Service history
Upon commissioning, I-40 was attached formally to the Yokosuka Naval District and assigned to Submarine Squadron 11 in the 1st Fleet for work-ups. [1] During August 1943, she took part in testing of sonar and magnetic anomaly detector equipment in the Seto Inland Sea, serving as an antisubmarine warfare target for the minelayer Nuwajima. [1]
With her work-ups completed, I-40 was reassigned to Submarine Division 1 in Submarine Squadron 2 in the 6th Fleet on 31 October 1943. [1] She departed Yokosuka on 13 November 1943 bound for Truk, which she reached on 19 November 1943. [1]
The Gilbert and Marshall Islands campaign began on 20 November 1943 with the U.S. invasion of Tarawa and of Makin in the Gilbert Islands. [1] That day, I-40 and the submarines I-19, I-21, I-35, I-39, I-169, I-174, I-175, and Ro-38 all received orders to proceed to the Gilberts and oppose the invasion. [1] I-40 got underway from Truk on 22 November 1943 to begin her first war patrol, assigned a patrol area off Makin Island. [1] The Japanese never heard from her again. [1]
On 26 November 1943, the 6th Fleet ordered I-40 to join I-19, I-169 and Ro-38 in forming a picket line north of Makin, [1] and on 2 December 1943 it ordered I-19, I-20, and I-40 to report their positions. [1] I-40 did not respond to either message. [1]
The circumstances of I-40′s loss remain a mystery. The destroyer USS Boyd (DD-544) sank a Japanese submarine southwest of Tarawa on 23 November 1943 which probably was I-39 but could have been I-40. [1] It also has been proposed that land-based United States Navy aircraft teamed with the destroyer USS Radford (DD-446) to sink her [1] and that Radford alone sank her. [1]
On 21 February 1944, the Imperial Japanese Navy declared I-40 to be presumed lost with her entire crew of 97 in the Gilbert Islands area. [1] She was stricken from the Navy list on 30 April 1944. [1]
I-10 was an Imperial Japanese Navy Type A1 submarine that served during World War II. Designed as a submarine aircraft carrier, she was commissioned in 1941 and supported the attack on Pearl Harbor, operated in the Indian Ocean — including support for the 1942 midget submarine attack on Diego Suarez — and in the New Caledonia and New Zealand areas, and took part in the Guadalcanal campaign and Marianas campaign before she was sunk in 1944 during her seventh war patrol.
Ro-106 was an Imperial Japanese Navy Ro-100-class submarine. Completed and commissioned in December 1942, she served in World War II, operating in the Solomon Islands campaign, New Guinea campaign, and central Pacific Ocean. She was sunk in May 1944 during her eleventh war patrol.
I-75, later I-175, was an Imperial Japanese Navy Kaidai-type cruiser submarine of the KD6B sub-class commissioned in 1938. During World War II, she took part in the attack on Pearl Harbor, the Battle of Midway, the Guadalcanal campaign, the Aleutian Islands campaign, and the Gilbert and Marshall Islands campaign and operated off Australia, before she was sunk in 1944 during her tenth war patrol. She is best known for sinking the United States Navy escort carrier USS Liscome Bay on 24 November 1943.
I-16 was one of five Type C cruiser submarines of the C1 sub-class built for the Imperial Japanese Navy, Commissioned in 1940, she deployed a midget submarine for the attack on Pearl Harbor and for an attack on ships at Diego-Suarez in Madagascar, conducted an anti-shipping patrol in the Indian Ocean, and took part in the Guadalcanal campaign, New Guinea campaign, and Bougainville campaign before she was sunk in May 1944.
I-69, later I-169, was an Imperial Japanese Navy Kaidai-class cruiser submarine of the KD6 sub-class commissioned in 1935. She served in World War II, during which she conducted six war patrols and took part in operations supporting the attack on Pearl Harbor, the Battle of Midway, the Guadalcanal campaign, the Aleutians campaign, and the defense of the Gilbert Islands. She sank in a diving accident in April 1944.
I-71, later I-171, was a Kaidai-class cruiser submarine of the KD6 sub-class built for the Imperial Japanese Navy during the 1930s. She served in World War II, and took part in operations supporting the attack on Pearl Harbor, the Battle of Midway, and the Aleutian Islands campaign. She was sunk on1 February 1944 after being detected on the surface by U.S. Navy destroyers off Buka Island.
I-20 was one of five Type C cruiser submarines of the C1 sub-class built for the Imperial Japanese Navy. During World War II, she operated as the mother ship for a midget submarine during the attack on Pearl Harbor and the attack of Diego-Suarez, conducted war patrols in the Pacific Ocean and Indian Ocean, and served in the Guadalcanal campaign and New Guinea campaign. She was last heard from on 31 August 1943.
I-35 was an Imperial Japanese Navy B1 type submarine. Completed and commissioned in 1942, she served in World War II, operating in the Aleutian Islands campaign and the Battle of Tarawa before she was sunk in November 1943.
I-39 was an Imperial Japanese Navy B1 type submarine. Completed and commissioned in 1943, she served in World War II, operating in support of Japanese forces in the Battle of Tarawa before she was sunk in November 1943.
I-32 was an Imperial Japanese Navy B1 type submarine. Completed and commissioned in 1942, she served in World War II, operating in the Pacific Ocean and Indian Ocean and supporting Japanese forces in the New Guinea campaign and the Guadalcanal campaign before she was sunk in March 1944.
I-42 was an Imperial Japanese Navy Type B2 submarine. Completed and commissioned in 1943, she served in World War II and was sunk during her first war patrol in March 1944.
I-43 was an Imperial Japanese Navy Type B2 submarine. Completed and commissioned in 1943, she served in World War II and was sunk during her first deployment in February 1944.
The second I-54 was an Imperial Japanese Navy Type B3 submarine. Completed and commissioned in March 1944, she served in World War II and took part in the Marianas campaign and the Philippines campaign before she was sunk in October 1944.
Ro-38 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in July 1943, she served in World War II and was sunk in November 1943 during her first war patrol.
Ro-40 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in September 1943, she served in World War II and was sunk in February 1944 during her first war patrol.
Ro-41 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in November 1943, she served in World War II and conducted six war patrols, sinking a destroyer escort USS Shelton (DE-407) on one of them, before she was sunk in March 1945.
Ro-104 was an Imperial Japanese Navy Ro-100-class submarine. Completed and commissioned in February 1943, she served in World War II, operating in the Aleutian Islands campaign, New Guinea campaign, and Solomon Islands campaign before she was sunk in May 1944 during her tenth war patrol.
Ro-105 was an Imperial Japanese Navy Ro-100-class submarine. Completed and commissioned in March 1943, she served in World War II, operating in the Aleutian Islands campaign, New Guinea campaign, and Solomon Islands campaign and in the vicinity of Truk, Rabaul, and the Admiralty Islands before she was sunk in May 1944 during her fourth war patrol.
Ro-108 was an Imperial Japanese Navy Ro-100-class submarine. Completed and commissioned in April 1943, she served in World War II, operating in the Solomon Islands campaign, the New Guinea campaign — during which she sank the United States Navy destroyer USS Henley (DD-391) — and off the Admiralty Islands. She was sunk in May 1944 during her fifth war patrol.
Ro-116 was an Imperial Japanese Navy Ro-100-class submarine. Completed and commissioned in January 1944, she served in World War II and was sunk in May 1944 during her second war patrol.
Japan
