49 CFR 230.7: Responsibility for compliance.

(a) The locomotive owner and/or operator is directly responsible for ensuring that all requirements of this part are satisfied, and is the entity primarily responsible for compliance with this part.

(b) Although the duties imposed by this part are generally stated in terms of the duties of a railroad or a steam locomotive owner and/or operator, any person, including a contractor for a railroad, who performs any function covered by this part must perform that function in accordance with this part.

(c) Chapter 207 of Title 49 of the United States Codes makes it unlawful for any railroad to use or permit to be used on its line any steam locomotive or tender unless the entire steam locomotive or tender and its parts and appurtenances are in proper condition and safe to operate in the service to which they are put, without unnecessary danger of personal injury and have been inspected and tested as required by this part.