Type A2 submarines were versions of the preceding Type A1 with less powerful engines, adopted to reduce their construction time. I-12 was the only submarine completed to the original Type A2 design; subsequent Type A2s were constructed to a modified design as the Type AM. Like the preceding Type A1 submarines, I-12 was fitted as a squadronflagship.[3] She displaced 2,967 tonnes (2,920 long tons) on the surface and 4,217 tonnes (4,150 long tons) submerged. She was 113.7 meters (373 ft 0 in) long and had a beam of 11.7 meters (38 ft 5 in) and a draft of 5.89 meters (19 ft 4 in). She had a diving depth of 100 meters (328 ft).[3]
For surface running, I-12 powered by two 4,700-
propeller shaft. When submerged each propeller was driven by a 1,200-horsepower (895 kW) electric motor. She could reach 17.5 knots (32.4 km/h; 20.1 mph) on the surface[4] and 6.2 knots (11.5 km/h; 7.1 mph) submerged. On the surface, she had a range of 22,000 nautical miles (40,700 km; 25,300 mi) at 16 knots (30 km/h; 18 mph); submerged, she had a range of 75 nmi (139 km; 86 mi) at 3 knots (5.6 km/h; 3.5 mph).[5]
As in Type A1 submarines, I-12′s aircraft hangar was integrated into her conning tower and faced forward, and the aircraft catapult was forward of the hangar, while the deck gun was aft of the conning tower. This allowed aircraft launching from I-12 to use the forward motion of the submarine to supplement the speed imparted by the catapult.[5]
Construction and commissioning
Built by
laid down as Submarine No. 620 on 5 November 1942.[6] On 5 July 1943 she was renamed I-12 and attached provisionally to the Yokosuka Naval District.[6] She was launched on 3 August 1943[6] and was completed and commissioned on 25 May 1944.[6]
Service history
May–September 1944
On the day of her commissioning, I-12 was formally attached to the Yokosuka Naval District and assigned to Submarine
United States West Coast and Hawaii, and the 6th Fleet selected I-12 for the operation.[6] Attached directly to 6th Fleet headquarters, she departed Kobe on 4 October 1944 for her first war patrol, ordered to attack shipping along the U.S. West Coast, in the Hawaiian Islands area, in the Tahiti area, and in the Pacific Ocean east of the Marshall Islands.[6] She proceeded through the Seto Inland Sea and Sea of Japan to Hakodate, where she paused in Hakodate Bay on 7 October 1944 for an overnight stop.[6] She then got back underway and passed through the Tsugaru Strait into the Pacific Ocean.[6]
automatic weapons fire.[14] For 45 minutes, I-12 moved about in the vicinity of the lifeboats, attempting to ram Lifeboat No. 4, discovering the life raft with 17 survivors aboard and opening fire on it with her 25-millimeter guns, all the while shooting any survivors she found and attempting to slice up men in the water with her propellers.[6][14] She then opened gunfire on both sections of John A. Johnson from a range of 2,000 yards (1,800 m), and after she fired eight 140-millimeter (5.5 in) rounds, scoring four hits, both sections were on fire.[6][15] She remained on the scene for another two hours, although she did not resume firing at the remaining survivors, who believed that she was waiting for dawn so that she could continue the massacre in daylight.[15]
Just after 01:00 on 30 October 1944, a
patrol vessel USS Argus (PY-14), whose crew had heard the explosion of John A. Johnson′s bow section from 90 nautical miles (170 km; 100 mi) away and already was headed toward the scene.[6] A search-and-rescue aircraft sighted the survivors at 08:00 on 30 October,[15] and at 14:00 Argus reached the scene and brought aboard 60 survivors.[16]Argus disembarked the survivors at San Francisco on 3 November 1944.[6][17] They described I-12 as a very large submarine, painted black or dark grey above the waterline and light grey below it, with a 6-inch (15 cm) horizontal stripe running around her stern.[6]
Sources differ on casualties during the sinking and subsequent massacre, but at least six men were killed,[6] one source claims that four crewmen, five Navy Armed Guard personnel, and the U.S. Army cargo security officer were left missing and presumed dead,[6] and another specifies that 10 men died.[17] Because John A. Johnson had broken in half, the Japanese erroneously credited I-12 with sinking two ships.[6]
Diesel oil, air bubbles, and debris including teak deck planks, ground cork covered in diesel oil, pieces of varnishedmahogany inscribed in Japanese, a wooden slat from a vegetable crate with Japanese writing and advertisements on it, and a piece of an instrument case inscribed with Japanese characters.[6][18] Both Ardent and Rockford received credit for the probable destruction of a Japanese submarine, which probably was I-12.[6][18]
On 19 December 1944, 6th Fleet headquarters ordered I-12 to return to Kure,
transport and tanker in the mid-Pacific Ocean between 20 and 31 December 1944[6] and U.S. Navy sightings of a Japanese submarine in the Hawaiian Islands area on 2 and 4 January 1945, leading the 6th Fleet staff to conclude that I-12 still was on patrol.[6] The 6th Fleet staff also assessed that a garbled interception of an Allied report of a surfaced Japanese submarine seen north of the Marshall Islands at 14°10′N171°02′E / 14.167°N 171.033°E / 14.167; 171.033 on 5 January 1945 was a sighting of I-12 as she returned from her patrol.[6] On 31 January 1945, however, the Imperial Japanese Navy declared I-12 to be presumed lost with all 114 hands in the mid-Pacific Ocean.[6] The Japanese removed her from the navy list on 10 August 1945.[6]
References
Footnotes
^ abcI-11. Ijnsubsite.info. 2018. Retrieved 2 June 2023.
Imperial Japanese Navy
