This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 6. Elevator Safety Orders
Article 18. Design Data, Formulas, Tests on Approved Devices, and Electrical Regulations

Return to index
New query

§3109. Guide Rails, Guide Rail Brackets, Fastenings and Supports for Electric Elevators.

(a) Stresses and Deflections.

(1) The stresses in a guide rail, or in a rail and its reinforcement, due to the horizontal forces imposed on the rail during loading, unloading, or running, calculated without impact, shall not exceed 15,000 pounds per square inch based upon the class of loading. The deflection, calculated on the same basis, shall not exceed 1/4 inch.

EXCEPTION: Where steels of greater strength than those specified in Section 3109(b) are used, the stresses may be increased proportionately based on the ratio of the ultimate strengths.

(2) The guide rail brackets, their fastenings and supports, such as building beams and walls, shall be capable of resisting the horizontal forces imposed by the class of loading with a total deflection at the point of support of not more than 1/8 inch.

(b) Requirements for Steel.

(1) Rails, brackets, fishplates, and rail clips shall be made of open-hearth steel or its equivalent having a tensile strength of not less than 55,000 pounds per square inch and having an elongation of not less than 22 percent in a length of 2 inches.

(2) Bolts shall conform to ASTM A-307.

(3) Rivets shall conform to ASTM A-502.

(c) Rail Section. When shapes other than those specified in Section 3030(e) are used, they shall:

(1) Have a section modulus and moment of inertia equal to or greater than that of the sections shown in Figure 3030 E for a given loading condition.

(2) Have a sectional area sufficient to withstand the compressive forces resulting from the application of the car or counterweight safety device.

(d) Moment of Inertia for a Single Guide Rail. The minimum moment of inertia about an axis (1-1) parallel to the base of a single rail or to the base of a single rail and its reinforcement for a car or counterweight with a safety device, is given in Figure 3109 D for total weight per pair of rails and bracket spacing.

NOTE: The moments of inertia of the most common size standard T-rails are shown in Figure 3109 D as vertical lines.

Minimum Moment of Inertia About 1-1 Axis for a Single

Guide Rail With Its Reinforcement

FIGURE 3109 D (continued)


1. Amendment of subsection (d) filed 6-23-77; effective thirtieth day thereafter (Register 77, No. 26).

2. Editorial correction of subsection (c)(1) (Register 95, No. 41).

Go BackGo Back to Article 18 Table of Contents