Tennessee Code Title 65. Public Utilities and Carriers § 65-10-111

(a) In any written contract of or for the sale of the railroad equipment or rolling stock, deliverable immediately or subsequently at stipulated periods, by the terms of which the purchase money, in whole or in part, is to be paid in the future, it may be agreed that the title to the property so sold or contracted to be sold shall not pass to or vest in the vendee until the purchase money shall have been fully paid, or that the vendor shall have and retain a lien thereon for the unpaid purchase money, notwithstanding delivery thereof to and possession by the vendee; provided, that the terms of credit for the payment of the purchase money shall not exceed fifteen (15) years from the execution of the contract.

(b) In any written contract for the leasing or renting of railroad equipment or rolling stock, it is lawful to stipulate for a conditional sale thereof at the termination of such lease, and to stipulate that the rentals received may, as paid or when paid in full, be applied and treated as purchase money, and that the title of such property shall not vest in such lessee or vendee until the purchase money shall have been paid in full, notwithstanding delivery to and possession by such lessee or vendee, subject, however, to the proviso contained in subsection (a).

(c) Every such contract specified in this section shall be good, valid, and effectual, both in law and equity, against all purchasers and creditors; provided, first, the same shall be acknowledged by the vendee or lessee before some officer authorized by law to take acknowledgments of deeds in the form required as to conveyance of real estate; second, such instrument shall be registered in the office of the register of the county in which, at the time of the execution thereof, is situated the principal office of the vendee or lessee in this state; and third, each locomotive engine or car so sold or contracted to be sold or leased as aforementioned shall have the name of the vendor or lessor, or the assignee of such vendor or lessor, plainly placed or marked on each side thereof, or be otherwise marked so as to indicate the ownership thereof.