Adif gives the green light to Thales track circuit 100% designed in Spain

The latest generation TTC audio frequency track circuit, developed entirely by Thales in Spain, provides predictive information for the maintenance of the system and ensures the safety of railway operations by detecting the occupation, presence and departure of a train in a given area. Its assembly can be carried out both indoors and in outdoor cabinets, as it has local and remote diagnosis. The solution complements the Thales Axle Counter family to provide the most comprehensive Train Detection Portfolio in the market.


The TTC audio-frequency track circuit designed with Thales technology has been included in the register of products and companies validated by Adif, publicly accessible through the Adif and Adif AV web pages.

 With this inclusion, the ADIF validation process for this solution applicable to both high-speed and conventional networks is approved and closed. It also complies with the technical specifications for interoperability (ETI) related to the Command and Signaling Control subsystems of the trans-European rail system, allowing possible extensions in the future. Adif is not considered an accredited conformity assessment body and, therefore, this validation only has effects for Adif.

This new Thales track circuit is currently being laid out and put into service on the ADIF network, in the Salamanca-Fuentes de Oñoro line, on the Parets-La Garriga section belonging to the Barcelona commuter network and at the Vicálvaro Merchandise terminal in the conventional network in Madrid. It will also be installed on the new section La Encina-Xátiva-Valencia High Speed line of the ADIF network. Additionally, a pilot installation has been carried out in Portugal, on the Amara-Benfica line, after the approval of the Portuguese Infrastructure for the deployment in that country.  In order to complete the validation process of Adif, Thales has deployed several pilots in the Railway Network of general interest (RFIG) as well as the implementation of the corresponding tests in accredited laboratories and tests on track, to verify the compliance with the requirements of train detection systems, based on audio-frequency track circuits.

For over 70 years, Thales has been a key supplier and pioneer of security systems and technological advances for Adif, the principal Spanish railway operator. Thales participated in the construction of the first Spanish high speed line between Madrid and Seville, inaugurated in 1992, and currently has a presence on the main high speed lines in Spain. More than 900 km of Adif railway is equipped with Thales ETCS L1 system; and Thales has signed 12 network maintenance contracts with Adif to oversee 2620 km of Spanish railway.