The type 9 was similar to the type 16 type sharing the same improvements of the type 7-P type. Length 105 feet and a displacement of 227 (light)-265 (submerged) tons.
Average achievements of the design on official trials. The guaranteed achievements were somehow slightly lower. For surface purposes fitted out with a gasoline engine.
In the so-called light condition was the maximum speed 11 knots, endurance 60 hours and the range 660 nautical miles. With the cruising speed of 8,5 knots was the endurance 120 hours and the range 1.020 nautical miles.
In the so-called intermediate condition was the maximum speed 10 knots, endurance 60 hours and the range 600 nautical miles. With the cruising speed of 8 knots was the endurance 120 hours and the range 960 nautical miles.
In the so-called submerged condition carrying a periscope was the maximum sustained sped 8 knots, the endurance 4 hours and the range 32 nautical miles, at 7 knots an endurance of 9 hours and a range of 63 nautical miles and with a speed of 5 knots respectively 30 hours and 150 nautical miles.
In contrary to the 8 was the type 9 fitted out with twin screws and was the auxiliary machinery doubled.
The armament was similar to the Type 16 designs although the number of torpedoes she could carry with her was increased to another two. Strangely enough the E.B.C. did not recommended to do this.
SourceArchive Kon. Mij. De Schelde 1875-1960 (Municipality Archive Vlissingen) T 214.802.