Multiple-lift rigging of precast concrete joists

OSHA archive notice: "This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only."

August 20, 2000

Mr. Daniel Rodriguez

Director of Safety

Prestress Systems of Florida

[Recipient address omitted]

Dear Mr. Rodriguez:

This is in response to your letter of January 20 in which you request an interpretation on christmas treeing of reinforced precast keystone joists. In your letter, you request an interpretation that would allow christmas treeing of reinforced precast keystone joists in the same manner as steel members, following the criteria in §1926.753(c) of the proposed steel erection standard.

As you are aware, OSHA published the proposed steel erection rule on August 13, 1998. In that proposed rule, §1926.753(c) provides criteria for performing a "Multiple Lift Rigging Procedure (MLRP)" (also known as "christmas treeing") for steel members. The proposed paragraph was developed through negotiated rulemaking and subsequent formal OSHA rulemaking. The Steel Erection Negotiated Rulemaking Advisory Committee (SENRAC) spent countless hours developing criteria specifically for christmas treeing steel beams based on extensive industry experience with multiple lifts. ~~Under OSHA Steel Erection Directive 00-03 (CPL 2-1), issued February 11, 2000, employers are permitted to christmas tree steel members using these procedures if they comply with the rest of the requirements of the proposed rule and the Directive.~~

[Correction 6/20/2005. See OSHA Directive CPL 02-01-034 "Inspection policy and procedures for OSHA's steel erection standards for construction" published on 3/22/2002 for the current policy on OSHA's steel erection standards (1926 Subpart R) for construction.]

Section 1926.550(a)(19) requires that "all employees shall be kept clear of loads about to be lifted and of suspended loads." As far as we are aware, by the nature of the christmas treeing process, exposure to the suspended load is unavoidable. While you indicate that your procedure would keep the employees "outside of the ends of the members," it is not clear to us how they could be far enough back from the ends for them to be clear of the multiple suspended load and still be able to do their work. We would consider any information you might have in this regard. If you can demonstrate that the employees would be out of the range of danger from a failure of the lift at all times, the lift would be permissible under §1926.550(a)(19). Note, however, that where use of a crane for a multiple lift is contrary to the crane manufacturer's specifications or limitations, §1926.550(a)(1) prohibits the use of such a crane for a multiple lift.

To the extent it is not possible to keep employees clear of the multiple load, any consideration by the Agency of a policy permitting christmas treeing of these precast joists would require, as a first step, detailed information demonstrating the similarity of the physical dynamics, processes and other factors involved with christmas treeing steel. At present, we do not have such information.

In sum, notwithstanding any apparent similarities, we cannot simply apply the proposed §1926.753 criteria to precast members without a complete evaluation of the nature of the hazards involved in christmas treeing precast members and the criteria needed.

If you require any further assistance, please do not hesitate to contact us again by writing to: U.S. Department of Labor, Directorate of Construction (OSHA), Office of Construction Standards and Compliance Assistance, 200 Constitution Avenue, N.W., Room N3468, Washington, D.C. 20210.

Sincerely,

Russell B. Swanson, Director

Directorate of Construction