Kawasaki-type oiler

Kyokutō Maru (left), Kokuyō Maru, Nippon Maru and Shinkoku Maru (right) on 1 December 1941
Class overview
Name:	Kawasaki-type oilers Tōa Maru class Tatekawa Maru class Nisshō Maru class Kuroshio Maru class Akatsuki Maru class
Builders:	Kawasaki Shipbuilding Corporation Harima Zōsen Corporation Mitsubishi Heavy Industries
Operators:	Asano Bussan Chūgai Line Iino Lines Japan Line Kawasaki Line Kōbe Pier Kokuyō Line Mitsu Line Nippon Suisan Nittō Mining Nihon Tanker Yamashita Line Imperial Japanese Navy Imperial Japanese Army
Preceded by:	Fujisan Maru
Succeeded by:	Type 1TL wartime standard ship
Cost:	Tōa Maru: 2,600,000 JPY
Built:	1933 – 1943
In commission:	1934 – 1964
Planned:	17
Completed:	17
Lost:	17
Retired:	(1)
General characteristics
Type:	Oiler
Displacement:	approx. 10,000 long tons (10,160 t) gross
Length:	around 152 m (498 ft 8 in) Lpp
Beam:	around 20.0 m (65 ft 7 in)
Draught:	around 11.4 m (37 ft 5 in)
Propulsion:	1 × diesel, single shaft, around 10,000 bhp or boiler and turbine
Speed:	around 20 knots (23 mph; 37 km/h)
Armament:	(example) Shinkoku Maru, 1941 2 × 150 mm (5.9 in) naval guns 2 × 76.2 mm (3.00 in) AA guns 2 × 7.7 mm machine guns Gen'yo Maru, 1941 2 × 76.2 mm (3.00 in) AA guns 2 × Type 96 25 mm AA guns Itsukushima Maru, 1944 1 × 120 mm (4.7 in) naval gun 16 × Type 96 25 mm AA guns 18 × depth charges 1 × Type 93 hydrophone Kyokutō Maru, 1944 2 × 120 mm (4.7 in) AA guns 16 × Type 96 25 mm AA guns Nichiei Maru, 1944 2 × 120 mm (4.7 in) AA guns 16 × Type 96 25 mm AA guns 12 × depth charges 1 × Type 93 hydrophone

The Kawasaki-type oiler (川崎型油槽船,, Kawasaki-gata Yusōsen) was a type of oiler of Japan, serving during the 1930s and World War II. They do not have official class name.^[1] Therefore, this article uses common class names. And, this type has some variants. This article handles them collectively.

Background

Iino Lines Fujisan Maru

• The London Naval Treaty forced shrinkage of a budget to the Imperial Japanese Navy (IJN). And it meant cooling of the Japanese shipbuilding industry worlds. The Great Depression more accelerated it. The IJN wanted to update their Notoro-class oilers and Ondo-class oilers, because these oilers were not able to chase the aircraft carrier.
• In 1929, the IJN decided their combat ship (battleship, aircraft carrier, cruiser, destroyer, submarine and torpedo boat) fuel only to heavy crude oil. And, the IJN was paid a grant to newly build large/high-speed tankers.
• In 1931, two marine transportation companies built the tankers which the IJN wanted. One was the 9,900 tons/17.5 knot Teiyō Maru, the other the 9,500 tons/18.8 knots Fujisan Maru.
• The IJN was satisfied by Fujisan Maru. The IJN recommended building of the improved Fujisan Maru class tanker.

Construction

• In 1932, the Iino Kaiun Kaisha (飯野海運,, Iino Lines) ordered two tankers Tōa Maru and Kyokutō Maru to the Kawasaki Shipbuilding Corporation. In total 17 tankers were built with the same basic drawings, until 1943.
• All sisters participated to World War II. However, they were not able to survive at all.

Ships in classes

Tōa Maru class

• First production model of the Kawasaki-type tankers. Their success gave courage to other steamship companies.

Tatekawa Maru class

• Second production model. They were built by the same as Tōa Maru class drawings. However, their details were different by steamship company which they placed an order for (example: Nippon Maru removed one dry cargo hold). Narrow sense of the Kawasaki-type tanker was until the Kyūei Maru. Kyūei Maru was equipped surplus stocks of the Argentina Maru machinery.

Nisshō Maru class

• One of the variant of the Kawasaki-type tankers. The Mitsubishi used many curves to reduce her air friction strength.

Kuroshio Maru class

• One of the variant of the Kawasaki-type tankers. Kuroshio Maru was equipped with a La-Mont boiler. Her design was used for the Type 1TL wartime standard ship.

Akatsuki Maru class

• One of the variant of the Kawasaki-type tankers. The Harima Zōsen used the Sulzer diesel.

Service

Characteristics

Photos

• 

  Iino Lines Tōa Maru

• 

  Iino Lines Kyokutō Maru

• 

  Iino Lines Tōhō Maru

• 

  Japan Line Akatsuki Maru

• 

  IJN Tōei Maru in February 1941

• 

  IJN Shinkoku Maru in September 1941

• 

  IJN Kokuyō Maru on 9 December 1941

• 

  IJN Nippon Maru in June 1943

• 

  IJN Kyokutō Maru and carrier Hiryū in May or June 1942

• 

  IJN Kokuyō Maru and cruiser Tone on 17 June 1944

Footnotes

1. ↑ Iino Lines called Tōa Maru class, Kawasaki Line called Tatekawa Maru class, Nittō Mining called Nichiei Maru class, and more..
2. ↑ Kyokutō Maru renamed Kanji name 極東丸 to 旭東丸 on 5 July 1938.
3. ↑ In the IJN official document, Ōyashima Maru appears once. However, their later official document used Kyokutō Maru.
4. ↑ Akatsuki Maru was not registered to naval ship list.
5. 1 2 Shutei Kyokai Shuppanbu, p. 69
6. ↑ Shutei Kyokai Shuppanbu, p. 86. Original book was described 644,590 cubic meters oil. Perhaps it is a misprint.
7. ↑ Shutei Kyokai Shuppanbu, p. 86

Bibliography

• Tashirō Iwashige, The visual guide of Japanese wartime merchant marine, "Dainippon Kaiga".  (Japan), May 2009
• Monthly Armor Modelling special issue, "Navy Yard Vol.8 Tora! Tora! Tora!", Dainippon Kaiga (Japan), July 2008
• Kunio Matsumoto, The Lives of the Japanese Tankers, "Seizando-Shoten".  (Japan), January 1995
• Shinshichirō Komamiya, The Wartime Convoy Histories, "Shuppan Kyōdōsha".  (Japan), October 1987
• The Maru Special, Japanese Naval Vessels No.53, "Japanese support vessels", "Ushio Shobō".  (Japan), July 1981
• 60 Years of the Iino Lines, "Iino Lines".  (Japan), June 1959
• 50 year History of Harima Zōsen, Harima Zōsen Corporation, November 1960
• Photo Gallery of the Japanese merchant ships, Shutei Kyokai Shuppanbu (Japan), August 1950
• Instruction sheets from 1/700 scale resin model kit "AX-02 Nippon Maru", "AX-03 Tōei Maru" and "AX-05 Shinkoku Maru", Kikakushitu Kuroshio (personal resin kit manufacture)