A. Two independent means of signaling shall be provided between the top, bottom, and every intermediate landing of each shaft, slope, or surface incline and the hoisting station. At least one of these means of signaling shall be audible to the hoisting engineer or other person operating the equipment. Bell cords shall be installed in each shaft in such a manner as to prevent unnecessary movement of such cords within the shaft.
B. A uniform signal code approved by the Chief shall be in use at each mine and shall be kept at the cage station designated by the mine foreman.