Nayoro class Scout Cruiser
Displacement: 4,950 tonnes standard
Dimensions: 428ft x 45ft x 14ft
Machinery: 2 geared Parsons steam turbines, 10 high pressure water tube boilers, 21,000 shp
Speed: 24 knots
Endurance: 6000 nautical miles at 10 knots
Armor: Deck 1.5-5.6cm, Conning Tower 10cm
Armament: Nayoro as commissioned 1906
7x1 Type-98 14cm
10x1 Type-91 4cm
Armament: Teteshihoro as decommissioned 1927
7x1 Type-98 14cm
10x1 Type-91 4cm
2x1 Type-12 10cm
2x2 Type-18 machine guns
what eventually would become the Nayoro class, was a result of both naval construction act of 1903 and the Admiralties enquiry into a brand new class of Scout cruiser to replace it aging fleet of protected and unprotected cruises which by 1903 / 1904 were beginning to show their age, design work for the class will be relatively quick and Swift with the first, with the first two members being laid down in late 1903, the namesake of the class, Nayoro would be commission on the 17th of October 1906, in terms of appearance, her profile was overall very similar to a British scout Cruiser, with the biggest difference between the lack of a fourth funnel, she would be followed by 3 more sisters, with all members of the class being in commission by late 1907
Throughout the rest of the 1910s the four cruisers, would be primarily attached to the first and second scouting divisions, with occasional goodwill visit to other ports in Asia, however with the start of WWI, Nayoro and Asatoro would be dispatched along with several other Zipang vessels would be dispatched to Britain, at the request of the Royal Navy Admiralty, Tateshihoro and Yakuyako would stay in the Pacific, and would primarily partake in convoy escort Duty, as well as helping the Australians and Japanese forces, to catch up the few Pacific holdings the Germans had, one particular operation where both cruisers part, was the operation to destroy the German wireless station located on German New Guinea, this involved them operated together, with the Australian naval and military expeditionary Force, with both Cruiser's providing fire support to the Australian troops, during the capture and subsequent destruction of the radar station, however this would be the most involved that any of the class would be during the First World War, in the Atlantic Theatre, Nayoro and Asatoro would pretty much be exclusively assigned to Patrol Duty, in and around the British Isles and North Sea, both Nayoro and Asatoro would see out the rest of the war, without partaking in any ship-to-ship combat.
With their arrival back in Zipang after the First World War, Nayoro and Asatoro would go into drydock for extensive refit and overhaul, the main changes done during the refit was the addition of a main mast at the stern, as well as the forward main mast having a pair of support legs added, turning it into a tripod style main mast, the superstructure was built up with a secondary rangefinder being added, to supplement the main rangefinder at the stern, another change was the addition of two 100mm AA guns, with one located between the first and second funnel, and be other being located behind the rear most 140mm mount.
All four of the cruises would be spared from the Washington naval Treaty, and would continue to serve into the mid 1920s, but with newer and more powerful cruises being commissioned, in the late 1910s and throughout the 20s, they quickly found themselves surplus to requirement, and in 1927 it was finally decided that they had outlive their usefulness, and as a result, all four of them were decommissioned, with Yakuyako and Nayoro both been scrapped 1928, however, Tateshihoro and Asatoro would be held in reserve, until 1929 when they were converted into fast mine laying ships.
Ships in class: (laid down-launched-commissioned - fate)
Nayoro (SC-5) 1903-1905-1906 - Decommissioned 1926
Asatoro (SC-6) 1903-1905-1906 - Decommissioned 1927
Yakuyako (SC-7) 1904-1906-1907 - Decommissioned 1927
Tateshihoro (SC-8) 1904-1906-1907 - Decommissioned 1927