SS Kokai Maru (1939)

Kokai Maru was a Japanese cargo steamship. She was built in Hokkaido in 1939, and sunk in the Pacific Ocean by United States Army Air Force aircraft in 1944.

History
Japan
Name	Kokai Maru
Owner	Simatani Kisen Kabushiki Kaisha
Operator	1941: Imperial Japanese Navy
Port of registry	Kobe
Builder	Hakodate Dock Company, Hakodate
Completed	1939
Identification	call sign JOSJ
Fate	Sunk by air attack, 21 February 1944
General characteristics
Type	cargo ship
Tonnage	3,871 GRT, 2,286 NRT
Length	340.4 ft (103.8 m)
Beam	48.2 ft (14.7 m)
Depth	26.2 ft (8.0 m)
Decks	2
Installed power	232 NHP
Propulsion	triple expansion engine driving steam compressor
Sensors and processing systems	wireless direction finding, echo sounding device

Building

The Hakodate Dock Company built Kokai Maru, completing her in 1939. Her registered length was 340.4 ft (103.8 m), her beam was 48.2 ft (14.7 m) and her depth was 26.2 ft (8.0 m). Her tonnages were 3,871 GRT and 2,286 NRT.^[1]

She had a single screw, driven by a three-cylinder triple expansion engine. Exhaust steam from her engine's low-pressure cylinder drove a compressor, which re-pressurised steam exhausted from the high-pressure cylinder before it entered the intermediate-pressure cylinder. Compressing the steam also increased its temperature, counter-acting steam's tendency to condense as it expands.^[2]

Kokai Maru's owner was Simatani Kisen Kabushiki Kaisha, who registered her at Kobe. Her wireless telegraph call sign was JOSJ.^[1]

War service and loss

In 1941 the Imperial Japanese Navy requisitioned Kokai Maru.^{[citation needed]} On 10 March 1942, during the Japanese invasion of Salamaua–Lae, US Navy SBD Dauntless aircraft from the carriers USS Lexington and Yorktown damaged her off Lae, New Guinea.^{[citation needed]}

On 21 February 1944 Kokai Maru was part of a convoy off New Hanover Island. USAAF B-25 Mitchell^[3] aircraft bombed her, and she sank at position 02°16′S 150°12′E.^[4] Fifty people aboard the ship were killed.^[3]