 The problem was that the tonnage cap for new carrier construction had been set at 27 @,@ 000 tons , which was too low for any practical conversion of the battlecruisers . An exception , spearheaded by Assistant Secretary of the Navy Theodore Roosevelt Jr . , was added to the treaty . This gave the five nations the option to convert no more than two capital ships that were under construction to 33 @,@ 000 ton aircraft carriers . But even that increase of 6 @,@ 000 tons ( from 27 @,@ 000 to 33 @,@ 000 ) was almost not enough for a conversion — it took creative interpreting of a clause in the treaty to allow for the conversion without removing half of the power plant , which the General Board did not want to do . The clause ( Chapter II , Part III , Section I , ( d ) ) : 
