Between 1939 and 1945 the Imperial Japanese Navy commissioned 187 Kaibokans (literaly "ocean defense ships" ) in seven different classes. This particular ships were originally concieved as multi-purpose units dedicated to escort, patrol and even fishery protection. Late units, and early ones focused solely on anti-air and anti-submarine-warfare after the start of the Pacific War. 83 were lost during the conflict.
Four of the seven classes had been represented by Radome a few years ago. My intent is to add the three misisng classes and refresh te original drawings, fixing a few inaccuracies and updating weaponry, color schemes and systems to current standards.
-Shimushu Class:
Initially intended for patrol and fishery protection, minesweeping and as convoy escorts, the ships measured 77.72 meters (255 ft 0 in) overall, with a beam of 9.1 meters (29 ft 10 in) and a draft of 3.05 meters (10 ft 0 in). They displaced 870 metric tons (860 long tons) at standard load and 1,040 metric tons (1,020 long tons) at deep load. The ships had two diesel engines, each driving one propeller shaft, which were rated at a total of 4,200 brake horsepower (3,100 kW) for a speed of 19.7 knots (36.5 km/h; 22.7 mph). The ships had a range of 8,000 nautical miles (15,000 km; 9,200 mi) at a speed of 16 knots (30 km/h; 18 mph). The main armament consisted of three Type 3 120-millimeter (4.7 in) guns in single mounts, one superfiring pair aft and one mount forward of the superstructure. They were built with four Type 96 25-millimeter (1.0 in) anti-aircraft guns in two twin-gun mounts, but the total was increased to 15 guns by August 1943. A dozen depth charges were stowed aboard initially, but this was doubled in May 1942 when their minesweeping gear was removed. The anti-submarine weaponry later rose to 60 depth charges with a Type 97 81-millimeter (3.2 in) trench mortar and six depth charge throwers. Four ships were built between 1939 and 1941.
Shimushu as of 1940:
Lead ship of the class and first to be commissioned, she survived the war and was ceded to the Soviet Union, serving as patrol ship EK-31 until 1948, dispatch ship PS-25 until 1957 and repair ship PM-74 until her deommissioning in 1959.
Ishigaki as of 1941:
Last ship to be laid down but third to be commissioned. Ishigaki was the only ship of the class to be lost during WWII, Torpedoed and sunk by submarine USS Herring on 31 May 1944.
Shimushu as of 1944:
Late-war fit of the class, the minesweeping gear is removed to allow 60 depth charges to be carried. A Type 97 81-millimeter (3.2 in) trench mortar is also added and the anti-air suite increased to fifteen 25mm machine guns iin five triple mounts. A Type22 radar is also embarked.
-Etorofu Class:
The Etorofu class was an improved version of the preceding Shimushu class with a greater emphasis on anti-submarine warfare. The ships measured 77.72 meters (255 ft 0 in) overall, with a beam of 9.1 meters (29 ft 10 in) and a draft of 3.05 meters (10 ft 0 in). They displaced 880 metric tons (870 long tons) at standard load and 1,040 metric tons (1,020 long tons) at deep load. The ships had two diesel engines, each driving one propeller shaft, which were rated at a total of 4,200 brake horsepower (3,100 kW) for a speed of 19.7 knots (36.5 km/h; 22.7 mph). The ships had a range of 8,000 nautical miles (15,000 km; 9,200 mi) at a speed of 16 knots (30 km/h; 18 mph).
The main armament consisted of three Type 3 120-millimeter (4.7 in) guns in single mounts, one superfiring pair aft and one mount forward of the superstructure. They were built with four Type 96 25-millimeter (1.0 in) anti-aircraft guns in two twin-gun mounts, but the total was increased to 15 guns by August 1943. 36 depth charges were stowed aboard initially, but this later increased by August 1943 to 60 depth charges with a Type 97 81-millimeter (3.2 in) trench mortar[2] and six depth charge throwers. They received Type 22 and Type 13 radars and Type 93 sonar in 1943–44.
Fourteen ships were built between 1942 and 1944 -the first units entering service in March 1943. Eight units were lost during the war.
Etorofu as of 1943:
Lead ship of the class but fourth to be laid down and commissioned. She survived the war and served as a repatriation vessel until August 1947 and scrapped shortly thereafter.
Oki as of 1943:
Among the first ships of the class to be commissioned in late March 1943 (along with Sado and Matsuwa), distinctive features were the different gun shields and higher number of portholes. She survived the war and was ceded to Taiwan and renamed Gu An, serving from 1947 to 1949. She then ended in Chinese serivice as Chang Bai and was ultimately retired in 1982.
Fukue as of 1943:
Commissioned in June 1943, the fifth ship to be commissioned overall and the first to enter service with reduced minesweeping gear and a modified foremast fitting a Type22 radar. She survived the war abd was scrapped in 1947 after serving as a repatriation vessel.
Amakusa as of 1943:
Commissioned in November 1943, she initially didn't fit the Type22 radar, which was installed later. On 9 August 1945, while lying in harbor at the Onagawa Bay the ship came under air attack led by Canadian Lieutenant Robert Hampton Gray. Despite his Corsair was hit by anti-aircraft fire Lt. Gray managed to hit Amakusa before crashing into the bay. Amakusa sank with with 71 crewmen, and Lt. Gray phostumously earned the Victoria Cross.
Manju as of 1944:
Also commissioned in november 1943, She survived the war in damaged state in hong Kong and was scrapped in 1946.
Kanju as of 1945:
Initially commissioned in October 1943, she was fitted in 1944 with a Type 97 81-millimeter (3.2 in) trench mortar and the anti-air suite increased to fifteen 25mm machine guns iin five triple mounts. She hit soviet air-dropped mines and sank on August 15th 1945 at Wonsan.
Kasado as of 1945:
Last ship of the class to be commissioned in February 1944, she had the lowest number of portholes of the entire class. Damaged in April 1944 she recieved a Type 97 81-millimeter (3.2 in) trench mortar and the anti-air suite increased to fifteen 25mm machine guns iin five triple mounts. She later landed one of her 120mm guns for eight more 25mm machine guns. She ended the war in damaged state in Hong Kong and ultimately scrapped in 1948.
-Mikura Class:
The eight ships of the Mikura class were denoted "Type B" and were the third class of Kaibokan. The Mikuras, unlike the two preceding Etorofu and Shimushu classes, were dedicated to the anti-aircraft (AA) and anti-submarine role. The ships measured 78.8 meters (256 ft 9 in) overall, with a beam of 9.1 meters (29 ft 10 in) and a draft of 3.05 meters (10 ft 0 in). They displaced 940 metric tons at standard load. The ships had two diesel engines, each driving one propeller shaft, which were rated at a total of 4,400 brake horsepower for a speed of 19.5 knots (36.1 km/h; 22.4 mph). The ships had a range of 5,000 nautical miles (9,300 km; 5,800 mi) at a speed of 16 knots (30 km/h; 18 mph).
Unlike the "Type A" armed with 120mm guns removed from old destroyers, Mikura class ships received dual-purpose guns of the same calibre in single and twin mounts. As built they carried three 120mm guns, a shielded single forward and a twin unshielded aft, four 25mm machine guns in two twin mounts and 120 depth charges. The number of AA machine guns was later increased to up to eighteen and they recieved an 81mm trench mortar. They were all commissioned between October 1943 and May 1944. Five were lost during the war.
Awaji as of 1944:
Third ship of the class to be commissioned, she entered service in late January 1944. She had a short career, sunk off Manila by submarine USS Guitarro in June of the same year.
Chiburi as of 1944:
One of the last units to enter service, in May 1944, she was sunk by US carrier-based aircrafts off Saigon in January 1945.
Nomi as of 1944:
She was commissioned in February 1944. On April 14th 1945 Nomi spotted and charged the submarine USS tirante while she was attacking a convoy northwest of Saishi Island (South Korea). She was however hit by thwo torpedoes that detonated her magazines, breaking her in half and sinking.
Yashiro as of 1945:
Commissioned in May 1944 -like sisters Chiburi and Kusagaki- she was hower the last to be laid down, in December 1943. She differed from all other Mikura-class units for having her funnel almost rectangular-shaped, with only the edges smoothed out, contrary to the oal shape of the others. In 1945 she was refitted to increase the anti air armament, carrying five triple 25mm machine guns and an unspecified number of singles (the aft mast was shifted towards the funnel to make space). The minesweeping gear was also removed in order to increase the depth charge complement. Yashiro survived the war and served as a repatriation vessel until 1947, she was then ceded to china as war reparation and renamed Cheng An, serving until 1963.
-Ukuru Class:
-Hiburi Class:
-Type C Class:
-Type D Class: