§ 33.252. Examination of cavern.

 (a)  The cavern foreman of each cavern or some other qualified competent person or persons designated by him shall examine at least once each day all main roads, shafts, slopes, escapements, travelways and signal apparatus to see that they are in safe and efficient operating condition, and a daily record of these examinations shall be kept. The cavern superintendent shall insure that such inspection is made.

 (b)  The cavern superintendent or the foreman of each cavern or some other person or persons designated by him shall visit and examine each working place in the cavern while the men are or should be at work at least once every day and more often should individual cavern conditions require. He shall insure that each working place is properly secured by props or timbers and that safety in all respects is maintained. He shall further insure that no person is permitted to work in a place known to be unsafe except for the purpose of making that place secure.

 (c)  When approach is made to old workings or other areas likely to contain an accumulation of water or gas, working places shall not exceed 12 feet in width. There shall be constantly kept at a distance of not less than 20 feet in advance of such workings at least one drill hole of not more than 2 inches in diameter near the center of the working face, except that a hole only 10 feet in advance shall be required in flint clay mines.