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Subchapter 4. Construction Safety Orders
Article 23. Suspended Scaffolds
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§1662. Boatswains' Chairs.

(a) Persons shall be trained and/or experienced in the use of boatswains' chairs before being permitted to use such equipment.

(b) When a boatswains' chair is suspended over an area traversed by employees, pedestrians or vehicular traffic, the ground area immediately below shall be effectively blocked by barricades, or an attendant shall be stationed to keep the area clear. Warnings signs shall also be posted below.

(c) An employee using a boatswains' chair shall wear a safety belt with attached lanyard secured to a separate drop line or other means affording equivalent safety.

(d) Rope attachment to a block shall be by a thimble and splice.

(e) Hooks shall be provided with a means to prevent accidental disengagement or a shackle shall be used in place of a hook.

(f) Each double block of luff (or watch) tackle shall be branded or otherwise clearly marked so as to indicate the fully extended length in feet from block to block. A knot or splice shall be made in the end of the line to prevent it from running through the block.

(g) Thimbles shall not be used where the chair connects to the hook.

(h) Tackle shall consist of rope equivalent in strength to at least 5/8 inch rope of first grade Manila as well as properly-sized blocks.

(i) The chair shall be suspended from its four corners by means of rope slings. It shall have a seat not less than 24 inches long by 10 inches wide and, if of soft wood, 2 inches thick (1 1/8 inches if of oak or ash). It shall be reinforced across the full width by cleats securely fastened to each end. The seat may be constructed of material other than wood, provided the material used is equivalent in strength to 2 inches of soft wood or 1 1/8 inches of oak or ash. If constructed of material of equivalent strength, cleats across the full width of the seat shall be provided unless structural analysis indicates that they are not necessary. Other design and construction of equivalent safety and strength may be substituted.

(j) Boatswains' chairs with fiber rope slings shall not be used to support an employee with welding, burning torch, sandblasting equipment, or chemicals harmful to fiber rope. In such cases, the slings shall be at least 3/8 inch wire rope, or equivalent. Further, the wire rope shall be protected against burning or welding arc by covering with a rubber hose or other equally effective means.



(k) Fiber rope seat slings shall be of 5/8 inch Manila rope, or equivalent, reeved through the four seat holes so as to cross each other on the underside of the seat.

(l) Boatswains' chairs, their supports and all accessories shall be capable of supporting, without failure, at least 4 times the maximum load.

(m) Parapet or cornice hooks or clamps used to support chairs shall be provided with rings for tie-back use.


Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Amendment filed 11-14-75; effective thirtieth day thereafter (Register 75, No. 6).

2. Amendment of subsection (b) filed 4-27-79; effective thirtieth day thereafter (Register 79, No. 17).

3. Renumbering and amendment of former Section 1662 to Section 1667, and renumbering and amendment of Section 1651 to Section 1662 filed 7-24-87; operative 8-23-87 (Register 87, No. 33).

4. Change without regulatory effect amending ``Moused Hook” graphic in subsection (j) filed 6-25-2001 pursuant to section 100, title 1, California Code of Regulations (Register 2001, No. 26).

5. Change without regulatory effect repealing and adopting new illustration within subsection (j) filed 5-19-2008 pursuant to section 100, title 1,California Code of Regulations (Register 2008, No. 21).

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