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NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

December 2, 1983

George N. Hailey, Jr.
W. S. Bellows Construction Corp.
P. O. Box 2132
Houston, Texas 77001

Dear Mr. Hailey:

This is in response to your letter addressed to OSHA's Area Director in Houston, Texas, dated October 7, 1983, requesting an interpretation of the term "closed hook" in OSHA Instruction STD 1-11.2B, paragraph F.2.c.

The Lifting Bridle Requirements in the above-referenced instruction refer to working platforms suspended from cranes used to hoist and suspend employees in unique work situations, when such action would result in the least hazardous exposure to employees. In order to permit employers to use crane-suspended work platforms, OSHA has determined that certain conditions must be met to ensure a greater degree of protection for employees. The lifting bridle on working platforms suspended from cranes for employee access or egress must be secured by a shackle or attached by a closed hook which cannot open due to the load position in the hook. Experience has shown that spring loaded safety latches can open with certain changes in the load position in the hook. Therefore, spring loaded safety latched hooks are not considered "closed hooks" for hoisting and suspending employees on a work platform.

There are available and in use hooks that can be closed and locked which will not allow the load to escape should the load position shift in the hook. Use of this type of hook or of a shackle will ensure controlled conditions to permit employee hoisting.

The requirements set forth in OSHA Instruction STD 1-11.2B are designed to further the protection of employees working on platforms suspended from cranes, and the proposed standard 29 CFR 1926.550(g) will reflect these attachment requirements.

If we can be of further assistance, please let us know.


John B. Miles, Jr., Director
Directorate of Field Operations