Train derailment near Córdoba, Spain

[mpthomson]

In almost all railway accidents, the immediate cause (what happened) is quickly apparent and can be deduced by most railway professionals or even in many cases by enthusiasts, from a few clear pictures of the aftermath. The main job of investigators is far more complex - to establish the root causes - ‘why did it happen?’…

He's guessing, unless he's on the ground in Spain and has access to the investigation. And we can safely assume that he's not and doesn't.

== Doublepost prevention - post automatically merged: 19 Jan 2026 ==

It's hardly uninformed speculation given who the speculation is from.

Without access to the investigation that's exactly what it is...

 

[azOOOOOma]

Do we think that the Renfe collided almost immediately after the derailment of the Iryo?

Just in 2026 I would suspect everyone to be videoing/live-streaming on Iryo and for there to be footage or audio of the collision.

The lack of this makes me wonder if it was all super quick and that there was no time between derailment and collision.

Given that in recent years we’ve had someone livestreaming an actual plane crash (!) and also someone filming their escape from an upside down crashed jet, I find it odd that there’s a lack of audio/video of a collision.

 

[Peterthegreat]

He's guessing, unless he's on the ground in Spain and has access to the investigation. And we can safely assume that he's not and doesn't.

== Doublepost prevention - post automatically merged: 19 Jan 2026 ==


Without access to the investigation that's exactly what it is...

Totally agree. He may very well be right but he is implying it as fact and not his own opinion.

 

[physics34]

Without speculating as to why it does appear that the rear of the northbound IRYO train derailed partially fouling the southbound track. The RENFE train then made a glancing blow on the wreckage derailing it to the right and buckling those coaches.
It’s evident that the wreckage of the RENFE train is some distance south of the IRYO one.
Sorry if this is obvious to many already but I’ve not seen any aerial shots until recently.

It looks like the Renfe train was partically derailed by the glancing blow of the nortbound derailed train and then fully derailed at the start of a set of points.

 

[Nippy]

Thank you!

I've found another video that perhaps shows where the collision might have taken place. It looks to my uneducated eye like a potential glancing blow, which would explain why the Iryo train is relatively undamaged.

View attachment 196172

If you pause the video right at the very end you can see what appears to be the facing connection (in the top right of the screen) coming from the adjacent line just ahead of where the Renfe train has come to rest. The connection appears to very badly damaged.

 

[Jamesrob637]

Do we think that the Renfe collided almost immediately after the derailment of the Iryo?

Just in 2026 I would suspect everyone to be videoing/live-streaming on Iryo and for there to be footage or audio of the collision.

The lack of this makes me wonder if it was all super quick and that there was no time between derailment and collision.

Given that in recent years we’ve had someone livestreaming an actual plane crash (!) and also someone filming their escape from an upside down crashed jet, I find it odd that there’s a lack of audio/video of a collision.

On a dark Sunday in January, many were probably reading or snoozing.

 

[cambsy]

I think a fractured rail, from looks of it caused this terrible derailment and train wreck, then just extremely bad luck, meant a train travelling at high speed in the opposite direction, was too close to stop in time. I dont think any signalling system would have stopped the RENFE train as was too close to Slow down enough in time too make this accident a lot less severe. Can all rail fractures be detected with right ultrasound and detection equipment, or can certain fractures remain insidiously undetectable till they break? is rail fractures just a risk of travelling by train which can never be totally eliminated? I still see rail travel as very safe, just disaasters like these make ones think a bit about safety.

 

[chrisjo]

If you pause the video right at the very end you can see what appears to be the facing connection (in the top right of the screen) coming from the adjacent line just ahead of where the Renfe train has come to rest. The connection appears to very badly damaged.

If you look on Google maps satellite view you can see where the points north and south of the 'station' are. They are not there.

 

[williamn]

Totally agree. He may very well be right but he is implying it as fact and not his own opinion.

That's not like Gareth!

 

[chrisjo]

Just in 2026 I would suspect everyone to be videoing/live-streaming on Iryo and for there to be footage or audio of the collision.

It seems from the few interviews with survivors (quoted in El Pais, etc.), that the Iryo derailment was still happening when the Renfe train hit it.

BBC live says "We were in carriage five (Iryo) and we started to feel some banging on the track, nothing unusual," he tells Spanish news broadcaster, La Sexta Noticias. Then, the banging became louder, he says. Another train passed us and everything started vibrating. There was a jolt behind us and the feeling that the whole train was going to fall apart"

 

[Smwrff]

Totally agree. He may very well be right but he is implying it as fact and not his own opinion.

Gareth is not guessing - he has considered the available video evidence and presented a realistic hypothesis. He may not be on the ground or part of any official investigation but his hypothesis appears to be credible.

I expect that the final official investigation will not vary by much.

 

[DerekC]

Gareth is not guessing - he has considered the available video evidence and presented a realistic hypothesis. He may not be on the ground or part of any official investigation but his hypothesis appears to be credible.

I expect that the final official investigation will not vary by much.

But even if Gareth is right about what happened during the crash, he can't and shouldn't speculate as to which of the various underlying causes is relevant to this particular event, and that's the really important bit of the accident report. Speculation by "experts" is wrong in these circumstances - and it's the fact that contributors to this forum might be considered expert that I am sure makes the mods keep reminding us of that. In the case of the Santiago crash, headlines screaming "driver error" helped the Spanish authorities cover up the real underlying causes. Providing reasoned information as to what the various causes could be and making it clear that the conclusions must be based on the evidence can help, however.

 

[Peterthegreat]

But even if Gareth is right about what happened during the crash, he can't and shouldn't speculate as to which of the various underlying causes is relevant to this particular event, and that's the really important bit of the accident report. Speculation by "experts" is wrong in these circumstances - and it's the fact that contributors to this forum might be considered expert that I am sure makes the mods keep reminding us of that. In the case of the Santiago crash, headlines screaming "driver error" helped the Spanish authorities cover up the real underlying causes. Providing reasoned information as to what the various causes could be and making it clear that the conclusions must be based on the evidence can help, however.

Absolutely. Couldn't have written a better response myself.

 

[Failed Unit]

It looks like the Renfe train was partically derailed by the glancing blow of the nortbound derailed train and then fully derailed at the start of a set of points.

I think this is similar to great Heck with respect that there was no time to stop the train in the opposite direction before the impact. No signal system in the world could have stopped the Renfe train. If it was 5 minutes later it is very possible we wouldn't be looking much better situation. Sadly an unfortuanate set of circumstances.

 

[edwin_m]

Without speculating as to why it does appear that the rear of the northbound IRYO train derailed partially fouling the southbound track. The RENFE train then made a glancing blow on the wreckage derailing it to the right and buckling those coaches.
It’s evident that the wreckage of the RENFE train is some distance south of the IRYO one.
Sorry if this is obvious to many already but I’ve not seen any aerial shots until recently.

I'm thinking this separation may suggest the IRYO was still moving. The RENFE train would have come to a stop pretty quickly when it was derailed into a ditch, but the IRYO was partly on the rails and partly sliding along them so could have continued some way before it came to a stop.

An alternative explanation for the rail gap pictured above might be that there was only a single break, but as the rail was at least partly rolled over and released from the fastenings, the fracture surfaces could have moved away from the break due to forces from the wheels or from thermal contraction when no longer under tension and colder than Critical Rail Temperature. The actual break could have been a result of the accident, but I think the lack of any other damage in the vicinity makes that unlikely.

 

[The Prisoner]

For the people speculating as to the time taken for the Renfe service to hit the Iryo one it was 20 seconds according to the BBC https://www.bbc.co.uk/news/articles/clye22ljxw4o so not enough to be able any sort of meaningful action. We don't know, but it's highly possible that the driver of the second service may well have slammed the brakes on and ultimately saved lives in doing so (in which case they are undoubtedly a hero).

I can't quote the article as the 20 seconds reference is made in a graphic as attached.

 

[BahrainLad]

Quite a few videos emerging of apparently extremely rough riding on this section of line in recent weeks. Certainly rougher than I’ve ever witnessed on LGV Nord, for example.

 

[Angmering1974]

The failure of a track weld at kilometer 318.7, specifically on track L-10717 number 23117 as it passes through Adamuz (Córdoba), is the cause of the derailment of the Iryo 6189 train, as confirmed by investigators, ABC has learned.

El raíl número 23117 saltó e hizo descarrilar al tren Iryo en el trágico accidente de Adamuz, en Córdoba

Los investigadores ya han corroborado que la soldadura del raíl en el kilómetro 318,7 se rompió y ahora se centran en averiguar la razón

www.abc.es

As a total layman: why would a track be welded at all versus just replacing a piece of track?

 

[MarkyT]

It's possible facing points south of the impact site contributed to the spread of the southbound train wreckage. If some axles had been derailed in the initial collision, once those wheels got to the turnout area, bouncing along the sleepers, they may have been diverted sideways more radically when hitting the turnout rails, as at Ufton Nervet in 2004.

In another turnout-related incident, the Gotthard base tunnel derailment of 2023, a single broken axle with a wheel dragging in the four foot made contact with components of a point machine linkage resulting in the switches moving from the straight to turnout position under the train, diverting following freight vehicles into a crossover tunnel, where they derailed and piled up, damaging the airtight safety door.

 

[Annetts key]

El raíl número 23117 saltó e hizo descarrilar al tren Iryo en el trágico accidente de Adamuz, en Córdoba

Los investigadores ya han corroborado que la soldadura del raíl en el kilómetro 318,7 se rompió y ahora se centran en averiguar la razón

www.abc.es

As a total layman: why would a track be welded at all versus just replacing a piece of track?

Rails are welded together on high speed lines. It's a more robust solution compared to fishplated joints.

 

[Angmering1974]

Rails are welded together on high speed lines. It's a more robust solution compared to fishplated joints.

Ahh thank you

 

[westcoaster]

El raíl número 23117 saltó e hizo descarrilar al tren Iryo en el trágico accidente de Adamuz, en Córdoba

Los investigadores ya han corroborado que la soldadura del raíl en el kilómetro 318,7 se rompió y ahora se centran en averiguar la razón

www.abc.es

As a total layman: why would a track be welded at all versus just replacing a piece of track?

Does anyone know the distance between this and where it stopped (IRYO train).

 

[neonison]

Given that it’s RH running this looks like a trailing crossover.

https://maps.app.goo.gl/eKDVPhpgr314Bd7r9?g_st=ic

 

[westcoaster]

El raíl número 23117 saltó e hizo descarrilar al tren Iryo en el trágico accidente de Adamuz, en Córdoba

Los investigadores ya han corroborado que la soldadura del raíl en el kilómetro 318,7 se rompió y ahora se centran en averiguar la razón

www.abc.es

As a total layman: why would a track be welded at all versus just replacing a piece of track?

If you cross reference the milage with the picture @yorkie posted on page one (the signalling panel).
Would that make the point of derailment between the tunnel exit and the facing crossover. The tunnel has the milage above it.

Also i never noticed in the aforementioned picture, how much of the line is in red showing the line occupied, all the way back to the tunnel and out the other side.

 

[35B]

Gareth is not guessing - he has considered the available video evidence and presented a realistic hypothesis. He may not be on the ground or part of any official investigation but his hypothesis appears to be credible.

I expect that the final official investigation will not vary by much.

I agree with @DerekC. There's an additional point, though. He has a hypothesis. That means something that falls short of a theory, and a theory falls short of being a fact. "I believe X happened because of A, B and C" is very different from "X happened because of A, B, and C". As a professional engineer, he should know that.

 

[chrisjo]

'The failure of a track weld at kilometer 318.7, specifically on track L-10717 number 23117 as it passes through Adamuz (Córdoba), is the cause of the derailment of the Iryo 6189 train, as confirmed by investigators, ABC has learned'

The ABC report then goes on to say that the break was caused by something wrong on the underside of car #6 of the Iryo train, so we're back into the world of unsubstantiated speculation AGAIN.

 

[Angmering1974]

'The failure of a track weld at kilometer 318.7, specifically on track L-10717 number 23117 as it passes through Adamuz (Córdoba), is the cause of the derailment of the Iryo 6189 train, as confirmed by investigators, ABC has learned'

The ABC report then goes on to say that the break was caused by something wrong on the underside of car #6 of the Iryo train, so we're back into the world of unsubstantiated speculation AGAIN.

You're right to point this out. But you say "was caused by". Is that confirmed or speculation? The article is paywalled for me now

 

[lfc84]

El raíl número 23117 saltó e hizo descarrilar al tren Iryo en el trágico accidente de Adamuz, en Córdoba

Los investigadores ya han corroborado que la soldadura del raíl en el kilómetro 318,7 se rompió y ahora se centran en averiguar la razón

www.abc.es

The ABC website link above has one paragraph which translates as follows:

Initial on-site investigations and passenger testimonies suggest that the derailment may have been caused by a weight being pulled by carriage 6 of the Iryo train. Witnesses traveling in that carriage (the one that derailed, pulling carriages 7 and 8 along with it) reported feeling strange disturbances in the carriage shortly before the accident. For this reason, it is believed that the train was pulling an extra weight (attached to the underside of the carriage) which, upon contact with the track, caused it to break and derail.

 

[MarkyT]

Given that it’s RH running this looks like a trailing crossover.

https://maps.app.goo.gl/eKDVPhpgr314Bd7r9?g_st=ic

I think the Renfe train wreckage ended up ~1.5km further south, where there is a facing crossover, and the surrounding landscape seems to match the photos better.

 

[Annetts key]

'The failure of a track weld at kilometer 318.7, specifically on track L-10717 number 23117 as it passes through Adamuz (Córdoba), is the cause of the derailment of the Iryo 6189 train, as confirmed by investigators, ABC has learned'

The ABC report then goes on to say that the break was caused by something wrong on the underside of car #6 of the Iryo train, so we're back into the world of unsubstantiated speculation AGAIN.

You have to be careful drawing conclusions from these initial reports. The rail (weld) may have failed, then a further failure of the rail may have occurred.

A typical failure of a rail (as in break due to a stress defect) normally does not result in a derailment if the resulting gap between the different broken rails is small. Which if the rail has been stressed correctly should be the case (all the broken rails of this type that I have seen have had gaps of 10mm or less).

However, if the sleepers are not well packed or not in good condition, or if the break occurs near a existing weld, or there are cracks or other defects in the rail, there is a possibility that the hammering caused by a fast or heavy train passing over the defect will cause another break. This increases the likelihood of a derailment. How much depends on how big the overall gap is.