Second London Naval Treaty
The limits set in the Washington Naval Treaty were reiterated by the London Naval Treaty signed in 1930. A limit of 57,000 tons for submarines was decided upon, and the battleship building holiday was extended for a further ten years. Signed in 1936, the Second London Naval Treaty further limited guns to 14-inch calibre. The Second London Treaty contained a clause which allowed construction of battleships with 16-inch guns if any of the signatories of the Washington Treaty failed to ratify the new one. It contained an additional clause which allowed displacement restrictions to be relaxed if non-signatories built vessels more powerful than the treaty allowed.