Overview and identity
IJN I-57 is documented as a ship with time-bounded service identities where renaming or reclassification occurred.
IJN I-157 is identified through service with Imperial Japanese Navy and membership in Kaidai IIIb. Its history belongs to the interwar period and the Second World War and to the wider development of submarine warfare. These identity checks separate the vessel from other ships that may have carried the same or a similar name.
Construction and class context
IJN I-157 was built by Kure Naval Arsenal. The documented chronology records laid down 1927-07, launched 1928-10-01, and completed 1929-12. These dates place the vessel within the construction sequence of Kaidai IIIb and provide fixed points for distinguishing original features from later alterations.
Five improved Japanese Kaidai IIIb fleet submarines completed from 1928 to 1930. The hull was lengthened and revised after IIIa trials identified stability, vibration, and speed shortcomings. This class-level history explains the common requirement and design; the present article remains focused on evidence that can be attached specifically to IJN I-157.
Service history
Improved Kaidai IIIb fleet submarine with revised hull form and stability changes from the IIIa design.
The operating context of Kaidai IIIb included fleet submarine and long range submarine. That context explains why the ship was built, but it is not treated as proof that IJN I-157 participated in an undocumented deployment or action. Ship-specific operations require dated orders, logs, official histories, or equivalent evidence.
Configuration and change
As a member of Kaidai IIIb, IJN I-157 shared a design baseline associated with fleet submarine and features such as diesel-electric propulsion and large submarine. The baseline is useful for understanding the vessel’s intended capabilities, but it does not establish that every weapon, sensor, boat, aircraft, or machinery arrangement remained aboard throughout the ship’s career.
Any dated configuration for IJN I-157 must distinguish original construction from later refits, wartime additions, repair work, transfers, and changes in mission. Where the reviewed evidence provides only class-level data, this profile presents it as context and avoids converting it into a permanent ship-specific specification.
Later service and disposition
The final status recorded for IJN I-157 is scuttled on 1946-04-01.
scuttled after surrender.
Historical significance and evidence
IJN I-157 provides an individual case within the history of Kaidai IIIb. Its value lies in connecting one documented hull, construction chronology, service identity, and outcome to the broader design and operational history of the class.
Shows rapid iterative refinement in Japan’s interwar large-submarine program. For IJN I-157, historical significance should remain ship-specific: the article must show what this vessel did, how it changed, and how its career differed from other members of Kaidai IIIb, rather than repeating the class article as if every ship shared one service history.
The evidence used for IJN I-157 includes Robert Gardiner (ed.), Conway's All the World's Fighting Ships, 1922–1946, Conway Maritime Press, 1980, 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, 1922, and Kaidai 3b submarines (I56), 1928–1930, Navypedia. These sources support the chronology and identification presented here; where they do not establish a ship-specific event or configuration, the profile says so rather than borrowing details from another vessel.
Class relationship
This ship is recorded as a member of Kaidai IIIb. Shared design history belongs on the class page; this page concentrates on the individual hull where evidence is available.
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 3b submarines (I56), 1928–1930 ↗Navypedia · accessed 2026-09-18