Dimensions 143’6” (over all) x 15’4” (maximum diameter) x 15’9 3/8” (maximum beam) and a displacement of 331 (light)-432 (total submerged including superstructure) tons. Surface buoyancy 21% of surface displacement. Metacentric height submerged 15”. Metacentric height light 11”. Range of positive stability 180 degrees. Fitted out with a conning tower of non-magnetic metal accessible from the hull by a watertight hatch. A well equipped navigation bridge was on top of this tower about 10 feet above the water level.
Total horsepower of the main multipolar direct current motors (2x-160 continuously and 310ho in one hour)620hp and of the heavy oil-fuelled 4-cylinder vertical inverted type motors 760hp. Each
Guaranteed surface speed was 14 knots. Fuel endurance 80 hours or 1.120 knots. Standard range with a cruising speed of 11 knots was 2.100 knots and maximum range with same speed 3.500 knots. Guaranteed maximum submerged speed 11 knots with an endurance of one hour. With a speed of 6 knots was the range 50 knots. Diving time from light to submerged condition 6 minutes and from intermediate to submerged condition 3½ minutes. The hull proper was constructed of steel allowing to dive to a depth of 200 feet. Main bunker capacity is around 2.500 US gallons with the possibility of almost doubling this capacity by using the ballast tanks for fuel storage.
Armament consisted of 4-45cm internal in the bow fitted torpedo tubes firing torpedoes with a length of 5,2 metres. Each tube was loaded and in this manner available for immediate response. The torpedoes were launched by air pressure controlled by the commanding officer or his substitute located at one of the two withdrawable periscopes. There were at the same time two tubes opened. When these two torpedoes were fired, could within seconds the other two tubes be opened. Standard was no storage for spare torpedoes available.
SourceArchive Kon. Mij. De Schelde 1875-1960 (Municipality Archive Vlissingen) T 214.802.