27-357. Hoist release signal
A. At a mine where men are hoisted by mechanical means, a hoistman charged with the hoisting shall be kept on duty at the hoist at all times when men are underground, except as provided in subsection B.
B. The requirements of subsection A shall not apply to an automatic hoist equipped with the following devices:
1. A device which automatically cuts off the power to the hoist motor and sets the brakes when the hoist ropes of a winding-drum machine becomes slack, and safety dogs or devices on the cage which will stop the cage in the event of slack rope or a broken hoisting cable.
2. A governor which will prevent unsafe speeds and a device to set the brakes and stop the cage if the safe speed is exceeded.
3. Devices which will reduce the speed of the cage before the approximate stopping points so that it can be stopped properly.
4. A manually operated safety switch and other device by means of which the cage may be stopped, started or directed to another level or stopping point.
5. A call button located at each stop which, when actuated, will cause the cage to move to that stop providing the gates and gate switches are closed on all stations.
6. A magnetic brake which will stop the hoist motor and hold the cage in fixed position whenever the power applied to the hoist motor is removed or fails.
7. An opening or escape hatch in the cage and a shaft manway with ladders which may be reached from the cage.
8. A means of signaling or communicating from the cage to a designated place in the mine or on surface where a responsible person on duty can be notified in the event of an emergency.
C. An automatic hoist is one that does not require the attendance of a hoist engineer and in which the hoist cage and shaft are equipped with operating and safety devices which control the movement of the hoist from the cage and from all stations or levels.