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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.
Letter # 20051207-6795
Re: Whether a multiple lift of pre-cast concrete members is permissible
Question: Is 1926.753(e) of the steel erection standard applicable to hoisting pre-cast concrete members? Do OSHA construction standards permit multiple rigging lifts of pre-cast concrete members?
Answer: We understand your reference to "multiple rigging lifts" as a procedure in which several members are hoisted simultaneously on a single load line by a series of sequential attachment points (see illustrations of two different types of such lifts below):
29 CFR 1926.753(e), Multiple Lift Rigging Procedure, is in 1926 Subpart R, Steel Erection. As we noted in our August 23, 2005 letter to Mr. Leadbetter, the steel erection standard does not apply to the erection of pre-cast concrete members.1 Instead, 1926 Subpart Q, Concrete and Masonry Construction, applies to an employer engaged in pre-cast erection work. The cranes and derricks requirements in 1926 Subpart N also apply to hoisting precast concrete members.
Multiple lift rigging is, in effect, prohibited for activities other than steel erection by 29 CFR 1926.550(a)(19), which states:
All employees shall be kept clear of loads about to be lifted and of suspended loads.
During the multiple lift (or "christmas treeing") procedure, the hoisted members need to be attached to the rigging assembly beginning with the topmost attachment. That means that employees have to be under the already attached members while continuing the attachment process. Also, the hoisted members are detached from the assembly beginning with the bottom member, so employees are under the remaining members during the unhooking phase of the operation (see the description of this process in steel erection in Volume 66 of the Federal Register at page 5212, January 18, 2001). Consequently, the application of this procedure to pre-cast concrete erection during the initial rigging of the members onto the hoist line would violate 1926.550(a)(19).
In addition, a provision that applies specifically to concrete and masonry work is 29 CFR 1926.704(e), which states:
No employee shall be permitted under precast concrete members being lifted or tilted into position except those employees required for the erection of those members.
Since the pre-cast members can be lifted individually, rather than as part of a multiple lift rigging procedure, there is no need for employees engaged in rigging the members onto the hoist line to be under a load. Similarly, when placing a member individually, once the member nears its placement point, employees engaged in the erection process are typically no longer under the load. However, if a multiple lift rigging procedure is used, they would remain under the other members on the load line at that point. Therefore, using a multiple lift rigging procedure would violate 1926.704(e).
We note that the Steel Erection Negotiated Rulemaking Advisory Committee (SENRAC) developed the procedure in Subpart R specifically for steel erection.2 There has been no comparable OSHA rulemaking addressing multiple lift rigging for pre-cast concrete members.
If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.
Richard E. Fairfax, Acting Director
Directorate of Construction
1 Available on the OSHA website at: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=25128 [ back to text ]
2For example, SENRAC believed that the typical steel member in a multiple lift would weigh no more than 1800 pounds (see Volume 66 of the Federal Register at page 5211), which is considerably less than a typical pre-cast concrete member [ back to text ]