The main coupling chain, attached to the socket of the wire rope, shall be made of the best quality of iron and shall be tested by weights, or otherwise, to the satisfaction of the mine inspector of the district where the mine is located, and the bridle chains shall be attached to the main hoisting rope above the socket from the top cross piece of the carriage or cage so that no single chain shall be used for lowering persons into or hoisting them out of the mine. R.L.1910, § 3968.
Oklahoma Legal Code