S.C. Code Ann. § 58-17-1660
The Commission shall, when necessary, investigate so much of the books and papers of the railroad companies doing business in this State as it may think proper, ascertain if the rules and regulations have been complied with, make personal visitations of railroad offices, stations and other places of business for the purpose of examination and make rules and regulations concerning such examinations, which rules and regulations shall be observed and obeyed as other rules and regulations of the Commission.