Tenshi Class Destroyer:
By 1938 -despite assembling a respectable fleet of 60 units- Koko no Kaigun was in a dire need of a new Destroyer class, with new constructions struggling through the decade because of treaty, limitations, multiple design changes and overly complex rebuilds. Aiming at putting newer units in service as quick as possible, Kokoan take for the design bore high similarity to the Japanese Kagero, but with the usual Koko no Kaigun take on it. The ships give way the IJN styled slanted stern retaining the straight curved fantails of all previous kokoan destroyers. Internal compartimentation was modified as well, all to standardize and increase construction rates. most importantly, the ships introduced the first Kokoan domestic designed high performace boilers -all KnK Destroyers had previously used licensed copies of the Japanese Kampons- derived from the high-pressure ones developed for the Kimmei class fast minelayers. The new boilers were slighty bigger than the usual Kampons, so the ships were slighty stretched as well to 118,8m overall, beam was 10,8m and draft 3,8, displacement 2.038T at standard load. Despite the slighty increased dimensions, the boiler and turbine sets generated enough extra power (57.000 shp instead of 52.000)to actually made the ships achieve top speeds over 35,5knots, half a knot faster than a Kagero. Endurance was 5.000 nautical miles at 18 knots. Armament was more conventional, but still with some differencies: six 127mm guns in three twin turrets -one fore, two aft- and two quadruple sets of launchers for 610mm long lance torpedoes carrying 8 ready and 8 reload warheads. Anti-air consisted of four 25mm machine guns in two twin mounts, four depth charge racks and two rails at the stern, with 36 warheads carried. Final differing points from a Kagero were the bow-mountted hydrophone since completion and an internal degaussing cable.
Once the design phase was completed fifteen ships were ordered: seven at Toumachi Naval Arsenal, six at Hoshiguma and another two at Kousaten. The first unit and lead ship, named Tenshi, was laid down in june 1938. Six more units were ordered at Yamatogawa Shipyards in 1941 when it was clear that Koko was going to war against the United states alongside Japan, bringing the total units of the class to 21.
Tenshi was the first ship to be completed as well, joining the fleet in early 1940, four were in service by December 1941.
Four more ships were commissioned in 1942, with another five during the course of 1943. One of them, Nemuno, was the first of the Yamatogawa-built ships to enter service, laid down in January 1943 and commissioned in record-breaking time by late december of the same year. Compared to the other ships of the class, the six sisters built at Yamatogawa were commissioned with an improved type of hydrophone, carried 40 depth charges instead of 36 and had three triple 25mm machine guns as the light anti-aircraft armament, the third set fitted on a platform forward of the bridge.
The year 1944 saw the most units completed -with 8-, but also saw the first losses, with Kisume, Unzan, Hatate and Kyouko beign lost in action during the year. Satono was the last ship of the class to be commissioned, on June 12th 1944. She featured less portholes than her sisters and a sonar in addition to the hydrophones, further increased the number of depth charges carried to 60, and saw the addition of two more racks. The ship also recieved radars, in the guise of a Type22 surface-search, Thiarian-designed RF2A air-search and R4CA fire-control set. Anti-air suite was also augmented with the addition of new machine-gun mounts, for a total of five triple and ten single 25mm machine guns, plus two twin 13mm MGs as well. with the exception of those lost, all ships recieved refits along the same lines by the end of the year.
During the year 1945 the ships were refitted again. They had most protholes sealed, R12CAD fire-control and Type33-Kai surface radar replacing the earlier sets and a Type65 high frequency direction finder fitted on the foremast. the forward torpedo reaload boxes were removed to allow for more anti-aircraft guns, which reached a total of seven triple and twelve single 25mm machine guns (33 barrels). Sonar was fitted on all units and boats, already reduced in numbers in the previous years, were landed leaving only life rafts to be carried, stowed on deck in five different boxes. Finally, all recieved a two-tone blue and black dazzle camouflage to reduce visibility.
During the year, however, the class suffered heavily from wartime attriton. Falling to air, submarine and surface attack, especially during the disastrous operations in the Philippines, eight ships were lost and another three seriously damaged. Three more were stuck at Singapore under Japanese command after the Kokoan uprisings started. Satono, one of the three units at singapore, was the last of the class to be lost, torpedoed in early 1946. Of the eight surviving ships at the time of the Armistice with the allies, three -Yuugi, Utsuho and Ichirin- actively joined the co-belligerent squadron after recieving a small refit. Four triple and two twin 25mm machine guns were removed, replaced by four twin Type5 40mm mounts, a Jammer was fitted on the foremast and the standard USN Measure 22 camouflage painted, albeit featuring the name of the ships in western letters on the side.
After the war, all but two of the surviving units were decommissioned. This pair of sisters -Utsuho and Ichirin- Joined the reformed Koko Kaijou and recieved a series of upgrades and modernizations between 1948 and 1950. Al light anti-air armament was removed and replaced by six quadruple 40mm bofor mounts and eight single 20mm oerlikon machine guns. A new sonar system fitted and depth charge racks and reails replaced as well, increasing the overall stowage of warheads to 80, two hedgehog launchers were added, side-by-side in front of the bridge. All electronics with the exception of the DP fire-control radar were replaced by US ones, leading to the foremast geing modified and lowered, the original mainmast was cut down too and moved near the aft funnel. The forward torpedo mount was removed to allow for a radio room and boat davit (on the post side) to be fitted, other than reducing topweigh. The ships also recieved a standard grey pintscheme.
Afer serving during the Korean war and beyond, Ichirin was decommissioned in 1958, with Utsuho following the next year. Both remained in the mothball fleet for a decade and were ultimately scrapped in the early 70's.
Ships in class: (laid down-launched-commissioned - fate)
Tenshi 1938 1939 1940 - Decommissioned 1946
Kisume 1938 1939 1940 - Sunk 1944
Yamame 1939 1939 1941 - Sunk 1945
Yuugi 1939 1941 1941 - Decommissioned 1946
Satori 1940 1941 1942 - Decommissioned 1946
Rin 1940 1942 1943 - Decommissioned 1946
Utsuho 1940 1941 1942 - Decommissioned 1959
Koishi 1941 1942 1942 - Sunk 1945
Kogasa 1941 1942 1943 - Sunk 1945
Ichirin 1941 1942 1943 - Decommissioned 1958
Unzan 1941 1942 1942 - Sunk 1944
Murasa 1942 1943 1944 - Sunk 1945
Shou 1942 1943 1943 - Decommissioned 1946
Hatate 1942 1943 1944 - Sunk 1944
Seiran 1942 1943 1944 - Sunk 1945
Sagume 1942 1943 1944 - Sunk 1945
Junko 1942 1943 1944 - Sunk 1945
Kyouko 1943 1944 1944 - Sunk 1944
Nemuno 1943 1943 1943 - Decommissioned 1946
Narumi 1943 1943 1944 - Sunk 1945
Satono 1943 1944 1944 - Sunk 1946