NAVYPEDIA

Photo

RO50  

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
呂35 [RO35]			Mitsubishi, Kobe	10.1941	4.6.1942	3.1943	sunk 25.8.1943
呂36 [RO36]			Mitsubishi, Kobe	3.1942	14.10.1942	5.1943	sunk 13.6.1944
呂37 [RO37]			Mitsubishi, Kobe	10.1941	30.6.1942	6.1943	sunk 22.1.1944
呂38 [RO38]			Mitsubishi, Kobe	6.1942	24.12.1942	7.1943	sunk 24.11.1943
呂39 [RO39]			Sasebo K K	8.1942	6.3.1943	9.1943	sunk 2.2.1944
呂40 [RO40]			Mitsubishi, Kobe	8.1942	6.3.1943	9.1943	sunk 16.2.1944
呂41 [RO41]			Mitsubishi, Kobe	10.1942	5.5.1943	11.1943	sunk 23.3.1945
呂42 [RO42]			Sasebo K K	4.1942	25.10.1942	8.1943	sunk 11.6.1944
呂43 [RO43]			Mitsubishi, Kobe	10.1942	5.6.1943	12.1943	sunk 26.2.1945
呂44 [RO44]			Tamano Zosen, Tamano	2.1942	11.11.1942	9.1943	sunk 16.6.1944
呂45 [RO45]			Mitsubishi, Kobe	10.1942	21.7.1943	1.1944	sunk 30.4.1944
呂46 [RO46]			Mitsubishi, Kobe	6.1942	23.4.1943	2.1944	sunk 18.4.1945
呂47 [RO47]			Tamano Zosen, Tamano	12.1942	20.8.1943	1.1944	sunk 25.9.1944
呂48 [RO48]			Mitsubishi, Kobe	3.1942	15.10.1943	3.1944	sunk 14.7.1944
呂49 [RO49]			Tamano Zosen, Tamano	11.1942	3.8.1943	5.1944	sunk 5.4.1945
呂50 [RO50]			Tamano Zosen, Tamano	2.1943	27.11.1943	7.1944	surrendered 8.1945, scuttled 1.4.1946
呂55 [RO55]			Tamano Zosen, Tamano	8.1943	23.4.1944	9.1944	sunk 9.2.1945
呂56 [RO56] (ex-呂75 [RO75])			Tamano Zosen, Tamano	12.1943	5.7.1944	11.1944	sunk 9.4.1945

Technical data

Displacement standard, t	960
Displacement normal, t	1115 / 1447
Length, m	76.5 pp 79.0 wl 80.5 oa
Breadth, m	7.05
Draught, m	4.07
No of shafts	2
Machinery	2 Kampon diesels / 2 electric motors
Power, h. p.	4200 / 1200
Max speed, kts	19.7 / 8
Fuel, t	diesel oil 115
Endurance, nm(kts)	5000(16) / 45(5)
Armament	1 x 1 - 76/40 88-shiki, 1 x 2 - 25/60 96-shiki or 1 x 2 - 13.2/76, 4 - 533 TT (bow, 10)
Electronic equipment	presumably 93-shiki sonar, 93-shiki hydrophone
Complement	54 - 61
Diving depth operational, m	75

Standard scale images

Graphics

Project history

Kaichu 6 (Medium Admiralty 6) type. Development of Kaichu 5 type. Larger and a little bit faster than predecessors, but with smaller endurance. Originally artillery was not provided, however 76mm gun was installed during outfitting. In total under 4th and 5th Supplementary programmes of 1939 and 1941, and also under the 1942 War programmes (basic and additional) building of 88 submarines was scheduled (RO49-56, 70-74, 76-99, 200-227 and nine unnamed hulls No715-723). Actually 18 submarines entered service, orders for remaining (RO51-54, 70-74, 76-99 and 200-227) were cancelled in 1943. Nos715-723 were never ordered.

Modernizations

None.

Naval service

RO35 was sunk 25.8.1943 SE off San Cristobal by US destroyer Patterson. RO38 after 19.11.1943 was lost between Truk and Gilbert Islands. RO37 was sunk 22.1.1944 E off San Cristobal by US destroyer Buchanan. RO39 was sunk 2.2.1944 W off Gilbert Islands by US destroyer Walker. RO40 was sunk 16.2.1944 at Kwajalein by US destroyer Phelps and minesweeper Sage. RO45 was sunk 30.4.1944 at Truk by US destroyers MacDonough, Stephen Potter and carrier aircraft. RO42 was sunk 10.6.1944 at Kwajalein by US escort destroyer Bangust. RO36 was sunk 13.6.1944 at Saipan by US destroyer Melvin. RO44 was sunk 16.6.1944 E off Eniwetok by US escort destroyer Burden R. Hastings. RO48 after 14.7.1944 was lost, possibly she was sunk 14.7.1944 at Saipan by US escort destroyer William С. Miller. RO47 after 24.9.1944 was lost, presumably sunk 26.9.1944 in Carolina Islands area by US escort destroyer McCoy Reynolds. RO55 was sunk 7.2.1945 at Luzon by US escort destroyer Thomason. RO43 was sunk 26.2.1945 at Iwojima by US carrier aircraft. RO41 was sunk 23.3.1945 SE off Okinawa by US destroyer Haggard. RO49 after 25.3.1945 was lost, possibly sunk 5.4.1945 at Okinawa by US destroyer Hudson. RO56 after 18.3.1945 was lost, possibly she was sunk at Okinawa 9.4.1945 by US destroyers Mertz and Monssen. RO46 after 17.4.1945 was lost, possibly sunk at Okinawa 25.4.1945 by US fast personnel transport Horace A. Bass (under other version, she was sunk 18.4.1945 at Wake by US submarine Sea Owl). RO50 was scuttled by Americans 1.4.1946.