Investigation of accident involving tank wagons in Mäntyharju on 7 April 2018 – several safety recommendations emerge from the investigation

Published 3.1.2019

The Safety Investigation Authority, Finland, has completed its investigation and safety recommendations on the tank wagon accident at the Kinni station in Mäntyharju on 7 April 2018. In the accident, 50 tank wagons began moving of their own accord, rolled 145 metres and collided with a buffer stop. The first two wagons were derailed. A hole was made in the tank of the first wagon, from which 35,000kg of Methyl tert-butyl ether (MTBE) used as an additive in petrol, leaked into the environment. The chemical caused serious damage and harm to the nearby environment, residents and businesses.

The Safety Investigation Authority, Finland issues six new recommendations, and repeats one previous one, on managing track capacity for the transport of dangerous goods (RID substances), improving the safety of the temporary storage and transport of tank wagons, the development of rescue operations, the prevention of similar accidents, and damage control.

The Safety Investigation Authority emphasises that accident investigations conducted on the basis of Section 1 of the Safety Investigation Act (525/2011) are not performed in order to attribute responsibility.

The Safety Investigation Authority recommends that railway operators, the Finnish Transport Agency, and the competent authorities develop means of preventing congestion among transports of dangerous goods that have arrived in Finland from Russia. The acquisition and use of predictive information must be developed. Information on the number of transports entering Finland was not used for the management of railway network capacity and the restriction of RID traffic coming from Russia. According to their own interpretations, the Finnish Transport Agency and VR had no means of restricting traffic. For their part, the Finnish Transport Safety Agency (Trafi) and the Ministry of Transport and Communications lacked information on the safety risk posed by congestion.

Secondly, the Safety Investigation Authority recommends that railway operators and infrastructure managers perform a risk assessment of the temporary storage of RID wagons in locations other than designated RID railway yards, and ensure that the due care and attention required under law be observed.

- The safety of tank wagons containing dangerous goods is dramatically reduced when they are stored outside RID railway yards. The risks associated with temporary storage outside RID railway yards has not been clearly recognised. The identification and management of rail traffic risks must be given much more detailed attention in all operators’ safety management systems and risk management should be implemented in everyday activities, emphasises Veli-Pekka Nurmi, Executive Director of the Safety Investigation Authority, Finland.

Thirdly, the Safety Investigation Authority recommends that railway operators and the Finnish Transport Agency develop the identification and management of risks related to normal rail traffic in their safety management systems. The investigation has found that the Finnish Transport Agency’s railway safety management system is focused on the management of risks in railway infrastructure management and construction projects. In VR’s safety management system, the assessment of change-related risks is emphasised, while less attention is given to risks related to daily traffic.

The Safety Investigation Authority also recommends that the Finnish Transport Agency draw up guidelines on ensuring that wagons remain stationary in the Finnish state rail network. Tests carried out on so-called stop blocks demonstrated that the Safety Investigation Authority's calculations on their insufficient holding power were correct.

- The railway operator’s guidelines on the number of stop blocks failed to take account of the weight of the wagons or the longitudinal gradient of the track. The guidelines overestimate the holding power of the stop blocks. The wagons began moving as their rolling resistance decreased due to warmer weather, and a reduction in the holding power of the stop blocks due to moisture on the rails. The guidelines should be drawn up by the infrastructure manager in order to ensure their consistency in a multi-actor environment. The number of stop blocks must take account of the longitudinal gradient of the track, the weight of the wagons and the true holding power of the stop blocks, comments Esko Värttiö, investigator-in-charge.

The Safety Investigation Authority, Finland recommends that the Finnish Transport Agency inform all stakeholders of its role and scope of responsibility. Not all stakeholders are aware of the changed roles and responsibilities or operators in the railway sector. Neither practical procedures nor the parties responsible for environmental damage in the event of rail accidents have been defined with sufficient clarity. The guidelines on notifying the rescue authority of the wagons’ temporary storage were unclear. The role of the Finnish Transport Agency's railway accident rescue team should also be clarified.

The Safety Investigation Authority recommends that the Finnish Transport Safety Agency ensure the implementation of the five above-mentioned safety recommendations.

Rescue service cooperation, safety and leadership should be developed

The Safety Investigation Authority recommends that the Rescue Department of the Ministry of the Interior ensure that rescue operations define principles for remote management and the communication of the situational awareness of the scene of the accident, and draw up guidelines for remote management. The communication of a realistic situational awareness is very important in remote management situations. No qualitative requirements have been drawn up on the content and development of the situational awareness. It would also be important to identify situations for which remote management is unsuitable.

The rescue operation during the tank wagon accident at Mäntyharju was led remotely. No use was made of the support functions of the rescue cooperation body, the Eastern Finland Situation Centre. The interpretation of the situation did not match the situation at the scene of the accident, and the situational awareness did not develop sufficiently. Emergency medical services only joined the operation on the day after the accident. The risks present at the scene of the accident were not systematically assessed, and insufficient account was taken of occupational safety and the danger of further accidents.

The Safety Investigation Authority, Finland also repeats its safety recommendation given with regard to the accident involving four fatalities at the Skogby level crossing in Raasepori on 26 October 2017, according to which the Ministry of the Interior must ensure that operational area command (OAC) is established for long-term or exceptional multi-authority tasks.

The rescue authorities and other participants did not organise rescue operations and after-care for the tank wagon accident. Cooperation was inadequate and no use was made of rescue equipment and resources suitable for the situation. The issue of post-accident preventative measures was left open after the rescue operation had ended. This was partly due to lack of clarity about what would be involved in placing the scene of the accident under the responsibility of the Finnish Transport Agency. In extensive accidents requiring cooperation between several operators, an operational area command would create a basis for better and more effective cooperation

Report (in Finnish) (pdf, 2.84 Mt)

More information:
Veli-Pekka Nurmi, Executive Director, tel. +358 295 150701
Värttiö Esko, Chief Rail Safety Investigator, tel. +358 295 150708