S.C. Code § 47-1-90
No railroad company in the carrying or transportation of animals shall overload the cars nor permit the animals to be confined in cars for a longer period than thirty-six consecutive hours without unloading them for rest, water and feeding for a period of at least five consecutive hours, unless prevented from so unloading by storm or other accidental causes beyond the control of such railroad company; provided, however, that when animals shall be carried in cars in which they can and do have proper food, water and space and opportunity for rest, the foregoing provisions in regard to their being unloaded shall not apply.
In estimating such confinement the time during which the animals have been confined without such rest on connecting roads from which they are received shall be included, it being the intent of this section to prohibit their continuous confinement beyond the period of thirty-six hours, except upon the contingencies hereinbefore stated.
S.C. Code § 47-1-90