Сlarification: the PCW abbreviation means, that this ship is a part of Pacific Confederacy World - AU, where the Peru-Bolivian Confederacy won the war with Chile in 1836-1839 and became a major (relatively, of course) South American power.
In the mid-1920, the bulk of Pacific Confederacy cruiser forces was consisted of various armored and protected cruisers - slow, outdated and unable to operate with new battlecruisers or destroyers. To solve this problem, the confederacy naval command decided to send technical missions to the leading naval powers.
In Japan, the confederacy delegation was fascinated by the new IJN small cruiser "Yubari"; it's revolutionary design made this ship smaller, but far more powerfull than any previously build japanese light cruiser. Confederacy admirals decided, that cruisers of this type would be exellent in the role of fast fleet scouts and destroyer flotilia leaders; eventually a modified design were ordered.
Initially, the Confederacy Navy wanted a slightly larger version of "Yubari", with additional twin turret on the rear, instead of two deck guns. But during designing, the data about french "Duguay-Trouin" class cruisers were obtained. The french ships were armed with four twin 155-mm turrets; eventually, the Confederacy naval command decided, that this armament would be the standard for new light cruisers, and requested to add a fourth turret in the design.
The new cruiser, named "Javary", was launched in Yokohama in 1927, and completed in 1928. After some improvements, she was accepted by the Confederacy navy in 1929, and cross the Pacific Ocean toward the Peru.
Description:
Eventually the enlarged version of japanese cruiser, the "Javary" was about 4000 tonnes, and able to go at 35,1 knots. She was armed with four A-class turret (based on the "Yubari" design), but with Confederacy-build 145-mm/50 guns. An armored belt with the 40 mm thickness protected the vital parts; the belt was designed as part of ship constructions, to save weight.
As the "destroyer leader-cruiser", she carried heavy torpedo armament, represented by the two quadruple 533-mm tubes. The additional torpedoes were stockpiled in the rear superstructure. Her anti-aircraft armament consisted of two 2-pdr Vickers guns.
Service:
The "Javary" was comissioned into service in late 1929. Initiallym the second ship of her type, "Amazonas", was planned. But before any additional light cruisers was laid, the Argentina ordered two heavy cruisers from Italy; eventually, the Confederacy admirals decided, that they didn't need more light cruisers, and ordered a pair of heavy cruisers instead.
During her initial service in Confederacy Navy, the "Javary" was found to be top-heavy, so during the repair in 1934, her rear superfiring turret were replaced by the aircraft catapult. The torpedo supply was limited to the combat-ready eight torpedoes, without the reloading rounds. But the problems with stability remained. During the repair, her two 2pdr single guns were replaced by the british-build quadruple "pom-pom"
The "Javary" served well on the South American theater of World War II, agains the pro-Axis Argentina and United Republic of Paraguai and Uruguai. She participated in the Tierra del Fuego campaign in early 1942, and later - in the Falcland Naval battle, where she leaded the Confederacy and British destroyers in pursuit of retreating argentinean forces, and scored two torpedo hits on the damaged argentinean battleship "Rivadavia". In early 1932, she was equipped with experimental RG/0.1 air search radar.
Late in war, she was damaged by the argentinean torpedo bombers in San-Matias bay in 1943, and her crew were forced to run her around to prevent loss. Few weeks after, she was raised, and towed to safety. During repairs, the possibility of rebuilding her as anti-aircraft cruiser with four or five twin 127-mm DP mounts were considered, but eventually abandonded due to the lack of avaliable turrets, much more needed for destroyers. She was rebuild closely to her original appearance, but with new masts and improved anti-aircraft armament; her catapult was replaced by the 40-mm Bofors, and another two were placed in the center. Two 23-mm autocannons were placed by the sides of her bridge, and american-build navigation and fire control radars were installed.
After recomissioning, the "Javary" participated in final campaings against Paraguai (the Argentina already capitulated in summer of 1944) on the Rio de La Plata. In 1946, she was reclassifed into the training ship, and served in this role until 1949, when she was paid off in reserve. She wa eventually scrapped in 1958.