Standard Interpretations - Table of Contents|
| Standard Number:||1926.502(d)(8); 1926.502(b); 1926.251(c); 1926.760(d); 1926.502(d)(14); 1926.451(a); 1926.451(b); 1926.451(f); 1926.251(a)(4); 1926.451(d)(12); 1926.550(g)(4)(iv)(B) ; 1926.753(d); 1926.550(g) ; 1926.502(d)(15)|
|OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.|
Horizontal lifelines shall be designed, installed, and used, under the supervision of a qualified person, as part of a complete personal fall arrest system, which maintains a safety factor of at least two.Subpart M does not specify what type of wire rope clip or how many clips/clamps must be used when installing a horizontal lifeline. However, under §1926.502(d)(8), these decisions must be made under the supervision of a qualified person when the system is designed. The determination of the horizontal spacing criteria for uprights is also left to the qualified person's supervisory approval.1
Extreme care should be taken in considering a horizontal lifeline for multiple tie-offs. The reason for this is that in multiple tie-offs to a horizontal lifeline, if one employee falls, the movement of the falling employee and the horizontal lifeline during arrest of the fall may cause other employees to fall also. Horizontal lifeline and anchorage strength should be increased for each additional employee to be tied-off. For these and other reasons, the design of systems using horizontal lifelines must only be done by qualified persons.Although the possibility of one person falling may raise the risk of another person being pulled into a fall, it is not our position that the lifeline must necessarily be designed so that it can withstand a simultaneous fall by all the individuals tied-off to it. In assessing the total strength required for the lifeline, the qualified person must make a determination on the likelihood of simultaneous falls based on factors such as the type of walking/working surface the workers will be on, the length of their lanyards, and whether their work assignments call for them all to be near the edge at the same time.
Horizontal lifelines shall be designed, installed, and used, under the supervision of a qualified person, as part of a complete personal fall arrest system, which maintains a safety factor of at least two.Therefore, a qualified person is required to determine how tight the lifeline should be based on site-specific factors. No other requirements are imposed by OSHA regarding the tightness of the lifeline, so long as it comports with a safety factor of at least two.
Ropes and straps (webbing) used in lanyards, lifelines, and strength components of body belts and body harnesses shall be made from synthetic fibers.Therefore, the standard permits the use of synthetic rope (instead of wire rope) for a horizontal lifeline.
Scaffolds shall be designed by a qualified person and shall be constructed and loaded in accordance with that design. Non-mandatory Appendix A to this subpart contains examples of criteria that will enable an employer to comply with paragraph (a). [Emphasis added.]Section 1926.450(b) defines "qualified" as:
Qualified means one who, by possession of a recognized degree, certificate, or professional standing, or by extensive knowledge, training, and experience, has successfully demonstrated his/her ability to solve or resolve problems related to the subject matter, the work, or the project.The employer is responsible for designing and assembling components in such a way that the completed system will meet the requirements of §1926.451(a). Scaffold components which are not selected and loaded in accordance with this Appendix, and components for which no specific guidelines or tables are given in this Appendix, must be designed and constructed in accordance with the capacity requirements of §1926.451(a).
Scaffold components manufactured by different manufacturers shall not be intermixed unless the components fit together without force and the scaffold's structural integrity is maintained by the user. Scaffold components manufactured by different manufacturers shall not be modified in order to intermix them unless a competent person determines the resulting scaffold is structurally sound. [Emphasis added.]Section 1926.451(f) sets out requirements involving the use of the scaffold. Where scaffolding is erected, moved, dismantled, or altered, §1926.451(f)(7) provides:
Scaffolds shall be erected, moved, dismantled, or altered only under the supervision and direction of a competent person qualified in scaffold erection, moving, dismantling, or alteration. Such activities shall be performed only by experienced and trained employees selected for such work by the competent person. [Emphasis added.]A "competent person" is defined in §1926.450(b):
Competent person means one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them.When erecting the scaffold you describe, the employer must ensure that the scaffold has been designed by a qualified person and constructed and loaded in accordance with that design. If the designer requires the scaffold to be erected from the top down, then it must be erected in that manner. If the designer requires it to be erected from the bottom up, then that order must be followed. If the designer does not indicate one or the other order, then the competent person must determine whether the scaffold may be erected from the top down or the bottom up.
(4) Special custom design grabs, hooks, clamps, or other lifting accessories, for such units as modular panels, prefabricated structures and similar materials, shall be marked to indicate the safe working loads and shall be proof-tested prior to use to 125 percent of their rated load.The custom design lifting accessories you describe above must be tested and marked in accordance with §1926.251(a)(4) before being used.
eyes in wire rope bridles and slings or bull wires shall not be formed by wire rope clips or knots.This provision specifically prohibits eyes in wire rope bridles and slings or bull wires being formed by wire rope clips. There is no exception for lifting scrap boxes or pendants.
Each employer shall furnish to each of his employees employment and a place of employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.In our view, the industry recognizes that the following engineering factors, among others, must be considered when designing horizontal high-lines: the span and sag of the wire rope line, the weight of the load being lifted, the initial tension of the rope line, and the size of the columns.
Hooks on overhaul ball assemblies, lower load blocks, or other attachment assemblies shall be of a type that can be closed and locked, eliminating the hook throat opening. Alternatively, an alloy anchor type shackle with a bolt, nut and retaining pin may be used.This provision is intended to prevent personnel platforms from falling as a result of becoming accidentally unfastened from the hook.
Hooks with self-closing safety latches or their equivalent shall be used to prevent components from slipping out of the hook . . .This provision was intended to prevent the components from becoming accidentally unfastened from the hook and falling on the worker below. The preamble to the proposed rule explained that an "equivalent" device would include:
A hook with another type of closing device, i.e., a hook with a spring-loaded gate or another type of safety hook that would provide the same level of safety as a safety hook with a self-closing latch. (At 63 FR 43464, August 13, 1998.)Neither the personnel platform nor the steel erection/working under load requirement has an exception for large hooks - the requirements apply irrespective of the size of the hook. Also, there is no "grandfather" exception for older hooks without safety latches.
Wire rope shall not be secured by knots, except on haul back lines on scrapers.Knotting wire rope compromises the integrity of the strength of the wire rope and is therefore prohibited. Based on the picture provided, which showed a knot in wire rope secured by a U-bolt clip, this practice would be in violation of §1926.251(c)(3).
This standard applies to the design [and]* * * use of personnel platforms on the load lines of cranes or derricks and the hoisting of personnel platforms on the load lines of cranes or derricks.Section 1926.550(g)(6)(vii) provides:
Except over water, employees occupying the personnel platform shall use a body belt/harness system with lanyard appropriately attached to the lower load block or overhaul ball, or to a structural member within the personnel platform capable of supporting a fall impact for employees using the anchorage. When working over water, the requirements of §1926.106 shall apply. [Emphasis added.]In addition, §1926.550(4)(i) (Design Criteria)(C) notes in part:
* * *Section 1926.502(d)(15) of Subpart M states:
Criteria for guardrail and personal fall arrest system anchorages are contained in Subpart M [Fall Protection] of the Part. [Emphasis added.]
Anchorages used for attachment of personal fall arrest equipment shall be independent of any anchorage being used to support or suspend platforms and capable of supporting at least 5,000 pounds * * * per employee attached or shall be designed, installed, and used as follows: (i) as part of a complete personal fall arrest system which maintains a safety factor of at least two; and (ii) under the supervision of a qualified person.As you can see from the text of these provisions, §1926.550(g)(6)(vii) specifies the permissible locations of anchorage points - lower load block, overhaul ball, or the structural member within the personnel platform. Section 1926.502(d)(15) in Subpart M sets forth various criteria for anchorage points but does not establish a limit relative to the number of workers that can be attached to any one anchorage.
Anchorages used for attachment of personal fall arrest equipment shall be . . . capable of supporting at least 5,000 pounds per employee attached or shall be designed, installed, and used as follows: (i) as part of a complete personal fall arrest system which maintains a safety factor of at least two;[ back to text ]
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|Standard Interpretations - Table of Contents|