Submarines of the Imperial Japanese Navy

Submarines of the Imperial Japanese Navy
Name	Submarines of the Imperial Japanese Navy
Country	Empire of Japan
Service	Imperial Japanese Navy
First built	1904
Last built	1945
Wars	Russo-Japanese War, World War I, Second Sino-Japanese War, Pacific War

Submarines of the Imperial Japanese Navy were a vital component of the Imperial Japanese Navy's maritime strategy from the early 20th century through the Pacific War. Influenced by experiences in the Russo-Japanese War, World War I, and interwar naval treaties such as the Washington Naval Treaty and the London Naval Treaty, Japanese submarine development produced a diverse fleet including midget submarines, long-range cruiser submarines, and experimental aircraft-carrying boats. Japanese doctrine, technological innovation, and operational use intersected with events like the Attack on Pearl Harbor, the Battle of Midway, and the Guadalcanal Campaign, shaping outcomes across the Pacific Ocean.

History and Development

Japanese submarine development began under the Meiji-era modernization program influenced by Thomas Slade, John \"Jack\" Philip, and European submarine pioneers such as John Philip Holland and Simon Lake. Early purchases and licensed constructions from Holland Torpedo Boat Company and collaborations with Vickers Limited and Flotte Offensive led to classes like the Type 1 and Type 3. Post-World War I shifts, including reparations debates at the Paris Peace Conference, 1919 and constraints from the Washington Naval Treaty, pushed the IJN toward innovative designs exemplified in the interwar period by engineers associated with the Kure Naval Arsenal and the Yokosuka Naval Air Technical Arsenal. By the late 1930s, expansion driven by the Second Sino-Japanese War and strategic planning in the Imperial General Headquarters produced the cruiser and long-range submarines that saw extensive service during the Pacific War.

Types and Classes

Japanese submarines encompassed many types: coastal attack boats like the Type B and Type C, minelaying submarines such as the Ro-100 class, transport submarines supporting the Solomon Islands campaign, midget submarines used at Pearl Harbor and Sydney Harbour, and the remarkable I-400-class submarine aircraft carriers. Notable classes include the Kaidai-class, Junsen-class, Type B1, Type A1, Type D, Ha-201-class, and the I-400-class. Specialized vessels included the Ko-hyoteki-class midget submarines and experimental designs from the Sasebo Naval Arsenal and the Mitsubishi Heavy Industries yards. Shipyards such as Kawasaki Shipbuilding Corporation, Ishikawajima Shipyards, and Hitachi Zosen Corporation produced hulls alongside naval arsenals at Maizuru and Sasebo.

Design and Technology

Design advances incorporated technologies from Rudolf Diesel-style engines, Blechynden battery systems, and German-derived snorkel and hydrophone developments influenced by contacts with the Reichsmarine and later Kriegsmarine. Hull forms balanced surface speed for operations in the Pacific Ocean and submerged endurance for patrols near Hawaii and Aleutian Islands. Torpedo systems used the Type 91 and Type 95 oxygen-propelled designs developed at the Kobe Naval Arsenal and tested at ranges near Enoshima. Aircraft-carrying submarines integrated hangars and catapults for Aichi M6A Seiran floatplanes to extend reach toward targets like Panama Canal approaches and the U.S. West Coast. Sonar, periscope, and radio equipment evolved through collaborations with universities such as Tokyo Imperial University and industrial firms including Nippon Electric Company (NEC) and Mitsubishi Electric.

Operational Deployments and Campaigns

Japanese submarines operated across theaters from the Philippines campaign to the Aleutian Islands campaign, participating in fleet reconnaissance for the Battle of the Coral Sea, attacks during the Battle of Midway, and supply runs during the Solomon Islands campaign. Midget submarines saw action in the Pearl Harbor attack and in raids linked to operations against Sydney Harbour and Diego Suarez. Long-range I-class boats conducted commerce raiding against Allied merchant shipping and special operations including the attempted bombardment of Clydebank-style targets and reconnaissance for Operation Z. Notable operations included the rescue and evacuation missions at Truk Lagoon, transport missions to New Guinea, and coordination with Kaiten manned torpedo attacks late in the war as the IJN faced pressure from the United States Navy, Royal Navy, Royal Australian Navy, and Soviet Pacific Fleet.

Notable Vessels and Commanders

Prominent vessels included I-19, I-58, I-168, I-400-class boats, Ro-100-class subs, and the Ko-hyoteki midgets used by crews drawn from the Naval Academy Etajima and commands like Vice Admiral Matome Ugaki’s staff. Commanders and figures associated with IJN submarines include Commander Noboru Ishizaki, Captain Masao Teraoka, Commander Mochitsura Hashimoto, and Lieutenant Commander Hajime Nakagawa. I-19 became infamous for torpedo salvos against USS Wasp and merchantmen; I-58 is noted for the sinking of USS Indianapolis; I-168 sank the carriers Kaga and Akagi survivors after Midway. Other leaders with submarine backgrounds influenced doctrine via postings in the Naval General Staff and experiences tied to the Imperial Japanese Naval Academy.

Training, Doctrine, and Organization

Submarine crews trained at facilities like the Kure Naval District and specialized schools under instructors from the Imperial Japanese Naval Academy and the Naval Technical Department (Kansei-bu). Doctrine emphasized fleet reconnaissance, commerce raiding in alignment with strategies debated in the Combined Fleet and Imperial General Headquarters, and later special attack tactics including kaiten development influenced by officers attached to the Naval Research Department. Organizationally, submarines were grouped into squadrons and divisions under commanders posted to fleets such as the 1st Fleet, 6th Fleet, and regional commands at Yokosuka and Truk Lagoon.

Legacy and Preservation Records

After World War II, surviving submarines were examined by the United States Navy, Soviet Navy, and Royal Navy; many were scuttled in operations such as Operation Road's End or scrapped at yards including Kobe and Yokosuka. Wrecks like I-52 and I-401 have been subjects of underwater archaeology involving institutions such as the National Oceanic and Atmospheric Administration and universities like University of Tokyo and Woods Hole Oceanographic Institution. Museums preserving artifacts and records include the Yokosuka Naval Museum, Kure Maritime Museum, and naval archives in Tokyo Metropolitan Archives and the National Diet Library. Scholarship on IJN submarine operations is carried forward at centers such as the Museum of Maritime Science (Tokyo), and by historians contributing to collections in the Imperial War Museums and the Naval Historical Center.

Category:Imperial Japanese Navy