Koko Kyouwakoku (Republic of Koko)

Great additions to this thread this week.

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

F-18 Class Minelayer:

Afer the large F-13 and F-16 classes Koko no Kaigun issued the requirements for a class of smaller minelayers for coastal service. The design was based on that of the Japanese Natsushima class. The planned ships were thus to be 73m long, 7,5m abeam and with a draft of 2 meters with a displacement of 476T. 2.300shp engines would have been enought to push the ships to 19 knots and endurance was planned at 2.500 nautical miles at 14 knots. Other than a complement of 120 mines the ships were to be armed with two 76mm anti-air guns and a single 13mm machine gun. 18 depth charges could be also carried and, if needed, the mine complement could be replaced by a 510m anti-submarine net.
Ordered as a class of four, the ships were built at Fuyuki Dock Company and Shionseki Shipyards between 1931 and 1936 and named Fusetsukan 18, 20,21 and 23. The missing numbers beign take by the single ship of the F-19 class and by the lead ship of the F-22 class.
[ img ]

Fusetsukan 23, commissioned only in 1936, sported a different and more compact bridge and superstructure: this was to reduce topweight and improve stability after concern arose from the Tomozoru and Fourth Fleet incidents. The The ship was also fitted with bilge keels to reduce rolling. By 1939 the other three units had been such modified.
[ img ]

During the war the four ships repeatedly sortied to lay minefields around Koko home waters and towards Midway and the Aleutians. In 1943 they were sent to the Solomon Islands to support the attempted invasion of the Fiji islands. F-20 was torpedoed and sunk by an american Submarine in August 1944 whilee scorting a convoy bound for Truk. The three surviving sisters returned to Koko and where al the minelaying gear was removed, fitting four depth charge racks and two rails in their place, increasing the depth charge stowage to 126 warheads. An hydrophone was also installed. Anti-air layout was augmented with the addition of two twin and four single 25mm machine guns, two twin and a single 13mm ones. A type 13 air-search radar was also installed.
[ img ]

With their new fit F-18, F-21 and F-23 started operating as convoy escorts. F-18 was sunk on February 17th 1945 during the raid on Truk Lagoon. F-23 followed a few months later, shee to victim of an American submarine. F-21 held long enough to see the start of koko uprisings. Her crew choose to remain loyal to Morimoto, so the ship reached Nadayoko to embark loyal KnR and IJA troops, departing the harbor on December 6th morning bound for Hoshiguma. a Few hours into the trip, 27 miles off Kammu the ship hit an air-dropped mine (this time laid by the US forces) and blew up with just three survivors: a Rikugun soldier and two sailors.

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

F-18 1931-1933-1933 - Sunk 1945
F-20 1933-1934-1934 - Sunk 1944
F-21 1933-1933-1934 - Sunk 1945
F-23 1935-1936-1936 - Sunk 1945

_________________
[ img ]

MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

S-9 Class Minesweepers:

Successor class of the Sokaitei-1 units, the S-9 class were based on the Japanese W-13 Minesweepers. Differing from their IJN siblings by having a straight quarterdeck they were 74m long, 8,2m abeam and drafted 2,1m for a displacement of 525T. Armed with 2 120mm guns and two single 13mm machine guns for AA duties they were capable of 20 knots with a 2.600 nautcial miles endurance at 12-knots.
Koko no Kaigun ordered eight units for the class, the first two units S-9 and S-10, were laid down in December 1931 and ultimately commissioned in late 1933.
[ img ]

By the time the Tomozoru incident happened S-11 through S-14 had already been laid down. to correct the ensuing stability issues S-9 and s-10 were refitted to reduce topweigh, the other units recieved modifications before beign commissioned.
[ img ]

The last two units, S-15 and S-16 were delayed unitl early 1935 and were of an improved design. Draft was increased to 2,5m bringing the displacement to 616T, fuel bunkerage was increased to maintain the 2.600-nm range, but top speed decreased to 19 knots. Topweight was further reduced resulting in a slightly different bridge structure. They also featured a sighly different midship break. Such modified the last units of the class entered service in 1936.
[ img ]

As it was for the S-1 class, the war exacted it's toll. S-9 was sunk in 1942, with S-11 and S-13 following in 1943 and 1944 respectively. The 5 surviving units were recalled for minesweeping dutied around kokan home waters in response of the US advance. The ships were refitted by recieving an hydrophone and increased depth charge inventory. A type-13 air-search radar was also installed. The two 13mm machine guns were removed and replaced with two twin and four single 25mm machine guns. S-10 and S-12 were sunk in late 1945. Just before the start of Koko uprisings the remaining three units recieved a camouflage paintjob.
[ img ]

In early 1946 S-14 and S-16 were both sunk during an US bombardment on Mitsuminato Harbor. S-15 was bombed a few days later in Nadayoko's harbor, severly damaged she was beached to prevent her sinking. After the war she was declared a constructive total loss and was promptly decommissioned and scrapped.

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

S-9 1931-1933-1933 - Sunk 1942
S-10 1931-1933-1933 - Sunk 1945
S-11 1932-1933-1934 - Sunk 1943
S-12 1933-1934-1934 - Sunk 1945
S-13 1933-1934-1934 - Sunk 1944
S-14 1934-1935-1935 - Sunk 1946
S-15 1935-1935-1936 - Decommissioned 1946
S-16 1935-1935-1936 - Sunk 1946

_________________
[ img ]

MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

_________________
best regards
Martin

~~Normerr~~FD stuff~~

Nice additions, keep it up!

Suiraitei 1 Class Torpedo Boat:

Designed to skirt treaty limitations on Destroyers, Koko's three-unit Suiraitei 1 class was a semplified Chidori Class Torpedo boat sporting a straight quarterdeck. As it was for her half-sibling it suffered for all the design flaws that would eventually led to instability and top heavyiness.
Luckily for Koko no Kaigun, the first ship, laid down in 1931, was still fitting out when IJN Tomozuru capsized during torpedo trials. The ship thus landed the heavy 5-inch gun turrets in favour of lighter 4.-7inch shielded ones, torpedo armament was cut down from 4 to 2 tubes and the bridge was reduced in heght by a level. In order to increase engine power and not lose speed bulges were added and internal bulkheads were modified as to fit slightly more powerful engines. A ballast keel ensuderd stability when fuel tanks were empty. Such modified Suiraitei 1 entered service in december 1934.
[ img ]

Suiraitei 2 had her beam increased before her launch without the need to add bulges. The bridge was further modified and the foredeck design was simplified leading to a straight deck. Modification on Suiraitei 3 were even more extensive, with extra deckhouses added below the bridge and aft, other than a completely different midship break at the end of the forecastle that further simplified construction. The last unit was in service by early 1936.
[ img ]

Assigned to Goaitei1 (Escort Division) the three sisters acted as training units until the start of the Pacific War, when the 13mm anti-air machine gun was replaced by a single 25mm one.
[ img ]

During the course of the war the three Suiraitei-1 units operated as high-speed convoy escorts, with Suiraitei 2 and 3 beign sunk by US Submarines in 1945 and 1944 respectively.
Suiraitei 1 returned to Koko in early 1945 to be reiftted: the aft 4.7-inch gun was landed and the anti-aircraft armament increased to a triple and seven single 25mm machine guns, depth charges fit was increased to 48 warheads and a type 13 air-search radar fitted, deckhouses were expanded for radar room spaces and an hydrophone fitted. Later the year Suiraitei-1 had some of her portholes plated over and a partial camouflage painted.
[ img ]

Work was not completed as Koko uprisings started and the sip was sent to Teshigawa, were she remained until the end of the war. After a few trips as a repatriation vessel, Suiraitei-1 was decommissioned and scrapped.

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

Dai-1-Go Suiraitei 1931-1933-1934 - Decommissioned 1946
Dai-2-Go Suiraitei 1932-1934-1935 - Sunk 1945
Dai-3-Go Suiraitei 1933-1934-1936 - Sunk 1944

_________________
[ img ]

MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

Shipbucket

Who is online