DF "Hydro" – the sinking on Tinnsjø
Place: rjukan · Approximate position
When the Germans were to move the last barrels of heavy water out of the country, the saboteurs faced a grim calculation: how to stop the consignment without hitting the innocent. Knut Haukelid and his helpers chose the ferry. Before departure they fixed 8.4 kilos of plastic explosive in the bow of DF "Hydro", set to go off where the lake was deepest. At 10.30 on 20 February 1944 the hull was torn open in mid-lake, and the ferry sank in a few minutes with the barrels on board. Eighteen people went down into the depths with it – fourteen Norwegians and four Germans – a civilian loss the saboteurs carried heavily long afterwards. Only in 1993 was the wreck found again far down there in the darkness, and a recovered barrel confirmed what they had staked everything on preventing: the cargo still contained heavy water.
The wreck lies at about 430 metres depth in the deep, central part of Tinnsjø; the exact position has not been made public. The point is placed in open water in the south-central basin.