Which of the following best describes blue signals and their removal?

• A. Blue signals indicate workmen in the area and may only be removed by the same craft that displayed them.
• B. Blue signals indicate a train in approach and may be removed by any crew member.
• C. Blue signals indicate the track is clear and may be removed by the yardmaster.
• D. Blue signals indicate a signal failure and may be removed by the chief mechanical officer.

Answer: (A)

Blue signals are used to protect workers in the area. They alert train crews that people are working on or near the track, and the protection must stay in place until the work is finished and the area is safe. The person or craft that placed the blue signal is the only one authorized to remove it, ensuring the protection isn’t cleared prematurely. That’s why this description is the best: blue signals indicate workmen in the area and may only be removed by the same craft that displayed them. The other statements describe different meanings or removal authority that doesn’t align with blue-flag protection.