The
Kaidai-type submarines were divided into seven classes and two subclasses: • • • • • • • • •
Kaidai I (I-51 class) Project number
S22. The prototype for the class. The sole Kaidai I,
I-51, was based on
World War I-era German submarines. She was completed in 1924, refitted with new engines in 1932 and scrapped in 1941.
I-51 never saw combat. • Boat in class
Kaidai II (I-152 class) Project number
S25. There was only 1 Kaidai II,
I-152 planned under the
Eight-six fleet together with the
I-51. She was completed in 1924, used as a training vessel until mid-1942, then struck from service. She was scrapped in 1946. • Boat in class
Kaidai IIIa/b (I-153 class and I-156 class) Project number
S26 (Kaidai IIIa) and
S27 (Kaidai IIIb). The nine Kaidai IIIs were based on earlier designs, but featured a strengthened hull. The "IIIb" types were 40 cm longer and had a different bow design. All nine boats were constructed between 1927 and 1930. Of the nine Kaidai IIIs, seven survived the war, as they spent much of their time as training vessels. These were scuttled or scrapped shortly after the end of World War II.
I-63 was sunk in a collision with
I-60 in 1939, the former losing all her crew.
I-63 was refloated and scrapped in 1940.
I-60 was later sunk by .
Kaidai V (I-165 class) | builders = | operators = | class_before = | class_after = | subclasses = | built_range = 1929–1932 | in_commission_range = 1932–1945 | total_ships_building = | total_ships_planned = | total_ships_completed = 3 | total_ships_canceled = | total_ships_active = | total_ships_laid_up = | total_ships_lost = 3 | total_ships_retired = | total_ships_scrapped = | total_ships_preserved = }} | hide_header = | header_caption = | type = | displacement = *1,575 long tons (1,600 t) surfaced *2,330 long tons (2,367 t) submerged | length = 97.70 m (320 ft 6 in) | beam = 8.20 m (26 ft 11 in) | draught = 4.70 m (15 ft 5 in) | propulsion = *2 × Sulzer Mk.3 diesels 2 shafts 6,000 bhp *1,800 shp | speed = * surfaced * submerged | range = * at surfaced * at submerged | endurance = | test_depth = 75 m (246 ft) | complement = 60 | sensors = | EW = | armament = *6 × 533 mm (21 in)
torpedo tubes (4 × bow, 2 × stern) * 16 × Type 89 torpedo * 1 × 100 mm (3.9 in) or 120 mm (4.7 in) * 1 × 12.7 mm AA gun *1 × 7.7 mm MG | notes = }} }} Project number
S29. Three Kaidai Vs were constructed;
I-165, I-166, and
I-67 which were all completed in 1932. The design saw the upgrade of the deck weapon from a 50 caliber to a 65-caliber long
dual-purpose gun. The submarine was also slightly wider and taller, with an increased crew complement of 75 and an increased maximum depth of 230 ft (70 m).
I-165 was modified in 1945, her gun removed and two
Kaiten manned torpedo suicide attack craft substituted. None of the Kaidai Vs survived World War II.
I-67 was lost with all 87 crew during an exercise in 1940.
I-165 was sunk on 27 June 1945, off the east coast of
Saipan.
I-166 was sunk by the British submarine on 17 July 1944, off the coast of
Singapore. Kaidai VIs contributed to the sinking of two American aircraft carriers during World War II. The destruction of these submarines also hold some milestones;
I-70 was Japan's first major warship casualty in World War II, and the sinking of
I-73 represented the first warship kill by a
United States Navy submarine in the war. They were built in 1939 under the
Maru 4 Programme. The IJN called unofficially, and intended to replace this type with Kaidai III and Kaidai IV. Instead of possessing some aft-firing torpedo tubes as all other predecessors did, the Kaidai VII's six tubes all faced forward. They had an endurance of 75 days. Seven of the ten Kaidai VIIs were sunk within their first year of operation and all ten vessels were sunk by October 1944. • Boats in class ==Characteristics==