Who may remove a blue signal?

• A. The dispatcher
• B. Only a person of the same group or craft that displayed the signals may remove it, after all the workmen are clear
• C. A supervisor
• D. A safety officer

Answer: (B)

Blue signal protection is used to safeguard workers on or about to be on the track. The removal of that protection is reserved for the person who placed the signal, or for another person from the same group or craft who displayed it, and only after all workmen are clear. This keeps the protection in place until the area is truly safe, preventing premature release by someone not directly involved in the work. The dispatcher coordinates train movements but does not remove the blue signal; a supervisor or safety officer oversees safety broadly, but the actual removal authority rests with the crew that set the protection.