[rr2841]

What we know so far:

1. The last 3 cars from the Iryo train (Frecciarossa 1000) derailed for unknown reasons. It's a straight line, so this is extremely rare.

2. The Renfe train (Alvia) didn't have time to break and hit the derailed trains from Iryo, the two first cars derail as a consequence of the impact.

3. The Iryo train(Frecciarossa 1000), that caused the accident, was manufactured in 2022 and it passed a technical inspection just 4 days ago.

4. The renovation of this specific part of the infrastructure finished on May 2025, so it's practically new.

Spanish high speed trains are one of the best in the world and it had plenty investment from governments of different sign over the years. This has nothing to do with the regional network (Cercanias) and the local struggles in certain regions.

IMHO, this is a horribly timed accidental technical issue.

https://english.elpais.com/spain/2026-01-19/at-least-39-dead...

https://archive.ph/Ase0v

[t0mas88]

> 3. The Iryo train(Frecciarossa 1000), that caused the accident, was manufactured in 2022 and it passed a technical inspection just 4 days ago.

The inspection is a risk factor. There is data from the aviation industry for example that engine incidents on an engine that is certified for some thousands of hours of operation between inspection happen disproportionally in the first 100 hours (and then again at the end of the inspection interval). The inspection itself is an intervention that causes incidents.

[TaupeRanger]

Iatrogenesis is everywhere! Medicine, engineering, economics, politics, etc.

[impish9208]

I didn’t know this concept had a name, so thanks for that. Now I have a fancy sounding term to tell my manager why I won’t touch that ugly EnterpriseJavaBeans codebase and that we need to rewrite it from scratch.

[moralestapia]

That's not what Iatrogenesis means, though ...

Unless you plan to give medicine to your code.

[TaupeRanger]

“That’s not what Bug means though, unless you plan to put literal insects inside your computer”

[moralestapia]

Iatro- means medicine ...

Check a dictionary or something.

[IAmBroom]

Train inspections are far less intrusive. Wheel wear can be measured with calipers while standing beside the train. Software tests are physically null, except for alarms sounding. Brakeline tests can be verified without adding gauges; in many cases the braking mechanisms are externally observable.

Plane controls systems all live behind thin, deformable metal or plastic covers.

Trains aren't perfect, obv, but most train accidents reduce to "A human on the tracks fucked up". Drivers trying to maintain schedules by speeding, or vehicles or humans standing on rails where they had no business being (dodging crossing guards, suicide, etc).

[master_crab]

Came here to say. I don’t know enough about their inspection guidelines and how intrusive it is on the train’s systems, but anytime you do something outside the norm (including inspections) you introduce a variable that may have played a part.

[elnatro]

You left out that the machinists warned about the bad state of the railway tracks and asked for reducing the train speed[1].

There is underfunding in all the railway network.

[1]: https://www.eldebate.com/economia/20250809/maquinistas-piden...

[rr2841]

The machinist union requested the maximum speed to be lowered from 300 km/h to 250 km/h on multiple areas, the one where the accident happened being one of them. Both trains were driving under 210 km/h when the accident happened, so I don't think the "rattling" they reported was the issue.

As I mentioned before, this area was renovated last year, so attributing the accident to under-funding is highly unlikely. If the infrastructure happened to be the issue at the end, it might be because of different causes: eg. Planning the wrong materials for the amount of traffic / weather conditions / etc.

In general, when you talk about under-funding in the rail network it's often regional or small areas within the inter-city (larga distancia) and transport networks. High speed infrastructure is very well financed, it's not cheap to move trains close to 300 km/h.

[whizzter]

Doesn't need to be underfunding, may 2025 was last summer and this was the first winter, defects in laying the tracks didn't have a chance to show up until now.

The biggest part then might be that they should have listened to the operators warnings and scheduled a proper re-inspection of the route once they started warning of issues.

[1718627440]

> defects in laying the tracks didn't have a chance to show up until now.

Defects in laying the tracks have a chance to show up on an inspection, either the final one when building or one done at the regular intervals. If it doesn't shows up, your inspection is bad. If you can't inspect what you build, you can't build it.

[n3storm]

all in-laws experts in recession or vulcanology or bitcoin has turned to civil engineering experts.

[whizzter]

Not going to be claiming to be an expert, but buckling is a well documented phenomenon and I'd be surprised if there wasn't possible issues due to contraction on the other end of the spectrum when it gets colder, the track was laid this last spring/summer so it's probably not been as cold for long before on the tracks.

Also modern high speed rails are built with continious welding without thermal expansion joints.

https://www.youtube.com/watch?v=zqmOSMAtadc goes through track building and the effects and literally mentions at about 12:30 that they do need to do inspections when it gets cold if the track cracks (there was a photo linked in another post about a cracked track).

Is it the cause? No idea but doesn't feel far fetched.

Edit: Seems official investigators are now even pointing to that as an initial theory, https://www.reuters.com/world/europe/investigators-find-brok...

[anthk]

They fixed it long before this. That newspaper it's pretty much a right wing fake news source.

[axxto]

You seem very well informed, so I'm sure you've read that every single railway engineer and independent expert is saying that this seems like a freak accident and that the causes are totally unknown.

Knowing this, you're still all over the thread trying to score political points while there are dead people still on the tracks. One quick glance on your posting history is all one needs to see that you're happy to take any chance to do so, apparently including the death of at least 39 people. You disgust me. Y te creerás un "español de los buenos". Felicidades, patriota.

[logicallee]

>You left out that the machinists warned about the bad state of the railway tracks and asked for reducing the train speed

Since two trains collided, wouldn't that have happened regardless of the state of the railway tracks?

[whizzter]

The collision was due to one train derailing first, if that was due to the track (as mentioned in andy12_'s toplevel comment) then listening to warnings could perhaps have avoided the accident.

[zdragnar]

Could have, though both trains were going slower than what the mechanic union asked for. Either or wasn't a factor, or the conditions were even worse than all parties believed.

[whizzter]

Some have mentioned that the tracks were installed during may 2025, it's also the first winter so track issues and then thermal contraction could've cause too much strain.

[zdragnar]

Most recent reports indicate a broken weld on the track, so definitely possible damage from frost heave (is that a thing in the area it derailed?) or poor construction practices.

[Rygian]

One possible scenario is that the tracks fail in a way that causes one of the trains to derail and hit the other one.

[dust42]

There are reports from passengers that the train rattled before the accident. So my guess is a broken wheel rim and subsequently the train derailed at the track switch then also damaging the opposite track. Accident location: https://maps.app.goo.gl/Cek9DgChguXJxVpd6 The italian is about 400m north at the technical building with the two antennas.

[cft]

latest: https://www-elmundo-es.translate.goog/economia/2026/01/19/69...

looks like it's a rail welding failure.

[verytrivial]

Assuming no foul play, it's going to be a Points Failure, isn't it? Like Potters Bar (2002) where most of the train makes it through, but rattles/breaks some weak point that was just holding on, and the last carriages change tracks. But at 250mph. Shocking stuff.

[rayiner]

This is tragic, but I hope it doesn't put a damper on Spanish high-speed train development. They've really done a remarkable job building out their network in a cost-effective manner.

[Rygian]

In point number 3, you state that one of the trains caused the accident, whereas the cause of the accident is not yet known and could be for example an issue in the rails themselves.

[rr2841]

Yes, that was not accurate and you're correct, it's still not clear what caused the first train to derail to begin with.

The way I looked at it is that the first train derailing wasn't a big issue, I don't think it caused any injuries. What was really catastrophic was the impact with the second train.

[Rygian]

It is now confirmed that the cause of the accident was the welding on rail track number 23117.

https://www.abc.es/espana/andalucia/cordoba/via-l10717-salto...

[didntknowyou]

also the derailed carriages crashed rolled down a hill which complicated things further