Overview
Four large Japanese Kaidai IIIa fleet submarines completed from 1927 to 1928.
Developed for Imperial Japanese Navy, Kaidai IIIa belongs to the Submarines family and is associated with Interwar period and World War II. Its documented designations include Fleet submarine, while its intended roles include Fleet submarine and Long range submarine.
Development and construction
The IIIa group pursued long-range fleet cooperation with high surface speed; trials exposed stability and vibration issues addressed in the IIIb follow-on.
The documented program for Kaidai IIIa lists 4 planned, 4 ordered, 4 laid down, 4 completed, and 0 cancelled, with design work beginning in 1923, construction beginning in 1924, and construction ending in 1928. These figures define the scale and chronology currently supported by the class sources.
Design characteristics and intended role
The surviving classification data associates Kaidai IIIa with Diesel electric and Large submarine. Read together with the recorded roles of Fleet submarine and Long range submarine, these attributes show the operational problem the design was intended to address without implying specifications that the sources do not establish.
The class record identifies Imperial Japanese Navy as the principal design or service authority. Where individual ships changed navy, name, or pennant, those later identities are retained on the ship pages rather than treated as separate vessels.
Service history and class roster
All four were later renumbered into the I-150 series in 1942.
The class roster currently links 4 ships. Named members include IJN I-153, IJN I-154, IJN I-155, and IJN I-158. The linked ships are associated with Imperial Japanese Navy.
Historical significance
An important developmental step in Japan’s interwar large-submarine lineage.
Kaidai IIIa is most useful when read as both a design and a group of individual careers. The class page establishes the shared technical and operational context; the linked ship pages preserve differences in construction, service identity, deployment, transfer, preservation, and fate where those details are documented.
Ships in this class
Showing 4 recorded class members.
Sources and further reading
- Conway's All the World's Fighting Ships, 1922–1946Conway Maritime Press
- Treaty Between the United States of America, the British Empire, France, Italy, and Japan, Limiting Naval Armament ↗U.S. Department of State, Office of the Historian · accessed 2026-09-18
- Kaidai 3a submarines (I53), 1927–1928 ↗Navypedia · accessed 2026-09-18