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. 125 § 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 hazards. 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 126 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- 127 § 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. 128
"Occupational Safety and Health Admin, Labor § 191029"