Cal. Code Regs. tit. 8, § 7146 – Loading Men on Shaft Conveyance.

(a) The person in charge of the mine shall determine the maximum number of people allowed to ride in the shaft conveyance at one time.
(b) Legible signs stating the number of persons allowed to ride in the shaft conveyance at one time shall be posted conspicuously at the shaft collar and on each shaft station where employees board the shaft conveyance.
(c) (19-69) Some responsible person or persons shall be designated to supervise the loading of the shaft conveyance while the shift is being hoisted or lowered.
Such person or persons shall see that the men board the conveyance in an orderly fashion, that the posted maximum number of men allowed on the conveyance at one time is not exceeded, and that the proper hoisting signals are used.
(d) (19-50) It is forbidden to place boards across the top of a bucket or skip and permit men or materials to ride thereon. If boards are used, they shall be placed inside and at least 30 inches below the lip of the bucket or skip.
(e) Men shall be provided with a safe means for getting in and out of the shaft conveyance.
Where it is necessary for men to climb up or down inside the shaft conveyance for a distance of more than 4 feet, a ladder or some other device acceptable to the Division shall be kept in such conveyance while men are being hoisted or lowered.
(f) (19-71) Men shall not be permitted to ride on the bail or edge of the shaft conveyance.
(g) (19-70) The gates of the man-deck shall be closed and latched before a signal is given to move the shaft conveyance.
(h) No smoking or open-flame lights shall be permitted in the shaft conveyance while the shift is being hoisted or lowered.
(i) Crowding or scuffling of men in the vicinity of a shaft is strictly prohibited.