Ko-hyoteki class submarine - AbsoluteAstronomy.com

The class was a class of Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese midget submarine

Midget submarine

A midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to 6 or 8, with little or no on-board living accommodation...

s (Ko-hyoteki) used during 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...

. They had hull numbers but no names. For simplicity, they are most often referred to by the hull number of the mother submarine. Thus, the midget carried by イ-16 was known as I-16's boat, or "I-16tou."

This class was followed by: , , and , the last one better known as .

History

Fifty were built. The "A Target" name was assigned as a ruse: If their design was prematurely discovered by Japan's foes, the Japanese Navy could insist that the vessels were battle practice targets. They were also called or and other slang names.

The first two, No.1 and No.2, were used only in testing. They did not have conning towers, which were added to the later boats for stability underwater.

No.19
HA. 19 (Japanese Midget Submarine)
The HA. 19 is a historic Imperial Japanese Navy Type A Ko-hyoteki class midget submarine that was part of the Japanese attack on Pearl Harbor on December 7, 1941. Orders for this submarine were to enter Pearl Harbor...

was launched by at Pearl Harbor

Attack on Pearl Harbor

The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...

. Most of the other fifty are unaccounted for, although three were captured in Sydney (Australia), and others in Guam, Guadalcanal, and Kiska Island, accounting for some of the other hull numbers.

The submarines were each armed with two 450 mm torpedoes in muzzle-loading tubes one above the other on the port bow. In the Pearl Harbor attack, the specially designed Type 97 torpedo

Type 97 torpedo

The Type 97 was a diameter torpedo used by the Imperial Japanese Navy during World War II. Intended for use with Japan's Ko-hyoteki class midget submarines, the torpedo was based on the Type 93 "Long Lance" used by larger Japanese submarines, but redesigned to meet the smaller physical dimensions...

was used, but problems with the oxygen flasks meant that all later attacks used a different torpedo. Some have stated that a version of the Type 91 torpedo

Type 91 torpedo

The Type 91 was an aerial torpedo of the Imperial Japanese Navy which was designed to be launched from an aircraft. It was used in the naval battles of carrier task forces in World War II.The Type 91 aerial torpedo rev.2 won the admiration of the world...

, designed for aircraft launching, was used, but other reports indicate that the Type 97 torpedo was modified to the Type 98, otherwise known as the Type 97 special. There is no definitive information that the Type 91 was used. The Type 98 was later supplanted by the Type 02 torpedo. There was also a demolition charge which it has been suggested was large enough to enable the submarine to be used as a suicide weapon

Suicide weapon

A suicide weapon is a weapon that is specially designed for a suicide attack. It is typically based on explosives.In a wider sense, a suicide weapon is any weapon used in a suicide attack, and any object used as such, for example an aircraft.Examples:...

, but there is no evidence that it was ever used as one.

Each submarine had a crew of two men. A junior officer conned the boat while a petty officer manipulated valves and moved ballast to control trim and diving.

Pearl Harbor attack

Five of these boats participated in the Pearl Harbor attack, with two actually making it into the harbor. Of the five used at Pearl Harbor, No.19 was captured where it grounded on the east side of Oahu. During World War II, No.19 was put on tour across the United States to help sell War Bonds. Now a U.S. National Historic Landmark

National Historic Landmark

A National Historic Landmark is a building, site, structure, object, or district, that is officially recognized by the United States government for its historical significance...

, No.19 is an exhibit at the National Museum of the Pacific War in Fredericksburg, Texas

Fredericksburg, Texas

Fredericksburg is the seat of Gillespie County, in the U.S. state of Texas. As of the 2010 Census estimate, the city had a population of 10, 530...

.
A second Pearl Harbor midget submarine, No.18, was located by U.S. Navy divers off Keehi Lagoon east of the Pearl Harbor entrance on 13 June 1960. The submarine had been damaged by a depth charge attack and abandoned by its crew before it could fire its torpedoes. This submarine was restored and placed on display at the Imperial Japanese Naval Academy

Imperial Japanese Naval Academy

The was a school established to train officers for the Imperial Japanese Navy. It originally located in Nagasaki, moved to Yokohama in 1866, and was relocated to Tsukiji, Tokyo in 1869. It moved to Etajima, Hiroshima in 1888...

on 15 March 1962.

The midget submarine attacked by at 6:37 a.m. on 7 December was located in 400 meters (1,312 feet) of water five miles outside Pearl Harbor by a University of Hawaii

University of Hawaii

The University of Hawaii System, formally the University of Hawaii and popularly known as UH, is a public, co-educational college and university system that confers associate, bachelor, master, and doctoral degrees through three university campuses, seven community college campuses, an employment...

research submersible on 28 August 2002.

A fourth submarine, No.22, entered the harbor and fired its torpedoes at and . Both of those torpedoes missed and are believed to have hit a dock at Pearl City and the shore of Ford Island

Ford Island

Ford Island is located in the middle of Pearl Harbor, Hawaii. It is connected to the main island by the Ford Island Bridge. Before the bridge was built, Ford Island could only be reached by a ferry boat which ran at hourly intervals for cars and foot passengers. The island houses several naval...

. This submarine was sunk by Monaghan at 8:43 a.m. on 7 December and later recovered and used as fill during construction of a new landside pier at the Pearl Harbor submarine base. All of the crew's remains were still in the submarine when it was entombed.

In 2009, a research team assembled by PBS

Public Broadcasting Service

The Public Broadcasting Service is an American non-profit public broadcasting television network with 354 member TV stations in the United States which hold collective ownership. Its headquarters is in Arlington, Virginia....

Nova
Nova
A nova is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the surface of a white dwarf star, which ignites and starts nuclear fusion in a runaway manner...

positively identified the remains of a midget sub found outside the Pearl Harbor entrance as being the last of the 5 Ko-Hyoteki that participated in the December 7, 1941, attack. It was discovered in salvage from the wreckage of the West Loch Disaster

West Loch Disaster

The West Loch Disaster was a previously secret American World War II maritime accident which led to the deaths of 163 men at the U.S. naval base of Pearl Harbor in Hawaii on 21 May 1944...

of 1944, dumped three miles south of Pearl Harbor. Secret war records show that submarine crews had been ordered to scuttle their subs after the attack and provisions were made to recover stranded crews. It is believed the fifth sub successfully entered Pearl, fired on Battleship Row, and escaped to the relative quiet of neighbouring West Loch, where it was scuttled by the crew. When a series of explosions sank an amphibious fleet being assembled in the Loch in 1944, the remains of the sub were collected and dumped in the subsequent salvage operation, which was kept classified as secret until 1960. The torpedo tubes in the bow section were empty, indicating that the fifth midget had fired its torpedoes prior to being scuttled. A photograph taken from a Japanese plane during the Pearl Harbor attack appears to show a midget submarine inside the harbor firing torpedoes at Battleship Row

Battleship Row

Battleship Row was the grouping of eight US battleships in port at Pearl Harbor, Hawaii, when the Japanese attacked on December 7, 1941. These ships bore the brunt of the Japanese assault. They were moored next to Ford Island when the attack commenced. The ships were , , , , , , , and...

. This new evidence suggests that the capsizing of the may have been accelerated by a torpedo hit from a submarine-launched torpedo, the warhead of which was roughly twice the power of that carried by the air-dropped torpedoes. A war time report from Admiral Nimitz confirmed the recovery of dud torpedoes of the type employed by the midget submarines. This discovery is covered in PBS

Public Broadcasting Service

Japanese midget submarine attacks on Sydney

On the night of 29 May 1942, five large Japan

Japan

ese submarines positioned themselves 56 kilometres north-east of Sydney Heads

Sydney Heads

Sydney Heads , is the entrance to Port Jackson in Sydney, New South Wales, Australia.North Head and Quarantine Head are to the north, South Head and Dunbar Head are to the south. Middle Head, Georges Head and Chowder Head are to the west and within the bay...

. At 3 a.m. the next day one of the submarines launched a reconnaissance aircraft. After circling Sydney Harbour the aircraft returned to its submarine, reporting the presence of 'battleships and cruisers' moored in the harbour. The flotilla

Flotilla

A flotilla , or naval flotilla, is a formation of small warships that may be part of a larger fleet. A flotilla is usually composed of a homogeneous group of the same class of warship, such as frigates, destroyers, torpedo boats, submarines, gunboats, or minesweepers...

's commanding officer decided to attack the harbour with midget submarines the next night. The next day the five submarines approached to within 11 kilometres of Sydney Heads, and at about 4:30 p.m. they released three midget submarines, which then began their approach to Sydney Harbour.

The outer-harbour defences detected the entry of the first midget submarine at about 8 p.m., but it was not identified until it became entangled in an anti-torpedo net that was suspended between George's Head and Green Point. Before HMAS Yarroma was able to open fire, the submarine's two crew members destroyed their vessel with demolition charges and killed themselves.

The second submarine entered the harbour at about 9.48 p.m. and headed west towards the Sydney Harbour Bridge

Sydney Harbour Bridge

The Sydney Harbour Bridge is a steel through arch bridge across Sydney Harbour that carries rail, vehicular, bicycle and pedestrian traffic between the Sydney central business district and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic...

, causing a general alarm to be issued by the Naval Officer in Charge, Sydney. About 200 metres from Garden Island

Garden Island, New South Wales

Garden Island is an inner-city locality of Sydney, in the state of New South Wales, Australia. It is located to the north-east of the Sydney central business district, north of the suburb of Potts Point....

the submarine was fired on by the heavy cruiser . The submarine then fired its two torpedoes at the cruiser. One torpedo ran ashore on Garden Island, but failed to explode. The other passed under the Dutch submarine K9 and struck the harbour bed beneath the depot ship HMAS Kuttabul

HMAS Kuttabul (ship)

HMAS Kuttabul was a Royal Australian Navy depot ship, and former Sydney harbour ferry. During the Japanese midget submarine attack on Sydney Harbour on 31 May 1942, Kuttabul was torpedoed and sunk, with 21 Commonwealth naval personnel aboard....

where it exploded, killing 21 sailors (19 Royal Australian Navy

Royal Australian Navy

The Royal Australian Navy is the naval branch of the Australian Defence Force. Following the Federation of Australia in 1901, the ships and resources of the separate colonial navies were integrated into a national force: the Commonwealth Naval Forces...

and 2 Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

). The submarine then slipped out of the harbour, its mission complete, and disappeared. Its wreck was located, about 30 km north of the harbour and 5 km to seaward, in November 2006. It is now protected as a war grave.

The third submarine was sighted by HMAS Yandra at the entrance to the harbour and was depth-charged. Some four hours later, having recovered, it entered the harbour, but it was subsequently attacked with 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...

s and sunk in Taylor Bay by vessels of the Royal Australian Navy. Both members of the submarine's crew committed suicide.

The two submarines that were recovered were identical, and their remains were used to reconstruct a complete submarine, which toured New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

, Victoria

Victoria (Australia)

Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....

and South Australia

South Australia

South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

before being delivered to the Australian War Memorial

Australian War Memorial

The Australian War Memorial is Australia's national memorial to the members of all its armed forces and supporting organisations who have died or participated in the wars of the Commonwealth of Australia...

in Canberra

Canberra

Canberra is the capital city of Australia. With a population of over 345,000, it is Australia's largest inland city and the eighth-largest city overall. The city is located at the northern end of the Australian Capital Territory , south-west of Sydney, and north-east of Melbourne...

in 1943, where it remains on display.

Japanese midget submarine attacks on Madagascar

On the 29 May 1942, the Japan

Japan

ese 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...

s I-10, I-16 and I-20 arrived on Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

. I-10's reconnaissance plane spotted Revenge-class

Revenge class battleship

The Revenge class battleships were five battleships of the Royal Navy, ordered as World War I loomed on the horizon, and launched in 1914–1916...

battleship HMS Ramillies
HMS Ramillies (07)
HMS Ramillies was a Revenge-class battleship of the Royal Navy, named after the Battle of Ramillies. The ship is notable for having served in both the First and Second World Wars...

at anchor in Diego Suarez harbor

Harbor

A harbor or harbour , or haven, is a place where ships, boats, and barges can seek shelter from stormy weather, or else are stored for future use. Harbors can be natural or artificial...

but the plane was spotted and Ramillies changed her berth. I-20 and I-16 launched two midget submarines, one of which managed to enter the harbor and fired two torpedoes while under depth charge attack from two corvette

Corvette

A corvette is a small, maneuverable, lightly armed warship, originally smaller than a frigate and larger than a coastal patrol craft or fast attack craft , although many recent designs resemble frigates in size and role...

s. One torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

seriously damaged Ramillies, while the second sank the 6,993 ton oil tanker

Oil tanker

An oil tanker, also known as a petroleum tanker, is a merchant ship designed for the bulk transport of oil. There are two basic types of oil tankers: the crude tanker and the product tanker. Crude tankers move large quantities of unrefined crude oil from its point of extraction to refineries...

British Loyalty (later refloated). Ramillies was later repaired in Durban

Durban

Durban is the largest city in the South African province of KwaZulu-Natal and the third largest city in South Africa. It forms part of the eThekwini metropolitan municipality. Durban is famous for being the busiest port in South Africa. It is also seen as one of the major centres of tourism...

and Plymouth

Plymouth

Plymouth is a city and unitary authority area on the coast of Devon, England, about south-west of London. It is built between the mouths of the rivers Plym to the east and Tamar to the west, where they join Plymouth Sound...

.

The crew of one of the submarines, Lieutenant

Lieutenant

A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...

Saburo Akieda and Petty Officer

Petty Officer

A petty officer is a non-commissioned officer in many navies and is given the NATO rank denotion OR-6. They are equal in rank to sergeant, British Army and Royal Air Force. A Petty Officer is superior in rank to Leading Rate and subordinate to Chief Petty Officer, in the case of the British Armed...

Masami Takemoto, beached their submarine (M-20b) at Nosy Antalikely and moved inland towards their pick-up point near Cape Amber. They were informed upon when they bought food at a village and both were killed in a firefight with Royal Marines

Royal Marines

The Corps of Her Majesty's Royal Marines, commonly just referred to as the Royal Marines , are the marine corps and amphibious infantry of the United Kingdom and, along with the Royal Navy and Royal Fleet Auxiliary, form the Naval Service...

three days later. The second midget submarine was lost at sea and the body of one of its crew was found washed ashore a day later.

Characteristics

Type		*First prototype*	*Second prototype (Prod. No.1 to No.2)*	*Type A (Prod. No.3 to No.53)*	*Type B (Prod. No.49 to No.53)*	*Type C (Prod. No.54 to No.100)*
Displacement (Submerged)		41.525 long tons (42 t)	44.15 long tons (45 t)	46 long tons (47 t)	47 long tons (48 t)	49.09 long tons (50 t)
Length (overall)		23.3 metre	23.9 metre	23.9 metre	24.9 metre	24.9 metre
Beam		1.824 metre	1.85 metre	1.85 metre	1.85 metre	1.88 metre
Draft		3.074 metre	3.1 metre	3.4 metre	3.4 metre	3.43 metre
Draught		1.854 metre	1.88 metre	1.88 metre	1.85 metre	1.88 metre
Power plant and shaft		224 × Type Toku-B rechargeable batteries, electric motor (600 bhp), single shaft, contra-rotating propellers	224 × Type Toku-D rechargeable batteries, electric motor (600 bhp), single shaft, contra-rotating propellers	224 × Type Toku-D rechargeable batteries, electric motor (600 bhp), single shaft, contra-rotating propellers	224 × Type Toku-D rechargeable batteries, electric motor (600 bhp), 1 × electric generator (40 bhp), single shaft, contra-rotating propellers	208 × Type Toku-D rechargeable batteries, electric motor (600 bhp), 1 × electric generator (40 bhp), single shaft, contra-rotating propellers
Speed	Surfaced	25 knots (49 km/h)	25 knots (49 km/h)	19 knots (37.2 km/h)	19 knots (37.2 km/h)	18.5 knots (36.3 km/h)
Speed	Submerged	no data	no data	no data	6 knots (11.8 km/h)	6 knots (11.8 km/h)
Range	Surfaced	no data	no data	no data	500 nmi (926 km) at 6 knots (11.8 km/h)	500 nmi (926 km) at 6 knots (11.8 km/h)
Range	Submerged	no data	no data	15.8 nmi (29.3 km) at 9 knots (17.6 km/h) 84 nmi (155.6 km) at 6 knots (11.8 km/h)	15.8 nmi (29.3 km) at 9 knots (17.6 km/h) 84 nmi (155.6 km) at 6 knots (11.8 km/h)	15.4 nmi (28.5 km) at 8.5 knots (16.7 km/h) 120 nmi (222.2 km) at 4 knots (7.8 km/h)
Test depth		100 m (328.1 ft)	100 m (328.1 ft)	100 m (328.1 ft)	100 m (328.1 ft)	100 m (328.1 ft)
crew		2	2	2	2	3
Armament		2 × 533 mm (21 in) Type 89 torpedo Torpedo The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for... es	2 × 450 mm (18 in) Type 97 torpedo Type 97 torpedo The Type 97 was a diameter torpedo used by the Imperial Japanese Navy during World War II. Intended for use with Japan's Ko-hyoteki class midget submarines, the torpedo was based on the Type 93 "Long Lance" used by larger Japanese submarines, but redesigned to meet the smaller physical dimensions... es	2 × 450 mm (18 in) Type 97 torpedoes, later replaced Type 2 Torpedo	2 × 450 mm (18 in) Type 2 torpedoes	2 × 450 mm (18 in) Type 2 torpedoes
Builder		Kure Naval Arsenal Kure Naval Arsenal was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy. -History:The Kure Naval District was established at Kure, Hiroshima in 1889, as the second of the naval districts responsible for the defense of the Japanese home islands along with the establishment of the...	Kure Naval Arsenal	Karasukojima Island (Kure) Naval Armony (No.3 to No.20) 'P' (Ōurasaki) Naval Armony	'P' Naval Armony	'P' Naval Armony
Number of built		1	2	51 (later 5 boats were converted to the Type B)	5 boats were converted from the Type A	37 × general production model 10 × Type C trainer

External links

David Stubblebine: Type A-class Midget Submarine

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.