Okla. Stat. tit. 45 § 512
The operator or superintendent shall provide and maintain from the top to bottom of every shaft, where persons are raised or lowered, a metal tube suitably adapted to the free passage of sound through which conversation may be held between persons at the top and bottom of said shaft, and also a means of signaling from the top to the bottom thereof, and shall provide every cage or gear carriage used for the hoisting or lowering of persons with a sufficient overhead covering to protect those persons when using the same and shall provide also for each said cage or carriage a safety catch approved by the mine inspector, and the said operator or superintendent shall see that flanges with clearance of not less than four (4) inches when the whole of the rope is wound around the drum, are attached to the sides of the drum of every machine that is used for lowering persons into or hoisting them out of the mines, and also, that adjacent brakes are attached to the drums: Provided, that the rope shall be left around the drum at least two and one-half (2 1/2) times when the cage is at the bottom. At all shafts, safety gates to be approved by the mine inspector of the district, shall be so placed as to prevent persons from falling into the shaft.
Okla. Stat. tit. 45, § 512