The submarines were medium-sized submarines of the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, Potsdam Declaration, when it was dissolved followin ...

(IJN), serving during the 1920s and

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. The ''Type L'' submarines were built with

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

naval technical guidance. All boats were built in the

Mitsubishi Heavy Industries is a Japanese Multinational corporation, multinational engineering, electrical equipment and electronics corporation headquartered in Tokyo, Japan. MHI is one of the core companies of the Mitsubishi Group and its automobile division is the prede ...

-Kobe Shipyard by the contract with Vickers.

Class variants

The ''Type L'' submarines were divided into four classes: * * * *

''Type L1 (Ro-51-class)''

In 1916, the Mitsubishi Shipbuilding Corporation got the Vickers ''L'' class submarine informations. Mitsubishi which lost competition to the Kawasaki's ''Type F'' submarines (

Fiat Fiat Automobiles S.p.A., commonly known as simply Fiat ( , ; ), is an Italian automobile manufacturer. It became a part of Fiat Chrysler Automobiles in 2014 and, in 2021, became a subsidiary of Stellantis through its Italian division, Stellant ...

- Laurenti design, ''Ro-1'' class and ''Ro-3'' class), bought the license for the ''L'' class submarine from Vickers. The IJN hoped an improvement of submarine technologies will be achieved and ordered this submarine from Mitsubishi. Mitsubishi bought six submarine kits, and built two boats by semi-knock down. The submarine crews were satisfied with the Vickers diesels because they proved to be reliable. The IJN studied the

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

s and made many variants of similar design, for example:

Kampon The was the externally operating division of the Ministry of the Navy of Japan responsible for the administration of naval vessel construction. From 1923 onward, it took on the role of a research institution for the research and development of n ...

Mk.24 diesel for the ''Ro-100'' class. *Boats in class

''Type L2 (Ro-53-class)''

The ''Type L2'' had minor changes from the ''Type L1''. The changes were: *The ship's side torpedo tubes were removed. *Changed the batteries. (The ''L1'' was equipped 3 groups, 336 small-sized batteries. The ''L2'' was equipped 2 groups, 224 medium-sized batteries.) *Boats in class

''Type L3 (Ro-57-class)''

The ''Type L3'' is a license production model of the British ''L'' class submarine Group 2. *Boats in class

''Type L4 (Ro-60-class)''

The ''Type L4'' is a license production model of the British ''L'' class submarine Group 3. Their performance was good. The IJN was satisfied with them and stopped the development of ''Kaichū'' type submarines for a long time. Later the IJN was not able to regain the technical delay in development of the medium-sized submarines until the end of the

Pacific War The Pacific War, sometimes called the Asia–Pacific War or the Pacific Theatre, was the Theater (warfare), theatre of World War II fought between the Empire of Japan and the Allies of World War II, Allies in East Asia, East and Southeast As ...

. *Boats in class

Characteristics

Bibliography

*'', History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces"'', Gakken (Japan), March 2005, *''The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III'', Ushio Shobō (Japan), September 1980, Book code 68343–44 *''The Maru Special, Japanese Naval Vessels No.132 Japanese Submarines I "Revised edition"'', Ushio Shobō (Japan), February 1988, Book code 68344–36 *''The Maru Special, Japanese Naval Vessels No.133 Japanese Submarines II "Revised edition"'', Ushio Shobō (Japan), March 1988, Book code 68344-37

References

{{DEFAULTSORT:L0 type submarines L type submarine, Japan Submarines of the Imperial Japanese Navy