| Junctions and other features | Running Lines | Stations, Signal Boxes and Junctions | Distance from Signal Box above | Loops and Refuge Sidings | Notes | ||
|---|---|---|---|---|---|---|---|
| Up | Down | ||||||
| 1 | - | ↓ | Hengoed H.L. | - | |||
| 2 | ↑ | ↓ | Penalltau Junction | 1m 1117yds | |||
| 3 | ↑ | ↓ | Nelson & Llancaiach | 1m 215yds | DRS 58 UGL 85 |
||
| Trelewis Halt | |||||||
| 4 | ↑ | ↓ | Ocean & Taff Merthyr Collieries | 0m 1628yds | |||
| Treharris | |||||||
| 5 | ↑ | ↓ | Quaker's Yard East Junction | 0m 1408yds | |||
| 6 | ↑↑ | ↕ | Quaker's Yard H.L. | 0m 902yds | DRS 35 | ||
| 7 | ↕ | ↓ | Quarker's Yard West | 0m 1628yds | URS 35 | ||
| Penrhiwceiber H.L. | |||||||
| 8 | ↑ | ↓ | Cresselley Crossing | 1m 1507yds | |||
| 9 | ↑ | ↓ | Mountain Ash (Cardiff Road) | 0m 341yds | |||
| 10 | ↑ | ↓ | Middle Duffryn | 1m 391yds | DRS 30 | ||
| 11 | ↑ | ↓ | Lletty Shenkin | 0m 1441yds | |||
| Cwmbach Halt | |||||||
| 12 | ↑ | ↓ | Cwmbach Sidings | 0m 1249yds | DRS 51 | ||
| 13 | ↑ | ↓ | Aberdare H.L. | 1m 193yds | |||
| 14 | ↑ | ↓ | Gadlys Junction | 0m 357yds | |||
| 15 | ↑ | ↓ | Robertstown Crossing | 0m 523yds | |||
| Trecynon Halt | |||||||
| 16 | ↑ | ↓ | Gelli Tarw Junction | 1m 1281yds | DRS 25 | ||
| 17 | ↑ | ↓ | Hirwaun | 1m 533yds | |||
| 18 | ↑ | ↓ | Hirwaun Pond | 0m 1271yds | DGL 37 | ||
| Hirwaun Pond Halt | |||||||
| Rhigos Halt | |||||||
| 19 | ↑ | - | Rhigos | 1m 330yds | |||