When any such tube, tunnel, or subway, together with the equipment and appliances therein, is constructed, they may be leased, in whole or in part, to individuals, copartnerships, associations, or corporations; and rights therein may be so leased. No lease shall be for a term exceeding twenty-five years. Said cities shall have the right to renew said leases from time to time.
53 P.S. § 25494