Type U 13s had an overall length of 57.88 m (189 ft 11 in) The boats' beam was 6.00 m (19 ft 8 in), the draught was 3.44 m (11 ft 3 in). The boats displaced 516 tonnes (508 long tons) when surfaced and 644 t (634 long tons) when submerged.[1]
Type U 13s were fitted with two Körting 6-cylinder and two 8-cylinder two-stroke paraffin engines with a total of 1,200 metric horsepower (883 kW; 1,184 bhp) for use on the surface and two SSW double-acting electric motors with a total of 760 kW (1,033 PS; 1,019 shp) for underwater use. These engines powered two shafts, which gave the boats a top surface speed of 14.8 knots (27.4 km/h; 17.0 mph), and 10.7 knots (19.8 km/h; 12.3 mph) when submerged. Cruising range was 4,000 nautical miles (7,400 km; 4,600 mi) at 9 knots (17 km/h; 10 mph) on the surface and 90 nautical miles (170 km; 100 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged.[1] Constructional diving depth[a] was 50 m (164 ft 1 in).[2]
The U-boats were armed with four 45 cm (18 in) torpedo tubes, two fitted in the bow and two in the stern, and carried six torpedoes. The boats' complement was 4 officers and 25 enlisted.[1]
