An unsafe curve at high speeds

The provisional conclusion of the judge who is investigating the circumstances and causes that may have contributed to the railway accident on July 24 in Santiago, which caused 79 deaths, is that not only was the driver responsible, but also the railway’s safety professionals. They, the judge believes, failed to take preventive measures against the “clearly foreseeable” possibility that a slight distraction on the part of the driver might cause a catastrophe.

In line with this consideration, the judge has summoned to testify the person (or persons) who, within the agency that administers the Spanish railway infrastructures, Adif, was responsible for the safety of the Ourense-Santiago line. The reason for this summons is that, in the judge’s reasoning, the preventive measures were inadequate in relation to the specific risks of the accident site: a tight curve following a long straight stretch, on which speeds of up to 200km/h can be reached.

The writ minutely details the absence or insufficiency of the warning mechanisms necessary to ensure that the driver will duly effect the reduction of speed to a maximum of 80km/h. For example, the sign that indicates the speed limit, located less than 300 meters from the beginning of the curve, is quite useless; as is the sign that announces the proximity (at a distance of 2.5 kilometers) to the station of Santiago, and not to the above-mentioned curve.

But above all, the writ underlines the limitations of the cab-signaling and train-protection system known as ASFA, which activates the automatic brake when the train exceeds 200km/h — but not if it is moving at, for example, 180km/h, as was the case.

For this reason, Adif ought to have implemented other procedures capable of correcting possible human errors: for example, a momentary distraction on the part of the driver, induced by the conductor’s telephone call at a bad moment.

Safety protocols

The judge’s text is couched in clear and sensible terms, but it is possible that some considerations may yet be corrected by those who have more specialized technical knowledge.

This is why the judge is demanding from both Adif and rail firm Renfe a series of reports on criteria in regard to speed, safety protocols and other data. In his media appearance on August 8, the president of Adif explained that none of the five projects presented in a public tender for that particular section of the line questioned the profile of the curve at Angrois.

But we now know that, while this curve did not pose extreme danger under normal conditions, it was extremely dangerous should the train approach it at the speed permitted on the stretch of track located just a few kilometers back. Public Works Minister Ana Pastor said in her parliamentary appearance that since the catastrophe, everything was being reviewed. From the judge’s writ it can only be deduced that “everything” will mean rolling out to all lines the ERTMS system, which is currently in place in the high-speed AVE trains and is capable of automatically correcting human errors of this type.