Train derailment near Córdoba, Spain

[AlexNL]

No sign of the RENFE train coaches (although may have missed them).

As far as I'm aware, the coaches of the Alvia train were scrapped on site as they were not in a condition where they could be moved and there was nothing to be gained from trying to preserve them.

 

[chrisjo]

Listadotren.es

www.listadotren.es

 

[AlexNL]

Update:

Spain high-speed crash: possible rail break detected 22 hours before accident, but no alert triggered
Published on 2026-04-08 at 15:49

Spain’s infrastructure manager Adif picked up signs of a possible rail break on the track near Adamuz almost 22 hours before the deadly high-speed crash, but the alert was not triggered due to a “configuration” problem, according to a new report from Spanish law enforcement.
(...)
According to the report, investigators recorded an electrical disturbance “consistent with a break” at 21:46 on January 17, the evening before the crash.
(...)
Electrical data analysed by investigators shows that track voltage, typically around two volts, dropped to 1.5 volts from the moment the disturbance was recorded on January 17.
(...)
Hitachi Rail GTS Spain, the supplier responsible for the signalling system, said in a statement that while detecting a rail break was technically possible, the system would only issue an alert if the voltage dropped below 0.780 volts, the defined occupancy threshold.

Source and entire article: RailTech.com - Spain high-speed crash: possible rail break detected 22 hours before accident, but no alert triggered.

 

[Annetts key]

Update:


Source and entire article: RailTech.com - Spain high-speed crash: possible rail break detected 22 hours before accident, but no alert triggered.

If this is discussing the track circuit voltage, you have to be cautious about this report. Monitoring systems that I have worked on for track circuits only generate alarms/alerts if the track circuit voltage goes outside a defined range. The actual track circuit voltage may vary due to weather and ballast conditions (the highest voltage is when everything is bone dry, the lowest is during heavy rain or where the ballast is more like wet mud or or there is salt or mineral contamination). So some variation is normal. The alarms/alerts are I worked on in the U.K. were only used for maintenance purposes of the department responsible for the signalling equipment.

 

[Harpo]

I’ve known many instances of outright track circuit failure (signals at red etc.) where a broken rail has been found to be the cause, but can’t recall hearing of track circuits being used directly for rail condition monitoring.

Track circuits themselves have also been overtaken by axle counters, avoiding the costs of providing and maintaining insulation of rails from their surroundings.

 

[edwin_m]

A Web search throws up several systems that claim to monitor for broken rails. I don't know how effective or widespread they are.

 

[Annetts key]

A Web search throws up several systems that claim to monitor for broken rails. I don't know how effective or widespread they are.

As Harpo says, often a track circuit will detect a broken rail. However, the design of track circuits is not to intentionally do this. Track circuits are designed to detect when a section is clear of trains, nothing else.

There are many types of track circuit, some of which are less effective at detecting some types of break.

Furthermore, the bonding arrangements (where wires or cables "bypass" sections of rails) means that some breaks in the rail will not cause a break in that section to cause the track circuit to "fail" (show occupied). Indeed, some of these bonding arrangements (especially around points and crossings) are to prevent a broken rail from causing a train NOT to be detected (this type of bonding is called "parallel bonding").

Regardless of the track circuit type and the bonding arrangements, a track circuit cannot detect a break between where the cable or bond wire connects and the physical end of that steel rail (up to the insulated rail joint or IRJ). That's where you get breaks that expand from the fishplate bolt holes and cause the top of the rail to fall out once the crack gets to the top surface.

The U.K. railway has considered keeping track circuits as a broken rail detector, but hasn’t done so. Part of the reason would have been cost.

Note, I can't link to Network Rail documentation, as I don't think I have a copy and it's only available online to Network Rail staff who have access via a log-in.