The construction at a German shipyard responded to the intention of experimenting with a type of submarine that had already given excellent proof. The main feature was represented by the structure of the hull centered on two enclosures: one inside with a circular section closed at the ends by spherical shells, able to sustain strong pressures, and a partial light external.
This type of hull gave the submarine a strength much higher than that achieved by submarines "Laurenti" and such to allow a greater operational depth (50 m).
Source: Military Navy
