The C-9 between Cercedilla and Cotos remains closed after 25 months of works

The closure began in May 2024 with an initial estimate of one year. That deadline was exceeded, then a 25-month timeframe was mentioned, and now the line remains out of service, affecting residents, hikers, and regular users of one of the most distinctive railway routes in the Community of Madrid.

The C-9 is not just any line within Cercanías. Its route, about 18.2 kilometres long, crosses the mountains between Cercedilla, Navacerrada and Cotos, and for years has been an alternative for reaching the mountains without a car, especially on weekends, during the snow season, and in the hiking months.

Adif attributes the delays to the complexity of working in a particularly challenging environment. The line runs along steep gradients, a narrow track, and protected areas, which means work must be carried out with more environmental and safety restrictions than on other railway sections.

Added to this have been the snowfalls of the last two winters and the limitations of a forested area, where works must be adapted to protect sensitive habitats and reduce risks, including fire prevention. The result is a slower project than expected and no clear timetable for getting trains running again.

According to Adif, the installation of the new catenary is almost complete along the entire line. Rails, sleepers, and ballast have also been installed on more than 65% of the route, a phase that has progressed since mid-March, when track laying began.

The works also include the renovation of platforms at some stations and improvements to the Navacerrada tunnel, where the structural renewal has already been completed. Track installation at that point is still pending, one of the necessary steps before moving on to the final phase.

The project also incorporates a new traffic management system, known as BLAU, along with new interlockings, signal cabling, and axle counters. These are elements that are not very visible to users, but are essential for the line to operate safely when it reopens.

Once the works are finished, there will still be important steps before service can resume. Adif will need to carry out tests, train drivers, and obtain authorisation from the Agencia Estatal de Seguridad Ferroviaria to start operations.

The new trains that will run on the C-9 are already built and are waiting for the reopening at Renfe's maintenance base in La Sagra, in Toledo. Their entry into service will depend on the infrastructure being ready and passing all technical procedures.

For users, the lack of a concrete date keeps uncertainty alive. The line was a convenient option for getting up to the mountains without relying on a car, and its absence is felt in travel to Cotos, especially on busy days.

The renovation promises a more modern and safer C-9, but the prolonged closure also highlights the fragility of some railway connections outside the urban core. In the Madrid mountains, bringing this train back will not just mean reopening a line: it will mean restoring a way to reach the mountains without adding more cars to the roads.