– The process of going through data and the sequence of events in order to draw the correct conclusion, has been a demanding one. A major success factor in this demanding work, has been the good cooperation between the public and private bodies that have been involved in the investigation, says Acting Director General of Shipping and Navigation, Mr Lars Alvestad.
According to Corvus’ preliminary findings, the cause of the initial fire was most likely a leak from the cooling water system of the battery pack. Findings indicate that a twisted gasket in the cooling system most likely caused the leak. It has not yet been determined what caused the twisted gasket.
Due to the ongoing service work, no part the battery system was connected to the shipside systems at the time of the incident. Consequently, no alarms from the battery system were sent through the ships alarm system.
Like others that have looked at the incident, the Norwegian Maritime Authority has also focused on finding out why the incident escalated and resulted in an explosion several hours after the fire had been extinguished. Judging from the preliminary investigation, the escalation of the incident is connected to the use of the seawater sprinkler system for a short period of time, which among other things, caused several short circuits. With the intention to increase safety, seawater fighters were installed as a supplement to prevailing requirements. This will be considered in the future work to learn from the incident.
If you disregard the incident with the explosion, investigations have also shown that extinguishing in the first phase went according to plan and that the ferry was evacuated in a safe and secure manner.
– We still feel confident that the batteries do not pose a greater risk than more conventional energy sources on ferries. However, such an incident demonstrates the importance of continuously working on making improvements with regards to routines and safety measures. Therefore, the findings from Corvus and the report from Norwegian National Criminal Investigation Service (Kripos), as well as our own participation in the investigations, will be important contributions to the continued work on the phasing in of new technology, says Alvestad.
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