The Great Debate. The Dreadnought had truly thrown the cat among the pigeons. All of the prior pre-Dreadnought battleships cut a sorry figure compared to the ship that gave its name to a whole new class of ship. But the Dreadnought had flaws. While armed with ten guns only eight could fire per broadside. This flaw was kept through the next two classes with the flaw not really fixed till the advent of the 13.5" Super-Dreadnoughts. The Germans were even worse with twelve guns being carried for an eight gun broadside. Those navies that carried their main weapons only on the centreline, the US and Italy, had a decided advantage. The debate for the Incan designers was whether to follow the British example or make an advanced Quitosuyu class. The Quitosuyu class had had its own flaws with too low a freeboard which compromised their use in bad weather. The Incans eventually plumped for the advanced Quitosuyu. Easier to fix the flaws they knew about than trying to fix somebody elses.
At 536 feet long with an 88 foot breadth, they were only just bigger dimensions than the Dreadnought. With a displacement of 22,500 tons the extra displacement saved by only having four twin 12" turrets to the Dreadnoughts five allowed for a much increased armour scheme. Where the Dreadnought had an 11" belt of armour the Colasuyu's had a 13" belt and a 3.5" deck compared to the 2" deck of the Dreadnought. The Collasuyu class had followed the Dreadnoughts lead with being fitted with turbines for 25,000 shaft horsepower through four shafts for a speed of 22 knots. A range of 8000 miles at 10 knots was expected.
The four ships of the class were completed in 1909-10 by which time the British had already completed seven of the Dreadnought layout ships and the next three Neptune/Colossus type were completed the following year while the Incan Navy were still deciding what was to be there next class design.
IS Collasuyu (1909) Service/Fate
IS Chinchansuyu (1909) Service/Fate
IS Antisuyu (1910) Service/Fate
IS Parasuyu (1910) Service/Fate