A. The operator or his agent shall provide at or near each working place an ample supply of suitable materials of proper size with which to secure the roof, face, and ribs of such working place in a safe manner. Suitable supply materials shall be provided for variations in seam height. If the operator or his agent fails to provide such suitable materials, the mine foreman shall cause all miners to withdraw from the mine, or the portion thereof affected, until such materials or supplies are received.
B. Safety posts, jacks, or temporary crossbars shall be set close to the face before other operations are begun and as needed thereafter if any miner goes inby the last permanent roof support.
C. Unless an automated temporary roof support system is used, safety posts or jacks shall be used to protect miners during removal of roof material, installation of crossbars, drilling of roof bolt holes, installation of roof bolts, or performance of any other work that would reasonably require roof support to protect the miners involved.
D. The operator or his agent shall make immediately available for emergency use at each mine site at least two lifting devices with a combined total of at least 80 tons lifting capacity. Each individual lifting device shall have 20 tons or greater lifting capacity.