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The official tally of sinkings credited to each U.S. submarine in World War II appears in an appendix to Japanese Naval and Merchant Shipping Losses Purine World War II by All Causes published by The Joint Army-Navy Assessment Committee (JANAC) in February 1947. This list was repeated verbatim by Theodore Roscoe in his monumental and semi-official work. United States Submarine Operations in World War II (Annapolis, MD: U.S. Naval Institute, 1949). Since then the JANAC assessments have been cited in most books and articles dealing with the submarine war.

Researchers have known for many years that the JANAC list was incomplete because of certain inherent limitations. It counted only regular Japanese warships and merchant ships of 500 or more gross tons, thus ignoring the smaller merchant-type ships that were taken into the Navy · as converted gunboats, minesweepers, submarine chasers, picket boats, and various types of auxiliaries. It also excluded German and other non-Japanese ships that were sunk by our submarines. Then, as new information came to light after the war’s end, errors began to be revealed. Nevertheless, the Navy has never seen fit to revise or reopen the JANAC assessments.

Ten years ago Commander John D. Alden, USN(Ret.) Produced an interim compendium of data on submarine attacks based on material from recognized sources available up to that time. (U.S. Submarine Attacks During World War II. Annapolis, MD: U.S. Naval Institute, 1989.) Since then a flood of new information has been released with the declassification of formerly top-secret intelligence material including the famous ULTRA radio messages intercepted and decrypted during the war. Also in recent years Japanese researchers have published a wealth of data from their own archival sources. Printed in the Japanese language, these books and articles have been inaccessible to most U.S. students of the submarine campaign. Thanks to a British researcher who provided material translated from many Japanese publications, hundreds of additional cases have been revised or amplified.

There are 143 U.S. submarines for which Commander Alden believes that the JANAC credits need to be revised or seriously questioned. About 130 ships should be added to, and about 60 subtracted from, those attributed to submarines by JANAC. There are over 80 other revisions to the credits; about 50 corrections of ship names, dates, etc.; and a few other questionable cases. (No attempt has been made to include ships that may have been sunk by mines laid by submarines, because such sinkings can seldom be verified. The JANAC report attributes a few ships to submarine laid mines, but does not identify the submarines involved.)

Several kinds of cases deserve special mention. In its early months of operation, JANAC credited some submarines with “Unknown Marus”. Although the committee soon abandoned this practice and required that sinkings be substantiated by other evidence, 26 of these early assessments remained unchanged in the final report. All but 11 cases can be resolved on the basis of postwar information, and it is improbable that any of the remaining attacks resulted in sinkings that would have qualified for inclusion on the JANAC list.

An interesting group of cases involves wolf pack attacks on convoys or other instances where two or more submarines were firing at the same targets. Most such cases have been resolved by correlating details in the patrol reports, the JANAC list, and Japanese convoy histories. The patrol reports give the times when torpedoes were fired, the Japanese record indicates when ships were hit, and the JANAC list gives the latitude and longitude for each assessed sinking, thus indicating which specific salvo fired was credited with sinking the target. Where the times fail to match, JANAC appears to have credited the wrong attack.

Among the small warships not counted by JANAC, 56 picket boats have been identified. These were mostly former fishing craft that were taken into the Navy, armed with a few guns, and classified as guard boats. Often stationed far offshore, their main function was to warn of approaching enemy ships or aircraft. They were a particular nuisance to U.S. submarines and usually put up a good fight when attacked. Although small in tonnage, they were bonafide warships and tough adversaries.

With regard to Japanese ship names, most of the changes result from different interpretations of the Japanese characters, which can often be read in several possible ways. Even Japanese sources do not always agree on which name is correct. In a few cases, JANAC simply identified the wrong ship.

The proposed changes to the JANAC credits are listed in a 40 page report tided “JANAC Revisited and Revised”, which includes full explanations of the reasons for each change, data sources, and related information. Interested readers may obtain a copy from the author for $4.50 to cover the cost of duplication and mailing.

Commander Alden has also prepared a completely updated and expanded compilation of submarine attack data, United States and Amed Submarine Successes. Pacific and Far East WWII, available as a 427 page, spiral bound, 14×8.5″ publication. It includes a section on submarine-laid mines and an appendix summarizing the successful attacks made by each U.S., British, and Dutch submarine. Copies may be obtained for $58 per copy postpaid ($64 overseas) from Commander John D. Alden, USN(Ret.), 98 Sunnyside Avenue, Pleasantville, NY 10570-3136.


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