Covers two distinct methods of detecting train presence on a track section: Track Circuits (electrical continuity through the rails) and Axle Counters (counting wheel-axles in and out of a section). Covers BPAC (Block Proving by Axle Counters) and AFTC (Audio Frequency Track Circuits) specifically.
Exam Focus
- Axle counters don't depend on rail electrical continuity (useful where rusty rails cause track circuit problems), while track circuits provide continuous occupation status rather than just entry/exit counts.
Content Status
Draft note, grounded in real official syllabus text found via research but not yet cross-checked against the primary RBE PDF directly. Treat as study-aid only until verified.