Comments by "Steve Valley" (@stevevalley7835) on "The Drydock - Episode 261 (Part 2)" video.

@themanformerlyknownascomme777 the Washington Treaty prohibited improvements in main armament. Italy and France were given some extra latitude, as their ships were so obsolete, compared to those of the big three, so the Italians were able to bore out their 12" guns a bit. I saw an item in the contemporary newspapers that there was a general consensus at the Washington conference that 12" guns were obsolete. There was some controversy whether increasing the elevation was allowed under the treaty, The treaty explicitly prohibited changing the type of mount. When the USN started modifying the mounts to increase elevation, the UK called foul, claiming that violated the clause regarding mounts. After some discussion, it was decided that modifying the existing mounts was not a change in the type of mount, so then the UK started modifying it's mounts.
1