Koko Kyouwakoku (Republic of Koko)

Hyoto class protected cruiser:

The two ships of the Hyoto class were the first protected cruisers to be ordered by Koko no Kaigun after the turn of the century. Initially planned as a larger and improved Heian-class design, the ship were heavily modified both when still on the drawing board and while under construction to the point that they ultimately bore little resemblance to their predecessors. Both orderd at the Toumachi Naval Arsenal, Hoyo and Gensho -thus they were named- would have measured 119,8m in overal length, 14,2m in beam and 5,4m in draft, for a standard displacement of 4.641T. Eighteen boilers powered two vertical 3-cylinder triple-expansion engines that drove two propellers for an expected top speed of 21knots. Range was 7.000 nautical miles (12.964km) at 10 knots. Armament constisted of eight 152mm guns (four in two twin turrets, four in single casemate positions) and eight 76mm ones. Initially, two 450mm torpedo tubes were also planned to be installed, but were deleted from the design after stability problems emerged with the preceding Heian class. This made Hyoto and Gensho the only Kokoan protected cruisers with no torpedo armament. Armor protection consisted of 50mm thick decks, which increased to 75mm on the sloped section, turrets were 37mm thick and and the conning tower was protected by 100mm of armor. Complement was 353 officers and men.
Vastly more seaworthy than the preceding Heian class units, Hyoto and Gensho suffered from a relatively long boulding time, laid down in 1904 and 1905 respectively, they were commissioned only in 1908-1909. By that time HMS Dreadnought had indirectly made a lot of ship design obsolete, and there were more advanced protected cruisers in service with other navies as well.
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After WWI broke out the two ships took part in the siege of Tsingtao, then in May of 1916 Hyoto and Gensho joined the battlecruisers Kuromegami and Aomegami, the cruisers Shinjima and Kitajima, departing for the Atlantic Ocean to support British operations against Thiaria. Reaching Capetown, they joined the British squadron under the command of Rear Admiral Evan-Thomas, comprising the two Battleships Valiant and Malaya, three pre-dreadnoughts, four old armoured cruisers and ten light and protected cruisers. They took part in the Battle of Tristan da Cunha on June 25th 1916, although they had mostly spectator roles and little more, ultimately returning home by October of the same year.
After the end of the war Hyoto and Gensho were spared from retirement by the WNT and underwent a small refit by the mid 1920's. Bridge spaces were expanded, a spotting platform on the foremast added and two of the old 76mm guns were replaced by two high-angle mounts.
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As the 1930s dawned, the two cruisers were nearing complete obsolescence anyway and retirement was planned during the first half of the dacade. The London Naval Treaty just sped up the process. Both were decommissioned in 1931, Gensho was scrapped almost immediately, while Hyoto was sunk as target in late 1933 by the newly commissioned Battleship Owari.

Ships in class: (laid down-launched-commissioned - fate)

Hyoto 1904-1906-1908 - Decommissioned 1931
Gensho 1905-1907-1909 - Decommissioned 1931

Awesome work! Seeing all these older protected and armored cruisers makes me wish you'd consider trying your hand at the Asamas, Izumos, or Yakumo.

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MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

Gyoraitei 14,15,17,25,26,38 Class Torpedo Boat:

After the Toumachi treaty of 1897, and a shift from a pro-German inflence to a pro-British/Japanese one, the Naval Staff requested the budget to give Koko no Kaigun no less than thirty new torpedo boats to augment the planned naval expansion that also contemplated full fledged Destroyers and Cruisers. The diet approved the requested budget in early 1898 so that design and orders for what will result in six different classes of ships began basically on the spot.

The first was a single unit class that was designed and built domestically at the newborn Toumachi Naval Arsenal, loosely based on a blend of the previous German-built units and plans recieved from Yarrow. 41,4m long, 4,9 abeam and with a draft of 1,3m it displaced 92T. Propelled by a single screw it was able of 23,5knots. Armament consisted of two single 47mm cannons and two 360mm torpedo launchers, one in a fixed position at the bow, the other in a single trainable mount aft. Laid down in 1898, she was commissioned in 1900.
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More units of the same type would have been ordered if the design proved to be particulary satisfying, but this did not happen. Gyoriaitei 14 -thus named- or simply shortened as No.14 remained a lone child for its entire career. In 1910 she was fitted with an open bridge above the enclosed conning tower.
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Given a small extra stint of life by the outbreak of WWI, she was ultimately decommissioned and scrapped in 1918.

The next five units (No.15,16,21,22 and 23) were all ordered abroad at Yarrow Shipbuilders in the UK and delivered between January 1901 and December 1902. They measured 47,8m in length, had a beam of 4,6 and drafted 1,5m for a displacement of 113T. Like No.14 they had a single propeller but were capable of 26knots instead. They were armed with two 47mm cannons and three 360mm torpedoes, one fixed at the bow and two in trainable mounts slighltly forward of midship and at the stern.
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In 1911 they were fitted with an open bridge partially sponsoned over the midship torpedo launcher. Later on, in 1914, they also recieved a searchlight platform above the conning tower.
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After serving in patrol duties during the first World War all were decommissioned in 1923. 16 and 23 were converted into Patrol Boats, the other three were scrapped.

At the same time, another five Torpedo Boats were ordered. The first two (17 and 18) were built abroad at the John I.Thornycroft & Company Yard. The others were ordered domestically, one (19) at the Fuyuki Dock Company and the last two (20 and 24) at Yamatogawa shipyards. They were delivered between December 1900 and December 1902. Length was 44m, beam 5, draft 1,5m and displacement 119T, a single screw driven powerplant allowed for a top speed of 24knots. Two single 47mm cannons and three360mm torpedo tubes, two fixed at the bow and one trainable aft made up the armament.
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All five recieved a small refit in 1912 to fit an open bridge between the mast and the funnel, and all served in WWI undergoing patrol duties.
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After the war they served a few more years before beign converted into Patrol Boats in 1923, with the exception of No.20, which was scrapped instead.

Another class of five units started construction as soon as the previous ships were being delivered. Orders were spread in different yards, both domestic and foreign, as to speed up delivery. No.26 and 29 were built at Fuyuki Dock Company, No.28 at Shionseki Shipyards, No.30 at Nagaisaka Industries and finally No.31 at John I.Thornycroft & Company Yard. All were delivered between January 1903 and February 1904. Dimensions grew to 48,1m in lenght overall, 5,1m beam and 1,3m draft for a displacement of 130T. Driven by a single screw they were ably of 28knots and were armed with three 47mm guns and four 360mm torpedo launchers in two twin trainable mounts.
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Like all other Topredo Boats they recieved an open bridge platform, also fitting a searchlight, above the conning tower during a 1913 refit. Their service during World War One was largely uneventful, although No.28 was accidentally grounded in 1915 just off Teshigawa and damaged beyond repair.
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The other four units kept serving until 1923 when they were decommissioned and converted into Patrol boats.

Another class, this time totaling as much as eight boats, was orderd at the same time. Thi as well split between foreign and domestic yards. No.26 and No.27 were built at Yarrow, No.32 and No.33 at Thornycroft, No.34 and No.35 at Yamatogawa, No.36 at Nagaisaka, and Finally No.37 at Toumachi Naval Arsenal. Deliveries were spread between November 1902 and January 1905. All ships were 46,4m long, had a beam of 4,9m and a draft of 1,5m for a dispacement of 150T. They were the first Kokoan torpedo Boats to switch from a single to a twin-screw arrangement, and could reach 29knots with ease. They were armed with three 47mm guns and three 360mm torpedo launchers, all in trainable mounts, two side by side between the funnels and one aft.
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At ther start of WWI, in 1914, all recieved a small refit to enlarge the searchlight plaform and allow it to be used as an open bridge as well. They served for home waters patrols for the entire conflict.
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After the war No.34 was lost in 1920 after beign accidentally rammed by a British merchant vessel. The collision happened at night and, tragically, all hands were lost. The seven surviving sisters were decommissioned in 1923 and cnverted into Patrol Boats.

The final class of six torpedo boats (No.38 through No.43) was built domestically, with al units constructed at Thoumachi Naval Arsenal and commissioned between September 1906 and January 1908. Thos ships were the largest of the bunch, with an overall length of 52,8m, a beam of 5,8 and a draft of 1,7m, for a displacement of 213T. They had twin-screws and were capable of 29knots as well. Armament was three 47mm guns and as much as six 360mm torpedo launchers, fitted in two trainable triple mounts that, while somewhat daring for the time also proved to be a bit cumbersone and prone to malfuncions in service. Despite that, the Naval Staff seemed to be plased with them.
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The class was the only to not be refitted at the start of WWI or in the preceding years, and were also the only of all Kokoan torpedo boats to take part in the Siege and naval blockade of Tsingtao, although their record was negligible at best. They retunred home after the German threat in the Pacific was declared dealt with. After the war, they recieved minor modifications which included the addition of proper navigation lights on the bridge.
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Like all other kokoan Torpedo Boats they were decommissioned in 1923 and converted into Patrol Boats.

Ships in class: (laid down-launched-commissioned - fate)

Gyoraitei 14 1898-1899-1900 - Decommissioned 1918

Gyoraitei 15 1899-1900-1901 - Decommissioned 1923
Gyoraitei 16 1899-1900-1901 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 21 1900-1901-1902 - Decommissioned 1923
Gyoraitei 22 1900-1901-1902 - Decommissioned 1923
Gyoraitei 23 1900-1901-1902 - Decommissioned 1923 (converted to Patrol Boat)

Gyoraitei 17 1899-1900-1900 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 18 1899-1900-1901 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 19 1899-1900-1901 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 20 1899-1900-1902 - Decommissioned 1923
Gyoraitei 24 1900-1901-1902 - Decommissioned 1923 (converted to Patrol Boat)

Gyoraitei 25 1901-1902-1903 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 28 1902-1903-1903 - Grounded 1915, broken up
Gyoraitei 29 1902-1903-1903 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 30 1902-1903-1904 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 31 1902-1903-1904 - Decommissioned 1923 (converted to Patrol Boat)

Gyoraitei 26 1901-1902-1902 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 27 1901-1902-1902 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 32 1902-1903-1903 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 33 1902-1903-1904 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 34 1902-1903-1904 - Lost in a collision 1920
Gyoraitei 35 1903-1904-1904 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 36 1903-1904-1904 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 37 1904-1905-1905 - Decommissioned 1923 (converted to Patrol Boat)

Gyoraitei 38 1904-1905-1906 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 39 1904-1905-1906 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 40 1905-1906-1907 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 41 1905-1906-1907 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 42 1906-1907-1907 - Decommissioned 1923 (converted to Patrol Boat)
Gyoraitei 43 1906-1907-1908 - Decommissioned 1923 (converted to Patrol Boat)

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MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

Lovely additions to the Koko fleet, very well drawn small boats with nice detaliing.

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Hood's Worklist
English Electric Canberra FD
Interwar RN Capital Ships
Super-Darings
Never-Were British Aircraft

Excellent work as always.

Junshi-Sen 1,3,7,11,18 Class Patrol Boat

In 1923 Koko no Kaigun's Naval staff decided to convert all remaining Torpedo Boats into Patrol units. In total, twenty-three units recieved modifications for their new intender role, landing part of their gun and torpedo armament.
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Furthermore, fifteen of those boats were refitted again in 1925, landing all their original 47mm guns and recieved a single 76mm piece. They also had some of their boilers removed, resulting in their top speed dropping to 14-15 knots, depending on the ship.
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Eventually, all ships were decommissioned by the early 30's with the exception of the last two ships (JS-21 and JS-22) which were further modified to serve as training vessels with the addition of two small depth charge rails at the stern and , later, two single 13mm machine guns.
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By early 1942 they had been decommissioned as well.

Ships in class:

JS-1 (ex Gyoraitei 16) Converted 1923 - Decommissioned 1927
JS-2 (ex Gyoraitei 23) Converted 1923 - Decommissioned 1925

JS-3 (ex Gyoraitei 17) Converted 1923 - Decommissioned 1931
JS-4 (ex Gyoraitei 18) Converted 1923 - Decommissioned 1926
JS-5 (ex Gyoraitei 19) Converted 1923 - Decommissioned 1924
JS-6 (ex Gyoraitei 24) Converted 1923 - Decommissioned 1931

JS-7 (ex Gyoraitei 25) Converted 1923 - Decommissioned 1927
JS-8 (ex Gyoraitei 29) Converted 1923 - Decommissioned 1931
JS-9 (ex Gyoraitei 30) Converted 1923 - Decommissioned 1928
JS-10 (ex Gyoraitei 31) Converted 1923 - Decommissioned 1929

JS-11 (ex Gyoraitei 26) Converted 1923 - Decommissioned 1931
JS-12 (ex Gyoraitei 27) Converted 1923 - Decommissioned 1925
JS-13 (ex Gyoraitei 32) Converted 1923 - Decommissioned 1927
JS-14 (ex Gyoraitei 33) Converted 1923 - Decommissioned 1931
JS-15 (ex Gyoraitei 35) Converted 1923 - Decommissioned 1928
JS-16 (ex Gyoraitei 36) Converted 1923 - Decommissioned 1931
JS-17 (ex Gyoraitei 37) Converted 1923 - Decommissioned 1929

JS-18 (ex Gyoraitei 38) Converted 1923 - Decommissioned 1925
JS-19 (ex Gyoraitei 39) Converted 1923 - Decommissioned 1929
JS-20 (ex Gyoraitei 40) Converted 1923 - Decommissioned 1930
JS-21 (ex Gyoraitei 41) Converted 1923 - Decommissioned 1931
JS-22 (ex Gyoraitei 42) Converted 1923 - Training 1932 - Decommissioned 1939
JS-23 (ex Gyoraitei 43) Converted 1923 - Training 1932 - Decommissioned 1942

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MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

Shinjima class light cruiser:

Provision for a new class of cruiser emerged within Koko no Kaigun with the 1908 plan of capital ship construction. A class of four was requested for escort what would eventually become the battlecruisers Aomegami and Kuromegami, which required the new design to take into account the main requirement to fulfill its proposed mission: no less than 27 knots in top speed. With the first of the two battlecruisers being approved for construction already in 1909 designers had to work on very short terms to come up with a proper match. To their aid, came the fact that the IJN had been working under very similar provisions in the previous years, and Japan eagerly provied Kokoan designers with copies of the blueprints of their Chikuma class cruisers to work upon.
Compared to the Japanese plans, Kokoan designers modified and slightly refined both the stem and stern lines and increased hull depth by over half a meter (all going into draft) for an increase in displacement of over 580 T. The superstructure would also be slightlymodified, along with many other elements scattered through the ships. Most importantly, the armor layout was changed from that of a classic protected deck to an external belt one. The protected deck was flatteneed and moved slighly higher (which coupled with the increased hull depth increased machinery space below it), turning the ships more into a light cruiser (as they would be called later) than a classic protected cruiser like the Chikumas on which they were based.
The final design resulted in a ship 144,8m long, 14,2m wide and with a draft of 5,7m, all for a normal displacement of 5.588 T. Internal redesign of both hull depth and armor layout allowed to fit more powerful boilers (sixteen, the forward four burning oil, the others coal) and Parsons-type steam turbines that generated a maximum output of 32.000 shp. Driving two quadruple-screw propellers for the expected top speed of 27 knots. Maximum range was 10.000 nautical miles (18.520km) at 12 knots. Armament was made of eight 152mm guns in single shielded mounts and four 76mm ones placed at midship. Also fitted where three 450mm torpedo tubes, one on each broadside and one at the stern, with 12 torpedoes carried in total. Armor consisted of a main 88mm side belt that protected machinery spaces, with the addition of 50mm end plates reaching the bow and stern of the ship. The main deck was 57mm thick inside the main belt, thinning 37mm outside the citadel. 100mm of armor protected the conning tower. Complement was 426 officers and men.
The first ship, named Shinjima, started construction at Toumachi Naval Arsenal in 1910, was launched the next year and finally commissioned in December 1912. On trials, she easily made 27,6 knots.
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The second ship, named Kitajima, was also built at Toumachi between late 1911 and late 1914, and looked identical to her sister upon commissioning. On trials she clocked close to 27,9 knots.
The third ship of the class, Tojima, was built in Japan at the Yokosuka Naval Arsenal because of the lack of free military shipyards to build it domestically. Laid down in 1912 and delivered by the end of 1914 she slighlty differed from her two previous sisters. Her stem line was not vertical below the clipper bow but slighlty angled, her stern differed slightly as well, she had different guns hields and pilothouse structure, her aft 152mm gun sponsons were slighlty forward and she was armed with two 533mm torpedo tubes instead of three 450mm ones. On trials she topped at 27,5 knots.
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During WWI none of the three were deployed to blockade Tsingtao, but they later went to patrol the Pacific until all of the German East Asia Squadron ships had been dealth with. Later on, in May 1916, Shinjima and Kitajima joined the battlecruisers Kuromegami and Aomegami, the cruisers Hyoto and Gensho, departing for the Atlantic Ocean to support British operations against Thiaria. Reaching Capetown, they joined the British squadron under the command of Rear Admiral Evan-Thomas, comprising the two Battleships Valiant and Malaya, three pre-dreadnoughts, four old armoured cruisers and ten light and protected cruisers. They took part in the Battle of Tristan da Cunha on June 25th 1916, although their role in the battle was marginal, with the big guns seeing nearly all of the action. The fleet ultimately returned home by October of the same year.
The fourth ship, Borojima, was not started until 1914 when the new Hoshiguma Naval Yard was completed. Slowed by wartime commitments and by a run-in shipyard, Borojima was not launched until 1916 and was commissioned only in early 1918. The long building time had not been entierely wasted. Other than having a two-level aft bridge, a larger forward pilothouse, and different -taller- funnel tops Borojima hid more upgrades under her belly and displaced 5.596 T. Stern lines were changed and the rudder enlarged for better maneuverability, ventilation cowls for boilers and engines were completely different as well. More advanced boilers and state-of-the-art geared turbines (the other sthree ships had direct drive ones) allowed for a maximum output of 40.000 shp, enough for an ambitious top speed of 28,5 knots. The armament also saw the return of the third torpedo tube at the stern which had been deleted on Tojima, while the 533mm torpedoes were retained in place of the 450mm ones.
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During thrials Borojima made 28,7 knots under 40.885shp. Overall, all four didn't fail in delivering their speed expectations. Maintenance of the engines was troublesome at times, but both Naval Staff and crews considered the ships very satisfactory.
By 1925, all had two of their low-angle 76mm guns replaced by the same number of high-angle mounts. Then, between 1926 and 1929 the other pair of low-angle 76mm mounts was swapped well, in addition the bridge was partially enclosed, another spotting platform added on the foremast, a cap added on the forward funnel and a RDF antenna added at midship.
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All ships except Borojima (which had it since completion) added a second level to the aft bridge, Borojima instead had her bridge wings being given plated bulwarks.
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Even before plans for possible major refits were considered, limitations from the London Naval Treaty dictated all four ships to be removeed from service. Shinjima, Kitajima and Tojima were accordingly decommissioned in 1931, with Kitajima being eventually expended as a target ship and the other scrapped. Borojima instead was converted into a training vessel. Half of her boilers were removed, cutting speed to 20-21 knots, the entire battery of 152mm guns was also landed and replaced by two twin 127mm mounts. The four 76mm guns were relocated, while the torpedo tubes left untouched. Borojima entered service in her new role in 1932.
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Just a few years later, between 1934 and 1935, Borojima was refitted more extensively. Both masts were replaced by tripods and the forward bridge structure substantially enlarged. The midship deck was mostly enclosed and turned into more rooms and accomodations for cadets. Two extra 120mm guns, two twin trainable 533mm torpedo tubes were embarked (replacing the previous fixed ones) and a catapult with a single seaplane fitted. By 1939 four twin machine gun mounts (two 13mm and two 25mm ones) were added as well.
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Borojima served her training role for the entire duration of WWII, first at Toumachi and then at Kumoi. In 1944 she underwent one last refit recieving a small radar suite and improved armaments. A type 13 Air search and Type 22 surface search radars (the latter replacing the upper spotting top), plus two small Type R4CA for anti-air fire control. The 120mm guns were landed and the forward gun sponson that housed them completely enclosed. The 13mm machine guns were also removed, replaced by two triple and and six single 25mm mounts. An hydrophone was installed and two depth charge rails and racks added on the quarterdeck. Small modifications were made to both the forward and aft bridge structures and the seaplane was upgraded.
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Borojima ultimately survived the war, miracolously unschated. Towed to Mizushimo she was used as a barracks ship by US troops between 1946 and 1947. Decommissioned, she sat neglected and nearly abandoned until 1954 when it was decided to scrap the old and now derelict ship. Things didn't go as planned however, as Borojima sank while under tow in September of the same year.

Ships in class: (laid down-launched-commissioned - fate)

Shinjima 1910-1911-1912 - Decommissioned 1931
Kitajima 1911-1913-1914 - Decommissioned 1931
Tojima 1912-1913-1914 - Decommissioned 1931
Borojima 1914-1916-1918 – Training 1932 - Decommissioned 1947

I love your drawings !!! This is just fantastic !!!

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