Führer Headquarters
However, in October 1942, based upon a special request from Adolf Hitler, German Admiral Paul Wenneker, attached to the German Naval Attache in Japan, was allowed to inspect a "Yamato"-class battleship while it was undergoing maintenance in a dockyard, at which time Admiral Wenneker cabled a detailed description of the warship to Berlin. On 22 August 1943, Erich Groner, a German naval historian, and author of the book "Die Deutschen Kriegschiffe, 1815–1945", was shown the report while at the "Führer Headquarters", and was directed to make an "interpretation" and then prepare a "design sketch drawing" of the Japanese battleship. The material was preserved by Erich Groner's wife, Mrs. H. Groner, and submitted to publishers in the 1950s.