An earlier crack in the rail’s welding is being focused on as the main cause of the derailment of the Iryo high-speed train last Sunday in Spain.
The accident, after a collision with a train moving in the opposite direction, claimed the lives of at least 45 people.
The “imprint” of the fracture on the wheels
According to the Commission’s document, the main working case is based on specific indentations found on the right wheels of cars 2, 3, 4 and 5. These marks are “probably coincident” with the broken section of rail.
Experts explain that the passage of the first wagons caused the rail to gradually tilt outwards. When car 5 passed the spot, the rail had now lost its continuity, causing car 6 to completely derail. This derailment swept the following two carriages, which entered the opposite track seconds before the fatal collision.
“Trap” of 200 kilometers per hour
The report reveals a chilling detail: the line was already damaged before the fateful Iryo crossing. Three other trains that passed the same spot between 17:21 and 19:09 on the same day have similar notches on their wheels.
CIAF explains why the notches were only found on the first wheel of each bogie (of the axle frame)
- The speed: The train was traveling at 200 km/h.
- The distortion: After the first wheel hit the “step” of the broken rail, the rail was sinking.
- The time: The second wheel passed just 0.03 seconds later, before the rail had time to return to its original position, thus avoiding contact.
Laboratory investigations are ongoing
Despite the strong findings, CIAF clarifies that all evidence remains at a “working hypothesis” level until laboratory analyzes are completed. Fragments of the rail and the “black holes” (recorders) of the two trains have been taken to Madrid under the strict guard of the Civil Guard.
“Regarding the causes of the fracture, no case can be ruled out,” the report said, stressing that a final verdict could take months.
The Commission has now requested the analysis of the wheels of all trains that ran on the network in the 48 hours before the tragedy, in order to pinpoint when the initial welding shortfall occurred.
Welds and the phenomenon of discontinuity
Modern high-speed lines are “continuously welded” (CWR) to avoid traditional noise and vibration. In the case of Adamuth, the report cites a “lack of continuity.”
This is what happens when the rail breaks completely:
- Creating a “Step”: One part of the rail gives way under the weight of the wheel, while the next part remains fixed.
- Impact: The wheel “hits” the edge of the next rail at speed (in this case 200 km/h), creating the notches found in Iryo.
- Side Slope: Repeated pressure pushes the broken rail outwards, leading to the derailment.
The answers to the train recorders
In railway terminology, what we call a “black box” (modelled on airplanes) is officially called an Event Recorder. In the case of the Adamuth accident, these devices are critical because they provide an irrefutable representation of the seconds before the crash.
Let’s see how they work and what they record:
- What they are and where they are: Unlike airplanes, where black boxes are usually located in the tail, high-speed trains (like Iryo) have recorders built into the engine units (at the train heads). They are made of extremely durable materials (stainless steel or titanium) to withstand severe collisions, fire and immersion in liquids.
- What they record (Data Points): The train’s black box continuously “reads” data from the train’s control system (usually through the ERTMS – European Rail Traffic Management System). The main elements are: speed, brake use, accelerator operation, sounds and lights, signal status
- Voice Recording (CVR – Cockpit Voice Recorder): In addition to technical data, conversations in the cabin are also recorded. This helps CIAF investigators to understand: If there was any warning from the control center. If the driver noticed anything unusual (eg a vibration or noise) seconds before the derailment. The psychological state and reactions of the crew.
- The “Read” process: After the accident, investigators remove the memory unit under the supervision of judicial authorities to ensure the chain of custody, as stated in your report. The data is transferred to special software that creates a time-speed-distance diagram. In Adamuth’s case, researchers will compare the point where the black box recorded the first sharp deceleration or shock to the exact geographic location of the broken rail.
They are also looking for clues from the previous trains
Because the CIAF is looking into whether the track was already broken, the black boxes of the previous three trains that passed through the spot are equally important.
If their own data shows a subtle “shake” at the same spot, it confirms the theory that the infrastructure had collapsed earlier and the Iryo was just the train that “exhausted” the metal’s strength.
