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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, Climbing 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), Sections 5010 through 5010.3 and other provisions of these Safety Orders as applicable.
(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) Tower crane foundations and structural supports (including both the portions of the structure used for support and the means of attachment) shall be designed by a certified agent to prevent structural damage of such support.
(1) The controlling entity shall ensure the tower crane foundations and structural supports are installed in accordance with the manufacturer's or certified agent's instructions.
(2) The controlling entity shall provide a written statement of compliance with subsection (d)(1), to the erecting entity prior to erection or jump of the tower crane.
(3) The top of the support/foundation shall be accessible and free of debris, materials and standing water. No materials shall be stored on the support unless approved by a qualified person. The foundation and fasteners shall remain accessible and visible for inspection at all times.
(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.
(1) Climbing procedures. Prior to, and during, all climbing procedures (including inside climbing and top climbing), the employer shall:
(A) Comply with all manufacturer prohibitions.
(B) Have a certified agent verify that the host structure is strong enough to sustain the forces imposed through the braces, brace anchorages and supporting floors.
(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.
(i) Dangerous areas.
(1) Only employees directly involved in the erection, climbing, and dismantling operations of tower cranes are allowed to work in the area under the tower, jib, or rotating portion of the crane during these operations.
(2) Additional requirements for self-erecting tower cranes: Employees shall not be in or under the tower, jib, or rotating portion of the crane during erecting, climbing and dismantling operations until the crane is secured in a locked position and the competent person in charge indicates it is safe to enter this area, unless the manufacturer's instructions direct otherwise and only the necessary personnel are permitted in this area.
(j) Addressing specific hazards. In addition to the requirements in Section 5010.1(h)(1) through (9), the A/D director shall confirm the following:
(1) Foundations and structural supports. Prior to erection/installation of tie-ins, the controlling entity shall provide documentation to the A/D director that tower crane foundations and structural supports are installed in accordance with the design.
(2) Backward stability. All cranes shall be ballasted or counterweighted in accordance with the manufacturer's recommendation to ensure stability.
(3) Wind speed. Operations shall not be conducted when wind speed exceeds the speed tolerance recommended by the manufacturer or, where the manufacturer does not specify this information, the speed tolerance shall be determined by a qualified person.
(k) Plumb tolerance. Towers shall be erected plumb in accordance with the manufacturer's specifications and verified by a qualified person. Where the manufacturer does not specify plumb tolerance, the crane tower shall be plumb to a tolerance within 1:500 (approximately 1 inch in 40 feet).
(l) Multiple tower crane jobsites. Where more than one fixed jib (hammerhead) tower crane is installed, the cranes shall be located such that the structural members of the cranes cannot come in contact with one another. Cranes are permitted to pass over one another.
(m) Counterweight/ballast.
(1) Equipment shall not be erected, dismantled or operated without the amount and position of counterweight and/or ballast in place as specified by the manufacturer or a certified agent familiar with the equipment.
(2) The maximum counterweight and/or ballast specified by the manufacturer or certified agent familiar with the equipment shall not be exceeded.


Note: 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).
6. Amendment of section heading and section filed 7-26-2022; operative 7-26-2022 pursuant to Government Code section 11343.4(b)(3) (Register 2022, No. 30). Filing deadline specified in Government Code section 11349.3(a) extended 60 calendar days pursuant to Executive Order N-40-20 and an additional 60 calendar days pursuant to Executive Order N-71-20.

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