Tennessee Code Title 55. Motor and Other Vehicles § 55-7-107

(a) When timber, pulpwood, or logs are hauled upon a truck, tractor-trailer, or tractor-semitrailer combination, with a rated capacity of more than three-fourths ( 3/4 ) of a ton, every length of timber, pulpwood, or logs shall be securely fastened with either two (2) chains rated not less than three-eighths inch ( 3/8 ") proof coil, or two (2) wire rope cables of not less than three-eighths inch ( 3/8 ") diameter or any combination of the minimum size chain or cable, or two (2) nylon straps equivalent in tensile strength to the minimum size chain or cable.

(b) If the length of the timber, pulpwood, or logs hauled exceeds thirty-five feet (35'), every length shall be securely fastened with three (3) chains or cables, as described in subsection (a), or a combination of chains and cables, or three (3) nylon straps equivalent in tensile strength to the minimum size chain or cable.