Dimensions 105’3½” (over all) x 13.9” (maximum
diameter) x 13’10½” (maximum beam and a displacement of 240 (light)-274 (total
with superstructure)-294 (total submerged) tons. Surface buoyance 14% of surface
displacement 13¾”, metacentric height submerged 7¼”and range of positive
stability 180 degrees. Air capacity around 73 cubic feet at 2.500 pound/square
inch. She was fitted out with a superstructure and a flat deck for navigation
tasks while surfaced and to be used as shelter and storage of appliances.
The two main engines were inverted 6-cylinder single
acting marine type engines to supply each 250hp at 500rpm. The two multipolar
direct current main motors supplied each 125hp (continuously-260hp (during one
hour). Guaranteed surfaced speed 10¾ knots. Endurance 55 hours or590 knots.
Range with cruising speed of 8½ knots is 900 knots. Guaranteed submerged speed
11 knots. Endurance 1½ hours. Range with a speed of 6 knots is 60 knots. Fuel
bunker capacity around 3.900 US gallons.
To go from light to submerged condition was 5 minutes
needed and from intermediate condition to submerged 2 minutes. The hull proper
was constructed of steel allowing to dive to a depth of 200 feet.
The armament consisted of 2 internal torpedo tubes in
the bow for launching 45cm torpedoes with a length of 5,2 metres. Each tube was
loaded and in this manner available for immediate response and in cradles on
the battery deck were two spare torpedoes stored.
Source
Archive Kon. Mij. De Schelde 1875-1960
(Municipality Archive Vlissingen) T 214.802. 
