The investigation into the Atocha tunnel derailment describes the event as ‘serious’ and says that the train descended “without brakes and at high speed.”

The investigation with file number 108/204 places the time of the events at 4:20 p.m. last Saturday on the Madrid Chamartín Clara Campoamor – Valencia Joaquín Sorolla line with the Botanical Garden triage post as the closest point to the event. According to the story made public this Friday, the accident train was made up of two units of the series 114 high-speed regional train and left La Sagra bound for the Fuencarral workshops. The first unit was towing the second, which was damaged. The train crew consisted of a train driver and two maintenance technicians. But it is not specified whether these operators belonged to Alstom, the train manufacturing company (as various sources have pointed out over the last few days), or were from Renfe.

Following the narrative derived from the investigations, the train circulated through the high-speed tunnel from Atocha to Chamartín, but at the entrance to the Chamartín station the lead unit (tug) suffered a traction failure that prevented it from climbing the ramp. entrance to the station (about 30 thousandths). To overcome the ramp, the engineer and the command post agreed that the train would go backwards to gain momentum from a flatter section. “While this maneuver was being prepared, the damaged train unit (the towed one) broke free from its hitch and began to drift down the tunnel without brakes, without a battery and with the two technicians on board,” the investigations reveal.

four kilometers adrift

Investigators say that the convoy, after more than four kilometers of drifting through the tunnel (with slopes of between 12 and 30 thousandths), arrived at high speed at the Botanical Garden triage post, where it was changed from track 1 to track 1. 2. On the next curve after the change of track, the unit derailed and went off on a tangent, crashing into the tunnel wall, as was known from the story given by the Minister of Transportation, Óscar Puente. After this, the first three cars of the unit (in the direction of drift) overturned, while the fourth remained derailed, but in an upright position. It is not specified at any time if there was a risk of collision with any other train that may have been present in the tunnel.

«After sliding a certain distance losing speed, the unit stopped approximately at kilometer point 7,000. The two maintenance technicians who were on board the train were able to escape safely after it stopped,” it is detailed. As there were no fatalities or serious injuries, although there was serious damage, both to the accident unit and to the tunnel infrastructure, the event has been classified as ‘serious’ and not ‘very serious’. Although it is a qualification that requires a “technical investigation”, as confirmed by the investigative committee in the report, in accordance with the regulations governing the investigation. This will require “some time,” is specified in the preliminary report.