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Subchapter 7. General Industry Safety Orders
Group 13. Cranes and Other Hoisting Equipment
Article 96. Tower Cranes
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§4966. Erection, Dismantling and Operation.

(a) Erection and Dismantling.

(1) The erection, climbing (up and down) and dismantling of a fixed tower crane shall comply with the requirements of Title 8, Section 341.1(b)(2).

(A) Employees engaged in the erection and/or dismantling of tower cranes and the inspection, maintenance or repair related to such erection and/or dismantling, when working at elevations 15 feet or greater over ground or other surfaces shall be required to use fall protection as specified in Article 24 of the Construction Safety Orders.

(2) Guys, braces and other supports shall be employed as necessary to prevent damage or collapse of the equipment during the erection and dismantling procedures.

(b) The unbraced, free standing portion of the mast between the boom and the top support position shall be limited in height to the distance recommended by the certified agent.

(c) When the certified agent requires the mast to be secured in the shaftway of a structure, the structural members to which it is secured shall be adequate to safely sustain all anticipated loads including vibration.

(d) Where the vertical load of the crane assembly is supported by the edges of floor openings of a structure, measures shall be taken to prevent structural damage of such support.

(e) When the mast sections are raised to a new position, measures shall be taken to prevent damage or collapse of the crane assembly including vertical slippage of the mast unit.

(f) Load Limit Device.

(1) The load limit device shall be in effective operation and shall not be readjusted to handle loads greater than those specified by the certified agent.

(2) In addition to the requirements of Section 5000, whenever a load limit device is unsealed, repaired, or readjusted, a qualified person shall perform any testing necessary to ensure the continuing effective operation of the device. A test load or device capable of measuring 110 percent of the certified agent's load capacity shall be available at the job site.

(g) The load line shall be directly over the load to be lifted.

(h) The operator shall be stationed in a safe position where good visibility and control can be maintained.


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


1. New section filed 8-29-86; effective thirtieth day thereafter (Register 86, No. 39).

2. Amendment of subsection (a)(1) filed 4-16-93; operative 5-17-93 (Register 93, No. 16).

3. New subsection (a)(1)(A) filed 5-18-93; operative 6-17-93 (Register 93, No. 21).

4. Amendment of subsection (a)(1) filed 8-21-2000; operative 9-20-2000 (Register 2000, No. 34).

5. Amendment of subsection (a)(1) filed 1-3-2002; operative 2-2-2002 (Register 2002, No. 1).