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  Single-point Adjustable
Single-point AdjustableA single-point adjustable scaffold consists of a platform suspended by one rope from an overhead support and equipped with means to permit the movement of the platform to desired work levels. The most common among these is the scaffold used by window washers to clean the outside of a skyscraper (also known as a boatswain's chair). Note: The requirements on this page are specific to single-point adjustable scaffolds only. For requirements that apply to all types of suspended scaffolds, please refer to the Two-point (swing stage) module of this eTool.

General Requirements
  • The supporting rope between the scaffold and the suspension device must be kept vertical unless:
  • When combining two single-point scaffolds to form a two-point suspension system, the resulting scaffold must comply with 1926.452(p) requirements. [1926.452(o)(1)]


Non-mandatory Guidelines


Boatswain's Chairs
  • Boatswain's chair tackle must consist of:

    • Correct-size ball bearings or bushed blocks containing safety hooks, and

    • Properly eye-spliced first-grade manila rope, or other rope of equivalent strength, durability, etc. [1926.452(o)(3)].

  • Seat slings must:

    • Pass through four corner holes in the seat,

    • Cross on the underside of the seat,

    • Be rigged to prevent slippage which could cause the chair to be out-of-level [1926.452(o)(4)], and

    • Be at least 5/8-inch diameter fiber, synthetic, or other first-grade manila rope of equivalent criteria (strength, slip resistance, durability, etc.). [1926.452(o)(5)]

  • Seat slings used for gas or arc welding must be made of at least 3/8-inch wire rope. [1926.452(o)(6)]

  • Non-cross-laminated wood chairs must be reinforced on the underside with cleats to keep the board from splitting. [1926.452(o)(7)]

Non-mandatory guidelines from Subpart L Appendix A:

  • Wood seats for boatswain's chairs must be:

    • Not less than 1 inch thick (if made of non-laminated wood), or

    • 5/8-inch thick (if made of marine-quality plywood). [1926 Subpart L Appendix A (o)]
 
 
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