it's a special ship. It's made of concrete.
During almost all of World War II, Germany was constantly short of raw material. In order to save iron, German engineers revived an idea that was first conceived in France in 1848 - Concrete Ships. Starting in 1940, a series of fifty concrete ships was build in shipyards along the Baltic Sea. They were used as supply ships for the German Navy operating in the Baltic Sea and the North Sea. M/V "Capella", built in 1943 in Ostwine, is the last surviving ship of Hitler's old concrete fleet. Amazingly, she is still afloat. In 1988, the ship was declared a German Technical Monument and in 2003, it became part of the Rostock Maritime Museum.
43年下水的，到现在还完好！还是以寿命短著称的水泥船，我德意志科技真是世界第一！