Japanese submarine Yu 7

History
Japan
Name	Yu 7
Builder	Hitachi  Kasado Works, Kudamatsu,  Japan
Fate	Surrendered August 1945 Scuttled or scrapped
General characteristics Yu I type
Type	Transport submarine
Displacement	274 long tons (278 t) surfaced 346 long tons (352 t) submerged
Length	41.40 m (135 ft 10 in) overall
Beam	3.90 m (12 ft 10 in)
Draft	3.00 m (9 ft 10 in)
Propulsion	2 × Hesselman engines 298 kW (400 bhp) surfaced 56 kW (75 shp) submerged single shaft
Speed	10 knots (19 km/h; 12 mph) surfaced 4 knots (7.4 km/h; 4.6 mph) submerged
Range	1,500  nmi (2,800 km; 1,700 mi) at 8 knots (15 km/h; 9.2 mph) surfaced 32 nmi (59 km; 37 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	100 m (328 ft)
Capacity	24 tons freight or 40 troops
Complement	23
Armament	1 × Type 4 37 mm shipboard gun 5 × Type 99 light machine guns

Yu 7 was an Imperial Japanese Army transport submarine of the Yu 1 subclass of the Yu I type. Constructed for use during the latter stages of World War II, she served in the waters of the Japanese archipelago.

Construction

In the final two years of World War II, the Imperial Japanese Army constructed transport submarines — officially the Type 3 submergence transport vehicle and known to the Japanese Army as the Maru Yu — with which to supply its isolated island garrisons in the Pacific Ocean. Only submarines of the Yu I type were completed and saw service. The Yu I type was produced in four subclasses, each produced by a different manufacturer and differing primarily in the design of their conning towers and details of their gun armament. None carried torpedoes or had torpedo tubes. Yu 7 was a unit of the Yu 1 subclass. ^[1]

The Hitachi Kasado Works (Hitachi Kasado Seisakujo) at Kudamatsu, Japan, constructed Yu 7. ^{[1] [2]} Records of the details of the construction of Yu 7 have not been discovered, but the earlier Yu I-type submarines were laid down and launched during the latter half of 1943 and entered service at the end of 1943 or early in 1944. ^{[2] [3]}

Service history

Yu 7 spent her operational career in Japanese home waters. ^[4] She was assigned to Detachment 2, Transport Submarine Group, in November 1944.^{[ citation needed ]} In January 1945, several Type I transport submarines were sent to operate from Shimoda on the southern tip of the Izu Peninsula in Shizuoka Prefecture on Honshu, ^[4] and the submarines began transport missions from Shimoda in March 1945. ^[4] It is not clear when Yu 7 began operations from Shimoda, but she made a round-trip supply voyage from Shimoda to Hachijō-jima in the Philippine Sea sometime during 1945 as well as a round-trip supply voyage from the Army Transport Submarine Base on the Seto Inland Sea at Mishima in Ehime Prefecture ^[5] on Shikoku in Japan to Ōshima Island in March 1945. ^{[2] [4]}

World War II ended with the cessation of hostilities on 15 August 1945. Yu 7 surrendered to the Allies later in August 1945. ^[2] She was subsequently either scuttled or scrapped. ^[4]

References

Footnotes

1. Mühlthaler, p. 329.
2. IJA Subs, ijnsubsite.com Accessed 14 May 2022
3. Mühlthaler, pp. 329–330.
4. Mühlthaler, p. 330.
5. Muehlthaler, Erich, and Bob Hackett, "Strange but True Stories: The Exceptional Maiden Voyage of Imperial Japanese Army Transport Submarine YU 3001," Nihon Kaigun, 1 February 2014 Accessed 11 May 2022

Bibliography

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