5 ms·

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 w

by sva_ 9mo ago

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. 0. https://old.reddit.com/r/drehscheibe/comments/1qe9ko2/ich_glaube_das_soll_nicht_so/ https://old.reddit.com/r/drehscheibe/comments/1qe9ko2/ich_gl...

iSnow 9mo ago
In November, a bigger missing part of a train track was due to sabotage: https://www.bbc.com/news/articles/cp85g86x0zgo https://www.bbc.com/news/articles/cp85g86x0zgo
- red75prime 9mo ago
  It happened near Polish-Ukrainian border and officials were vocal about sabotage.
- dmix 9mo ago
  That’s pretty far from Spain
mschuster91 9mo ago
> I wonder how common it is for train tracks to fracture? That entirely depends on which class of tracks we're talking about. And on top of that, remember that Europe is at war with Russia, railway sabotage has been attributed to Russia already in Poland [1] - and if you ask me, I don't believe for a single goddamn second that "cable thieves" were the cause behind the infamous 2022 attack on Germany's railways [2] either. > And what systems are in place to actually detect this. In Germany, dedicated railway cars called "RAILab" [3] that can measure track performance at up to 200 km/h perform the bulk of the work. In addition, each piece of infrastructure has something called an "Anlagenverantwortlicher", a person responsible for it - and that person has to walk each piece of infrastructure every two years at the very least, sections that have shown to be problematic get walked sometimes weekly. [1] https://www.bbc.com/news/articles/c4gknv8nxlzo https://www.bbc.com/news/articles/c4gknv8nxlzo [2] https://en.wikipedia.org/wiki/October_2022_German_railway_attack https://en.wikipedia.org/wiki/October_2022_German_railway_at... [3] https://de.wikipedia.org/wiki/RAILab https://de.wikipedia.org/wiki/RAILab
- crote 9mo ago
  Copper theft has been a recurring problem in multiple European countries for well over a decade. Railway outages caused by damaged cabling increased as the copper price rose, and decreased as police cracked down on scrap dealers accepting railway cabling without proper provenance. Damaged aluminum and fiber cables are also common, as thieves usually aren't exactly the smartest people. The German Federal Police has nothing to gain by lying about this incident. They explicitly investigated the possibility of foreign sabotage, found the perpetrators, and concluded that it was just regular theft. Sometimes a horse is just a horse, even when there are zebras running around.
  - mschuster91 9mo ago
    > The German Federal Police has nothing to gain by lying about this incident. And yet, there are multiple different theories floating around on who bombed North Stream. The police and DA assume that Ukrainians were behind this mess, possibly under orders of back-then UA army chief Zaluzhnyi according to leaks and rumors, but official communication on that has been ... lacking and that's putting it mildly. It doesn't help that there are credible suspicions of Russia being behind it either, the only theory I'd move to the "conspiracy bin" is that it was a CIA operation. When it comes to anything involving this war, there really is no reason to trust anyone. > They explicitly investigated the possibility of foreign sabotage, found the perpetrators, and concluded that it was just regular theft. Sometimes a horse is just a horse, even when there are zebras running around. I agree... but still, the timing is so incredibly close that it's just as possible that for once the cable thieves were capable of good OPSEC practices.
blibble 9mo ago
> I wonder how common it is for train tracks to fracture? very > And what systems are in place to actually detect this. track circuit detection would pick up most cases I would have thought
- crote 9mo ago
  Yes, but it would be shown as a false "block occupied" signal. Which could also have plenty of other causes, such as broken cabling or defective track circuit equipment, and as the Weyauwega disaster taught us it wouldn't detect a partial break. Provided track circuit detection is even used, of course. I vaguely recall it not being compatible with either 25kV electrification or high-speed rail in general, and most modern tracks therefore using axle counters instead.
  - iggldiggl 9mo ago
    > I vaguely recall it not being compatible with either 25kV electrification or high-speed rail in general, and most modern tracks therefore using axle counters instead. Track circuits aren't incompatible with that per se, but axle counters are simply easier to install and much more maintenance-friendly – no longer having to worry about - mixing track circuit currents and traction return currents together - having to keep the rails sufficiently isolated from the ground and each other to prevent the track circuits from falsely showing occupied - insulated block joints - having to use each bit of track once every twenty-four hours to prevent rust from falsely showing a track as clear - extreme leaf fall and/or sanding potentially causing false clears, too - length restrictions on the maximum length of a single track circuit, although that's only really a problem on more sparse trafficked lines with long block sections In return, axle counters have the drawback that they - don't detect broken rails (although it needs to be said that track circuits very much aren't perfect broken rail detectors, either) - can be falsely reset (with more or less protections, depending on local operating practices) - don't detect maintenance vehicles freshly placed upon a track until they enter the next axle counter section but since most to almost all new installations seem to use axle counters, the trade-offs are apparently worth it to infrastructure operators.
bahmboo 9mo ago
Nice find. The gap in the Spanish track is massive. I don’t know enough to speculate on technical reasons but it seems quite odd.
- laurencerowe 9mo ago
  Rails expand and contract according to the temperature (11mm per degree C per km). They are continuously welded together and installed under tension and heated to a neutral / median temperature for the location. It was around 0C that night in an area that gets up to 47C (and rails might get hotter under the sun) so there was at least 300mm of contraction per kilometre of rail.
- crote 9mo ago
  The rail fractured into pieces during the derailment. You can see some of those pieces lying around in the photographs. As the article notes: the initial break left marks on the wheels of several previous trains. The final gap is big enough that no train could possibly make it past it, so it is pretty clear that the gap got larger as the incident progressed.
dv_dt 9mo ago
Fractures could happen with ground shifting - perhaps recent flooding could have contributed
crote 9mo ago
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?

by sva_ 9mo ago

iSnow 9mo ago

In November, a bigger missing part of a train track was due to sabotage: https://www.bbc.com/news/articles/cp85g86x0zgo https://www.bbc.com/news/articles/cp85g86x0zgo

red75prime 9mo ago
It happened near Polish-Ukrainian border and officials were vocal about sabotage.
dmix 9mo ago
That’s pretty far from Spain

mschuster91 9mo ago

> I wonder how common it is for train tracks to fracture? That entirely depends on which class of tracks we're talking about. And on top of that, remember that Europe is at war with Russia, railway sabotage has been attributed to Russia already in Poland [1] - and if you ask me, I don't believe for a single goddamn second that "cable thieves" were the cause behind the infamous 2022 attack on Germany's railways [2] either. > And what systems are in place to actually detect this. In Germany, dedicated railway cars called "RAILab" [3] that can measure track performance at up to 200 km/h perform the bulk of the work. In addition, each piece of infrastructure has something called an "Anlagenverantwortlicher", a person responsible for it - and that person has to walk each piece of infrastructure every two years at the very least, sections that have shown to be problematic get walked sometimes weekly. [1] https://www.bbc.com/news/articles/c4gknv8nxlzo https://www.bbc.com/news/articles/c4gknv8nxlzo [2] https://en.wikipedia.org/wiki/October_2022_German_railway_attack https://en.wikipedia.org/wiki/October_2022_German_railway_at... [3] https://de.wikipedia.org/wiki/RAILab https://de.wikipedia.org/wiki/RAILab

crote 9mo ago
Copper theft has been a recurring problem in multiple European countries for well over a decade. Railway outages caused by damaged cabling increased as the copper price rose, and decreased as police cracked down on scrap dealers accepting railway cabling without proper provenance. Damaged aluminum and fiber cables are also common, as thieves usually aren't exactly the smartest people. The German Federal Police has nothing to gain by lying about this incident. They explicitly investigated the possibility of foreign sabotage, found the perpetrators, and concluded that it was just regular theft. Sometimes a horse is just a horse, even when there are zebras running around.
- mschuster91 9mo ago
  > The German Federal Police has nothing to gain by lying about this incident. And yet, there are multiple different theories floating around on who bombed North Stream. The police and DA assume that Ukrainians were behind this mess, possibly under orders of back-then UA army chief Zaluzhnyi according to leaks and rumors, but official communication on that has been ... lacking and that's putting it mildly. It doesn't help that there are credible suspicions of Russia being behind it either, the only theory I'd move to the "conspiracy bin" is that it was a CIA operation. When it comes to anything involving this war, there really is no reason to trust anyone. > They explicitly investigated the possibility of foreign sabotage, found the perpetrators, and concluded that it was just regular theft. Sometimes a horse is just a horse, even when there are zebras running around. I agree... but still, the timing is so incredibly close that it's just as possible that for once the cable thieves were capable of good OPSEC practices.

blibble 9mo ago

> I wonder how common it is for train tracks to fracture? very > And what systems are in place to actually detect this. track circuit detection would pick up most cases I would have thought

crote 9mo ago
Yes, but it would be shown as a false "block occupied" signal. Which could also have plenty of other causes, such as broken cabling or defective track circuit equipment, and as the Weyauwega disaster taught us it wouldn't detect a partial break. Provided track circuit detection is even used, of course. I vaguely recall it not being compatible with either 25kV electrification or high-speed rail in general, and most modern tracks therefore using axle counters instead.
- iggldiggl 9mo ago
  > I vaguely recall it not being compatible with either 25kV electrification or high-speed rail in general, and most modern tracks therefore using axle counters instead. Track circuits aren't incompatible with that per se, but axle counters are simply easier to install and much more maintenance-friendly – no longer having to worry about - mixing track circuit currents and traction return currents together - having to keep the rails sufficiently isolated from the ground and each other to prevent the track circuits from falsely showing occupied - insulated block joints - having to use each bit of track once every twenty-four hours to prevent rust from falsely showing a track as clear - extreme leaf fall and/or sanding potentially causing false clears, too - length restrictions on the maximum length of a single track circuit, although that's only really a problem on more sparse trafficked lines with long block sections In return, axle counters have the drawback that they - don't detect broken rails (although it needs to be said that track circuits very much aren't perfect broken rail detectors, either) - can be falsely reset (with more or less protections, depending on local operating practices) - don't detect maintenance vehicles freshly placed upon a track until they enter the next axle counter section but since most to almost all new installations seem to use axle counters, the trade-offs are apparently worth it to infrastructure operators.

bahmboo 9mo ago

Nice find. The gap in the Spanish track is massive. I don’t know enough to speculate on technical reasons but it seems quite odd.

laurencerowe 9mo ago
Rails expand and contract according to the temperature (11mm per degree C per km). They are continuously welded together and installed under tension and heated to a neutral / median temperature for the location. It was around 0C that night in an area that gets up to 47C (and rails might get hotter under the sun) so there was at least 300mm of contraction per kilometre of rail.
crote 9mo ago
The rail fractured into pieces during the derailment. You can see some of those pieces lying around in the photographs. As the article notes: the initial break left marks on the wheels of several previous trains. The final gap is big enough that no train could possibly make it past it, so it is pretty clear that the gap got larger as the incident progressed.

dv_dt 9mo ago

Fractures could happen with ground shifting - perhaps recent flooding could have contributed

crote 9mo ago

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?