What is required for an Extra train to run in Single Track 251?

For an Extra train to operate in Single Track 251, it is essential to have either a Train Order or to be within Yard limits. This requirement ensures that there is a formal and clear directive allowing the Extra train to make use of the single track, thereby maintaining safe and efficient operations.

Train Orders provide specific instructions regarding the movement of the train, including its authority to occupy, pass, or leave a section of track. These documented instructions are critical in situations where multiple trains may interact on the same track to minimize the risk of accidents. Being within Yard limits means that the train is operating in an area designated for train movements while managing the priorities and movements of other trains in that same vicinity.

Verbal permissions alone or reliance solely on fixed signals do not provide the necessary level of formal authority and structure needed in a busy rail environment, especially for Extra trains moving outside of regular traffic patterns.