Finnish Environment Institute announces plans to empty fuel tanks of battleship Ilmarinen in Baltic Sea

The Finnish Environment Institute (Syke) has assessed that the fuel tanks of the battleship Ilmarinen, which lies on the seabed of the Baltic Sea, can be emptied. According to a statement from Syke, the aim is to carry out this operation between 2025 and 2026. The fuel removal will be conducted as an official project, with planning already underway.

In August of this year, the feasibility of the fuel removal was investigated during an expedition involving Syke, the Finnish Navy, and the Border Guard. Divers examined the wreck to determine the location of the fuel tanks and assess the condition of the vessel, though they did not enter areas containing the remains of those aboard.

Current estimates suggest that there are approximately 100,000 liters of light fuel oil in Ilmarinen’s tanks, with the wreck leaking a couple of drops of oil per minute. Inspections revealed corrosion was removed from several locations on the wreck, exposing intact steel surfaces. Given the construction method of riveting, corrosion can affect the rivets and steel plates differently. Based on these findings, Syke’s project manager Tommi Kontto indicated that the tanks can be emptied in a controlled manner prior to any significant environmental risk posed by the leaking oil.

The exploratory studies employed divers, underwater robots, remote imaging devices, hydroacoustic equipment, and ultrasound measurements. The battleship Ilmarinen sank on September 13, 1941, after hitting a naval mine off the coast of Utö, resulting in the loss of 271 sailors’ lives.