Lorraine Williamson
A Guardia Civil technical inspection has strengthened the hypothesis that a failure at a welded section of rail played a central role in the Adamuz train disaster, which killed 46 people in Córdoba in January.
Investigators documented a “complete transverse fracture” in the right-hand rail at kilometre point 318.681 of the Madrid-Sevilla high-speed line. The fracture was located at the welded joint between two sections of rail manufactured more than three decades apart.
The findings form part of the Guardia Civil’s final Technical Visual Inspection Record, prepared following the accident and now submitted to the court in Montoro investigating the disaster.
The document does not establish the definitive cause of the crash. However, the physical evidence recorded at the scene reinforces an existing line of investigation focusing on the rail and, particularly, the welded joint.
The crash happened on 18 January 2026 near Adamuz in Córdoba province and left 46 people dead and more than 120 injured.
Fracture found at welded joint
Investigators identified the first anomaly at the point where the derailment began.
The fracture was located in a welded connection between two sections of rail carrying different manufacturing markings. One was marked “ENSIDESA 89”, indicating manufacture in 1989, while the other carried a 2023 marking.
The break caused the rail to lose its structural continuity, separating the fractured ends and dislodging a section of track onto the ballast. Investigators also found a piece of rail measuring around 32 centimetres, which corresponded with the missing section between the rails.
The inspection recorded two different colours and textures on the fracture surface, a detail that investigators are examining as they seek to establish how and when the failure developed.
Evidence supports earlier investigation
The latest document reinforces a hypothesis that has been under investigation since shortly after the disaster.
The Commission for the Investigation of Railway Accidents (CIAF) had already identified the rail or its welded joint as a central focus of its investigation. Its president, Ignacio Barrón, said in January that the evidence appeared to point towards the failure of the weld rather than the rail itself.
In February, Guardia Civil investigators also identified the railway infrastructure as their principal line of inquiry. Among the possibilities being examined were a defective rail, a defective weld and the overall condition of the track.
Investigators subsequently sought further information after the CIAF identified what it described as inconsistencies in documentation relating to the weld, including aspects of its installation, supervision and quality controls.
Laboratory analysis still needed
Despite the significance of the physical evidence, investigators have not yet definitively established that failure of the weld caused the derailment.
Transport Minister Óscar Puente stressed on Thursday that the document is an inspection record rather than a final expert report determining the cause of the disaster. Laboratory examinations of the rail sections and weld are still required.
The court investigating the crash authorised the transfer of sections of rail for laboratory analysis in July. Those tests are expected to provide crucial evidence about whether the fracture existed before the train passed and, ultimately, what caused it.
The distinction is important. The Guardia Civil inspection confirms precisely where the rail fractured and records the condition of the infrastructure immediately following the accident, but the judicial and technical investigations remain open.
For the families of the 46 people who died at Adamuz, the laboratory findings will be a crucial next step in establishing exactly why one of Spain’s deadliest rail disasters occurred.