First World War (1914-1918)
The U-Boat Menace

The emergence of the submarine was a major development in naval warfare. German submarine - or U-Boat - attacks against Allied shipping in the Atlantic and in European waters posed a major threat to the Allied war effort.

German Naval Mine, U-153

German submarine U-153 placed this mine in the shipping lanes near Halifax, Nova Scotia, in September 1918, deploying it through a torpedo tube.

When struck by a ship's hull, the four "horns" on the top of the mine (left) were designed to break, detonating the mine's explosive charge. The resulting underwater explosion could sink or damage the ship. Canadian minesweepers discovered this mine and removed it from the water.

Naval Mine, German
CWM 19390002-460