One of the most guarded secrets of the Imperial Japanese Navy during World War Two, the 1-400 class of submarines were the largest ever built during the conflict, only to be surpassed by the entry of nuclear submarines in the early 1950s.
Several books have been written on specific types and classes of German U-Boats, but only a few shed light on the submarine force of Germany's ally in the Pacific. In this highly fascinating account, authors Henry Sakaida, Gary Nila and Koji Takaki delve into one of the secret weapons of the war. Through years of research, readers are taken to the design, construction, commissioning and operation of the 1-400 and its sister sub, the 1-401.
The book begins with a discussion of how it was conceived (another interesting story). This is followed by a foreword by former LT Og) Kazuo Takahashi and Captain Joseph McDowell, USN (Ret.). The former is a Seiran pilot of the 1-400, while the latter is the skipper of the prize crew that brought the submarines to Hawaii after Japan's surrender.
The opening chapter covers the Japanese Submarine Force, looking into its beginnings, the interwar years, submarine force dispositions of the Imperial Japanese Navy and the combined Allied Navies in the Pacific on the eve of hostilities, and operations after the attack on Pearl Harbor. The authors then turn their attention to how the type was conceived to attack
cities on the eastern seaboard of North America. They then take us into the construction phase of the submarine and to a discussion of its technical details. The 1-400 involved the latest technology of the era.
Solely designed for the 1-400 was the Aichi M6A Seiran Bomber. The aircraft's history is thoroughly covered from its conceptual stage, design and first flight. Notable and of importance are the inputs of the Seiran Pilots and observers into the aircraft's characteristics. Six pages of plans clearly illustrate the Seiran in different views. Two consecutive chapters look into the plan of attack and of Operations Hikari and Arashi. The Panama Canal was the primary target as destroying it would delay Allied forces in Europe in traversing the Pacific for the final push toward Japan. The preparation and execution of the attack plan is well examined. Notable was the participation of another large type of aircraft-carrying submarine in the UN-the sister boats 1-13 and 1-14. There also biographies of the key officers and personnel of the operation: the mission commander, the submarine skippers and the Seiran pilots, as well as details of the formation and training of the Seiran Air G!
The Panama Canal attack plan is thoroughly discussed, from the stage of gathering intelligence to consideration of specific bombing techniques to be used. After the fall of Okinawa, the target was changed from the Canal to Ulithi Atoll, where the massive USN TF 38 was anchored. Another interesting aspect revealed is the Seiran's use of US Markings for the operation rather than the national insignia.
The final chapters narrate the quartet's transit to Truk and Eniwetok for the Ulithi mission, where several encounters with US Navy destroyers and torpedo bombers resulted in the sinking of the 1-13 with all hands. It was after this that the message of Japan's surrender was received, and later on the vessels surrendered to American warships in Japanese home waters. From the trio's voyage (1-14, 1-400, 1-401) to Pearl Harbor for evaluation by US and British submarine experts, to its final fate in 1946, to the recent discovery of 1-401, we read a great story.
The naval war in the Pacific-or even the Atlantic might have been influenced had the type been constructed and produced in large numbers earlier than it was actually built.
The book is divided into seven chapters. Each is fully illustrated with photographs (most of which have never before been published). The three dimensional computer graphic images of 1-400 and Seiran aircraft are impressive. Appendices give details Japanese Navy Ranks, the submarines' radio equipment, the dry-dock report, and the crew lists of both Japanese and American vessels. The bibliography supplements the book well. Noteworthy are the vignettes on the UN technical schools and on the USS Tench.
In sum, the book is finely researched and well written. The authors are to be commended for this remarkable reference work which I believe will be a classic and become the definitive history of the /-400 and the Panama Canal Operation. The book is highly recommended and would be a valuable addition to the library of naval officers, specifically in the submarine, ASW, aviation, and sea systems communities, as well as of naval and military historians, academy and service college professors, scale modelers and enthusiasts.
LCDR Mark R. Condeno,
Philippine Coast Guard -- Australian Warship Issue 47