Adif has defended that the pothole located in October 2025 in the track area where, three months later, the railway accident in Adamuz occurred did not exceed at any time the thresholds set by European regulations. For this reason, the railway manager maintains that the anomaly always remained within the tolerance margins in terms of safety.
This has been stated by the general director of Operations and Exploitation of Adif, Ángel García de la Bandera, in statements to the media, after notes sent by the judicial experts to the investigation were made public, in which reference was made to the detection of this irregularity since October 2025.
In his words, the head of the public entity specified that this is not a judicial report as such, but a series of responses that the experts have sent following the requests made by the Civil Guard.
According to Adif, a geometric auscultation — tasked with measuring specific points of the layout and its evolution — identified in October an anomaly of 6.4 millimeters in the rail, although always within the parameters established by community regulation.
García de la Bandera has specified that this figure is "far from" the 16 millimeters from which a problem is considered to exist, and not even strictly a safety issue, but a comfort issue for travelers. For this reason, the regulation only requires monitoring the evolution of the defect, but not immediate intervention on the track.
Later, in November, a dynamic auscultation — focused on measuring the accelerations of the trains — was carried out, whose results also remained below the values that would have required corrective action. In this case, 40 meters per second squared (m/s2) were recorded, compared to the threshold of 70 m/s2 that would trigger an intervention.
A third parameter analyzed was the height difference between both rails over a one-meter stretch. The measurements reflected a difference of 0.14 millimeters, below the 0.15 millimeters from which some alert would be triggered.
"The thresholds are set by European directives, not Adif, and have been below in all the follow-ups carried out since October. Adif is fully committed to clarifying the causes of the accident with the utmost collaboration with Justice and the investigators," emphasized García de la Bandera.
Hypothesis of the experts on the origin of the failure
The experts have pointed out that when "a wheel falls into the 'bump' of 6.4 mm of the right rail of track 1, kilometer point 318+682 --where the Iryo would circulate--, the entire axle tilts to that side" and upon "recovering the horizontal position, milliseconds later, the right wheel hits the left rail (rocking effect)".
In this sense, they indicate that "the interaction between both rails is constant due to the rigidity of the axles of this type of train and the transfer of loads through the sleepers, producing amplification of damage due to fatigue" and affecting the "weakest area, such as the welded joint".
According to their criteria, the progression of this defect could have accelerated or even triggered the breakage of the aluminothermic welding of the rail, given that "the welds are the weakest part of the mixed structure formed by the rails and the sleepers".
In this line, they detail that "railway welds modify the metallurgical structure of the rail steel", so that if "there were an invisible internal microdefect in the left rail (such as a pore, a lack of fusion, or even a drop in the track), the unforeseen dynamic loads caused by the drop of the other rail accelerate the fatigue of the material", which "can cause microcracks to propagate much faster to even fracture the joint of the rails".