Railway Signaling Systems Overview
📌 Railway transportation utilizes various signals including home signals (for receiving trains) and starter signals.
⚙️ The automatic signal, or automatic block signaling system, autonomously regulates train movements for safety and efficiency.
🔗 This system operates based on Block and Interlocking Systems, where blocks are interconnected with the Junction Station control room for real-time monitoring.

Automatic Block Signaling Structure and Operation
🧱 A railway block is divided into insulated parts or joints, standardized to 120 m per block, allowing only one train per block at a time.
🚦 The number of signal aspects (RED, YELLOW, Double YELLOW, Green) depends on the distance between signals relative to the braking distance: three aspects if distance $\ge$ braking distance, and four aspects if distance $<$ braking distance.
🔎 Automatic block signals are identified by a distinctive black marker against a white background.

Signal Mechanism and Automation
🤖 The system relies on axle counters and evaluator boxes connected to signals, forming an interconnected network.
🟢 When the route is clear, all signals initially display green.
🔴 As a train passes a signal, the axle counter detects its axles, triggering the evaluator box to change the signal to red, while the preceding signal shifts to yellow, and the one before that shifts to double yellow, orchestrated by sensors and track circuits.

Key Points & Insights
➡️ The automatic block signaling system ensures safety by limiting occupation to one train per 120 m block section.
➡️ Signal aspect sequencing (RED $\rightarrow$ YELLOW $\rightarrow$ Double YELLOW) automatically occurs as a train proceeds through successive blocks, managed by axle counters and evaluator boxes.
➡️ Interlocking systems are crucial for coordinating signals and switches to prevent conflicting movements and maintain controlled, safe train guidance.

📸 Video summarized with SummaryTube.com on Nov 20, 2025, 03:29 UTC