The Japanese submarine I-28 was one of 20 Type B cruiser submarines of the B1 sub-class built for the Imperial Japanese Navy (IJN) during the 1940s.

Design and description

The Type B submarines were derived from the earlier KD6 sub-class of the Kaidai-class submarine and were equipped with an aircraft to enhance their scouting ability. They displaced 2589 LT surfaced and 3654 LT submerged. The submarines were 108.7 m long, had a beam of 9.3 m and a draft of 5.1 m. They had a diving depth of 100 m. For surface running, the boats were powered by two 6200 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 1000 hp electric motor. They could reach 23.6 kn on the surface and 8 kn underwater. On the surface, the B1s had a range of 14000 nmi at 16 kn; submerged, they had a range of 96 nmi at 3 kn. The boats were armed with six internal bow 53.3 cm torpedo tubes and carried a total of 17 torpedoes. They were also armed with a single 140 mm/40 deck gun and two single mounts for 25 mm Type 96 anti-aircraft guns. In the Type Bs, the aircraft hangar was faired into the base of the conning tower. A single catapult was positioned on the forward deck.

Construction and career

I-28 was commissioned at Kobe, Japan on February 6, 1942. The submarine participated in the Battle of the Coral Sea in May 1942. Returning to base at Truk in the central Pacific, I-28 was torpedoed and sunk with all hands (88 officers and men) by the United States Navy submarine USS Tautog (SS-199) at 6.5°N, 152°W on 17 May 1942.