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• Standard Number: 1910.66

June 16, 1988

Mr. Michael S. Hug
Smallwood, Reynolds, Stewart
Stewart and Associates, Inc.
One Piedmont Center, Suite 303
3565 Piedmont Road
Atlanta, Georgia 30305

Dear Mr. Hug:

This is in response to your letter of April 4, 1988, concerning a telephone conversation with Mr. Bode, a member of my staff. Your letter describes your understanding of the conversation regarding the C&S Plaza building in Columbia, South Carolina.

The apparent concern relative to servicing the building stems from an inability to rig service platforms at the roof level. However, there is roof access enough to mount davits and or outriggers and to gain access to work platforms by workers.

Unfortunately, there appear to be several misunderstandings. This is intended to clarify the issues discussed.
1. A 17-story building is approximately 170 feet tall and is therefore in excess of the height which should be serviced from a ground-rigged suspended working platform. (Ref. ANSI/ASME A39.1-1987, Section 10.4.3(b), portion enclosed.)
Buildings greater than 130 feet in height should be serviced from powered platforms and if no direct access is possible for rigging at the roof level, then the powered platform can be rigged and accessed at ground level if exterior building guides are provided throughout the entire lift. Such powered platforms are regulated at 29 CFR 1910.66 with additional guidance available in ANSI A120.1-1970.

Should it be feasible to suspend cables from the roof support systems to ground level and then remotely elevate and unmanned platform system to a roof access location, a system of intermittent stabilization could provide for worker safety during the subsequent occupied descent and ascent of the platform system. The proposed system would then be remotely lowered to ground level in the unoccupied mode. OSHA does not propose that this is a desirable concept, it only provides an interpretation of its acceptability under the regulations.
2. Your understanding expressed by paragraph 2. is correct regarding OSHA Instruction STD 1-3.3 CH-1.

3. OSHA requires that all workers at elevated locations exposed to falls be protected by personal protective equipment in the form of a lifeline and harness. (Ref. OSHA Instruction STD 1.1.13, copy enclosed.) Such equipment must be attached at all times when workers leave the protected areas of balconies, and at all times while occupying scaffold platforms.
It is necessary for safety drop lines (lifelines) to be completely separate from the scaffold support system and the anchorages must be capable of supporting at least 5400 pounds per worker attached.

The ANSI/ASME A39.1-1987, section 10.4.2(a), requires that single point suspended working platforms be equipped with a secondary wire rope separate from the suspension rope to support the platform should there be a failure of the primary means of support. A lifeline is in addition to this requirement.
4. OSHA has no specific requirements concerning the use of an unmanned stage so long as workers are not exposed to hazards resulting from its use.
If we may be of further assistance, please contact us.

Sincerely,



Thomas J. Shepich, Director
Directorate of Compliance Programs

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