49 CFR §180.517 covers reporting and record retention requirements. Tank car owners are required to maintain certain documents (such as drawings, COCs, qualification paperwork, etc) as specified in AAR CIII Chapter 1 paragraph 1.3.15 which specifies paragraph 1.6. The documents and retention periods are listed in a table under paragraph 1.6.4. These documents must be maintained by the car owner and transferred to the new car owner upon sale.
AllTranstek can help you review your car documentation to verify compliance with the regulations for your existing fleet or future acquisitions.