Displacement 570 (surfaced)-1.388 (submerged) tons, horsepower 1.800 (surfaced)-900 (submerged) hp, oil-fired internal combustion machinery (surfaced)-electric machinery (submerged) and an armament of 7 torpedo tubes.
Source
Archive Dutch Naval Staff 1886-1942 (National Archive at the Hague, Netherlands) inventory number 155. Fleets (the British Empire and foreign countries) on 1 February 1923.
