I-4 was an Imperial Japanese Navy J1 type submarine commissioned in 1929. She was a large cruiser submarine that served in the Second Sino-Japanese War and World War II. During the latter conflict she operated in support of the attack on Pearl Harbor, conducted anti-shipping patrols in the Indian Ocean, supported the Indian Ocean raid, and took part in the Aleutian Islands campaign, Guadalcanal campaign, and New Guinea campaign before she was sunk in December 1942.
Construction and commissioning
Built by Kawasaki at Kobe, Japan, I-4 was laid down on 17 April 1926. She was launched on 22 May 1928 and was completed and commissioned on 24 December 1929.
Service history
1929–1937
Upon commissioning, I-4 was attached to the Yokosuka Naval District and assigned to Submarine Division 7. Sources differ on whether Submarine Division 7 was assigned at the time to the Yokosuka Defense Division in the Yokosuka Naval District or to Submarine Squadron 2 in the 2nd Fleet, a component of the Combined Fleet. On 1 August 1930, when Submarine Division 8 was created, I-4 and her sister ship were placed in the new division. On 1 December 1930, Submarine Division 8 began duty with Submarine Squadron 1 in the 1st Fleet, a component of the Combined Fleet. The division was reassigned to the Yokosuka Defense Division in the Yokosuka Naval District on 1 October 1931, but it began another tour of duty in Submarine Squadron 1 in the 1st Fleet on 1 December 1931. I-4 was off Kyushu near the Mishima Islands taking part in an exercise in which a group of submarines practiced a mock combined attack on a line of zigzagging battleships on 14 June 1932 when she unexpectedly surfaced in front of the battleships. The battleship , making , took evasive action at the last minute and managed to avoid a direct collision with the stationary I-4, although Hyūga suffered minor damage to her hull plating when her bow grazed I-4′s hull.
Submarine Division 8 completed its assignment to Submarine Squadron 1 on 1 October 1932 and again was assigned to the Yokosuka Defense Division in the Yokosuka Naval District, but it returned to duty in Submarine Squadron 1 in the 1st Fleet on 15 November 1933. I-4 got underway from Sasebo, Japan, in company with the other vessels of Submarine Squadron 1 — , , and I-3 of Submarine Division 7 and and of Submarine Division 8 — for a training cruise in Chinese waters on 29 March 1935. The six submarines concluded the cruise with their return to Sasebo on 4 April 1935. On 15 November 1935, Submarine Division 8 again returned to the Yokosuka Defense Division in the Yokosuka Naval District, and that day I-4 was placed in reserve.
Submarine Division 8 returned to service in Submarine Squadron 1 in the 1st Fleet on 1 December 1936. On 27 March 1937, I-4 departed Sasebo in company with I-1, I-2, I-3, I-5, and I-6 for training in the vicinity of Qingdao, China. The six submarines concluded the training cruise with their arrival at Ariake Bay on 6 April 1937.
Second Sino-Japanese War
On 7 July 1937 the first day of the Marco Polo Bridge Incident took place, beginning the Second Sino-Japanese War. In September 1937 Submarine Squadron 1 was reassigned to the 3rd Fleet, which in turn was subordinated to the China Area Fleet for service in Chinese waters. The squadron, consisting of I-1, I-2, I-3, I-4, I-5, and I-6, deployed to a base at Hong Kong with the submarine tenders and in September 1937. From Hong Kong, the submarines began operations in support of a Japanese blockade of China and patrols of China′s central and southern coast. From 20 or 21 (sources disagree) to 23 August 1937, all six submarines of Submarine Squadron 1 operated in the East China Sea as distant cover for an operation in which the battleships , , , and and the light cruiser ferried troops from Tadotsu, Japan, to Shanghai, China.
Submarine Squadron 1 was based at Hong Kong until the autumn of 1938. In an effort to reduce international tensions over the conflict in China, Japan withdrew its submarines from Chinese waters in December 1938.
1939–1941
Submarine Division 8 was placed in Third Reserve in the Yokosuka Naval District on 15 November 1939. The division was resubordinated on 15 November 1940 to Submarine Squadron 2 in the 6th Fleet, a component of the Combined Fleet. On 7 January 1941, I-4 became flagship of Submarine Division 8. She briefly was in reserve from 19 to 31 October 1941.