Cal. Code Regs. tit. 8, § 7129 – (19-120). Shaft Conveyances--General.

(a) Every shaft conveyance shall be constructed of steel or other metal of equivalent strength acceptable to the Division.
(b) Safety dogs or catches shall be substantially constructed of steel. They shall be kept well oiled and in good working condition.
(c) At least once each work day, the weight on the hosting rope shall be relieved for activating and inspecting the safety dogs.
When deemed necessary by the Division of Industrial Safety, drop tests may be required in the presence of a representative of the Division.
(d) Should the safety dogs or catches fail to function properly while being tested, the shaft conveyance shall be removed from service until the safety dogs or catches have been put into satisfactory working condition.