Seiga Class Destroyer:
In 1941 with war looming, design works started for a successor of the Tenshi class as the new standard destroyer for Koko no Kaigun. In order to step-up from the already well rounded previous class, designers gave the ship six 127mm doual-purpose guns in improved turret mounts and two quintuple 610mm torpedo launchers with nine reloads, four for the forward mount and five for the aft one. A state-of-the-art (for an Axis country at least) hydrophone and sonar system was included, new fire-control system and electronics, large depth charge complement and a strong light anti-air armament (six triple and a twin 25mm mounts -20 barrels- almost four-fold what a KnK destroyer would usually fit at the time). Compared to the preceding Tenshi the hull was larger and deeper. The forecastle was of the same length at the waterline but featured a more pronounced clipper bow. The bridge structure was vastly enlarged to house radar rooms and had a flush, rounded, more aerodynamic front with a conical aft end that acted as a support structure for the main gun director. The midship section was longer and beamier to fit the larger boilers and turbines. Quarterdeck was longer as well, with enough space for three pairs of depth charge throwers compared to Tenshi's two. The resulting ship, at 122,7m in length, 11,1 beam, 4,1 draft and a planned displacement of 2.367T standard was to be among the largest destroyers in service at the time. Three boilers with a combined output of 60.000shp powered a set of turbines driving two three bladed propellers for a top speed of 35,5 knots, something that was reached and even slightly exceeded with most ships clocking 35,8 knots and above on trials. Endurance was 5.000 nautical miles (9.260km) at a cruising speed of 18 knots.
Eight ships were considered at first, but twenty-six were actually ordered in 1942 as the war was already raging. Of them eigth were allocated to Hoshiguma, six to Kousaten and four each to Kumoi, Toumachi and Yamatogawa yards. The lead ship of the class, Seiga, was laid down in 1943 and commissioned in August of 1944. She carried a TypeR4CA fire control, Type22 surface search and TypeR2FA air search radars, her anti air-suite had already been beefed up with the addition of ten single 25mm mounts.
Starting with the third ship the design was slightly modified to feature a straigther bow and revised internal compartimentation in order to improve survivability, simplify the desing and speed up construction, something reflected by the fact that four ships of the second batch were actually commissioned before Yoshika, the second ship to be laid down and the only one, other than Seiga, to be finished to the original design. Albeit with a reduced number of portholes and few smaller differing details.
The first five ships formed Kuchikutai 13 and served in the Solomon islands theatre with the cruiser Kumoi under Suirai Sentai 6. Early 1945 saw the improvement of anti-air suite and electronics. The TypeR4CA fire-control was replaced by a TypeR12CAD and the Type22 surface with a Type33-kai. The RDF was replaced and moved on top of the foremast, the crows nest removed and a TypeA8TR fitted in place. IFF sets were installed on each bridge wing, seven more single 25mm machine guns added and the forward twin mount replaced with a triple for a new grand total of thirty-eight barrels.
1945 saw the addition of Cuchikutai 11 as new units entered service and the entire class saw service at the battle of the Philippine Sea. After that, another small refit was undertaken. A type24 air-search mattress antenna was installed and the anti-air suite buffed, now made of five twin and four single 40mm plus nineteen single 25mm ones. All torpedo reloads were removed and a dark blue camouflage was painted. Kokoro, last ship of the class to be completed during the war, was so fitted upon completion in August 1945.
All seven sisters were part of Kurita and Minasoko center force during the Leye Gulf operations, here 2-months old Kokoro was lost on October 26th during the Battle of San Bernardino Strait. Seiga also suffered heavy damage during the campaign, but managed to return home safely with the other surviving Kokoan ships.
During Koko uprisings all ships but Seiga took an active part in the Rebels operations. After the Armistice with the Allies in early 1946 Seiga was laid up in Toumachi harbor, Soga, Kasen and Hieda were interned to Midway island while Yoshika and Sekibanki joined the co-belligerant fleet. The last two recieved USN supplied IFF sets, were painted in Measure22 camouflage with the addition of their name spelled o thier sides and had three extra single 25mm machine guns fitted.
In this guise the two ships followed Amagi's squadron in operations against Okinawa before returning home once hostilities ceased after the Japanese surrender. Postwar peace treaty allowed Koko to retain some ships while other had to be disposed of or given to other countries as war reparations. Regarding the Seiga class, three had to be handed over, which meant another three could have been kept. Eleven units sat in various state of uncompletedness, with another 8 that had not been laid down at all. As damage suffered by Seiga was considered to be excessive, the nevwly reformed Navy expressed interest in retiring her and exploit one of the uncompleted hulls to fill their allowances. The US observers allowed for that: two ships at Kumoi arsenal -Tsukumo and Iwaizumi- which having been controlled by Loyalist forces for most of the uprisings had seen work on them continuing past the start of the uprising, were inspected in order to choose one of the two. Tsukumo, which was in a more advanced state, was chosen and ultimately completed in late 1947. Seiga was retired the same year and scrapped in 1948. All other unfinished ships suffered the same fate between 1947 and 1949.
In addition to the newly built Tsukumo Koko Kaijou kept in service Yoshika and Sekibanki. All three ascorted Amagi during her involvement in the Korean war and were refitted in the early 1950s. During works the forward quintuple torpedo launcher was removed, along the entire light-anti air suite and electronics (the sole exception being the fire-control radar), aft tripod mast, depth charge and sonar system. A new smaller mast was fitted just aft of the second funnel, and SPS-4 and SR-2 radars, two ASW hedgehog launchers, new sonar and depth charge racks, six twin 40mm Bofor and four twin 20mm Oerlikon machine guns fitted on board.
Despite being the last ship to be completed Tsukumo began fairly quickly to show numerous faults caused by her troubled late wartime construction, including engine and rudder problems which necessitates numerous unplanned and costly drydock stints to attempt and remedy the issues. In the end, Tsukumo would be retired in 1960. Yoshika and Sekibanki were not left in service much longer however, as soon as similar issues started to emerge it was decided to retire the two in favour of newly built ships of the Raiko class.Yoshika was thus decommissioned in 1961 and Sekibanki in 1963. Contrary to Tsukumo, which was scrapped immediately, they were left in the mothballs until the mid 70s before being sent to the breakers.
Of the other ships designated as war reparation Soga was disarmed and delivered to the Republic of China Navy in 1947. The ship was rearmed with US assistance, carrying three 127mm and two 76mm guns in open mounts plus ten twin 40mm Bofors. SG-1 and SC-2 radars and other US built electronics and weapons were fitted. Renamed Fu Yang she took part in the Chinese Civil War, protecting the withdrawal of the ROC government and refugees to Taiwan in 1949. A much longer and uneventful service followed until her retirement in 1971.
Hieda was intended for delivery to the Philippine Navy, but was instead given to South Korea in 1951 after war broke out with the north and renamed Gwanju. Initially retaining pretty much all her original Kokoan systems and armament she recieved a number of small refits between 1955 and 1965. during such works she had bridge and aft deckhouse enlarged, recieved two new tripod masts with SPS-6, SPS-10 radars and ECM gear. The original Kokoan director was replaced with a US supplied Mk.37. Original light anti-air armament was switched out for four quad 40mm Bofor and eight twin 20mm Oerlikon machine guns (the latter disembarked fairly quickly). The two quintuple 610mm torpedo launchers were removed and replaced with two Mk.32 SVTT triple tubes. Depth charges, two hedgehog ASW mortar launchers and sonar were added as well. The Kokoan main turrets were kept instead, with ammunition and maintenance provided by Koko. Her career went on relatively peacefully until her Kokoan guns and magazines could not be refurbished and restocked further after the mothballed Yoshika and Sekibanki were scrapped and could not be stripped for parts anymore. Gwanju was retired in 1977.
Kasen was initially supposed to be handed either to Australia or the US for tests, inspections and eventual disposal, but when the start of the Korean War let to Hieda -initially desitned for the Philippines- to be hastily given to South Korea Kasen was selected as a replacement for the newly reborn Philippine Navy. With quad 40mm Bofors and 20mm Oerlikons in place of the original Kokoan machine guns, no torpedo tubes and US supplied SG-2 and SC-5 radars Kasen was finally delivered in late 1953 and renamed Jose Rizal. She was by far the largest ship the PN had at its disposal and would remain so for a good twenty years. By the early 70s she had also recieved a new sonar system, two hedgehog ASW mortar launchers and two triple Mk.32 SVTT torpedo tubes. Like with the Korean Hieda/Gwanju maintenance and ammunition for the 127mm guns was provided by Koko until there were no more stock and parts avaiable to do it. Willing to retain their longtime flagship the PN approached the USN for help and a series of talks and negotiations followed -mostly regarding costs- until a final plan for a refit was finalized in 1976.
During such works the three original 127mm turrets were removed and replaced with two Mk.38 5'/38 twin turrets and one Mk.27 3'/50 twin open mount, the latter replacing the original aft superfiring 127mm mount. A Mk.37 director was installed for fire control, SPS-10 and SPS-12 radars replaced the older electronics on a newly built forward tripod mast.
After having soldiered on into the early 90s Rizal material conditions had deteriorated, a situation that was exacerbated when US forces left, decommissioning Naval Base Subic Bay in 1992 after the end of the Cold War and the ruption of Mount Pinatubo. Leaving the PN without a close and plentiful source of maintenance and supplies. Rizal retirement was briefly contemplated in early 1994, but the start of Chinese incursions into Philippine-claimed areas of the South China sea quickly led to the PN's decision to keep the old destroyer in service if budget allowed or some third-party support could be found. Koko stepped in around the right time. With a large amount of surplus equipment at hand due to the recent fleet reductions and the Soviet Union Scare off the table the Kokoan Government was very willing to offer assistance to other Countries for the right amount of money and try to expand its foreign influence. The Philippine Government accepted the offer fairly quickly.
Rizal returned to Kousaten in early 1996, the very same yard she was originally built in, to underwent a very thorough refit that lasted almost 18 months.
Gutted down to main deck level Rizal had her engines completely refubished. A new superstructure and bridge was built, completed with new funnels with heat signature suppression caps. The aft 76mm mount was removed and replaced with an helicopter pad. All 40mm Bofor and 20mm Oerlikons were landed as well. The two SVTT torpedo tubes were moved forward of the bridge where the old hedgehog launchers once stood. Two new lattice masts were erected, housing KMS-3 surface search, KMS-4B air-search radars, new ECM and comunication gears. The sonar system was replaced, a towed array added on the fantail and an ASROC launcher fitted at midship.
After a 4-month delay caused by a lull in payments from Philippine's part on the onset of the 1997 Asian economic crisis, the newly rebuilt Jose Rizal returned home, the first of many military supplies, contracts and purchases from Koko that continue up to this day.
Rizal kept serving for another two decades, when the unavaliability of spare parts for her 5'/38 mounts led to her ultimate retirement in 2016. While she is awaiting a decision on her final fate, a new class of modern Frigates, whose lead ship was given the same name, are currenly being purchased from Koko.
Ships in class: (laid down-launched-commissioned – fate)
Seiga 1943-1944-1944 - Decommissioned 1947
Yoshika 1943-1944-1945 - Decommissioned 1961
Soga 1944-1944-1944 - Decommissioned 1946, to Taiwan 1947, Renamed Fu Yang, Decommissioned 1971
Kokoro 1944-1945-1945 - Sunk 1945
Sekibanki 1944-1944-1944 - Decommissioned 1963
Seija 1944-/-/ - Not completed
Raiko 1944-1945-/ - Not completed
Kasen 1944-1944-1944 - Decommissioned 1946, to Philippines 1953, Renamed Jose Rizal, Decommissioned 2016
Renko 1944-1945-/ - Not completed
Hieda 1944-1944-1944 - Decommissioned 1946, to South Korea 1951, Renamed Gwanju, Decommissioned 1977
Kosuzu 1945-/-/ - Not completed
Mootori 1945-1945-/ - Not completed
Yorihime 1945-/-/ - Not completed
Toyohime 1945-/-/ - Not completed
Morichika 1945-1945-/ - Not completed
Sukuna 1945-/-/ - Not completed
Tsukumo 1945-1947-1947 - Decommissioned 1960
Imaizumi 1946-/-/ - Not completed
8 unnamed ships - Canceled before being laid down in 1946