Japanese Submarine I-48

''I-48'' was the last of three Type C cruiser submarines of the C2 sub-class built for the Imperial Japanese Navy. Commissioned in September 1944, she operated as a ''kaiten'' manned suicide attack torpedo carrier during World War II and was sunk in January 1945.

Design and description

The Type C submarines were derived from the earlier KD6 sub-class of the with a heavier torpedo armament for long-range attacks. They displaced surfaced and submerged. The submarines were long, had a beam of and a draft of . They had a diving depth of .Bagnasco, p. 192

For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater.Chesneau, p. 201 On the surface, the ''C1''s had a range of at ; submerged, they had a range of at .

The boats were armed with eight internal bow torpedo tubes and carried a total of 20 torpedoes. They were also armed with a single /40 deck gun and two single or twin mounts for Type 96 anti-aircraft guns. They were equipped to carry one Type A midget submarine aft of the conning tower.Carpenter & Dorr, p. 104

Construction and commissioning

Ordered under the Rapid Naval Armaments Supplement Programme and built by the Sasebo Naval Arsenal at Sasebo, Japan, ''I-48'' was laid down on 19 June 1943 with the name ''Submarine No. 378''. On 12 December 1943 she was numbered ''I-48'' and Launched. She was completed and commissioned on 5 September 1944.

Service history

September 1944–January 1945

Upon commissioning, ''I-48'' was attached to the Yokosuka Naval District and assigned to Submarine Squadron 11 in the 6th Fleet. She was configured to carry four ''kaiten'' manned suicide attack torpedoes on her after deck, two of them with access tubes that allowed their pilots to enter them while she was submerged. On 7 December 1944 she was reassigned to Submarine Division 15 in the 6th Fleet, and on 8 December she was assigned to the ''Kongo'' ("Steel") ''kaiten'' unit.

''I-48'' completed work-ups in the Seto Inland Sea on 26 December 1944 and proceeded to the naval base at Otsujima. She embarked her ''kaitens'' and their pilots there, and on 9 January 1945 became the last submarine of the ''Kongo'' unit to get underway for the U.S. naval base at Ulithi Atoll in the Caroline Islands to participate in a ''kaiten'' attack on the U.S. fleet there scheduled for 21 January 1945. The Japanese never heard from her again.

Loss

On 21 January 1945, ''I-48'' was west of Ulithi Atoll proceeding toward the atoll on the surface at when a Tinian-based PBM Mariner flying boat of U.S. Navy Patrol Bombing Squadron 20 (VPB-20) spotted her on radar at 19:30. When the plane tried to ascertain ''I-48''′s nationality, she submerged, and the Mariner attacked her with two depth charges and a Mark 24 "Fido" acoustic homing torpedo. She survived, but aborted her ''kaiten'' attack on the anchorage.

After the Mariner′s crew reported the sighting, a hunter-killer group of three destroyer escorts — , , and , with ''Conklin'' serving as flagship — from U.S. Navy Escort Division 65 began a search for ''I-48''. The hunter-killer group′s commander made the assumption that ''I-48'' was damaged and would head for Japanese-held Yap at an average submerged speed of . After the group made no contact with ''I-48'', the group expanded its search all the way to Yap on 22 January 1945.

At 03:10 on 23 January 1945, ''I-48'' was on the surface northeast of Yap, proceeding southwest at when ''Corbesier'' detected her on radar at a range of . ''Corbesier'' closed the range and ''I-48'' submerged. ''Corbesier'' picked up sonar contact on ''I-48'' at 03:36 and fired a Hedgehog salvo that missed. ''Conklin'' and ''Raby'' also arrived on the scene. ''Corbesier'' fired five more Hedgehog salvoes without scoring any hits, then lost contact.

''Corbesier'' regained contact on ''I-48'' at 09:02 and fired another Hedgehog salvo, which missed. ''Corbesier'' again gained sound contact at 09:12, but lost it before she could attack again. ''Conklin'', however, was able to launch a Hedgehog attack at 09:34 from a range of . Seventeen seconds later, she heard four or five explosions at an estimated depth of , followed at 09:36 by a violent explosion that knocked out ''Conklin''′s engines and steering gear. ''Conklin'' observed huge air bubbles rising to the surface, soon followed by oil, wreckage, and large quantities of human remains. It marked the end of ''I-48'', sunk with the loss of all 122 men aboard — her crew of 118 and four embarked ''kaiten'' pilots — at either or , according to different sources. A motor whaleboat from ''Conklin'' later recovered pieces of planking, splintered wood, cork, interior woodwork with varnished surfaces, a sleeve of a knitted blue sweater containing human flesh, chopsticks, and a seaman's manual from the water north of Yap.

The Japanese 6th Fleet attempted to contact ''I-48'' on 31 January 1945, ordering her to proceed to Kure, Japan. She did not acknowledge the order. She was stricken from the Navy list on 10 May 1945.

Notes

References

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{{DEFAULTSORT:I-048
1943 ships
World War II submarines of Japan
Japanese submarines lost during World War II
Ships built by Sasebo Naval Arsenal
Type C2 submarines
Maritime incidents in January 1945
World War II shipwrecks in the Philippine Sea
World War II shipwrecks in the Pacific Ocean
Warships lost in combat with all hands
Submarines sunk by United States warships