The chain of contracts across the suspicious Adamuz welding is the main target of the accident investigation | Economy | EUROtoday

What could also be level zero of the Adamuz (Córdoba) railway tragedy, the welding of kilometer 318,681 of the Madrid-Seville line, has a succession of contracts round it that has been positioned within the political debate and is the main target of the investigations of the Railway Accident Investigation Commission (CIAF). Sources near the administration of the renovation work on the Guadamez-Córdoba part, supervised by the general public firms Adif (railway infrastructure supervisor) and Ineco (engineering depending on the Ministry of Transport), guarantee that “many turns have been made in recent days to all the processes without detecting non-compliance or failures in the execution and inspection of the welding.”

Throughout the chain of firms that shall be concerned within the investigation of the incident, Adif promotes the work, supervises it and is finally answerable for receiving all of the work. But there are numerous others in operation. Ineco gives help to the administration of the challenge, which is carried out by 4 of the biggest development firms within the nation, Ferrovial, FCC, OHLA and Azvi; Maquisaba carries out the welding, commissioned by the development consortium, which can then check Redalsa, additionally chosen by Ferrovial and its companions, and examine Ayesa, which labored for Adif. The documentation of all these processes has been arriving since final week by the hands of the CIAF. Responsibility for welding, rail set up and inspections is distributed, taking into consideration that the final particular person answerable for the work is Adif.

The technicians use as a central speculation {that a} break at that junction level between rails triggered the Iryo convoy to go away the observe, with which a Renfe Alvia collided instantly afterwards. Behind the execution and supervision of the welding, of a particular nature for linking steels of various ages (one rail is from 1989 and one other from 2023), are a few of the firms with the longest historical past within the railway sector. Faced with criticism from the opposition of subcontractors in railway work, the Minister of Transport, Óscar Puente, granted on Tuesday in Congress his willingness to debate the degrees of contracting of personal actors, however referring to the upkeep of the infrastructure, to not new work.

In this case, the subcontracting of inspection companies seems as crucial within the challenge itself. The complete enchancment of the Madrid-Seville line in its part C (Guadalmez-Córdoba), with regard to the renewal of detours reminiscent of Adamuz, begins with a previous security research signed by the general public engineering firm Ineco in July 2023. Its pages warn of the danger issue of welding new and used lanes, one thing widespread in observe alternative and which is contemplated within the Adif laws (Norma Adif Vía 3-3-2.1.). The fracture of a weld, Ineco burdened, may cause a practice to derail.

It is these kind of alerts that require excessive critiques. Along with the preparation of the earlier studies, the infrastructure supervisor Adif has granted help within the administration of the challenge to the aforementioned Ineco, and on March 4, 2022, it contracts one other of the biggest engineering firms within the nation, Ayesa, to offer “technical assistance for the control and surveillance (ACO in engineering jargon) of the works included in the renovation and improvement projects of the superstructure of the Madrid-Seville High-speed Line.”

There are already two top-level firms, Ineco and Ayesa, conscious of the transforming of the infrastructure. The Andalusian Ayesa, on this case, “supports the Adif construction director in the pre-construction, execution, commissioning and closure phases of the project,” clarify sources conversant in the actions. Its mission contains the management and surveillance (within the phrases established by the challenge’s Quality Control Plan) of what are referred to as weld distinction checks.

In parallel, Adif itself awards the works on this part to the consortium fashioned by Ferrovial, FCC, OHLA and Azvi, “the cream of the crop of construction,” Minister Óscar Puente has even mentioned. The alternative of rails at completely different factors of the route, particularly in observe deviations reminiscent of these in Adamuz, prompts development firms to subcontract the Galician specialist in aluminothermal welding Maquisaba, which carries out the work at level 318,681 on May 25, 2025. In flip, to manage this and different metal rail joints, Ferrovial and its companions depend on Redalsa (managed by Adif by 51%), which is answerable for testing every of the welds. The work of the latter, with penetrating liquids and ultrasounds, is included in a report dated June 4, 2025.

Last supervision

With the Adamuz part virtually prepared, the final critiques that Adif calls for for its exterior inspection remained, with the aforementioned Ayesa finishing up visible and geometric critiques of all of the welds. A report on this firm’s evaluation of the 114 welds on each roads (between kilometers 316,790 and 318,829) signifies that each one of them have been “accepted” on June 25, 2025. Ayesa additionally verifies that the agency chosen by the development firms for his or her self-control, Redalsa, had verified the integrity of 100% of the welds with ultrasounds and penetrating liquids. Seeing that they have been all appropriate, Ayesa itself studied 30% of these welds once more, as a distinction check (the proportion is the one contemplated within the Quality Control Plan permitted by Adif and contemplated within the latter’s technical normal).

Ayesa stamps its seal on June 25 on the 114 inspections, which can elevate a query: lack of fabric time to undertake them in a single evening shift. Sources near the investigation level out that these visible inspections (together with the usage of penetrating liquids) and geometric inspections final a whole month, between May 22 and June 25, 2025. And the ultrasound distinction checks are dated June 24 and 25. Ayesa had 4 inspectors permitted by Adif.

Civil engineers consulted by this newspaper insist that it have to be the investigation that determines whether or not the speculation of the weld failure crystallizes as a certain reason behind the derailment. And there isn’t a scarcity of those that converse of an “intact weld, attached to the old rail, and a rail that could have fragmented in the area adjacent to the weld affected by thermal stresses.” This standpoint, from specialists who request anonymity, is linked to the Minister of Transport’s assertion in regards to the existence of an oval stain on the brand new rail, which can point out a defect within the metal casting utilized by ArcelorMittal to mould as much as 20 rails. The producer has demanded an impartial investigation.

The journey of the brand new rail

The hint left by the rail that was blown up within the Adamuz accident, from its manufacturing in 2023 in Gijón by ArcelorMittal to the laying on the observe in Adamuz, means that there was no less than one inspection previous to the work by Adif.

The metal bar in query obtained the reference 312592101Y and got here out of metal casting 312592, like 19 different rails. A batch of 42, with a complete of 91,000 kilos, was inspected on January 9, 2024 to go away the metal mill heading to Toledo, to the Talleres Alegría warehouse within the city of Villarrubia de Santiago. They got here from 4 completely different castings and all of them have a resistance and hardness diploma of R350HT. The manufacturing unit inspection, supervised by Adif, included ultrasounds and induced currents from one finish to the opposite of every rail, as said within the minutes “with satisfactory results.”

The metal used is hardened by warmth remedy within the head, therefore the HT end of Head Hardened. The 312592101Y rail was welded to a different from the identical ArcelorMittal from 1989 with conventional R260 grade resistance, on which Adif laws specify that it have to be executed with the bottom load grade. A spokesperson for Adif assured days in the past that the method was carried out appropriately: “When new detours have been put in within the Adamuz space, a brand new lane was welded to the lane that already existed in that part. To perform this welding, Adif used the technical process included in its inside laws and by the Spanish Association for Standardization (UNE normal), guaranteeing a higher capability for absorbing efforts. The union of the lane of the brand new detour, R350H, with the one put in in the remainder of the part, R260, the load comparable to grade 260 metal was used.