Tenn. Code Ann. § 4-6-115

The commissioner of correction has the authority to detail any engineer or skilled worker connected with the main prison or other penitentiaries under the commissioner's control for special service at the other penitentiaries named in § 4-6-102. Services thus rendered and the expense thereof shall be paid by the penitentiary for which the work is performed to the penitentiary furnishing same, such sum as may be fixed by the commissioner.