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Subchapter 7. General Industry Safety Orders
Group 4. General Mobile Equipment and Auxiliaries
Article 24. Elevating Work Platforms and Aerial Devices
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§3637. Definitions.

Aerial Device. Any vehicle-mounted or self-propelled device, telescoping extensible or articulating, or both, which is primarily designed to position personnel.

Aerial Ladder. An aerial device consisting of a single-or-multiple-section extension ladder.

Articulating Boom. An aerial device with two or more hinged boom sections.

Boom. An elevating member; the lower end of which is so attached to a rotating or non-rotating base that permits elevation of the free or outer end in vertical plane.

Elevating Work Platform. A device designed to elevate a platform in a substantially vertical axis. (Vertical Tower, Scissor Lift, Mast-Climbing Work Platform)

Extensible Boom Platform. An aerial device (except ladders) with an extensible boom. Telescopic booms with personnel platform attachments shall be considered to be extensible boom platforms.

Insulated Aerial Device. An aerial device designed for work on energized lines and apparatus.

Mast-Climbing Work Platform. A powered elevating work platform or platforms, supported on one or more vertical masts, for the purpose of positioning personnel, along with necessary tools and materials, to perform their work.

Orchard Man-Lift (Pruning Tower). An aerial device designed to elevate and position personnel for the purpose of harvesting and/or pruning fruit and nut trees.

Override. The taking over of primary control functions from a secondary location.

Pin-On Platform. A platform other than basket or tub, without a guardrail which is attached to a boom by hinge or pivot connection allowing movement in the vertical plane, including such hinge down platforms used at the upper end of aerial ladders.

Platform. Any personnel-carrying device (bucket, basket, cage, stand, tub, or equivalent) which is a component of an aerial device.

Rated Work Load. The safe design live load carrying capacity of the work platform.

Stability. A condition of a work platform in which the sum of the moments, which tends to overturn the unit is less than the sum of the moments tending to resist overturning.

Work Platform, Adjustable. Any device that has a platform which is vertically, horizontally or rotationally adjustable and supported by a structure.

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


1. Amendment filed 10-12-84; effective thirtieth day thereafter (Register 84, No. 41).

2. Amendment of section filed 9-10-91; operative 10-10-91 (Register 91, No.51).

3. Amendment adding definition for "Orchard Man-Lift (Pruning Tower)" filed 10-28-91; operative 11-27-91 (Register 92, No. 7).

4. Amendment of definitions of "Elevating Work Platform" and "Work Platform" and new definition of "Mast-Climbing Work Platform" filed 2-27-2006; operative 3-29-2006 (Register 2006, No. 9).

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