According to the author of the note had the German navy made a step forward with the development of the design of the high ocean submarine of the U 21 type. Submarines with a displacement of 800 tons were still an exception.(1) The fact that the Germany navy developed such a good design was to be complimented. The armament consisted of 4-50cm bow torpedo tubes just like the American Lake-submarines placed transverse. Furthermore were the submarines to be fitted out with 2-8,8cm L/30 guns on folding pivots (so-called Fall-sockels) fore and behind the conning tower on the poop and on deck. Brand new was that tower, deck and waterline had armour protection. 2-900 hp Diesel machinery allowed a speed of 17,5 (surfaced)-12 (submerged) miles. The crew numbered 32 men. The U 21 was already commissioned and achieved a surfaced speed of 20 miles. Her three sister ships were to add to the fleet in 1913. Displacement 650 (surfaced)-809 (submerged) tons and as dimensions 72,0 x 5,8 x 3,6 metres. For surface drive was she fitted out with 1.800 hp diesels and for submerged drive 800 hp electric machinery. Fuel capacity 50 tons. Range 2000 (surfaced)-400 (submerged) tons. Two screws.
Dutch submarine Hr. Ms. K I
Note
1. The largest Dutch submarine at that time was the Hr. Ms. K I with an armament of 3-45,7cm torpedo tubes, a speed of 17 (surfaced)-8 (submerged) knots, a displacement of 333 (surfaced)-358 (submerged) tons and as dimensions 46,2 x 4,7 x 3,0 metres. Laid down at the shipyard Of the Kon. Mij. De Schelde at Vlissingen, Netherlands on 16 September 1911 and launched on 20 May 1913 In 1916 is she towed towards the Dutch East Indies.
