Displacement was 1,350 tons when surfaced, and 1,870 tons when submerged. The boats had diesel motors for surface running and electricity generation, but when underwater ran off electric motors. They had two propeller shafts.
Displacement was 1,350 tons when above water and 1,870 tons when beneath the surface. These boats relied on diesel engines for surface cruising and electrical propulsion when submerged, with two propeller shafts.