S.C. Code Regs. § § 63-361
All road machinery which is temporarily moved over the highways of this State and which exceeds 12' -0"' in width or which weighs 90,000 pounds or more (including pulling equipment) shall first obtain from the Department a routing permit for the movement which shall specify the routes to be traveled and conditions to be observed during the trip. This permit, which will be issued without charge, shall be carried in the vehicle and be available for inspection at all times. The Department will determine the minimum spacing of axles and the maximum loads to be permitted on single, double and triple tandem axles.
Loads moved in violation of this regulation will be considered in violation of Chapter 5, Title 56, of the Code of Laws of South Carolina and subject to the penalties provided therefor.
S.C. Code Regs. § 63-361