Like most countries, the demise of the various Treaties in 1935 made it possible for the Incan Navy to lay down its first 35,000 ton battleships. A class of four was laid down, one per year, 1936, 1937, 1938 and 1939. This gave completion dates from late 1940 to late 1942. The design was a conventional layout with three triple 15" turrets, two forward and one aft. A dual purpose armament of 130mm/5.1" in twin turrets was fitted to save weight. Armour was to be as thick as possible within the limits set, and this amounted to a 14" strake of belt armour with a very useful 7" of deck armour. Propulsion for a speed of 30 knots was fitted. Four aicraft with two catapults were fitted in the center of the ship around the funnel. The AA battery featured a new triple 40mm mounting while the light AA was made up of the 20mm Oerlikon in twin and single mountings. All in all a well balanced class of battleships well able to take on any other of the Treaty battleships completed.
