Automatic Block Signals are protected by which system?

• A. Train Stop System
• B. Interlocking ABS
• C. Strobe
• D. General Notice

Answer: (A)

Automatic Block Signals rely on a Train Stop System to enforce safe movement. The Train Stop System provides the fail-safe mechanism that physically stops a train if it encounters a red signal or a fault in the signaling, preventing entry into a blocked or unsafe section. This direct protection is what keeps ABS effective, ensuring trains cannot proceed when the block is not clear. Interlocking coordinates routes and prevents conflicting moves at junctions, which is important for overall safety, but the specific protection of ABS signals comes from the train stop devices. The other options don’t provide this protective stopping function, with strobe being a visual cue and a General Notice serving only as information.