The Spanish high-speed rail network is second only to China's in its size and number of passengers carried per year. From its opening in 1992 until this year, there were no fatal accidents on the high-speed trains, which travel at speeds up to 160 MPH (250 KPH) across the countryside. But the Madrid-Seville line, which goes south of the capital through the province of Toledo, was the site of not one, but two major accidents this year that caused dozens of fatalities.
Both private and publicly-owned train systems share the line. The private system, Iryo, and the public system, Renfe, must share maintenance responsibilities on some basis. The January accident happened when a poorly welded rail joint separated. The stresses of supporting trains going faster than some planes can fly must have contributed to the failure. But even a slight unevenness in the track is intolerable at such speeds. When the northbound Iryo train hit the faulty joint, three of its carriages derailed and landed on the adjacent southbound track. Twenty seconds later, a southbound Renfe train collided with the wreckage. Forty-six people were killed and over two hundred were injured. Systems designed to detect a breaking rail failed to activate in time to warn either train.
Last Wednesday, October 28, all trains on a 39-mile (63-km) stretch of the Madrid-Seville line near Toledo were stopped automatically when a computer failure disabled the LZB (short for Linienzugbeeinflussung) automatic train-control system. This included both the Iryo train, which left Madrid first, and the Renfe train, which followed only six minutes later. When it works, LZB resembles what in the U. S. is called "positive train control" in that it monitors speeds and can automatically apply brakes if the engineer neglects to do so in an emergency.
But without LZB, rail traffic controllers had to get into radio communications with all the affected trains in order to bypass the automatic directions from the now-nonfunctioning LZB system.
At 8:36, a controller told the Renfe train it could start running at normal speed, as the Iryo train was 15 miles (25 km) ahead of it, and presumably would get going at about the same time. What the Renfe driver didn't know was that the Iryo engineer couldn't restart the train. Although details of the communications between the two trains and controllers have not been fully investigated, it is clear that the Renfe driver didn't get the message that the Iryo train was still stopped, and that he shouldn't proceed.
The line has an older backup train-control system, possibly using signal lights, but unfortunately both trains were on the same control "block" (section of track). So there were no signals from the older backup system to inform the Renfe driver of the stopped Iryo train ahead.
When the Iryo train came into view, it was too late to stop the Renfe train, as it takes at least a kilometer (0.6 miles) to come to an emergency stop. The train was going over 100 MPH when it collided with the rear of the Iryo train, killing at least 69 people and injuring hundreds more.
Although dull and boring compared to the excitement accompanying the opening of a new system such as Spain celebrated with the inauguration of its first high-speed rail line in 1993, maintenance of equipment is crucial to the safe and reliable operation of any system as complex as a high-speed rail line. Without having detailed information on the conditions that prevail among controllers, maintenance workers, and management of the Spanish high-speed rail system, anything I say at this point must be speculative. But based simply on the causes of these two accidents, which spoiled the system's safety record in a spectacular way, I would say that those responsible for system maintenance have come up short, for whatever reason.
The track failure in the January crash was due to a faulty weld. I don't know how the Spanish system inspects its tracks, but it's at least possible that the fault would have shown up in a routine track inspection, which often uses sophisticated equipment to detect flaws before they become as obvious as a broken welded joint. And the system designed electrically to detect a track breakage also failed, whether due to faulty maintenance on it or for some other reason.
Turning to the October crash, failures on the Spanish tracks of the German LZB system are so common as to have become unremarkable. It relies on physical cables laid along the tracks, and is thus vulnerable to vandalism and other types of damage. But this particular outage was due to a computer problem, which might have been avoided by running identical backup systems as NASA and other agencies do when human lives are involved.
Instead, controllers and engineers became accustomed to LZB failures, and relied instead on overworked train controllers, overworked at least according to the train-controller's union. And somehow, the critical information that the Iryo train wasn't moving failed to get from the Iryo train's engineer, to a controller, to the Renfe train. If LZB had been operational, it would have probably detected the Iryo train's presence and stopped the Renfe train, or prevented it from starting in the first place.
While the controllers played a role in this tragedy, it would be unfair to accuse them of being the sole cause. Poor maintenance and the lack of fail-safe systems for the LZB control devices are at least as much to blame. The world's greatest safety system is no use if it's out of commission.
Spain's Minister of Transportation, Óscar Puente, has attributed the accident mainly to controller error, but is under pressure to resign in the face of the second major fatal accident on high-speed rails this year. The first accident should have occasioned a major housecleaning in which accidents waiting to happen, such as poorly inspected rails and LZB systems that fail several times a month, would be cleaned up. But that didn't get done, and now there will be 69 fewer rail passengers looking forward to Christmas—or to anything else.
Sources: I referred to an Associated Press article "Spain's latest deadly crash puts human error and systemic failure under scrutiny" at https://apnews.com/article/spain-train-crash-toledo-causes-unions-669ef8c0c12c8c9b720e721e7532ccbb, the Wikipedia articles "2026 Toledo train collision" and "2026 Adamuz rail disaster," and incidental questions to Google's AI function, which is hard to avoid but convenient when a specific question comes up.
