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Subchapter 6. Elevator Safety Orders
Article 8. Machinery and Equipment for Power Cable-Driven Passenger and Freight Elevators

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§3033. Car Frames and Platforms.

(a) Car Frames Required. Every elevator suspended by wire ropes shall have a car frame consisting of a cross head, uprights (stiles), and a plank located approximately at the middle of the car platform, and in no case farther from the middle than 1/8 of the distance from front to back of the platform.

(b) Guiding Members. Car frames shall be guided on each guide rail by upper and lower guiding members attached to the frame.

(c) Design of Car Frames and Guiding Members. The frame and its guiding members shall be designed to withstand the forces resulting under the loading conditions for which the elevator is designed. See Section 3037.

(d) Underslung or Sub-Post Car Frames. The vertical distance between the top and bottom guide shoes of an elevator car having a subpost car frame, or having an underslung car frame located entirely below the car platform, shall be not less than 40 percent of the distance between guide rails.

(e) Car Platforms. Every elevator car shall have a platform consisting of a nonperforated floor attached to a platform frame supported by the car frame, and extending over the entire area within the car enclosure. The platform frame members and the floor shall be designed to withstand the forces developed under the loading conditions for which the elevator is designed and installed.


Platform frames are not required where laminated platforms are provided. Laminated platforms may be used for passenger elevators having a rated load of 5,000 lbs. (2270 kg) or less. The deflection at any point of a laminated platform, when uniformly loaded to rated capacity, shall not exceed 1/960 of the span. The stresses in the steel facing shall not exceed 20% of its ultimate strength. The stresses in the plywood core shall not exceed 60% of the allowable stresses specified in Table 3. Allowable stresses for Plywood, in the American Plywood Association, Plywood Design Specification (PDS), Form No. Y510, August 1986/Revised December, 1990, which is hereby incorporated by reference.

(f) Materials for Car Frames and Platform Frames.

(1) Materials used in the construction of car frames and platforms shall conform to the following:

(A) Car frames and outside members of platform frames shall be made of steel or other metals.

(B) Platform stringers of freight elevators designed for Class B or C loading shall be of steel or other metals.

(C) Platform stringers of passenger elevators and of freight elevators designed for Class A loading shall be made of steel or other metals, or of wood.

(D) Cast iron shall not be used for any part subject to tension, torsion, or bending.


1. Guiding supports.

2. Guide shoes.

3. Compensating rope anchorages.

(2) Steel, where used in the construction of car frames and platforms, shall conform to the requirements of Design Section 3101(a).

(3) Metals other than steel may be used in the construction of car frames and platforms provided the metal used has the essential properties to meet all the requirements for the purpose in accordance with acceptable engineering practices, and providing the stresses and deflections conform to the requirements of Sections 3101(a)(4) and 3101(a)(5).

(4) Wood used for platform stringers and for platform floors and subfloors shall be of clear, structural quality lumber conforming to the requirements of Design Section 3101(a)(2).

(g) Car Frame and Platform Connections. Connections between members of car frames and platforms shall be riveted, bolted, or welded, and shall conform to Design Section 3101(a)(4) and to the following:

(1) Bolts used through flanges of structural members where the flanges slope more than 5o shall have boltheads of the tipped-head type or shall be fitted with beveled washers.

(2) Nuts used on the flanges of structural members where the flanges slope more than 5o shall seat on beveled washers.

(3) Welding of parts upon which safe operation depends shall be done in accordance with the appropriate standards established by the American Welding Society. All welding of such parts shall be done by welders qualified in accordance with the requirements of the American Welding Society. At the option of the manufacturer, the welders may be qualified by one of the following:

(A) By the manufacturer.

(B) By a California licensed Professional Engineer.

(C) By an approved testing laboratory.

EXCEPTION: Tack welds not later incorporated into finished welds carrying calculated loads.

(h) Protection of Platforms Against Fire. The underside of wood platforms and the exposed surfaces of wood platform stringers of passenger elevators shall be protected against fire by one of the following methods:

(1) By covering with sheet steel of at least No. 27 M.S. gage or with equally fire retardant material.

(2) By painting with fire retardant paint. See Design Section 3101(a)(3).

(3) Fire retardant treated wood.

(i) Platform Guards (Aprons). The entrance side of the platform of passenger and freight elevators equipped with leveling devices or truck-zoning devices shall be provided with smooth metal guard plates of not less than No. 16 M.S. gage steel, or material of equivalent strength and stiffness, adequately reinforced and braced to the car platform and conforming to the following:

(1) It shall extend not less than the full width of the widest hoistway door opening.

(2) It shall have a straight vertical face, extending below the floor surface of the platform, of not less than the depth of the leveling or the truck zone, plus 3 inches.

(3) The lower portion of the guard shall be bent back at an angle of not less than 60 degrees nor more than 75 degrees from the horizontal. The bent portion shall be not less than 3 inches long.

(4) The guard plate shall be securely braced and fastened in place to withstand a constant force of not less than 150 pounds applied at right angles to and at any position on its face without deflecting more than 1/4 inch, and without permanent deformation.

(j) Maximum Allowable Stresses in Car Frame and Platform Members. The stresses in car frame and platform members, based on the static load imposed upon them, shall not exceed those specified in Design Section 3101(a)(4).

(k) Maximum Allowable Deflections of Car Frame and Platform Members. The deflections of car frame and platform members, based on the static load imposed upon them, shall be not more than those specified in Design Section 3101(a)(5).

(l) Car Frames With Crosshead Sheaves. Where a hoisting rope sheave is mounted on the car frame, the construction shall conform to Design Section 3101(b).

(m) Hoisting Rope Hitch Plates or Shapes. Where cars are suspended by hoisting ropes attached to the car frame by means of rope shackles, the shackles shall be attached to steel hitch plates or to structural or formed steel shapes. Such plates or shapes shall be secured to the underside or to the webs of the car frame member with bolts, rivets, or welds so located that the tensions in the hoisting ropes will not develop direct tension in the bolts or rivets. The stresses shall not exceed those permitted by Design Sections 3111(c) and 3111(d).

(n) Calculation of Stresses in Car Frame and Platform Frame Members. The calculation of the stresses and deflections in the car frame plank and uprights, and platform frames, shall be based on the formulas and data in Design Section 3101.

(o) Platform Side Braces. Where side bracing and similar members are attached to car frame uprights, the reduction in area of the upright shall not reduce the strength of the upright below that required by Design Section 3101(a)(4).

(p) Hinged Platform Sills. Hinged platform sills shall conform to the following requirements:

(1) They shall be provided with electric contacts which will prevent operation of the elevator by the normal operating device unless the hinged sill is within 2 inches of its fully retracted position, provided that when in this position the sill shall not reduce the clearance specified in Section 3018(d).

(2) The elevator may be operated by the leveling device in the leveling zone with the sill in any position.

(Title 24, Part 7, Section 7-3033)

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943, Health and Safety Code.


1. Amendment of subsections (g)(1) and (g)(2) filed 6-23-77; effective thirtieth day thereafter (Register 77, No. 26).

2. New Exception to subsection (e), statement prior to Note and Note filed 3-9-93; operative 4-8-93 (Register 93, No. 11).

3. Editorial corrections (Register 95, No. 26).

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