Occupational Safety and Health Admin, Labor § 191029 by ps94506


									Occupational Safety and Health Admin., Labor                                    § 1910.29

driven through and clinched on the un-        rigged lines, which will safely suspend
derside. The crawling board shall ex-         the workman in case of a fall.
tend from the ridge pole to the eaves           (v) Scope. This section establishes
when used in connection with roof con-        safety requirements for the construc-
struction, repair, or maintenance.            tion, operation, maintenance, and use
  (2) A firmly fastened lifeline of at        of scaffolds used in the maintenance of
least three-quarter-inch rope shall be        buildings and structures.
strung beside each crawling board for a       [39 FR 23502, June 27, 1974, as amended at 43
handhold.                                     FR 49746, Oct. 24, 1978; 49 FR 5321, Feb. 10,
  (3) Crawling boards shall be secured        1984; 53 FR 12121, Apr. 12, 1988]
to the roof by means of adequate ridge
hooks or equivalent effective means.          § 1910.29 Manually propelled mobile
  (u) Float or ship scaffolds. (1) Float or         ladder stands and scaffolds (tow-
ship scaffolds shall support not more               ers).
than three men and a few light tools,            (a) General requirements—(1) Applica-
such as those needed for riveting, bolt-      tion. This section is intended to pre-
ing, and welding. They shall be con-          scribe rules and requirements for the
structed in accordance with paragraphs        design, construction, and use of mobile
(u) (2) through (6) of this section, un-      work       platforms  (including   ladder
less substitute designs and materials         stands but not including aerial ladders)
provide equivalent strength, stability,       and rolling (mobile) scaffolds (towers).
and safety.                                   This standard is promulgated to aid in
  (2) The platform shall be not less          providing for the safety of life, limb,
than 3 feet wide and 6 feet long, made        and property, by establishing minimum
of three-quarter-inch plywood, equiva-        standards for structural design require-
lent to American Plywood Association          ments and for the use of mobile work
Grade B–B, Group I, Exterior.                 platforms and towers.
  (3) Under the platform, there shall be         (2) Working loads. (i) Work platforms
two supporting bearers made from 2- x         and scaffolds shall be capable of car-
4-inch, or 1- x 10-inch rough, selected       rying the design load under varying
lumber, or better. They shall be free of      circumstances depending upon the con-
knots or other flaws and project 6            ditions of use. Therefore, all parts and
inches beyond the platform on both            appurtenances necessary for their safe
sides. The ends of the platform shall         and efficient utilization must be inte-
extend about 6 inches beyond the outer        gral parts of the design.
edges of the bearers. Each bearer shall          (ii) Specific design and construction
be securely fastened to the platform.         requirements are not a part of this sec-
  (4) An edging of wood not less than 3⁄4     tion because of the wide variety of ma-
x 11⁄2 inches, or equivalent, shall be        terials and design possibilities. How-
placed around all sides of the platform       ever, the design shall be such as to
to prevent tools from rolling off.            produce a mobile ladder stand or scaf-
  (5) Supporting ropes shall be 1-inch        fold that will safely sustain the speci-
diameter manila rope or equivalent,           fied loads. The material selected shall
free from deterioration, chemical dam-        be of sufficient strength to meet the
age, flaws, or other imperfections.           test requirements and shall be pro-
Rope connections shall be such that           tected against corrosion or deteriora-
the platform cannot shift or slip. If two     tion.
ropes are used with each float, each of          (a) The design working load of ladder
the two supporting ropes shall be             stands shall be calculated on the basis
hitched around one end of a bearer and        of one or more 200-pound persons to-
pass under the platforms to the other         gether with 50 pounds of equipment
end of the bearer where it is hitched         each.
again, leaving sufficient rope at each           (b) The design load of all scaffolds
end for the supporting ties.                  shall be calculated on the basis of:
  (6) Each workman shall be protected
                                                Light— Designed and constructed to carry
by a safety lifebelt attached to a life-      a working load of 25 pounds per square foot.
line. The lifeline shall be securely at-        Medium— Designed and constructed to
tached to substantial members of the          carry a working load of 50 pounds per square
structure (not scaffold), or to securely      foot.

§ 1910.29                                            29 CFR Ch. XVII (7–1–99 Edition)
  Heavy— Designed and constructed to carry     have a standard (4-inch nominal)
a working load of 75 pounds per square foot.   toeboard.
All ladder stands and scaffolds shall be         (vii) All work levels 10 feet or higher
capable of supporting at least four            above the ground or floor shall have a
times the design working load.                 guardrail of 2- by 4-inch nominal or the
  (iii) The materials used in mobile           equivalent installed no less than 36
ladder stands and scaffolds shall be of        inches or more than 42 inches high,
standard manufacture and conform to            with a mid-rail, when required, of 1- by
standard specifications of strength, di-       4-inch nominal lumber or equivalent.
mensions, and weights, and shall be se-          (viii) A climbing ladder or stairway
lected to safely support the design            shall be provided for proper access and
working load.                                  egress, and shall be affixed or built into
  (iv) Nails, bolts, or other fasteners        the scaffold and so located that its use
used in the construction of ladders,           will not have a tendency to tip the
scaffolds, and towers shall be of ade-         scaffold. A landing platform shall be
quate size and in sufficient numbers at        provided at intervals not to exceed 30
each connection to develop the de-             feet.
signed strength of the unit. Nails shall         (4) Wheels or casters. (i) Wheels or
be driven full length. (All nails should       casters shall be properly designed for
be immediately withdrawn from dis-             strength and dimensions to support
mantled lumber.)                               four (4) times the design working load.
  (v) All exposed surfaces shall be free
                                                 (ii) All scaffold casters shall be pro-
from sharp edges, burrs or other safety
                                               vided with a positive wheel and/or
                                               swivel lock to prevent movement. Lad-
  (3) Work levels. (i) The maximum
                                               der stands shall have at least two (2) of
work level height shall not exceed four
(4) times the minimum or least base di-        the four (4) casters and shall be of the
mensions of any mobile ladder stand or         swivel type.
scaffold. Where the basic mobile unit            (iii) Where leveling of the elevated
does not meet this requirement, suit-          work platform is required, screw jacks
able outrigger frames shall be em-             or other suitable means for adjusting
ployed to achieve this least base di-          the height shall be provided in the base
mension, or provisions shall be made to        section of each mobile unit.
guy or brace the unit against tipping.           (b) Mobile tubular welded frame scaf-
  (ii) The minimum platform width for          folds—(1) General. Units shall be de-
any work level shall not be less than 20       signed to comply with the require-
inches for mobile scaffolds (towers).          ments of paragraph (a) of this section.
Ladder stands shall have a minimum               (2) Bracing. Scaffolds shall be prop-
step width of 16 inches.                       erly braced by cross braces and/or di-
  (iii) The supporting structure for the       agonal braces for securing vertical
work level shall be rigidly braced,            members together laterally. The cross
using adequate cross bracing or diago-         braces shall be of a length that will
nal bracing with rigid platforms at            automatically      square    and     align
each work level.                               vertical members so the erected scaf-
  (iv) The steps of ladder stands shall        fold is always plumb, square, and rigid.
be fabricated from slip resistant treads.        (3) Spacing. Spacing of panels or
  (v) The work level platform of scaf-         frames shall be consistent with the
folds (towers) shall be of wood, alu-
                                               loads imposed. The frames shall be
minum, or plywood planking, steel or
                                               placed one on top of the other with
expanded metal, for the full width of
                                               coupling or stacking pins to provide
the scaffold, except for necessary open-
ings. Work platforms shall be secured          proper vertical alignment of the legs.
in place. All planking shall be 2-inch           (4) Locking. Where uplift may occur,
(nominal) scaffold grade minimum 1,500         panels shall be locked together
f. (stress grade) construction grade           vertically by pins or other equivalent
lumber or equivalent.                          means.
  (vi) All scaffold work levels 10 feet or       (5) Erection. Only the manufacturer of
higher above the ground or floor shall         a scaffold or his qualified designated

Occupational Safety and Health Admin., Labor                                 § 1910.29

agent shall be permitted to erect or su-      shall be designed so that the horizontal
pervise the erection of scaffolds exceed-     bearers provide supports for multiple
ing 50 feet in height above the base, un-     planking levels.
less such structure is approved in writ-        (7) Erection. Only the manufacturer of
ing by a registered professional engi-        the scaffold or his qualified designated
neer, or erected in accordance with in-       agent shall be permitted to erect or su-
structions furnished by the manufac-          pervise the erection of scaffolds exceed-
turer.                                        ing 50 feet in height above the base, un-
  (c) Mobile tubular welded sectional         less such structure is approved in writ-
folding scaffolds—(1) General. Units in-      ing by a licensed professional engineer,
cluding sectional stairway and sec-           or erected in accordance with instruc-
tional ladder scaffolds shall be de-          tions furnished by the manufacturer.
signed to comply with the require-              (d) Mobile tube and coupler scaffolds—
ments of paragraph (a) of this section.       (1) Design. Units shall be designed to
  (2) Stairway. An integral stairway          comply with the applicable require-
and work platform shall be incor-             ments of paragraph (a) of this section.
porated into the structure of each sec-         (2) Material. The material used for
tional folding stairway scaffold.             the couplers shall be of a structural
  (3) Bracing. An integral set of piv-        type, such as a drop-forged steel, mal-
oting and hinged folding diagonal and         leable iron or structural grade alu-
horizontal braces and a detachable            minum. The use of gray cast iron is
work platform shall be incorporated           prohibited.
into the structure of each sectional            (3) Erection. Only the manufacturer of
folding ladder scaffold.                      the scaffold or his qualified designated
  (4) Sectional folding stairway scaffolds.   agent shall be permitted to erect or su-
Sectional folding stairway scaffolds          pervise the erection of scaffolds exceed-
shall be designed as medium duty scaf-        ing 50 feet in height above the base, un-
folds except for high clearance. These        less such structure is approved in writ-
special base sections shall be designed       ing by a licensed professional engineer,
as light duty scaffolds. When upper sec-      or erected in accordance with instruc-
tional folding stairway scaffolds are         tions furnished by the manufacturer.
used with a special high clearance base,        (e) Mobile work platforms—(1) Design.
the load capacity of the entire scaffold      Units shall be designed for the use in-
shall be reduced accordingly. The             tended and shall comply with the re-
width of a sectional folding stairway         quirements of paragraph (a) of this sec-
scaffold shall not exceed 41⁄2 feet. The      tion.
maximum length of a sectional folding           (2) Base width. The minimum width of
stairway scaffold shall not exceed 6          the base of mobile work platforms shall
feet.                                         not be less than 20 inches.
  (5) Sectional folding ladder scaffolds.       (3) Bracing. Adequate rigid diagonal
Sectional folding ladder scaffolds shall      bracing to vertical members shall be
be designed as light duty scaffolds in-       provided.
cluding special base (open end) sections        (f) Mobile ladder stands—(1) Design.
which are designed for high clearance.        Units shall comply with applicable re-
For certain special applications the          quirements of paragraph (a) of this sec-
six-foot (6′) folding ladder scaffolds, ex-   tion.
cept for special high clearance base            (2) Base width. The minimum base
sections, shall be designed for use as        width shall conform to paragraph
medium duty scaffolds. The width of a         (a)(3)(i) of this section. The maximum
sectional folding ladder scaffold shall       length of the base section shall be the
not exceed 41⁄2 feet. The maximum             total length of combined steps and top
length of a sectional folding ladder          assembly, measured horizontally, plus
scaffold shall not exceed 6 feet 6 inches     five-eighths inch per step of rise.
for a six-foot (6′) long unit, 8 feet 6         (3) Steps. Steps shall be uniformly
inches for an eight-foot (8′) unit or 10      spaced, and sloped, with a rise of not
feet 6 inches for a ten-foot (10′) long       less than nine (9) inches, nor more than
unit.                                         ten (10) inches, and a depth of not less
  (6) End frames. The end frames of sec-      seven (7) inches. The slope of the steps
tional ladder and stairway scaffolds          section shall be a minimum of fifty-

§ 1910.30                                             29 CFR Ch. XVII (7–1–99 Edition)

five (55) degrees and a maximum of               (3) Wood platforms used on the floor
sixty (60) degrees measured from the           in front of machines shall be substan-
horizontal.                                    tially constructed.
  (4) Handrails. (i) Units having more           (c) Veneer machinery. (1) Sides of
than five (5) steps or 60 inches vertical      steam vats shall extend to a height of
height to the top step shall be equipped       not less than 36 inches above the floor,
with handrails.                                working platform, or ground.
  (ii) Handrails shall be a minimum of           (2) Large steam vats divided into sec-
29 inches high. Measurements shall be          tions shall be provided with substantial
taken vertically from the center of the        walkways between sections. Each
step.                                          walkway shall be provided with a
  (5) Loading. The load (see paragraph         standard handrail on each exposed side.
(a)(2)(ii)(a) of this section) shall be ap-    These handrails may be removable, if
plied uniformly to a 31⁄2 inches wide          necessary.
area front to back at the center of the          (3) Covers shall be removed only from
width span with a safety factor of four        that portion of steaming vats on which
(4).                                           men are working and a portable railing
                                               shall be placed at this point to protect
§ 1910.30 Other working surfaces.              the operators.
                                                 (4) Workmen shall not ride or step on
   (a) Dockboards (bridge plates). (1) Port-   logs in steam vats.
able and powered dockboards shall be
strong enough to carry the load im-            [39 FR 23502, June 27, 1974, as amended at 49
posed on them.                                 FR 5322, Feb. 10, 1984; 61 FR 9235, Mar. 7, 1996]
   (2) Portable dockboards shall be se-
cured in position, either by being an-             Subpart E—Means of Egress
chored or equipped with devices which
will prevent their slipping.                     AUTHORITY: Sections 4, 6, and 8 of the Occu-
   (3) Powered dockboards shall be de-         pational Safety and Health Act of 1970 (29
signed and constructed in accordance           U.S.C. 653, 655, 657); Secretary of Labor’s
                                               Order No. 12–71 (36 FR 8754), 8–76 (41 FR
with Commercial Standard CS202–56              25059), 9–83 (48 FR 35736), or 1–90 (55 FR 9033),
(1961) ‘‘Industrial Lifts and Hinged           as applicable.
Loading Ramps published by the U.S.
Department of Commerce, which is in-           § 1910.35 Definitions.
corporated by reference as specified in           As used in this subpart.
§ 1910.6.                                         (a) Means of egress. A means of egress
   (4) Handholds, or other effective           is a continuous and unobstructed way
means, shall be provided on portable           of exit travel from any point in a build-
dockboards to permit safe handling.            ing or structure to a public way and
   (5) Positive protection shall be pro-       consists of three separate and distinct
vided to prevent railroad cars from            parts: the way of exit access, the exit,
being moved while dockboards or                and the way of exit discharge. A means
bridge plates are in position.                 of egress comprises the vertical and
   (b) Forging machine area. (1) Machines      horizontal ways of travel and shall in-
shall be so located as to give (i) enough      clude intervening room spaces, door-
clearance between machines so that             ways, hallways, corridors, passage-
the movement of one operator will not          ways, balconies, ramps, stairs, enclo-
interfere with the work of another, (ii)       sures, lobbies, escalators, horizontal
ample room for cleaning machines and           exits, courts, and yards.
handling the work, including material             (b) Exit access. Exit access is that por-
and scrap. The arrangement of ma-              tion of a means of egress which leads to
chines shall be such that operators will       an entrance to an exit.
not stand in aisles.                              (c) Exit. Exit is that portion of a
   (2) Aisles shall be provided of suffi-      means of egress which is separated
cient width to permit the free move-           from all other spaces of the building or
ment of employees bringing and remov-          structure by construction or equip-
ing material. This aisle space is to be        ment as required in this subpart to pro-
independent of working and storage             vide a protected way of travel to the
space.                                         exit discharge.


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