(a) The operator of each mine shall keep on hand at the mine a sufficient supply of timbers of suitable length and cap pieces to be used as required in timbering underground workings. Timbers and cap pieces in required quantities and lengths as ordered shall be delivered to the working places designated or in cars to the point at which cars are accepted by the miners.
In hand loading mines, the miner shall order timbers and cap pieces at least one day in advance in order to have in his working place a sufficient supply for his needs. He shall place his order with the mine foreman or subordinate supervisor, stating the number and length of timbers needed. In mechanical mining, the mine foreman shall set up a systematic procedure for ordering and supplying of timbers and cap pieces. When timbers are needed in any working place and are not available, no person shall work in that place.
(b) In mines using roof supports other than timber, it shall be the responsibility of the operator to maintain an adequate supply of materials required and to insure their delivery in sufficient quantities to the working places as needed.