Interlocking signals governing entrance to or within the affected track require which authority?

Interlocking signals governing entrance to or within the affected track require which authority?

• A. Dispatcher verbal instruction
• B. Timetable authorization
• C. Form D line 2 authority
• D. Bulletin Order

Answer: (C)

Interlocking signals control entry to and movement within a set of tracks where routes are coordinated by switches and signals. To keep those movements from conflicting, a formal, written authority is required, detailing the exact route and any restrictions. That authority is provided on Form D, line 2, issued by the dispatcher, and it must be in effect before entering or moving within the affected track. This written authority creates a clear, auditable record of who has permission for the specific interlocking movement and what limits apply. Verbal instructions from the dispatcher aren’t sufficient here because they can be misheard or forgotten and lack a formal record. A timetable authorization covers routine movements on fixed timetable routes rather than the dynamic routing through an interlocking. Bulletin Orders give temporary directions but do not replace the specific Form D line 2 authority needed for entering or moving within an interlocking.

Interlocking signals control entry to and movement within a set of tracks where routes are coordinated by switches and signals. To keep those movements from conflicting, a formal, written authority is required, detailing the exact route and any restrictions. That authority is provided on Form D, line 2, issued by the dispatcher, and it must be in effect before entering or moving within the affected track. This written authority creates a clear, auditable record of who has permission for the specific interlocking movement and what limits apply.

Verbal instructions from the dispatcher aren’t sufficient here because they can be misheard or forgotten and lack a formal record. A timetable authorization covers routine movements on fixed timetable routes rather than the dynamic routing through an interlocking. Bulletin Orders give temporary directions but do not replace the specific Form D line 2 authority needed for entering or moving within an interlocking.