''Yu 1'' was an Imperial Japanese Army transport submarine, the lead vessel of the ''Yu 1'' subclass of the Yu I type. Constructed for use during World War II and entering service in the last days of 1943, she participated in the Philippines campaign of 1944–1945, supplying Japanese forces in the Battle of Leyte, and was sunk at the beginning of 1945.

Construction

In the final two years of World War II, the Imperial Japanese Army constructed transport submarines — officially the

Type 3 submergence transport vehicle The was a class of transport submarines built for the Imperial Japanese Army (IJA) during World War II. The IJA called them . Design and construction The six-month-long Guadalcanal campaign came to an end in early February 1943, when the last ...

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 tower A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and gro ...

s and details of their gun armament. None carried torpedoes or had torpedo tubes. ''Yu 1'' was both the first ''Maru Yu'' submarine constructed and the lead unit of the ''Yu 1'' subclass.Mühlthaler, p. 329. ''Yu 1'' was laid down on 23 June 1943 by the

Hitachi () is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...

Kasado Works (''Hitachi Kasado Seisakujo'') at Kudamatsu, Japan. She was launched on either 16IJA Subs, ijnsubsite.com Accessed 13 May 2022
/ref>Bailey, p. 55. or 29 October 1943 (according to different sources) and delivered to the Imperial Japanese Army sometime between 22 and 31 December 1943.

Service history

''Yu 1'' initially remained in Japanese home waters while the Japanese Army constructed additional submarines of her

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

and established a training program for their crews.Mühlthaler, p. 330. In May 1944, the Army created its first submarine combat unit (''jissen butai''), the Manila Underwater Transport Detachment (''Manira Sensuiyuso Hakentai''), consisting of ''Yu 1'', her

sister ship A sister ship is a ship of the same class or of virtually identical design to another ship. Such vessels share a nearly identical hull and superstructure layout, similar size, and roughly comparable features and equipment. They often share a ...

s and , and a mother ship. The detachment got underway from Japan on either 28 or 30 May 1944 (according to different sources) bound for Manila on Luzon in the Philippines. The vessels had a difficult voyage which included a number of mechanical breakdowns, but finally arrived at Manila on 18 July 1944. After their arrival, the three submarines underwent repairs and thorough overhauls. On 20 October 1944, United States Army forces landed on Leyte, beginning both the Battle of Leyte and the broader Philippines campaign of 1944–1945. In November 1944, all three submarines got underway on their first supply run to Leyte. ''Yu 2'' never arrived, but ''Yu 1'' and ''Yu 3'' reached Ormoc on Leyte's west coast on 27 November 1944 and discharged a combined 600 bags of white rice, 50 boxes of field rations, and 300 boxes of radio

batteries Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

. In December 1944, ''Yu 1'' and ''Yu 3'' were sent to

San Fernando San Fernando may refer to: People *Ferdinand III of Castile (c. 1200–1252), called ''San Fernando'' (Spanish) or ''Saint Ferdinand'', King of Castile, León, and Galicia Places Argentina *San Fernando de la Buena Vista, city of Greater Buenos ...

on the northwest coast of Luzon. On 2 January 1945, U.S. aircraft surprised ''Yu 1'' on the surface and sank her in

Lingayen Gulf The Lingayen Gulf is a large gulf on northwestern Luzon in the Philippines, stretching . It is framed by the provinces of Pangasinan and La Union and sits between the Zambales Mountains and the Cordillera Central. The Agno River and the Balili ...

just off Port Poro on Luzon's coast.

References

Footnotes

Bibliography

* * * * * *Rekishi Gunzō, History of Pacific War Extra, ''Perfect guide, The submarines of the Imperial Japanese Forces'', Gakken, Tokyo Japan, 2005, . *Rekishi Gunzō, History of Pacific War Vol.45, ''Truth histories of the Imperial Japanese Naval Vessels'', Gakken, Tokyo Japan, 2004, . *Ships of the World No.506, Kaijinsha, Tokyo Japan, 1996. *The Maru Special, Japanese Naval Vessels No.43 ''Japanese Submarines III'', Ushio Shobō, Tokyo Japan, 1980. *Atsumi Nakashima, ''Army Submarine Fleet, "The secret project !, The men challenged the deep sea"'', Shinjinbutsu Ōraisha, Tokyo Japan, 2006, . *''50 year history of the Japan Steel Works'' (first volume and second volume), Japan Steel Works, 1968. {{DEFAULTSORT:Yu 0001 1943 ships Ships built in Japan Submarines of the Imperial Japanese Army World War II submarines of Japan Maritime incidents in January 1945 Ships sunk by US aircraft Japanese submarines lost during World War II Shipwrecks of the Philippines World War II shipwrecks in the South China Sea