Japanese submarine Ha-103

History
Japan
Name	Small Supply Submarine No. 4603
Builder	Mitsubishi, Kobe, Japan
Laid down	29 June 1944
Launched	21 October 1944
Renamed	Ha-103 on 21 October 1944
Completed	3 February 1945
Commissioned	3 February 1945
Fate	Surrendered 2 September 1945; Stricken 30 November 1945; Scuttled 1 April 1946;
General characteristics
Type	Transport submarine
Displacement	436 t (429 long tons) surfaced; 501 t (493 long tons) submerged;
Length	44.5 m (146 ft 0 in)
Beam	6.1 m (20 ft 0 in)
Draft	4.04 m (13 ft 3 in)
Installed power	400 bhp (300 kW) (diesels); 150 hp (110 kW) (electric motor);
Propulsion	Diesel-electric; 1 × diesel engines; 1 × electric motor;
Speed	10 knots (19 km/h; 12 mph) surfaced; 5 knots (9.3 km/h; 5.8 mph) submerged;
Range	3,000 nmi (5,600 km; 3,500 mi) at 10 knots (19 km/h; 12 mph) surfaced; 46 nmi (85 km; 53 mi) at 2.3 knots (4.3 km/h; 2.6 mph) submerged;
Test depth	100 meters (328 ft)
Capacity	60 metric tons (59 long tons)
Complement	22
Armament	1 × single 25 mm (1 in) Type 96 anti-aircraft gun

Ha-103 was an Imperial Japanese Navy Ha-101-class submarine. Completed and commissioned in February 1945, she served during the final months of World War II, conducting a supply run and operating on radar picket duty. She surrendered at the end of the war in September 1945 and was scuttled in April 1946.

Design and description

The Ha-101-class submarines were designed as small, cheap transport submarines to resupply isolated island garrisons. They displaced 436 metric tons (429 long tons) surfaced and 501 metric tons (493 long tons) submerged. The submarines were 44.5 meters (146 ft 0 in) long, had a beam of 6.1 meters (20 ft 0 in) and a draft of 4.04 meters (13 ft 3 in). They were designed to carry 60 metric tons (59 long tons) of cargo.^[1]

For surface running, the boats were powered by a single 400-brake-horsepower (298 kW) diesel engine that drove one propeller shaft. When submerged the propeller was driven by a 140-horsepower (104 kW) electric motor. They could reach 10 knots (19 km/h; 12 mph) on the surface and 5 knots (9.3 km/h; 5.8 mph) underwater.^[2] On the surface, the Ha-101s had a range of 3,000 nautical miles (5,600 km; 3,500 mi) at 10 knots (19 km/h; 12 mph); submerged, they had a range of 46 nmi (85 km; 53 mi) at 2.3 knots (4.3 km/h; 2.6 mph). The boats were armed a single mount for a 25 mm (1 in) Type 96 anti-aircraft gun.^[3]

Construction and commissioning

Ha-103 was laid down on 29 June 1944 by Mitsubishi at Kobe, Japan, as Small Supply Submarine No. 4603.^[4] She was launched on 21 October 1944 and was named Ha-103 that day.^[4] She was completed and commissioned on 3 February 1945.^[4]

Service history

Upon commissioning, Ha-103 was assigned to Submarine Squadron 11 for workups.^[4] On 15 April 1945, she was reassigned to Submarine Division 16 for supply operations.^[4] She got underway from Kure, Japan, on 16 April 1945 for her first supply run, bound for Minamidaitōjima in the Daitō Islands southeast of Okinawa.^[4] After arriving there, she unloaded her cargo, embarked stranded Imperial Japanese Navy Air Service pilots for transportation to Japan, and quickly departed for her return voyage, reaching Kure on 22 April 1945.^[4]

On 29 April 1945, Ha-103 was reassigned to Submarine Unit No. 1, and she departed Kure that day to operate 300 nautical miles (560 km; 350 mi) south of Honshu on radar picket duty.^[4] She returned to Kure on 20 May 1945.^[4]

Hostilities between Japan and the Allies ended on 15 August 1945, and on 2 September 1945, Ha-103 surrendered to the Allies at Kure.^[4] On 2 November 1945, she was reassigned to Japanese Submarine Division Two under United States Navy command along with her sister ships Ha-105, Ha-106, Ha-107, Ha-108, Ha-109, and Ha-111.^[4] In November 1945, the U.S. Navy ordered all Japanese submarines at Kure, including Ha-103, to move to Sasebo, Japan.^[4]

Disposal

The Japanese struck Ha-103 from the Navy list on 30 November 1945.^[4] She was among a number of Japanese submarines the U.S. Navy scuttled off the Goto Islands in Operation Road's End on 1 April 1946, sinking at 32°30′N 128°40′E / 32.500°N 128.667°E / 32.500; 128.667 (Ha-103).^[4]

Notes

^ Carpenter & Dorr, p. 140
^ Chesneau, p. 204
^ Bagnasco, p. 195
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Hackett, Bob; Kingsepp, Sander (2015). "IJN Submarine HA-103: Tabular Record of Movement". combinedfleet.com. Retrieved 7 October 2020.

References

Bagnasco, Erminio (1977). Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
Carpenter, Dorr B. & Polmar, Norman (1986). Submarines of the Imperial Japanese Navy 1904–1945. London: Conway Maritime Press. ISBN 0-85177-396-6.
Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7.
Hackett, Bob; Kingsepp, Sander (2015). "IJN Submarine HA-103: Tabular Record of Movement". SENSUIKAN! Stories and Battle Histories of the IJN's Submarines. Combinedfleet.com. Retrieved 8 October 2020.
Hackett, Bob; Sander Kingsepp (2015). "Sen Yu Sho". Sensuikan!. Combinedfleet.com. Retrieved 7 October 2020.
"Rekishi Gunzō"., History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", Gakken (Japan), March 2005, ISBN 4-05-603890-2
Ships of the World special issue Vol.37, History of Japanese Submarines, "Kaijinsha"., (Japan), August 1993
The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III, Ushio Shobō (Japan), September 1980, Book code 68343-43
The Maru Special, Japanese Naval Vessels No.132 Japanese Submarines I "Revised edition", Ushio Shobō (Japan), February 1988, Book code 68344-36
Senshi Sōsho Vol.88, Naval armaments and war preparation (2), "And after the outbreak of war", Asagumo Simbun (Japan), October 1975