Podcast Summary: "Cómo se investiga un accidente como el de Adamuz: 'Una de las tres cosas que damos por seguras ha tenido que fallar'"

Podcast: Más de uno
Host: Carlos Alsina (OndaCero)
Guest: José Trigueros (Ingeniero, Asociación de Ingenieros de Caminos)
Date: January 19, 2026

Overview

This episode centers on the recent and shocking railway accident near Adamuz, involving a high-speed train. Host Carlos Alsina interviews expert José Trigueros to explore how such accidents are investigated, dissecting possible failures in technical, infrastructural, or security systems within Spain’s high-speed rail network. The conversation focuses on trying to understand how an incident considered "almost impossible" could occur on a modernized line with updated safety systems.

Key Discussion Points and Insights

1. Initial Reaction and the Rarity of the Accident

• Both host and guest stress the surprising nature of the accident given recent updates and high safety standards.
  • José Trigueros points out (00:26):
    • The accident occurred on a straight, recently renovated track (May last year).
    • The involved train and its safety systems (EZB) had passed technical review just days prior.
    • Human error is considered highly unlikely due to the automated system:

      "Incluso fallo humano no se puede dar porque el sistema de seguridad para el tren..." (00:30)

    • The incident is labeled "casi imposible" considering these factors.

2. Possible Points of Failure

• Trigueros outlines three critical elements where failure could have occurred (01:15):

  • Infrastructure:
    • A rare undetected failure like track fatigue or unexpected rail deterioration.
  • Train/Technical:
    • Mechanical issue like an axle (eje) breaking, possibly causing derailment of a specific car ("bugiles" are likened to rear wheels of a car).
  • Operational/Security System:
    • A potential yet unidentified lapse in the operating safety systems.

  "[...] alguna de estas tres cosas tiene que haber fallado, o bien la técnica, o bien el tema de la infraestructura, o bien el sistema operativo de seguridad." (02:47)

3. Sequence and Mechanism of the Accident

• Alsina describes the accident’s developing sequence (04:30):
  • The starting event was the derailment of the last cars of the Irio train.
  • Catastrophically, at that moment, another train (Alvia) was passing in the opposite direction on the adjacent track.
  • The motion of the derailed cars produced a “whiplash” effect (efecto látigo), colliding with the Alvia’s head and causing severe destruction:

    "El descarrilamiento se produzca justo cuando está el Alvia pasando a su lado y entonces lo embistes como un efecto látigo..." (04:40)

  • Emphasized is the improbability: both train and tracks had been reviewed recently.

4. Status of the Rail Network and Maintenance

• Host questions social media narratives about increased train volumes and whether high-speed rails are now inadequate (06:14).

• Trigueros responds assertively (06:52):

  • The Madrid-Andalucía line can handle up to 350km/h and has recently been completely renovated.
  • While maintenance delays are recognized, the specific section involved in the accident was recently updated—contradicting claims that higher traffic or obsolete infrastructure is to blame.
  • Calls attention to past advocacy by the Association for better maintenance globally, but confirms that in this case, procedures were followed.

  "Nuestras infraestructuras están perfectamente diseñadas para ir a esa velocidad..." (06:54)
  "No digamos que se debe a que circulan más trenes..." (07:39)

5. Distinction Between Incidents and Catastrophes

• Alsina highlights the difference between regular operational incidents and true catastrophes like this:

  “Esto no es una incidencia, esto es un accidente muy grave que habrá que ver cuál es la causa… que no tiene nada que ver con otros fallos..." (08:20)

• Warns listeners against conflating service delays/incidents with catastrophic accidents.

Notable Quotes & Memorable Moments

• On the rarity of such failures:

  "Aquí hay tres elementos que son donde tiene que estar el fallo... cosa que no sucede nunca, pero podía. Todo lo que va a decir es que no sucede prácticamente nunca."
  — José Trigueros, 01:00

• On the investigation’s complexity:

  “Las cajas negras de los trenes puede que den alguna luz sobre este accidente, pero a priori todo debería estar en perfecto estado de revisión y lógicamente alguna de estas tres cosas tiene que haber fallado...”
  — José Trigueros, 02:37

• On the opportunity to improve safety with lessons learned:

  “Descubrir que hubiera sido un fallo mecánico, pues sería dentro de lo malo, lo mejor para saber que efectivamente el resto del sistema de seguridad… funciona correctamente.”
  — José Trigueros, 03:59

• On misinformation and public suspicion:

  "En redes sociales se puede decir muchas cosas. Nosotros desde la Asociación de Ingenieros de Caminos hemos abogado por la falta de mal durante los retrasos del verano pasado. Ojalá se tomaran las medidas que están tomadas en la línea Madrid Andalucía en todas las líneas de alta velocidad..."
  — José Trigueros, 07:09

• On differentiating types of railway problems:

  “No vinculemos ambas cosas porque no tienen vínculo posible… esto es un accidente muy grave... no tiene nada que ver con otros fallos que vienen sufriendo los trenes en nuestro país por no andar mezclando cosas…”
  — Carlos Alsina, 08:15

Timestamps for Key Segments

• 00:26-02:47 — Trigueros breaks down the rare possible technical, infrastructural, or operational points of failure.
• 04:30-05:32 — Alsina and Trigueros reconstruct the accident’s sequence and rare convergence of factors.
• 06:14-07:39 — Discussion on whether increased traffic or aging rail explains the accident; debunking the social media narrative.
• 08:06-08:58 — Alsina distinguishes between operational incidents and catastrophic accidents.

Tone and Language

The conversation maintains a measured, technical tone—with Trigueros providing expertise and cautioning against speculation, while Alsina guides listeners through breaking news and complex engineering realities. There is a clear emphasis on transparency, the need for ongoing investigation, and resisting simplistic or sensationalist interpretations.

Conclusion:
The episode provides a knowledgeable, nuanced look at how theoretically “impossible” rail accidents are methodically investigated, emphasizes engineering rigor and recent maintenance on the affected line, and clarifies the crucial difference between routine incidents and rare disasters in Spain’s high-speed rail network. The take-home is a call for patience and technical rigor as investigators work to identify which system—previously considered secure—failed in this tragic event.