What is the CTC, the Adif control center that has failed and forced the suspension of train traffic again?

BarcelonaCercanías lives an unprecedented chaos. Service was scheduled to resume this Monday after 48 hours without trains and a chaotic week following the derailment in Gelida which cost the life of a young trainee train driver. Early this morning, Cercanías (commuter rail) began to "progressively" restart service, as announced yesterday by the Catalan government, but half an hour after the start, two consecutive incidents at Adif's Centralized Traffic Center (CTC), located at Barcelona's França station, prevented a return to normal service.

The first system outage occurred around 6:30 a.m. A few minutes later, the computer systems activated the emergency or backup system.backup [in English] and this resolved the issue temporarily. At 7:25 a.m., still in the middle of rush hour, the CTC suffered a second failure, which added even more chaos and confusion to the resumption of service, especially among passengers at the stations who didn't know where they were going, as there was little information available at the Renfe ticket offices, they point out. But what exactly is this control center, how does it work, and why is it key for Cercanías (commuter rail)?

What is the CTC?

We're talking about the Centralized Traffic Control Center (CTC) at França station: it's the core technological and IT system that serves as the nerve center for operations and runs the entire commuter rail service. It belongs to Adif, the state-owned company responsible for managing railway infrastructure. The CTC displays track conditions and train status, establishes routes, and manages traffic. Today, it suffered two consecutive failures: these are infrequent "computer crashes," but when they occur, they bring the entire network to a standstill. "It's as if all the traffic lights in Catalonia turned red at the same time," explained Antonio Carmona, spokesperson for Renfe, the commuter rail operator. It's infrequent, but it's not the first time the CTC has gone down during service. In September of 2022, the system suffered another outage that also affected the entire commuter rail network, leaving thousands of passengers unable to board trains. In that instance, the outage primarily affected radio communications with the trains, and it was concluded that the error occurred during a system update. In 2015 another failure caused similar effectsIn both cases, the government deemed the situation unacceptable and demanded "guarantees" that the problems "would not happen again." For its part, the company assured that it would upgrade its technology and double its emergency systems to prevent these failures from taking hours to resolve.

Origin of the blackout

At this point, Adif explains that they are still working and investigating to determine what may have caused the two failures this morning. For the moment, company spokespeople stated that no hypothesis is being ruled out: neither an error on their own nor the possibility of sabotage.

The Minister of Transport, Óscar Puente, went a little further in his explanations during an interview on TVE: "The system crashed twice and recovered thanks to the backup, but the resumption of service has obviously been hampered by this incident," he summarized. "We still don't know what happened, and all hypotheses are open; a cyberattack is also one of them, yes," Puente confirmed.