On 22 April 1930 was the London Naval Treaty or the Treaty for the Limitation and Reduction of naval Armament signed between the France, Italy, Japan, United Kingdom and the USA. This Treaty included the restricting of the standard displacement and the gun calibres of submarines. The result was that the big gun submarine concept like that of the French submarine Surcouf was doomed to disappear. There were lists made of the submarines of the above mentioned five countries less than 13 years old. Tonnage 1.635 tons, completed in 1929 and with an armament of 1-12cm4.7”gun.
Source
Archive Dutch Naval Staff 1886-1942 (National Archive at The Hague, Netherlands T.2.12.18) inventory number 155. London, Naval Conference, 1930. Third report of the first committee dated 12th April 1930 dealing with the submarine topic.
