Blowing Up The Hydro

By James Donahue

The Hydro was a 53-foot steam powered ferry that carried railway cars and passengers on Lake Tinnsja in Norway between Mael and Tinnoset during the war years from 1914 to 1944. The little ferry was blown up and sunk in the deepest part of Tinnsja by resistance fighters on February 20, 1944, to destroy a cargo of heavy water that Nazi scientists were allegedly using to create a nuclear bomb.

The little ferry, operated by Norsk Transport, was one of two small ferries used on the 19-mile-long route to connect the railway between Rjukan and the port at Skien. The rail cars carried mostly fertilizer and chemicals from the Norsk Hydro plant at Rjukan, plus passengers.

During the German occupation of Norway, there were rumors that the Nazi scientists were working on a terrible new weapon, an atomic bomb. The Americans also were working on such a bomb. It was feared that if Hitler had the bomb first he would win the war.

The barrels of heavy water were loaded on the ferry the night before the vessel was to make its trip across the lake. Four saboteurs broke their way into the ship where they placed plastic explosive. The plan was designed to sink the ferry in deep water, but close enough to shore that passengers and crew could escape. The blast was calculated to blow a hole in the hull and sink the ship, but not cause casualties among the people on board.

As the ferry was steaming its way across the lake, just before reaching the lighthouse at Urdalen, the bomb exploded. The crew attempted to turn the vessel toward land but the ship sank quickly in 1,410 feet of water. Farmers on the lake brought boats out to rescue the crew and passengers. 

Strangely, the ship’s crew failed to release the lifeboats and there were no life vests handed out. Consequently 18 people were killed. These included eight German soldiers, a crew of seven and the rest were passengers. There were 29 survivors.

A mini-submarine located the wreck of the Hydro in the 1990s. Barrels of heavy water were found on board, thus erasing all doubt concerning the significance of the decision to sink the ferry.