| Junctions and other features | Running Lines | Stations, Signal Boxes and Junctions | Distance from Signal Box above | Loops and Refuge Sidings | Notes | ||
|---|---|---|---|---|---|---|---|
| Up | Down | ||||||
| 1 | – | ↓ | Caerphilly West | – | |||
| 2 | ↑ | ↓ | Watford Crossing | 0m 599yds | |||
| 3 | ↑ | ↓ | Penrhos Junction | 0m 1276yds | |||
| 4 | ↑ | ↓ | Interchange Sidings | 4m 869yds | |||
| 5 | ↑ | – | P.C. & N. Junction, Pontypridd | 0m 1051yds | |||