Cal. Code Regs. tit. 8, § 3902 – Manufacturer's Analyses.

(a) For new model rides and for all existing models of rides for which this information may be requested, manufacturers, fabricators, or ride [The next page is 647.] owner/operators shall furnish stress analysis or other pertinent data deemed necessary by the Division. Such stress analysis or other data pertinent to the design, structure, factors of safety, or performance characteristics shall be in such detail as to be acceptable to the Division. When such data on a particular ride is acceptable to the Division, it shall be deemed to apply to all rides of the same make and model where there have been no modifications.
(b) When no engineering calculations are available from the manufacturer or fabricator on a particular ride and when experience has been insufficient to warrant acceptance, the Division may require the owner/operator to furnish a structural analysis signed by a registered engineer.
Note: In evaluating rides where specific engineering specification data is lacking, the Division may not require a structural analysis on slow moving rides such as, but not limited to, merry-go-rounds and kiddie rides where the basic design has been proven safe through years of operation. A permit to operate, however, will be required.