http://forum.axishistory.com/viewtopic. ... 5&t=143261
"... At least one of these RTN submarines closely resembles Japan's Kaichu-type (K5) medium submarines, such as the RO-33. Sister boat RO-34 had also been built at Mitsubishi, like those for the Thais. However, there seem to be some differences in the conning towers. ..."
More on Siamese Submarines
Displacement: 374.5 ton (floating) 430 ton (under sea)
Dimension: Length 51 m Beam 4.1 m height to tower 11.65 m
Draft : 3.6 m
Armaments: One 76-mm cannon, four 45-cm torpedo tubes (All Thai torpido launchers are 18-inch type [45-cm])
Engines: Two 8-cylinder diesel @ 1100 HP, 540HP Generator
Speed: 10 knots (ecojnomic)
Operatign range: 74770 nautical mile
Crews: 33 men (5 Cos, 28 Enlisted)
HTMS Matchanu submarine
Krill Laying: 6 May 1936
Launching: 24 December 1936
Depart from Mitsubishi SHipyard (Kobe): 5 June 1938
Reaching Siam: 29 June 1938
Commissioned: 19 July 1938
Decommissioned: 30 November 1951
HTMS Wirun
Krill Laying: 6 May 1936
Launching: 24 December 1936
Depart from Mitsubishi SHipyard (Kobe): 5 June 1938
Reaching Siam: 29 June 1938
Commissioned: 19 July 1938
Decommissioned: 30 November 1951
HTMS Sinsamut
Krill Laying: 1 October 1936
Launching: 14 May 1937
Depart from Mitsubishi SHipyard (Kobe): 5 June 1938
Reaching Siam: 29 June 1938
Commissioned: 19 July 1938
Decommissioned: 30 November 1951
HTMS Plaichumphon
Krill Laying: 1 October 1936
Launching: 14 May 1937
Depart from Mitsubishi SHipyard (Kobe): 5 June 1938
Reaching Siam: 29 June 1938
Commissioned: 19 July 1938
Decommissioned: 30 November 1951
Jakoś nie przekonuje mnie informacja, że syjamska czwórka była siostrzana z japońskimi Ro 33/Ro 34 typu K-5 (Kaichu-type). Wystarczy porównać wyporność i wymiary.
Może ktoś zna historię zamówienia tych okrętów w Japonii.