The liberalization of the tracks and the multiplication of the number of trains that have to pass through them is the reason why a track fractured at high speed near Adamuz, Córdoba, causing an accident that has ended with 45 deaths and 22 people in the hospital, five of them in the ICU.
That is the position, at least preliminary, of Iñaki Barrón, president of CIAF, entity in charge of the investigation of the biggest railway accident in our country since train derailment in Angrois (Santiago de Compostela) that ended the lives of 80 people.
With the first investigations on the table, the indications suggest that the Iryo train derailed due to a fracture in a weld between rails carried out during the renovation last May. The fracture would have left traces on the first carriages of the Italian train and on the trains that circulated on that track that same day.
At the time of the derailment, an Alvia train was traveling in the opposite direction and passed in a very short period of time (there was talk of 20 seconds at first but now it is pointed out that it could have been nine seconds) that prevented him from stopping before crashing. The blow caused the second derailment and the Renfe train ended up at the bottom of a four-meter embankment. It was on this train that the majority of the deceased were counted.
In an interview with The CountryBarrón defends that the roads have endured slight traffic until the liberalization that put Ouigo and Iryo to compete with Renfe but that the mere multiplication of routes does not explain the breakdown of the tracks. Ensure the following on the affected lane:
“For a long time it has had relatively light traffic. Lately, it has endured a little more intensity, but the lines should still give much more being of high capacity. The current traffic is by no means saturation. What was decided was to renew the detours, which are very critical elements and it was clear that it had to be done”
In the interview, the president of CIAF explains how the renewal of the tracks is carried out and points out that the use of tracks manufactured in 1989 should not be a cause for alarm. On the contrary, the first bet from the investigative committee It was the welding that joined a section manufactured in 1989 with one manufactured in 2023 that really failed, leading to the breakage of the track and subsequent derailments.
How two tracks are welded 34 years apart
In recent days, the information regarding the Adamuz railway accident has focused on one fact: one of the split rails was manufactured in 1989. Adif, in the comprehensive renovation of the track, decided that it would not change sections that were more than 30 years old but this should not be a problem in itself, according to the president of CIAF:
(On why Adif did not change all the lanes in 1989) “That is what we have asked, why the lanes have not been changed. Maybe it was not planned or should not be done. Many people have interpreted that when we talk about a comprehensive renovation, practically all the material is changed, and that everything that is usable goes to other lines, not high-speed lines. That has been done all our lives. When we realized that the detours had been changed, because that is what It was critical and there had been some incidents in the past, and also some more pieces of rail, but not all of them, we asked Adif about it. The fact that we continue with rails manufactured in 1989 is not particularly serious in itself. It is not something to raise our hands as long as they were in a position to provide service. But we have to carefully analyze the issue of renovation to see exactly what has been done and how it has been done.
To questions from Xatakahe General Council of Industrial Engineers They point out that “it makes all the sense in the world” to point to welding as the source of the problem. “The joint is a unique point on the track. First because it is a discontinuity and any millimeter imperfection is amplified as the wheels pass. And second, because the welding process generates a zone that is thermally affected around it and can generate residual stresses.” And they emphasize: “when a rail breaks, the typical hypothesis, and which seems to be being confirmed, is that the break begins in the weld or in its immediate surroundings and from there evolves to the final failure.”
Regarding the reason why the welding could have failed, the CIAF and the General Council of Industrial Engineers point to examinations in laboratories to determine what could have happened.
The experts consulted by Xataka they point out that the Causes why a weld can fail in their execution they are multiple:
- Execution problems: such as the creation of a pore due to not reaching the appropriate melting temperature.
- Geometric finishing problem: a millimeter-sized burr or microstep is generated
- Problems with alignment: the alignment between lanes is not perfect
These same experts point out that the derailment can be caused by various factors and that, by itself, one of the previous causes does not have to explain the entire problem. They point out that the laboratories will have to confirm if there was a previous problem in the material, if a failure occurred during the welding process and to what extent the thermal conditions and the frequency of train passage could have aggravated the problem.
All of these are problems that revolve around two issues to take into account.
The first points to the different degree of hardness of the steel between the rails. The 1989 track was made up of R260 steel, which is softer than the R350 HT steel that makes up the track produced in 2023. “The base steel is very similar,” they explain to us from the General Council of Industrial Engineers, who point out that the greater hardness of the most recent rail affects the temperature reached in the upper area of the rail, which comes into contact with the wheels, and does not have to be a problem.
The rails, everything indicates, that a kit-type procedure with R260 steel (the softest) was used. “Even in the hypothetical case that a R350 HT steel kit had been taken, it would not be a problem. The important thing is that the process is certified. In general terms the steels are very similar and the important thing is good execution and a good review,” they explain to us.
For these experts, there should be no problem with the materials used in the designated lanes. And, they explain, the material incompatibilities It only occurs in very specific cases:
“When we talk about really different rails, it is because there is a metallurgy problem, not a hardness problem. This usually occurs in detours or crossings where special steels are used, such as austenitic manganese steel. These are used because they resist wear better and harden with work. In that case, specific procedures with specific consumables and an adequate thermal transition would be necessary. When this is necessary, there are regulations and technical procedures that specify which combinations can be welded and which require special techniques, but This does not seem to be the case.”
It remains to be understood, therefore, what caused the breakage in the welding, if the rail arrived defective with damage to its steel that was not detected in time or if a execution problem occurred during the welding phase. Or if, if necessary, the combination of both variables occurred, triggering the breakage of the rail and subsequent derailments. It’s something we’ll have to wait for..
Photo | Óscar Puente, Minister of Transport, in X
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