What are the some of the ways that tracks are monitored for fractures like this? It must have been pretty substantial in order to be described as "complete lack of continuity". Makes me think of literally electronic continuity tests -- are those ever used in this context? Or how about cameras mounted on trains using image processing? Or drones?
It seems a shame that a few other trains passed beforehand with this anomaly in place and yet it went undetected.
You can look at the Wikipedia page on railway defect dectectors [0].
Under "rail break monitors" it mentions both electrical continuity and time-domain reflectometry can be used, and are most frequently used on high-speed tracks.
In addition, there are vast array of other detectors using acoustic sensors, strain gauges, accelerometers, cameras in the visible and infrared spectrum or laser measurement, that potentially could have detected an anomaly (i.e. damage to the wheels of other trains before the incident).
Wheel impacts are the main way. But hardware can be bulky and trains can be surprisingly cramped.
We squeezed some track condition monitoring hardware into some locos but it was single-driver operations locations and we cannibalised some of the room that would have otherwise been occupied by the second driver.
My gut feeling says a lot of fatalities could have been prevented with a physical barrier between both tracks. Shouldn't this be mandatory with high speed trains?
Pure economics. In Minneapolis the railroad demanded a crash wall to separate the light rail trains from their trains. It runs 1 mile and somehow cost nearly $100 million. This is a 5x increase from the original estimate but still $20 million for a 1 mile wall is a heck of a lot of money
While these events are statistically very rare, it is worth remembering that there have been two separate events in the past twenty years in Spain where high-speed trains have derailed leading to multiple fatalities [1][2]. In contrast, the Japanese Shinkansen has a spotless record since its introduction in the 1960s [3]. Not a single fatality due to a crash or derailment. And that's in a country with a much larger population and much higher passenger count per year.
My understanding is that Shinkansen that is high speed rail in Japan is grade separated system. That is tracks are only used by high speed rail. In Europe generally tracks are shared outside few specific links.
This means that Shinkansen tracks are designed and build to much higher standard.
Japanese rails are all built on commuter style architectures and the tracks are generally owned by its users. So train operators are strongly incentivized to keep them in good shape.
Also, Far East right now is also massively cash poor yet labor rich relative to the rest of the world. Everything is crazy undervalued and there are clear gaps between amounts of money changing hands vs work being done. Skilled-labor-intensive tasks are going to be much easier when cheap skilled labor is just perpetually available.
These events happening 4 times in 3 days are statistically nonexistent. Even less existent is them starting to happen right on the day before a major politician in Spain visits Israel to talk about buying Israeli security and monitoring systems.
I wonder how common it is for train tracks to fracture? And what systems are in place to actually detect this. There was recently a post on a German subreddit where the OP found a fracture in the German rail[0], albeit much smaller.
Rare, but not unheard of. See for example the Hatfield disaster in 2000, or the 2021 Ghotki rail crash.
Most railways regularly inspect their tracks to detect issues before they turn into a disaster. The big question here will be: why wasn't this caught earlier?
AFAIK continuously welded tracks (like those used in high speed rail) are also slightly tensioned, so a break in a single point could make it look like a whole section of track is missing, as tension is released.
Spain needs to rethink the way it operates trains. I think Switzerland
handles this better, overall, though they probably also don't have
as many fast trains because there are so many mountains. But I refer
more to the intrinsic quality control and assumption made. If I recall
correctly in Spain, there was the other train also coming in. I am
sure they could have built the tracks differently. Granted, the issue
here is cost, and an attempt to keep the cost down, but if you then
accept disasters like that, it seems really awkward to me to want to
save money here. And now that we know the track was already damaged,
that just adds more validity to questioning whether the quality control
systems were overall proper.
“…not only did Iryo train's front carriages which stayed on the track have "notches" in their wheels, but three earlier trains that went over the track earlier did too.”
This sounds like something a camera mounted on a sample of trains watching a wheel could catch.
An article published in Saturday's edition of the Mexican newspaper La Jornada provides more details about the cause of the crash. The article is in Spanish; here are some of the main points, translated into English:
1. According to the CIAF, the break in the track was "practically undetectable." The fracture on the track was not noticed by the trains that passed over it, or by the technicians responsible for the maintenance of the infrastructure.
2. The damaged train, which belongs to the Italian company Iryo, is heavier than other trains running on the track; the additional weight of the Iryo train may have been a factor, or possibly even one of the causes, of the derailment.
3. The CIAF said that the notches registered in the wheels and the deformation in the rail are "compatible" with the fact that the track was broken before the Iryo train passed over it.
4. Spanish Transportation Minister Óscar Puente rejected criticism of the delay of the rescuers; according to the Minister, rescuers arrived within "18 minutes."
On Spain’s conventional and high-speed rail network, inspection frequency is defined by ADIF rules and EU railway safety standards.
High-speed lines (AVE):
Visual and geometry inspections are performed daily to weekly using inspection trains and onboard measurement systems. Ultrasonic rail flaw detection is typically done every 1 to 3 months, depending on traffic and tonnage.
Source: ADIF high-speed maintenance programs and EU interoperability maintenance requirements.
~4 'derailing' accidents within 3 days, starting right before the president of the province of Madrid visits Israel to talk about buying Israeli security monitoring systems. Coincidence indeed.
31 comments
[ 32.1 ms ] story [ 309 ms ] threadIt seems a shame that a few other trains passed beforehand with this anomaly in place and yet it went undetected.
Under "rail break monitors" it mentions both electrical continuity and time-domain reflectometry can be used, and are most frequently used on high-speed tracks.
In addition, there are vast array of other detectors using acoustic sensors, strain gauges, accelerometers, cameras in the visible and infrared spectrum or laser measurement, that potentially could have detected an anomaly (i.e. damage to the wheels of other trains before the incident).
[0]: https://en.wikipedia.org/w/index.php?title=Defect_detector
We squeezed some track condition monitoring hardware into some locos but it was single-driver operations locations and we cannibalised some of the room that would have otherwise been occupied by the second driver.
Also the issues other comments described, including that any fault in the barrier means a new safety hazard
What do they do differently?
[1] https://en.wikipedia.org/wiki/Santiago_de_Compostela_derailm...
[2] https://en.wikipedia.org/wiki/2026_Adamuz_train_derailments
[3] https://en.wikipedia.org/wiki/Shinkansen#Safety_record
These are actually points making the Japanese system easier to maintain. Because of smaller surface area it’s much denser.
Japan having to build to earthquake standards, so being more robust overall? Or to specific failure modes, at least.
Accountability.
This means that Shinkansen tracks are designed and build to much higher standard.
Also, Far East right now is also massively cash poor yet labor rich relative to the rest of the world. Everything is crazy undervalued and there are clear gaps between amounts of money changing hands vs work being done. Skilled-labor-intensive tasks are going to be much easier when cheap skilled labor is just perpetually available.
These events happening 4 times in 3 days are statistically nonexistent. Even less existent is them starting to happen right on the day before a major politician in Spain visits Israel to talk about buying Israeli security and monitoring systems.
0. https://old.reddit.com/r/drehscheibe/comments/1qe9ko2/ich_gl...
Most railways regularly inspect their tracks to detect issues before they turn into a disaster. The big question here will be: why wasn't this caught earlier?
Spain needs to rethink the way it operates trains. I think Switzerland handles this better, overall, though they probably also don't have as many fast trains because there are so many mountains. But I refer more to the intrinsic quality control and assumption made. If I recall correctly in Spain, there was the other train also coming in. I am sure they could have built the tracks differently. Granted, the issue here is cost, and an attempt to keep the cost down, but if you then accept disasters like that, it seems really awkward to me to want to save money here. And now that we know the track was already damaged, that just adds more validity to questioning whether the quality control systems were overall proper.
https://people.com/train-collides-with-crane-arm-in-4th-rail...
It's clear some of them are probably caused by neglect in maintenance, others are freak accidents.
It's pretty crazy the statistical probabilities involved for something like this.
This sounds like something a camera mounted on a sample of trains watching a wheel could catch.
1. According to the CIAF, the break in the track was "practically undetectable." The fracture on the track was not noticed by the trains that passed over it, or by the technicians responsible for the maintenance of the infrastructure.
2. The damaged train, which belongs to the Italian company Iryo, is heavier than other trains running on the track; the additional weight of the Iryo train may have been a factor, or possibly even one of the causes, of the derailment.
3. The CIAF said that the notches registered in the wheels and the deformation in the rail are "compatible" with the fact that the track was broken before the Iryo train passed over it.
4. Spanish Transportation Minister Óscar Puente rejected criticism of the delay of the rescuers; according to the Minister, rescuers arrived within "18 minutes."
The full article is available here: https://www.jornada.com.mx/2026/01/24/mundo/020n3mun
High-speed lines (AVE): Visual and geometry inspections are performed daily to weekly using inspection trains and onboard measurement systems. Ultrasonic rail flaw detection is typically done every 1 to 3 months, depending on traffic and tonnage.
Source: ADIF high-speed maintenance programs and EU interoperability maintenance requirements.