisfactory.
Author: Marcus Davis, Workers' Compensation
Examiner.
