Japanese submarine Ha-109

Ha-109 was an Imperial Japanese Navy Ha-101-class submarine. Completed as a transport submarine, she was converted into a submarine tender for midget submarines. She served during the final months of World War II, 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 429 LT surfaced and 493 LT submerged. The submarines were 44.5 m long, had a beam of 6.1 m and a draft of 4.04 m. They were designed to carry 60 t of cargo.

For surface running, the boats were powered by a single 400 bhp diesel engine that drove one propeller shaft. When submerged the propeller was driven by a 140 hp electric motor. They could reach 10 kn on the surface and 5 kn underwater. On the surface, the Ha-101s had a range of 3000 nmi at 10 kn; submerged, they had a range of 46 nmi at 2.3 kn. The boats were armed a single mount for a 25 mm Type 96 anti-aircraft gun.

Construction and commissioning
Ha-109 was laid down on 1 August 1944 by Mitsbishi at Kobe, Japan, as Small Supply Submarine No. 4609. Renamed Ha-109, she was launched on 10 January 1945. She was completed and commissioned on 10 March 1945.

Service history
Upon commissioning, Ha-109 was attached to the Kure Naval District and assigned to Submarine Squadron 11 for workups. On 20 March 1945, however, she was reassigned to the 10th Special Attack Unit and began conversion to a submarine tender for midget submarines, the conversion involving modifying her cargo hold to accommodate ten 450 mm torpedoes for midget submarines.

Ha-109 was in Saeki Bay at Matsuura, Japan, when hostilities between Japan and the Allies ended on 15 August 1945. Upon receiving the news that day, her crew destroyed her secret documents and distributed some of the food and fuel on board to local fishermen. In late August 1945, she proceeded from Saeki Bay to Kure, Japan, her crew throwing all of her ammunition and the torpedoes in her hold overboard during the voyage. Only a skeleton crew consisting of her commanding officer and seven crewmen remained aboard after her arrival at Kure on 24 August 1945. She surrendered to the Allies at Kure on 2 September 1945.

On 2 November 1945, Ha-109 was reassigned to Japanese Submarine Division Two under United States Navy command along with her sister ships JAPANESE SUBMARINE Ha-103, JAPANESE SUBMARINE Ha-105, JAPANESE SUBMARINE Ha-106, JAPANESE SUBMARINE Ha-107, JAPANESE SUBMARINE Ha-108, and JAPANESE SUBMARINE Ha-111. In November 1945, the U.S. Navy ordered all Japanese submarines at Kure, including Ha-109, to move to Sasebo, Japan.

Disposal
The Japanese struck Ha-109 from the Navy list on 30 November 1945. She was among a number of Japanese submarines the U.S. Navy scuttled off the Goto Islands near Sasebo in Operation Road's End on 1 April 1946, sinking just beyond the 100 fathom line at 32.61667°N, 129.28333°W.