Out of curiosity, I decided to see if my Chinese designers would come up with something similar to the 12" gun Armoured Cruiser shown by mrchuck and they did, albeit with 11" guns. Those were the biggest I could fit on a domestically built design. The design checker didn't complain. It looked like it could be useful as I've mainly been building CAs. I didn't lay one down though as my yards were already busy building five of these.

- Chinese CA Fu Sheng
- CHI_CA_Fu_Sheng_1901.png (17.62 KiB) Viewed 304 times
I've always loved that design of cruiser, I'll pretty much always build at least one class of them. On this save I have some French-built 9,500t ones with 8" main guns and a smaller 8,000t design with 9" guns that was my first Chinese-built cruiser design.
Any further progress on big gun ships was brought to an end by a remarkably timed Arms Limitation Treaty, that came into effect in September 1905. As usual I'd had to negotiate a bit to try to preserve my build programme and the limitations are set at a maximum displacement of 20,000 tons and maximum calibre of 9". The Treaty is for 20 years and its immediate effect was to outlaw the BB and BC before anyone had managed to complete one! Britain had to cut up four or five.
Annoyingly, the treaty also affected me. I have been set a build limitation of 32,000 tons so had to break up three of the five Fu Sheng Class on the slipway immediately. A fourth was scrapped in December 1907 to make room for the construction of a B after the Chinese People donated a large amount of money for the construction of a battleship. Due to the Treaty this will have 9" guns. The remaining member of the class,
Fu Sheng, is sitting at 1 month to go waiting for me to decide what to scrap to make room for it in the fleet tonnage limit, which is a somewhat disappointing 150,000 tons.
The state of the art Armoured Cruisers in the game, currently at November 1908, are interesting. The largest designs are essentially what you'd normally expect to be Battlecruisers, but the 9" calibre cap means they're still classed as CA. These were all laid down after the Treaty came into effect.
This is the British Invincible-Class CA, launched in 1908.

- GB_CA_Invincible_1908.png (13.19 KiB) Viewed 304 times
US Independence Class, also launched in 1908.

- US_CA_Independence_1908.png (14.05 KiB) Viewed 304 times
I've shown some Italian designs from other saves before, and in this save they don't disappoint. This is the Lepanto Class and will be the biggest cruiser in the world when it's completed. Triple turrets. In this game world it's potentially a major threat.

- ITA_CA_Lepanto_1908.png (15.49 KiB) Viewed 304 times
I'm going to have to have a think about what to build. Despite Dreadnoughts not existing the Blockade Points of B's have still dropped down to 8 compared with 6 for a CA. This, together with the calibre limit in force, could make only building cruisers and destroyers a viable approach.