Toledo crash probe focuses on control error

The rear-end collision occurred at 08:53 on 28 October near Urda on the Madrid–Seville high-speed line. A Renfe AVE struck an Iryo train that was stationary on the same track. According to the preliminary account presented by Spanish Transport Minister Óscar Puente, the chain of events began at around 08:30, when the LZB train control system failed following a computer communications problem. The failure affected a section of around 69 kilometres and automatically brought several trains in the area to a halt. With LZB unavailable, management of train movements passed to Adif's control centre in Madrid Atocha. AVE allowed to resume normal running At around 08:36, the Renfe AVE involved in the accident was authorised to resume its journey under normal running conditions. The Iryo train ahead, however, remained stationary near Urda following a loss of transmission. According to reports based on communications between the drivers and the control centre, Adif was informed at around 08:41 that the Iryo had not resumed its journey. Its driver later reported again that the train was still stopped before the entry signal. At 08:53, around 17 minutes after the AVE had been authorised to continue, it struck the rear of the Iryo train. Puente described the decision to allow the AVE to resume normal running as erroneous and said the circumstances in which it was taken would be central to the investigation. Under the fallback procedure described by the minister, trains operating without LZB protection should have continued under restrictive conditions, including running on sight at a speed of no more than around 40 km/h. The investigation will now have to establish why the AVE was instead authorised to proceed normally and how information about the stopped Iryo was handled by the control centre. LZB failure not enough to explain collision The signalling failure itself is therefore not currently being treated as a complete explanation for the accident. LZB is designed so that trains stop when continuous supervision is lost. That appears to have happened as intended when the system failed on Wednesday morning. The focus has consequently shifted to the decisions made after automatic protection was no longer available. Investigators are examining communications between the drivers and Adif controllers, data from the trains and infrastructure systems, and the sequence of instructions issued before the collision. A technical investigation is being carried out alongside the judicial investigation led from Orgaz in Toledo province. Authorities have stressed that the preliminary reconstruction does not constitute a final determination of responsibility. The Madrid–Seville high-speed line still uses the LZB train control system, introduced when the route opened in the early 1990s. Spain is in the process of replacing it with the European ERTMS system. Madrid–Andalusia line remains closed The death toll had reached at least 68 people by Thursday morning, while rescuers continued searching the wreckage and authorities warned that further victims could still be found. High-speed traffic between Madrid, Ciudad Real and Andalusia remains suspended, with no confirmed date for reopening the affected section. Renfe has introduced conventional services between Madrid, Ciudad Real and Puertollano, adding around 90 minutes to journey times. From 30 October, the operator plans to introduce a wider alternative transport plan between Madrid and Andalusia while the high-speed line remains unavailable.