The U-station is named after its chief designer and equipment manager, Major Yrjö Urto.
When the attack began in the summer of 1944, the line was 55 kilometers long and best equipped in the direction of Uoma and Pitkäranta.
The line had 15 ready-made concrete bunkers, 300 meters of armored barriers and five kilometers of battle trenches.
In Battle of Nietjärvi, the Defensive fighting position of three separate lines, the last one, on a narrow sand ridge, was clearly the strongest.
[6] The Karelian Front of the Soviet Union attacked the U-station with the forces of four army units in July 1944.