The UK Marine Accident Investigation Branch (MAIB) has published its report on the engine failure and fire that occurred on 25 January 2025 aboard the research vessel “Kommandor Susan” in the Firth of Forth, Scotland.
During sea trials, a severe malfunction in the ship’s diesel generator led to a fire in the engine room and a complete loss of electrical power. Although the crew managed to respond quickly and extinguish the fire, the vessel lost control and began drifting. Due to the blackout, the anchor windlass could not be operated, and the ship had to be brought back to Leith port with only partially restored propulsion.
The investigation found that the primary cause of the accident was the use of non-original (counterfeit) engine components during a major overhaul in 2019. It was also determined that an extension of the maintenance interval had been approved, but this decision had been based on the assumption that only genuine parts were in use. Weak oversight by the ship owner over the repair process and contractors created conditions that allowed substandard components to be installed.
Although no formal safety recommendations were issued, the Chief Inspector wrote to the vessel’s former owner, Hays Ships Limited, reminding them of the importance of strict oversight and accountability systems in critical maintenance operations.
