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Subchapter 4. Construction Safety Orders
Article 23. Suspended Scaffolds
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§1660. Suspended Scaffolds for Loads of 425 Pounds or Less.

(a) Only one employee for each fall or hanger shall be allowed on this type of suspended scaffold. (See Plates B-24, B-26, B-26-a and B-27-a, Appendix).

EXCEPTION: Single, power-driven units described in Section 1667.

(b) Stirrups or slings shall be made of wire rope of at least 9,000 pounds breaking strength, or of solid round or square mild steel (reinforcing steel shall not be used) not less than 3/4 inch dimension, forged or welded into one piece. Loops in wire rope slings for the use of bolsters shall be spliced. The top loop shall have a galvanized thimble fastened in place with a clip.

(c) Bolsters shall be 2-inch by 4-inch "selected lumber," or stronger material, placed so that the 4-inch sides are vertical. An iron or steel bolt 6 inches long and 3/4 inch in diameter shall be fastened through wooden bolsters at right angles to same not nearer than 3 inches to the end to prevent sling from accidentally slipping off the end of bolster.

(d) Scaffold platforms shall be at least 14 inches wide. Planks of dressed 2-inch lumber shall consist of "structural plank" free from damage affecting its strength. Where platforms are composed of two 2-inch by 10-inch or two 2-inch by 12-inch dressed planks, side by side, they shall be firmly cleated together so as to act as a unit. Maximum platform width shall be 36 inches.

(e) The span between hangers or falls shall not be more than 10 feet when the planks are composed of two 2-inch by 10-inch planks or more than 12 feet when composed of two 2-inch by 12-inch planks as permitted in Subsection 1660 (d). The span between hangers or falls when being used with patented-type planks shall not exceed the manufacturer's specifications. The platform shall not extend beyond the hangers more than 18 inches. A bar or other effective means shall be securely fastened at each end of the platform to prevent it from slipping off the hanger.

(f) Ladder-Type and Needle Beam-Type Platforms.

(1) Platforms placed in service after April 18, 1999 shall Comply with the American National Standard (ANSI)Scaffolding-Safety Requirements A10.8-1988, which is hereby incorporated by reference. Patforms placed in service on or before April 17, 1999 shall comply with ANSI A10-1977, Safety Requirementsfor or before April 17, 1999 shall comply with ANSI A10.8-1977, Safety Requirements for Scaffolding, which is hereby incorporated by reference.

(2) Light metal-type platforms shall be approved.

(g) Each employee shall be provided with and use personal fall protection in accordance with the requirements of Article 24. Lanyards shall be securely attached to substantial members of the structure (not scaffold), or to securely rigged lines, which will safely suspend the employee in case of a fall. In order to keep the lanyard continuously attached, with a minimum of slack, to a fixed structure, the attachment point of the lanyard shall be appropriately changed as the work progresses.

(h) Hooks supporting scaffolds or stagings shall be made of mild steel (reinforcing steel shall not be used), free from flaws or other imperfections. Each hook shall, if loaded to point of failure, be capable of supporting a load 4 times that to which it will be subjected in service. The expected load per hook in service shall include its share (normally half) of the total scaffold and rigging weight plus the total weight of employees and movable tools or equipment, which shall never be considered as less than 500 pounds. All hooks shall be provided with rings for tie-back service. The ring should be fitted through a hole in the hook not more than 5 inches from the hook point. Hooks shall be kept clean at all times.

Each hook shall be tied back to a substantial object on the roof with at least a 3/4-inch diameter Manila rope or equivalent.

(i) Where the rope blocks supporting scaffolds or boatswains' chairs are not attached directly to hooks, the extension from the top block to the support shall be wire rope at least 1/2-inch in diameter, or equivalent, and sufficient protection shall be provided to prevent this wire rope from chafing.

The sheaves of all blocks, consisting of at least one double and one single block, shall fit the size and type of rope used.

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


1. Editorial correction in subsection (k) (Register 70, No. 48).

2. Amendment of subsection (g) filed 5-21-75; effective thirtieth day thereafter (Register 75, No. 21).

3. Amendment filed 11-14-75; effective thirtieth day thereafter (Register 75, No. 46).

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

5. Amendment filed 7-24-87; operative 8-23-87 (Register 87, No. 33).

6. Amendment of subsection (g) filed 7-2-98; effective 8-1-98 (Register 98, No. 5-Z).

7. Amendment of subsection (f)(1) filed 3-19-99; operative 4-18-99 (Register 99, No. 12).

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