In the Lecture dated 28 March 1930 for aspirant officers of the Royal Netherlands Navy Reserve in the Dutch East Indies was explained what kind of demands a designer had to deal with to come with a compromised design including as much as possible of the demands still without increasing the displacement. The lecturer mentioned that the main task of a submarine was to nearer the enemy without being sighted and to manoeuvre in such a position that she was able to torpedo her target. Large displacements were a disadvantage and submarines were just successful when they operated in large numbers. Large number of small submarines were to prefer above a few large submarines. The main reason to decide to increase the displacement was heavier military demands.
An armament of at least 4-53,3cm torpedo tubes pointing out in the same direction It was believed that a modern warship could not be sunk by a single torpedo and considering the low chance of success of a torpedo a salvo of several torpedoes was to be preferred. Usually 1-7,5cm/2,9”-10cm/2.93” gun probably also to be used as anti aircraft guns and some machineguns (4cm/1.57” anti aircraft machineguns were preferable).
Buoyancy of at least 20-25% of the displacement.
Maximum diving depth 60-100 metres needed to be invisible for air reconnaissance but also for escaping from attacks with depth charges. For the latter purpose was the as much as possible strength of the hull of utmost importance.
Surfaced speed and range were depending on the purpose of the submarine, when submerged a maximum speed of 8-10 miles. Increasing the submerged speed caused an relatively enormous increase of the weight.
Emergency dive time less than 60 seconds.
Source
Archive Dutch Naval Staff (National Archive, The Hague, Netherlands) inv. no. 291. Lecture dated 28 March 1930 for aspirant officers of the Royal Navy Reserve in the Dutch East Indies.
An armament of at least 4-53,3cm torpedo tubes pointing out in the same direction It was believed that a modern warship could not be sunk by a single torpedo and considering the low chance of success of a torpedo a salvo of several torpedoes was to be preferred. Usually 1-7,5cm/2,9”-10cm/2.93” gun probably also to be used as anti aircraft guns and some machineguns (4cm/1.57” anti aircraft machineguns were preferable).
Buoyancy of at least 20-25% of the displacement.
Maximum diving depth 60-100 metres needed to be invisible for air reconnaissance but also for escaping from attacks with depth charges. For the latter purpose was the as much as possible strength of the hull of utmost importance.
Surfaced speed and range were depending on the purpose of the submarine, when submerged a maximum speed of 8-10 miles. Increasing the submerged speed caused an relatively enormous increase of the weight.
Emergency dive time less than 60 seconds.
Source
Archive Dutch Naval Staff (National Archive, The Hague, Netherlands) inv. no. 291. Lecture dated 28 March 1930 for aspirant officers of the Royal Navy Reserve in the Dutch East Indies.
