An item referred to the magazine R.M. dated April 1936 which reported that ships larger as 35.000 ton were not able to pass the Panama Canal. It was believed that Japan probably would ignore the London Naval Conference (1) which limited the tonnage of battleships to 35.000 tons. To prevent that the USA would be at a disadvantage relative the Japanese naval strength was the canal to be widened. To this end, plans were already in preparation.
Note
1. In the second conference between 21 January-22 April 1930 resulted in an altered ration between England, the USA and Japan in the battleship tonnage. The two other major naval powers France and Italy were excluded although both countries agreed with a five-year stop on capital ship construction. The last and third conference in December 1935 resulted in a Japanese withdrew when her a parity with the British and American navies was refused. On 25 March 1936 was the Second London Naval Treaty signed which treaty ended effectively on 1 September 1939. Battleships were restricted to a maximum 35.000 long tons/36.000 tons standard displacement with a maximum calibre of 35,6cm/14” guns. The fear was correct that Japan would ignore the 35.000 ton maximum. The Yamato-class of which the Yamato and her sister ship Musashi which were completed had a displacement of 72.000 long tons/73.000 tons (full load) with a main armament of 3x3-18.1”/46cm guns.
