The Washington treaty contained the next naval race

Did treaty powers strictly demolish every ship required by the Washington Naval Treaty?

No. Some evasion was tolerated so long as it did not create an advantage large enough to trigger another naval arms race.

The treaty powers did not rigorously demolish every ship in the exact condition demanded by a literal reading. Negotiators expected some evasion and focused on keeping it below the level that would create an apparently unfair advantage and restart competitive building. The pre-1914 Anglo-German race had already ended, so the 1920s agreement addressed the feared next contest between Britain and the United States. Both governments preferred limits because the United States did not want the construction bill and Britain wanted to reduce debt and fund domestic priorities. The survival of HMS Hood also suggests that an existing prestige flagship was harder to sacrifice than ships still under construction. Any settlement Britain rejected would have lacked practical value, making British red lines part of the treaty's basic bargaining structure.