Spain’s high-speed train network is plagued by old signalling systems. They may have caused the deadly crash
The crash has killed 69 people, and injured scores more.
Shortly after 8am, two high-speed trains set off from Madrid’s Atocha station bound for Seville Santa Justa, but neither reached their destination. A failure in the LZB system – an automatic safety, signalling and protection system that monitors trains’ movement and activates automatic emergency braking – triggered a chain of events that led to a fatal accident, which killed 69 people and left many more injured.
Across the EU’s rail network, which spans almost 227,000km, there are more than 25 different, non-interoperable railway signalling systems. These systems (which include the German LZB, the French Crocodile, the Italian BACC and the Spanish ASFA) control and enable the safe movement of trains via blocks, sections of the track that can only have one train on them at any given moment.
On the Andalusia–Madrid line, the German LZB signalling system remains in operation, pending its replacement by the European Rail Traffic Management System (ERTMS) that is already in place on other, more modern lines.
The ERTMS specifications are set out in EU legislation. The aim is for this system to completely replace national ones across the entire EU by 2050.
In Spain, the ERTMS system is already in use on the Madrid–Barcelona and Madrid–Levante lines, which were the first to be opened up to private rail companies like France’s Ouigo.
The Madrid–Andalusia line is the only one that still uses the LZB system. More modern trains operating on this line have to “read” the signals managed by this system. This is done through a technical workaround, without which other companies would not be able to operate.
LZB failures
In the weeks and days leading up to the October 28 accident, LZB system failures caused many trains to come to a standstill on the tracks. This was what caused the two trains – one from Spain’s state-owned Renfe, the other from the private rail company Iryo – to collide. The accident took place near Urda, a town in Toledo less than 150km from Madrid, where track supervision was under the control of Madrid’s Atocha traffic control centre.
When the signalling system fails, the control centre orders trains to stop. Once the situation has been assessed, the trains resume running, with trackside beacons providing information to drivers.
The driver must follow the instruction from the control centre, which is generally to run on-sight. This means travelling at a maximum speed of 40km/h, so the train can stop if it encounters poor visibility or any potential obstacles on the track.
Audio recordings between the drivers’ cabs and the control centre have emerged, in which the driver of the AVE train was apparently authorised to proceed at “normal speed”. The driver of the Iryo train reported that the train could not check the LZB system, and that this was why the train was stationary in front of the signal (which was showing red, and thus presumed to be closed).
The Iryo driver was told to remain there and, in the event of any problems, to call again. It does not seem that the train was then permitted to resume the journey.
Measurements taken on the afternoon of the accident suggest that the collision may have occurred at a speed of between 170 and 180km/h, which supports the theory that the AVE train was not travelling at the correct speed.
The presence of an embankment and the force of the impact caused virtually the entire front section of the AVE train and the rear section of the Iryo train to be destroyed, along with the adjoining carriages. The crash occurred on a stretch of track with good visibility, which was mostly straight and surrounded by open fields.
An investigation is now underway into the actions of the traffic controller and the frequency of train passages at that time, as well as the orders given to the trains involved in the collision.
Spain’s deteriorating high-speed train system
After the Adamuz disaster in January this year, passenger traffic on the Madrid-Seville line fell by more than 30%. The decline was less severe on Spain’s other high-speed routes.
Spain was a pioneer in the roll-out of high-speed trains. It began in 1992 with just over 470 kilometres of track between Madrid and Seville, and will have more than 4,000 kilometres by 2026. In 2026, however, running speeds have been reduced as a precaution due to deteriorating infrastructure, and delays have become common.
Spain’s rail network operator, Adif, and the State must urgently prioritise the maintenance of existing infrastructure before opening new lines. New lines mean more maintenance requirements for tracks, cable and safety systems, all within a sector that has been partially opened up to privatisation in recent years. Safety must take precedence over expansion targets, which could ultimately undermine the quality and safety of the service.
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