''Kokai Maru'' was a

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

cargo In transportation, cargo refers to goods transported by land, water or air, while freight refers to its conveyance. In economics, freight refers to goods transported at a freight rate for commercial gain. The term cargo is also used in cas ...

steamship A steamship, often referred to as a steamer, is a type of steam-powered vessel, typically ocean-faring and seaworthy, that is propelled by one or more steam engines that typically move (turn) propellers or paddlewheels. The first steamships ...

. She was built in

Hokkaido is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...

in 1939, and sunk in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

United States Army Air Force The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

aircraft in 1944.

Building

The Hakodate Dock Company built ''Kokai Maru'', completing her in 1939. Her registered length was , her

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Radio beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially lo ...

was and her depth was . Her

tonnage Tonnage is a measure of the capacity of a ship, and is commonly used to assess fees on commercial shipping. The term derives from the taxation paid on '' tuns'' or casks of wine. In modern maritime usage, "tonnage" specifically refers to a cal ...

s were and . She had a single

screw A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the screw head, head. The most common uses of screws are to hold objects together and there are many forms for a variety ...

, driven by a three-cylinder

triple expansion engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be transf ...

. Exhaust steam from her engine's low-pressure cylinder drove a

compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Many compressors can be staged, that is, the gas is compressed several times in steps o ...

, 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. ''Kokai Maru''s owner was Simatani Kisen Kabushiki Kaisha, who

registered Registered may refer to: * Registered mail, letters, packets or other postal documents considered valuable and in need of a chain of custody * Registered trademark symbol, symbol ® that provides notice that the preceding is a trademark or service ...

her at

Kobe Kobe ( ; , ), officially , is the capital city of Hyōgo Prefecture, Japan. With a population of around 1.5 million, Kobe is Japan's List of Japanese cities by population, seventh-largest city and the third-largest port city after Port of Toky ...

. Her

wireless telegraph Wireless telegraphy or radiotelegraphy is the transmission of text messages by radio waves, analogous to electrical telegraphy using cables. Before about 1910, the term ''wireless telegraphy'' was also used for other experimental technologies fo ...

call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally as ...

was JOSJ.

War service and loss

In 1941 the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, Potsdam Declaration, when it was dissolved followin ...

requisitioned ''Kokai Maru''. On 10 March 1942, during the Japanese

invasion of Salamaua–Lae The invasion of Salamaua–Lae (8–13 March 1942), called ''Operation SR'' by the Japanese, was an operation by Imperial Japanese forces to occupy the Salamaua–Lae area in the Territory of New Guinea during the Pacific campaign of World War ...

, US Navy

SBD Dauntless The Douglas SBD Dauntless is a World War II American naval scout plane and dive bomber that was manufactured by Douglas Aircraft from 1940 through 1944. The SBD ("Scout Bomber Douglas") was the United States Navy's main carrier-based scout/dive ...

aircraft from the carriers and damaged her off

Lae Lae (, , later ) is the capital of Morobe Province and is the second-largest city in Papua New Guinea. It is located near the delta of the Markham River on the northern coast of Huon Gulf. It is at the start of the Highlands Highway, which is ...

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

. On 21 February 1944 ''Kokai Maru'' was part of a convoy off

New Hanover Island New Hanover Island, (), also called Lavongai, is a large volcanic island in the New Ireland Province of Papua New Guinea. This region is part of the Bismarck Archipelago and lies at . Measuring some , it had a population of 5,000 in 1960, which ...

USAAF The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

B-25 Mitchell The North American B-25 Mitchell is an American medium bomber that was introduced in 1941 and named in honor of Brigadier General William "Billy" Mitchell, a pioneer of U.S. military aviation. Used by many Allied air forces, the B-25 served ...

aircraft bombed her, and she sank at position . Fifty people aboard the ship were killed.

References

Bibliography

* * {{DEFAULTSORT:Kokai Maru (1939) 1939 ships Maritime incidents in February 1944 Ships sunk by US aircraft Shipwrecks of Papua New Guinea Steamships of Japan World War II merchant ships of Japan World War II shipwrecks in the Pacific Ocean