 They had two shafts driven by two MAN (Maschinenfabrik) diesel engines (when surfaced) or two Nancy electric motors (when submerged). The diesel engines were rated at 1,480 bhp (1,100 kW) and the electric motors at 1,000 shp (750 kW), and they were designed to reach a top speed of 14.5 knots (26.9 km / h) under diesel power while surfaced, and 9.2 knots (17.0 km / h) on their electric motors when submerged. They were armed with six 550 mm (22 in) torpedo tubes (four bow-mounted, two stern-mounted), one 100 mm (3.9 in) gun, and one 40 mm (1.6 in) anti-aircraft gun. They had a surfaced radius action of 3,500 nautical miles (6,500 km) at 9 knots (17 km / h), and 75 nautical miles (139 km) at 5 knots (9.3 km / h) submerged.
