Warships of the Imperial Japanese Navy, Seaplane Tenders: Nisshin, Kamikawa Maru, Kiyokawa Maru, Akitsushima, Kamoi, Notoro, and Mizuho

Imperial Japanese Navy Seaplane Tenders Nisshin, Kamikawa Maru, Kiyokawa Maru, Akitsushima, Kamoi, Notoro, and Mizuho

Seaplane Tender Nisshin-class

Seaplane tender Nisshin (1942–1943), 11,499 tonnes. Also a midget submarine carrier and minelayer. Nisshin was built at Kure Naval Arsenal as part of the (1937), she was originally planned as a minelayer but ultimately converted to a hybrid seaplane carrier/minelayer design, albeit the optional 700 mines reduced her seaplane complement from 20 to 12. Her seaplane operations were also hindered by the reduced number of catapults, 2 instead of 4 like in the Chitose class and Mizuho. Her armament was downgraded to three 14 cm/50 double mounts, but her diesel propulsion system was greatly enhanced compared to Mizuho, giving her more than twice the horse powers and allowing for a maximum speed of 28 knots. While she was launched in 1939 it took three more years before her formal completion because it was decided to modify her in order to carry 12 Type A midget submarines, like in the case of the mines this configuration halved her seaplane complement.Nisshin fst combat deployment was the Battle of Midway, where she was supposed to deploy her Type A midget submarines, together with Chiyoda, in order to reinforce the landing forces, but this never came to be. From 3 October 1942 she started doing runs, her high speed, large range and cranes capable of unloading heavy equipment like artillery pieces and tanks made her very valuable for this kind of missions (her half-sister Chitose was also part of the Tokyo Express for the same reasons). It was during one of such runs that Nisshin was sunk by American aircraft in the Bougainville Strait on 22 July 1943; she was transporting troops, tanks, artillery pieces, food and fuel for the troops fighting the Americans at Buin (Shortland islands) but her anchorage position was discovered by the Americans thanks to decrypted communications and an elaborately planned ambush was prepared for her. The first attack by B-17 (13:45) was successfully evaded with Nisshin reaching up to 34 knots during her manoeuvring, but the second wave (13:53) of dive bombers managed to hit her three times, on her second turret, on the forward end of the aircraft deck starting a fire and most importantly inside her hangar deck that was opened at the time in preparation of off-loading operations. As result of these hits her electric power was cut, speed more than halved and her rudder was jammed, still some countermeasures were taken in time and the rudder was recovered. Just after some more minutes the third wave of American aircrafts hit her again twice (13:59) striking the port sides amidships, tearing a large hole in the deck and blowing through the bottom. Nisshin kept moving but she started listing visibly to starboard and settling rapidly by the bow, one last 6th bomb hit her starboard side amidships and accelerated her listing. Nisshin's gunners showed remarkable courage, manning their guns to the very end, until they were washed away from their positions. At 14:05 Nisshin disappeared under the sea, Captain Ito, his XO Tanaka Eichu and Chief Engineer Cdr. Terada Torao went down with her, only seven officers and eighty men of her crew escaped and despite the best efforts of Nisshin's crew just 91 soldiers out of 630 on board survived, in total 1085 lives were lost; her accompanying destroyers already loaded with evacuated soldiers couldn't spare more than two hours in search of survivors. (Wikipedia)

Kamikawa Maru-class

Seaplane tenders Kamikawa Maru (1937–1943), Kiyokawa Maru (1941–1946), (1937–1944), Kunikawa Maru (1937–1945), 6,862 tonnes. Hirokawa Maru of the same class was converted to an auxiliary (anti-aircraft) cruiser instead of seaplane tender when it was impressed for Navy service.

(IJN Photos)

Kamikawa Maru (1937–1943).

(IJN Photo)

Kiyokawa Maru (1941–1946).

Akitshushima-class

(IJN Photo)

Seaplane tender Akitsushima (1942–1944), 4,725 tonnes.

Kamoi-class

(IJN Photo)

Seaplane tender Kamoi (1922-1947), 17,273 tonnes.

Notoro-class

(IJN Photo)

Seaplane tender Notoro (1934-1947)15,647 tonnes. Of 7 oilers in class, Notoro was converted to seaplane tender and Shiretoko to munition ship.

Mizuho-class

Seaplane tender Mizuho (1939-1942), 10,930 tonnes. Also served as a midget submarine carrier. The American submarine USS Drum torpedoed Mizuho at 23:03 hours on 1 May 1942 40 nautical miles (74 kilometres) off Omaezaki, Japan. She capsized and sank at 04:16 hours on 2 May 1942 with the loss of 101 lives. There were 472 survivors, of which 31 were wounded

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