49 C.F.R. § 240.105
Criteria for selection of designated supervisors of locomotive engineers
(a) Each railroad's program shall include criteria and procedures for implementing this section.
(b) The railroad shall examine any person it is considering for qualification as a supervisor of locomotive engineers to determine that he or she:
(1) Knows and understands the requirements of this part;
(2) Can appropriately test and evaluate the knowledge and skills of locomotive engineers;
(3) Has the necessary supervisory experience to prescribe appropriate remedial action for any noted deficiencies in the training, knowledge or skills of a person seeking to obtain or retain certification; and
(4) Is a certified engineer who is qualified on the physical characteristics of the portion of the railroad on which that person will perform the duties of a Designated Supervisor of Locomotive Engineers.
(c) If a railroad does not have any Designated Supervisors of Locomotive Engineers, and wishes to hire one, the chief operating officer of the railroad shall make a determination in writing that the Designated Supervisor of Locomotive Engineers designate possesses the necessary performance skills in accordance with § 240.127. This determination shall take into account any special operating characteristics which are unique to that railroad.
(d) Each railroad is authorized to designate a person as a designated supervisor of locomotive engineers with additional conditions or operational restrictions on the service the person may perform.