Operation RY
Encyclopedia
Operation RY was the name of the Imperial Japanese
plan to invade and occupy Nauru
and Ocean islands in the south Pacific during the Pacific conflict
of World War II
. The operation was originally set to be executed in May 1942 immediately following Operation MO
and before Operation MI, which resulted in the Battle of Midway
. The primary reason for the operation was to exploit the islands' supplies of phosphate
. After a postponement due to interference by enemy forces, the operation was completed in August 1942.
n mandate control with the British Phosphate Commissioners (BPC) running the phosphate mining. The phosphate deposits were mined for making ammunition, explosives and fertilizers.
The German
auxiliary cruisers Orion
and Komet
sank five merchant ships and bombarded the island
causing damage to the phosphate mining, disrupting the allies production of phosphate. Following the raids the Australian Commonwealth Naval Board
requested that the British Admiralty agree to redeploy Australian naval units to meet the threat posed by raiders. HMAS Manoora
arrived off Ocean Island on 4 January 1941 and Australian and New Zealand
warships maintained a continual presence off the islands during the subsequent months and a naval company and two field guns were deployed to each island. The attacks also led to the introduction of convoys between Australia and New Zealand.
In late February 1942, as a Japanese invasion of Nauru and Ocean Island was feared, the Free French
destroyer
Triomphant departed the New Hebrides
to evacuate both Nauru and Ocean Island. The ship arrived on 23 February and completed the evacuation without serious incident.
Although Operation MO
was cancelled on 8 May 1942 immediately following the Battle of the Coral Sea
, the Imperial Japanese Navy
forces departed Rabaul
and Bougainville
on 11 May to execute the RY operation.
Shima Kiyohide departed Rabaul consisting of the cruiser Tatsuta, the minelayers Okinoshima
(flagship) and Tsugaru
and destroyers Uzuki
and Yuzuki
, covered by 5th Cruiser Division, under the command of Rear Admiral Takeo Takagi
, consisting of heavy cruisers Myoko
and Haguro
with the Destroyer Division 30 destroyers Ariake
, Mochizuki
, Shigure
and Shiratsuyu
. The invasion troops from the 6th Special Naval Landing Force
(SNLF) and Kashima SNLF were carried by the transports Kinryū Maru and Takahata Maru.
While steaming through driving rain off New Ireland
and west of Buka Island
, Okinoshima, which had been damaged by planes from Yorktown during the invasion of Tulagi on 4 May 1942, was torpedoed at 0452 by the United States Navy
submarine
USS S-42
(Commander Oliver G. Kirk) and severely damaged. The invasion force's escorts closed S-42 and depth charge
d the area until 1130, causing damage. The submarine left the area to return to base at Moreton Bay
, Brisbane
. Rear Admiral Shima transferred his flag to Yuzuki southwest of Buka Island
, Bougainville
. At 0640, Okinoshima capsized under tow by Mochizuki in St. George's Channel at 05°06′S 153°48′E.
While returning to Rabaul after being dispatched to assist repair work on Okinoshima, the repair ship Shoei Maru was torpedoed off Cape St George, New Ireland, by USS S-44
. She sank at 1440 at 04°51′S 152°54′E.
In spite of the loss of Okinoshima, the rest of the Japanese forces continued with the operation. As these forces were en route, however, a Japanese reconnaissance aircraft from Tulagi
sighted the United States Navy
aircraft carrier
s Enterprise
and Hornet
heading towards Nauru. The two US carriers, acting on intelligence taken from intercepted Japanese communications, had been sent to the area as a feint
to try to stop the Japanese operation.
The feint was successful. Fearing the threat posed by the US carriers to the RY forces, which did not have air cover, the Japanese cancelled the operation on 15 May and the naval forces returned to Rabaul.
, the destroyers Oite
, Yuzuki, Ariake, Yugure
and Yunagi
and the transport Hakozaki Maru.
The landing forces landed on Nauru on 29 August and Ocean Island on 30 August unopposed.
)
Empire of Japan
The Empire of Japan is the name of the state of Japan that existed from the Meiji Restoration on 3 January 1868 to the enactment of the post-World War II Constitution of...
plan to invade and occupy Nauru
Nauru
Nauru , officially the Republic of Nauru and formerly known as Pleasant Island, is an island country in Micronesia in the South Pacific. Its nearest neighbour is Banaba Island in Kiribati, to the east. Nauru is the world's smallest republic, covering just...
and Ocean islands in the south Pacific during the Pacific conflict
Pacific War
The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...
of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The operation was originally set to be executed in May 1942 immediately following Operation MO
Operation Mo
Operation Mo or the Port Moresby Operation was the name of the Japanese plan to take control of the Australian Territory of New Guinea during World War II as well as other locations in the South Pacific with the goal of isolating Australia and New Zealand from their ally the United States...
and before Operation MI, which resulted in the Battle of Midway
Battle of Midway
The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...
. The primary reason for the operation was to exploit the islands' supplies of phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
. After a postponement due to interference by enemy forces, the operation was completed in August 1942.
Background
Before and during World War II, Nauru and Ocean Island were isolated but fabulously rich with phosphate deposits. The islands were under AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n mandate control with the British Phosphate Commissioners (BPC) running the phosphate mining. The phosphate deposits were mined for making ammunition, explosives and fertilizers.
The German
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
auxiliary cruisers Orion
German auxiliary cruiser Orion
Orion was an auxiliary cruiser of the German navy which operated as a merchant raider during World War II. Built by Blohm & Voss in Hamburg in 1930/31 as the freighter Kurmark, she was requisitioned by the Kriegsmarine at the outbreak of World War II and converted into the auxiliary cruiser Orion,...
and Komet
German auxiliary cruiser Komet
Komet was an auxiliary cruiser of the German Kriegsmarine in the Second World War, intended for service as a commerce raider...
sank five merchant ships and bombarded the island
German attacks on Nauru
There were two German attacks on Nauru in December 1940. These attacks were conducted by auxiliary cruisers between 6 and 8 December and on the 27th of the month. The raiders sank five Allied merchant ships and inflicted serious damage on Nauru's economically important phosphate-loading...
causing damage to the phosphate mining, disrupting the allies production of phosphate. Following the raids the Australian Commonwealth Naval Board
Australian Commonwealth Naval Board
The Australian Commonwealth Naval Board was the governing authority over the Royal Australian Navy from its inception and through World Wars I and II. The board was established on 1 March 1911 and consisted of civilian members of the Australian government as well as naval flag officers....
requested that the British Admiralty agree to redeploy Australian naval units to meet the threat posed by raiders. HMAS Manoora
HMAS Manoora (1935)
HMAS Manoora was a motor vessel laid down for the Adelaide Steamship Company by Alex Stephen and Son at Govan in Scotland in July 1934, launched on 25 October 1935 and completed in 1935....
arrived off Ocean Island on 4 January 1941 and Australian and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
warships maintained a continual presence off the islands during the subsequent months and a naval company and two field guns were deployed to each island. The attacks also led to the introduction of convoys between Australia and New Zealand.
In late February 1942, as a Japanese invasion of Nauru and Ocean Island was feared, the Free French
Free French Forces
The Free French Forces were French partisans in World War II who decided to continue fighting against the forces of the Axis powers after the surrender of France and subsequent German occupation and, in the case of Vichy France, collaboration with the Germans.-Definition:In many sources, Free...
destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...
Triomphant departed the New Hebrides
New Hebrides
New Hebrides was the colonial name for an island group in the South Pacific that now forms the nation of Vanuatu. The New Hebrides were colonized by both the British and French in the 18th century shortly after Captain James Cook visited the islands...
to evacuate both Nauru and Ocean Island. The ship arrived on 23 February and completed the evacuation without serious incident.
Although Operation MO
Operation Mo
Operation Mo or the Port Moresby Operation was the name of the Japanese plan to take control of the Australian Territory of New Guinea during World War II as well as other locations in the South Pacific with the goal of isolating Australia and New Zealand from their ally the United States...
was cancelled on 8 May 1942 immediately following the Battle of the Coral Sea
Battle of the Coral Sea
The Battle of the Coral Sea, fought from 4–8 May 1942, was a major naval battle in the Pacific Theater of World War II between the Imperial Japanese Navy and Allied naval and air forces from the United States and Australia. The battle was the first fleet action in which aircraft carriers engaged...
, the Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...
forces departed Rabaul
Rabaul
Rabaul is a township in East New Britain province, Papua New Guinea. The town was the provincial capital and most important settlement in the province until it was destroyed in 1994 by falling ash of a volcanic eruption. During the eruption, ash was sent thousands of metres into the air and the...
and Bougainville
Bougainville Island
Bougainville Island is the main island of the Autonomous Region of Bougainville of Papua New Guinea. This region is also known as Bougainville Province or the North Solomons. The population of the province is 175,160 , which includes the adjacent island of Buka and assorted outlying islands...
on 11 May to execute the RY operation.
First invasion attempt
On 11 May 1942, the Imperial Japanese invasion force, under the command of Rear AdmiralRear Admiral
Rear admiral is a naval commissioned officer rank above that of a commodore and captain, and below that of a vice admiral. It is generally regarded as the lowest of the "admiral" ranks, which are also sometimes referred to as "flag officers" or "flag ranks"...
Shima Kiyohide departed Rabaul consisting of the cruiser Tatsuta, the minelayers Okinoshima
Japanese minelayer Okinoshima
was a large minelayer of the Imperial Japanese Navy, which was in service during the early stages of World War II. She was named after the Okinoshima Island in the Sea of Japan and the earlier...
(flagship) and Tsugaru
Japanese minelayer Tsugaru
was a large minelayer of the Imperial Japanese Navy that was in service during the early stages of World War II. She was named after the earlier , which in turn was named after Tsugaru Peninsula in northwest Aomori Prefecture of Japan...
and destroyers Uzuki
Japanese destroyer Uzuki (1925)
was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:...
and Yuzuki
Japanese destroyer Yuzuki
was the final of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War...
, covered by 5th Cruiser Division, under the command of Rear Admiral Takeo Takagi
Takeo Takagi
was an admiral in the Imperial Japanese Navy during World War II.-Biography:Takagi was a native of Iwaki city, Fukushima prefecture. He was a graduate of the 39th class of the Imperial Japanese Naval Academy, ranking 17th of 148 cadets in 1911...
, consisting of heavy cruisers Myoko
Japanese cruiser Myoko
was the name-ship of the four-member of heavy cruisers of the Imperial Japanese Navy — the other ships of the class being the Nachi, Ashigara, and Haguro....
and Haguro
Japanese cruiser Haguro
|-External reference links: -External links:**...
with the Destroyer Division 30 destroyers Ariake
Japanese destroyer Ariake
was the fifth of six destroyers, built for the Imperial Japanese Navy under the Circle One Program . Three were laid down in JFY 1931 and the next three in JFY 1933...
, Mochizuki
Japanese destroyer Mochizuki
was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War...
, Shigure
Japanese destroyer Shigure
was the second of ten s, and the first to be built for the Imperial Japanese Navy under the Circle One Program . Along with the destroyer , she developed a reputation within the Imperial Japanese Navy for being "lucky" or "unsinkable", emerging as the sole surviving Japanese warship from numerous...
and Shiratsuyu
Japanese destroyer Shiratsuyu
was the lead ship of ten destroyers, and first of six to be built for the Imperial Japanese Navy under the Circle One Program .-History:...
. The invasion troops from the 6th Special Naval Landing Force
Japanese Special Naval Landing Forces
The Japanese Special Naval Landing Forces , were the marine troops of the Imperial Japanese Navy and were a part of the IJN Land Forces...
(SNLF) and Kashima SNLF were carried by the transports Kinryū Maru and Takahata Maru.
While steaming through driving rain off New Ireland
New Ireland (island)
New Ireland is a large island in Papua New Guinea, approximately 7,404 km² in area. It is the largest island of the New Ireland Province, lying northeast of the island of New Britain. Both islands are part of the Bismarck Archipelago, named after Otto von Bismarck, and they are separated by...
and west of Buka Island
Buka Island
Buka Island is the second largest island in the Papua New Guinean province of Bougainville.- History :Buka was first occupied by humans in paleolithic times, some 30,000 years ago...
, Okinoshima, which had been damaged by planes from Yorktown during the invasion of Tulagi on 4 May 1942, was torpedoed at 0452 by the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
USS S-42
USS S-42 (SS-153)
USS S-42 was the first member in the third group of S-class submarines of the United States Navy. Her keel was laid down on 16 December 1920 by the Bethlehem Shipbuilding Corporation in Quincy, Massachusetts. She was launched on 30 April 1923 sponsored by Mrs. Henry A...
(Commander Oliver G. Kirk) and severely damaged. The invasion force's escorts closed S-42 and depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
d the area until 1130, causing damage. The submarine left the area to return to base at Moreton Bay
Moreton Bay
Moreton Bay is a bay on the eastern coast of Australia 45 km from Brisbane, Queensland. It is one of Queensland's most important coastal resources...
, Brisbane
Brisbane
Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...
. Rear Admiral Shima transferred his flag to Yuzuki southwest of Buka Island
Buka Island
Buka Island is the second largest island in the Papua New Guinean province of Bougainville.- History :Buka was first occupied by humans in paleolithic times, some 30,000 years ago...
, Bougainville
Bougainville Island
Bougainville Island is the main island of the Autonomous Region of Bougainville of Papua New Guinea. This region is also known as Bougainville Province or the North Solomons. The population of the province is 175,160 , which includes the adjacent island of Buka and assorted outlying islands...
. At 0640, Okinoshima capsized under tow by Mochizuki in St. George's Channel at 05°06′S 153°48′E.
While returning to Rabaul after being dispatched to assist repair work on Okinoshima, the repair ship Shoei Maru was torpedoed off Cape St George, New Ireland, by USS S-44
USS S-44 (SS-155)
USS S-44 was a third-group S-class submarine of the United States Navy.Her keel was laid down on 19 February 1921 by the Bethlehem Shipbuilding Corporation in Quincy, Massachusetts. She was launched on 27 October 1923 sponsored by Mrs. H.E. Grieshaber, and was commissioned on 16 February 1925...
. She sank at 1440 at 04°51′S 152°54′E.
In spite of the loss of Okinoshima, the rest of the Japanese forces continued with the operation. As these forces were en route, however, a Japanese reconnaissance aircraft from Tulagi
Tulagi
Tulagi, less commonly Tulaghi, is a small island in the Solomon Islands, just off the south coast of Florida Island. The town of the same name on the island Tulagi, less commonly Tulaghi, is a small island (5.5 km by 1 km) in the Solomon Islands, just off the south coast of Florida...
sighted the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
s Enterprise
USS Enterprise (CV-6)
USS Enterprise , colloquially referred to as the "Big E," was the sixth aircraft carrier of the United States Navy and the seventh U.S. Navy ship to bear the name. Launched in 1936, she was a ship of the Yorktown class, and one of only three American carriers commissioned prior to World War II to...
and Hornet
USS Hornet (CV-8)
USS Hornet CV-8, the seventh ship to carry the name Hornet, was a of the United States Navy. During World War II in the Pacific Theater, she launched the Doolittle Raid on Tokyo and participated in the Battle of Midway and the Buin-Faisi-Tonolai Raid...
heading towards Nauru. The two US carriers, acting on intelligence taken from intercepted Japanese communications, had been sent to the area as a feint
Feint
Feint is a French term that entered English from the discipline of fencing. Feints are maneuvers designed to distract or mislead, done by giving the impression that a certain maneuver will take place, while in fact another, or even none, will...
to try to stop the Japanese operation.
The feint was successful. Fearing the threat posed by the US carriers to the RY forces, which did not have air cover, the Japanese cancelled the operation on 15 May and the naval forces returned to Rabaul.
Second Invasion Attempt
A second invasion force departed Truk on 26 August 1942, consisting of the cruiser YubariJapanese cruiser Yubari
was a light cruiser built between 1922 and 1923 for the Imperial Japanese Navy. She fought in World War II and was sunk by the US Navy.-Design:The ship originated as an experimental scout cruiser, which would have the combat potential of the standard Japanese light cruisers on a much lighter ship....
, the destroyers Oite
Japanese destroyer Oite (1924)
was the sixth vessel of the Kamikaze-class destroyers built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:Construction of the...
, Yuzuki, Ariake, Yugure
Japanese destroyer Yugure
was the sixth and last destroyer, built for the Imperial Japanese Navy under the Circle One Program . Three were laid down in JFY 1931 and the next three in JFY 1933...
and Yunagi
Japanese destroyer Yunagi (1924)
was the ninth and final vessel of the Kamikaze-class destroyers built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:Construction...
and the transport Hakozaki Maru.
The landing forces landed on Nauru on 29 August and Ocean Island on 30 August unopposed.
Base Development
Japanese forces occupied the two islands until the end of the war, but became increasingly isolated as the war progressed.Web
(translation of excerpts from the Senshi SōshōSenshi Sōshō
The , also called the , is a military history of Imperial Japan's involvement in the Pacific War from 1937 to 1945. The history was compiled and is currently kept by the War History Office of Japan's Ministry of Defense in Tokyo, Japan...
)