There shall be at least two effective approved methods of signaling between each of the shaft stations and hoist room, one of which shall be a telephone or speaking tube.
Ariz. Admin. Code § R11-1-1176
There shall be at least two effective approved methods of signaling between each of the shaft stations and hoist room, one of which shall be a telephone or speaking tube.
Ariz. Admin. Code § R11-1-1176