Sunday, August 23, 2009

I-400–Japan's Secret Aircraft-Carrying Strike Submarine: Objective Panama Canal

I-400–Japan's Secret Aircraft-Carrying Strike Submarine: Objective Panama Canal
Henry Sakaida, Gary Nila, and Koji Takashi. Crowborough, U.K.: Hikoki Press, 2006. 144 pp, 250+ photographs, drawings, computer renderings, maps. Index. Bibliography.The original targets of what was intended to be a class of 18 submarines equipped to carry two (later three) Aichi M6A Seirun single-engined floatplane bombers was to have been cities on the East Coast of the U.S. mainland––hence the requirement (later somewhat reduced) for a range of over 40,000 nautical miles. As the program progressed, the number of submarines was cut sharply and the target redefined as the Panama Canal, which the Japanese mistakenly believed was ill-defended against air attack. The pace of the war, however, forced selection of an even closer target for the three submarines that actually were available in the closing days of World War II, the 5,223-ton I-400 and I-401 with three aircraft each and the smaller I-13, with two. The end of the war saw the three submarines on their way to conduct a kamikaze attack on ships at the vast Ulithi anchorage, all eight of their aircraft carrying U.S. markings and with their single bomb payloads permanently attached and their twin floats left behind to improve their range and speed. After their surrender on the high seas to U.S. forces and return to their defeated homeland, the submarines, along with other surviving Japanese submarines deemed worth technical exploitation, were repaired, defumigated, and despatched with volunteer U.S. Navy crews on a long, surface voyage to Pearl Harbor. There they were given a rather cursory examination by U.S. and British technical experts, but before their planned voyage onward to the U.S. mainland could be carried out, Russian pressure to receive some of the boats as war booty forced the U.S. Navy to expend them all as targets in deep water off Barber's Point, Hawaii, during March 1946. I-400 not only includes nearly two dozen photos of the demise of the I-400 but also has four underwater views of the giant submarine taken on 17 March 2005 by the University of Hawaii Undersea Research Laboratory.The I-400 and I-13 classes were unique primarily for their great size and were the largest submarines in the World at the time of their completion. They were also the largest submarines to employ riveted construction, which restricted their diving depth. The book usefully reproduces in facsimile the brief and rather superficial U.S. Navy exploitation report which concluded (as did the vastly more detailed reports done on interned German submarines at the Portsmouth Naval Shipyard) that little of interest was to be learned from them––although, curiously, while the Japanese carrier submarines had anechoic hull coatings to reduce their radiated noise signatures, the U.S. Navy didn't develop similar coatings for another three decades. The I-400 also had a snorkel system and an extensive array of radars and radar intercept equipment, and the basic concept of the aircraft hangar and its watertight door was later employed on the handful of cruise missile submarines deployed by the U.S. Navy.While sumptuously produced by one of the very best of the aviation history publishers, I-400 is clearly not the work of professional historians or authors with a broad knowledge of submarine technology, but it is exemplary in its description of the Seirun aircraft (one of which is on display at the Smithsonian's Dulles Airport annex) and how they were operated; descriptions by an actual Seirun pilot are included. As example of one of the minor nautical gaffes is a photo that identifies the submarines' external degaussing cable arrays as being intended to counter the static electricity built up with the passage of the boats beneath the sea! An aerial photo of a U.S. submarine tender with six submarines alongside is captioned as showing Japanese boats, but they are actually U.S. Navy submarines. The book depends perhaps too heavily on several Japanese-language memoirs about service on the I-400 and says very little about the I-401 or the I-13 class. There is too much repetition of information, the bibliography is disorganized and would be difficult to use, and some of the material about the careers of some of the surviving U.S. volunteer crewmen seem extraneous to the book's theme. The photographs, however, are numerous and of genuine high interest and quality. The special artwork done for the book, including a fold-out color computer plan and elevation rendering of the I-400, is magnificent. On balanceI-400 is well worth the rather stiff price demanded and is highly recommended to anyone interested in these little-known submarines and their thwarted operational careers.Review by A.D. Baker III

No comments:

Post a Comment

Post a Comment