Derailment of SJ train no 50562 between Iggesund and Hudiksvall

Summary in English

On 7 August 2023, a severe weather event (Hans) passed through Sweden, bringing significant rainfall and thunderstorms. In the Iggesund–Hudiksvall area, over 100 mm of rain fell within a 10-hour period. The storm caused major disruptions to train services.

An SJ train, carrying more than 100 passengers, was en route from Stockholm Central to Sundsvall Central. The driver of a preceding train reported that the embankment had begun to collapse at a location along the Iggesund–Hudiksvall line. Consequently, a decision was made to reduce the speed to 40 km/h. As the SJ train passed the site where the collapse had started, the embankment gave way, causing three out of four carriages to derail. There were no serious injuries, but 40 meters of the embankment collapsed, leaving the train with a steep incline on the last wagons. Both the infrastructure and the train suffered extensive damage. At the outset of the emergency response, there was a lack of information regarding the accident's location, which delayed the rescue operation.

The Swedish Accident Investigation Authority (SHK) found that while the Swedish Transport Administration (Trafikverket) possessed comprehensive knowledge regarding necessary preparedness measures for heavy rainfall, the governing documents for these measures were not implemented or known by all relevant personnel, and therefore were not applied to a sufficient extent. The investigation also revealed that the embankment had collapsed at the accident site in 1999, but the lessons learned from that incident were not known to the infrastructure manager, and the location had not been identified as a risk area.

During the course of the investigation, SHK made observations concerning the safety culture within the Swedish Transport Administration. Additionally, it was noted that the decision-making process at the traffic control center was questioned, which may indicate uncertainty regarding regulations and could also reflect deficiencies in safety culture and an imbalance between safety requirements and production demands. In light of these observations, SHK has issued a recommendation to the Swedish Transport Agency (Transportstyrelsen) in addition to those addressed to the Swedish Transport Administration.

Causes of the accident

The accident was caused by the fact that the Swedish Transport Administration, at the system level and in the proactive work of the regional operational management, has not managed the risks of the weather event Hans in an adequate way. The Swedish Transport Administration's governing document for heavy rainfall was only partially known and had not been implemented at the traffic center in question. It can also be questioned whether the Swedish Transport Administration's monitoring of ongoing precipitation was sufficient and whether the available support for regional operational management was utilized to an adequate extent. The Swedish Transport Administration had not identified these conditions and therefore train operations were not halted. This raises questions about the effectiveness of The Swedish Transport Administration's efforts to promote a positive safety culture within its operations.

The direct cause of the accident was that the drainage at the site was not dimensioned to handle the water flow that occurred during the weather event Hans. Significant rainfall on already water-saturated ground undermined the embankment, which affected the load-bearing capacity and leading to the collapse of the embankment as the train passed.

Safety recommendations

SHK submits the following recommendations:

The Swedish Transport Agency is recommended to:

• Carry out supervision aimed at how the Swedish Transport Administration promotes a positive safety culture against the background of the investigation into the Swedish Transport Administration’s safety culture that the Swedish Transport Agency carried out in 2015–2017.

The Swedish Transport Administration is recommended to:

• Take measures to strengthen preparedness for large amounts of precipitation by:

• Ensure that the safety inspection or other control covers the objects that have an impact on embankment and embankment drainage.
  
  
• Ensure that established documents and procedures in the organization are implemented and follow up that those routines and checklists are followed.
  

• Create better basis and support for the functions that are to identify and assess risks and problem areas.
  
  
• In collaboration with the railway companies, develop assessment support and criteria for train drivers and train dispatchers when reporting and assessing acute faults or risks of faults on the track. The work should include identifying and clarifying what information a train driver must convey to the train dispatcher when reporting.
  
  
• Investigate the need for and the possibilities for increased information about forest fellings affecting infrastructure, or other changes in land use with an impact on surface runoff next to the railway network and, if appropriate, introduce a routine for this.
  
  
  • In consultation with SOS Alarm Sverige AB and the railway companies work out a way to be able to position a railway accident without delay.