(c) Special automatic block system (track circuit detection system)
This system was developed to modernize branch lines with low traffic volumes.
The blocking method and signaling system are the same as the automatic block system type B, but track circuits are not installed between stations and trains are detected by a pair of short truck circuits.
Train detection methods are as follows.
Consecutive train detection track circuits are installed for block sections inside station yards to automatically ensure blocking.
Two types of detection track circuits (open track circuit: OT, closed track circuit: CT) are installed on both ends (near the home signals) of block sections between stations, and trains entering and exiting block sections are detected to automatically ensure blocking.
Fig. 8 Special automatic block system (track circuit detection system)
