The route between Orense and Lugo is composed of two different sections of single-track railway lines in Iberian gauge (1,668 mm) with their common point in Monforte de Lemos:
- Orense-Monforte de Lemos stretch: it belongs to the Monforte de Lemos-Bif. Chapela line (line 810), has a length of 46 km and is electrified at 3kV.
- Monforte de Lemos-Lugo stretch: it belongs to the León-A Coruña line (line 800), is 71 km long and is not electrified.
The measures adopted for the implementation of the obstacle gauge and the corresponding electrification of the line in the Monforte de Lemos - Lugo
stretch from km 375+305 to km 379+750 have been implemented in the following 3 tunnels:
- Nº70 Perecha (134 meters)
- Nº71 Peñas Negras (134 meters)
- Nº72 Cortijo (158 meters)
Among the measures adopted are the execution of backfill injections, sealing of the ground with shotcrete, placement of bolts and demolition and re-profiling of the tunnel sections.