§ 33.253. Props and timbering.

 (a)  Any person having charge of a working place in any cavern shall keep the roof and sides of the working place properly secured by timber or other material so as to prevent the roof and sides from falling. He shall not permit any work to be done under loose or dangerous materials except for the purposes of securing them. He shall also be instructed in the proper methods of testing the roof and sides. The cavern superintendent and cavern foreman shall be jointly responsible for insuring that this subsection is complied with.

 (b)  The method timbering used shall be subject to approval by the Department or its authorized representative.