Convoy GP55
Encyclopedia
Convoy GP55 was a convoy of Allied
ships that travelled from Sydney
to Brisbane
in June 1943 during World War II
. It comprised ten cargo ships, three landing ships, tank (LSTs) and an escort of five corvette
s. The Japanese submarine I-174
attacked the convoy on 16 June, sinking the United States Army
transport ship Portmar and damaging USS LST-469
. Two of the corvettes subsequently counter-attacked I-174, but only lightly damaged her.
The Australian military conducted an intensive search for I-174 in the days after the attack in the mistaken belief that she had been significantly damaged. This search was not successful and highlighted the unsatisfactory communications between the Royal Australian Navy
(RAN) and Royal Australian Air Force
(RAAF). Because of Japan's deteriorating strategic situation, I-174 was the last Imperial Japanese Navy
(IJN) submarine to operate off the Australian east coast.
s raided Sydney Harbour
on the night of 31 May – 1 June 1942 and attacks on merchant shipping travelling off the east coast began several days later. These attacks continued until August 1942, when the Japanese submarine force was redeployed. The I-174 made a 24-day patrol off Australia in July and August 1942, but did not attack any ships. In response to the Japanese attacks, the Australian naval authorities ordered that all ships with a displacement of more than 1,200 tons and a maximum speed of less than 12 knots travel in escorted convoys from 8 June. These convoys were successful in minimising losses, and no escorted ships were sunk off Australia during 1942.
Japanese submarines resumed operations in Australian waters in January 1943. I-21
made a highly successful patrol in January and February, during which she sank five ships, and two other submarines operated off Sydney and Brisbane in March. A force of five boats from the IJN's 3rd Submarine Squadron subsequently attacked shipping along the full length of the Australian east coast during April and May in an attempt to disrupt the Allied supply line to New Guinea
. This marked the peak of the Japanese submarine offensive against Australia and nine ships were sunk off the east coast within a month. In contrast with 1942, several successful attacks were made against ships travelling in convoys.
The large number of Japanese attacks in 1943 put great strain on the Allied forces responsible for protecting shipping off eastern Australia. The Australian naval authorities were forced in April to reduce the number of convoys that sailed so their escort could be increased to at least four warships. The RAAF also greatly increased the number of aircraft allocated to escort convoys and ships sailing independently. Further ships and aircraft fitted for anti-submarine warfare
(ASW) became available in May, but were still not adequate to counter the Japanese attacks.
The sinking of the hospital ship AHS Centaur
on 14 May 1943 with heavy loss of life led the Advisory War Council
to seek information from the RAN and RAAF on the actions being taken to protect shipping. While the RAN acknowledged that the Bathurst-class corvettes
that made up most of its escort force were too slow, it argued that the losses suffered by escorted convoys were no worse than those in other parts of the world. Despite the Navy's assurances, Australia's anti-submarine forces were constrained by a shortage of training opportunities and poor coordination between the RAN, RAAF and the United States Navy
. The Australian military had also not kept pace with improvements to British and United States ASW doctrine by fully implementing the tactics that had proven most successful in other theatres of the war.
on 16 May 1943 under the command of Lieutenant Nobukiyo Nanbu and arrived off Sandy Cape, Queensland
on 27 May. She was the only Japanese boat operating off Australia at the time, as all other available submarines were deployed to counter Allied advances in the Solomon Islands
. She made an unsuccessful torpedo attack on the American ship Point San Pedro on 1 June, exchanged gunfire with U.S. Army transport Edward Chambers three days later, and on 5 June was driven off by convoy PG 53's escorts. On 7 June, I-174 fired four torpedoes at the American Liberty ship John Bartram, all of which missed. She sighted another convoy on 13 June, too far away to attack. During this period, she was repeatedly attacked by Allied aircraft and warships, but did not sustain any damage.
Convoy GP55 was assembled in mid-June 1943 as one of at least 69 convoys that sailed from Sydney to Brisbane during 1943. It comprised ten cargo ships and three U.S. Navy Landing Ships, Tank (LST), and was escorted by the Bathurst-class corvettes (which embarked the convoy's senior officer), , , and . After departing Sydney at 8.45 am on 15 June the convoy maneuvered into five columns, with three ships in each of the centre columns and two in those at the edges. The escorts surrounded the convoy, with four sailing ahead of it and Deloraine to the stern. RAAF Anson
and Beaufort
aircraft also patrolled over the convoy at all times. U.S. Army transport Portmar, which had been badly damaged in the Bombing of Darwin on 19 February 1942, had difficulty maintaining her position in the convoy and at times straggled behind the other ships.
I-174 sighted Convoy GP55 about 35 nautical miles (64.8 km) east of Smoky Cape
at 4.37 pm on 16 June. The submarine immediately began preparations to attack the Allied ships and easily penetrated the escort screen. At this time Portmar was trying to return to her station and was passing to the port of USS LST-469. This made the ships an ideal target for Nanbu as they overlapped from the viewpoint of his periscope. Accordingly, he fired two torpedoes at them at 5.20 pm. A single torpedo struck the LST near her stern two minutes later, resulting in severe damage and the loss of 26 lives and 17 wounded. Portmar spotted the second torpedo and attempted to evade it but was also struck on her starboard side. The transport's cargo of petrol and ammunition quickly caught fire and she sank within ten minutes. One of her crew and a passenger were killed, and 71 survivors, including four who were injured, were rescued by Deloraine. Despite losing steerage LST-469 remained afloat and was taken under tow by the corvette. I-174s attack on Convoy GP55 was probably the most successful made by a Japanese submarine off Australia.
While Deloraine attended to the torpedoed ships, the other four escorts attempted to locate the Japanese submarine. I-174 had not been detected approaching the convoy, and after the attack the Australian corvettes reversed their courses to conduct a sonar sweep of the area from where she was presumed to have attacked. This was in accordance with tactics that had recently been adopted by the RAN after they proved successful in the Battle of the Atlantic. Warrnambool detected the submarine 23 minutes after the attack, and she and Kalgoorlie subjected I-174 to four depth charge
attacks over two hours until contact was lost. An Anson from No. 71 Squadron
was escorting the convoy at the time the two ships were torpedoed but was low on fuel and returned to base shortly after the attack. While the corvettes believed that they had sunk I-174, she was only lightly damaged and withdrew to the east. The Australian failure to sink the submarine was due to a lack of practice and too few ships being available to create an adequate search scheme.
After breaking off their attack Warrnambool rejoined the convoy while Kalgoorlie assisted Deloraine in protecting the damaged LST. Deteriorating weather broke the tow-line between Deloraine and LST-469, and instead the corvette proceeded to the nearby town of Coffs Harbour
with Portmars survivors and the LST's wounded personnel. The tugboat
was dispatched from Brisbane on 16 June to recover the LST and towed her to Sydney, where they arrived on 20 June. LST-469 had been carrying troops and supplies for Operation Chronicle
, an amphibious landing at Woodlark
and Kiriwina
islands on 30 June, and this operation was hindered by her unavailability.
, Admiral Sir Guy Royle, judged that the submarine had been damaged and ordered that "special measures" be taken to search for it. The RAAF commenced air searches of an 80 sqnmi box south-east of Coffs Harbour on the night of 16/17 June, while Deloraine, Kalgoorlie and the recently arrived destroyer
patrolled the area. On 17 June, Anson aircraft were assigned to patrol the submarine's most likely escape routes in the hope that this would force her to remain submerged during the day and surface at night. Radar-equipped Beauforts relieved the Ansons after dusk and continued the search.
In the early morning of 18 June, two No. 32 Squadron
Beauforts attacked with bombs and gunfire what they took to be a submarine. Deloraine was less than 6 miles (9.7 km) from the area of the RAAF attack, but did not acknowledge repeated attempts by the aircraft to communicate with her. The Beauforts reported that they had damaged the submarine and intensive efforts were made on 19 June to locate and sink her, with twelve Ansons continuously sweeping the area while six Vengeance dive bombers were held in readiness nearby. No further sightings were made and it was assumed that the submarine had been damaged by a No. 32 Squadron aircraft but escaped. The sighting made on 18 June appears to have been mistaken, as I-174 was at least 60 miles (96.6 km) to the east of where the RAAF attack took place and it was not recorded in her war diary. I-174 was ordered to depart from Australian waters on 20 June, and returned to Truk
on 1 July. She did not make contact with any Allied ships or aircraft after attacking GP55.
The seeming failure of the RAAF and RAN to cooperate to finish off a damaged submarine led Royle to order an inquiry into the attack. This found that a breakdown in communication between the two services was the main cause of the failure, with both the aircraft and the naval signal room in Sydney making procedural errors. Rear Admiral Gerard Muirhead-Gould
, the naval officer in command of the Sydney region, also noted that communications between the RAN and RAAF were unsatisfactory at higher levels, and that the communication procedures to be used in anti-submarine operations were not well known or understood. In response, he suggested that the RAN establish the position of Commander Escort Vessels Group to organise and command escorts and coordinate their tactics.
The attack on Convoy GP55 was the last attack made by a Japanese submarine on the east coast of Australia. Two submarines were dispatched to operate off Australia in July 1943, but were diverted to the Solomon Islands shortly before reaching the east coast. Following this, the Japanese submarines were fully occupied responding to Allied offensives and transporting supplies to isolated garrisons. As the threat to shipping declined, the RAN ceased running convoys in waters south of Newcastle
on 7 December 1943 and Sydney–Brisbane convoys ended on 10 February 1944.
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...
ships that travelled from Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
to 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...
in June 1943 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...
. It comprised ten cargo ships, three landing ships, tank (LSTs) and an escort of five 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. The Japanese submarine I-174
Japanese submarine I-174
Japanese submarine I-174 was a Kaidai class submarine operated by the Imperial Japanese Navy between 1938 and her sinking in 1944. She completed eight war patrols during the Pacific War. She attacked the Convoy GP55 on 16 June 1943. During her ninth war patrol she was sunk near Truk on 12 April...
attacked the convoy on 16 June, sinking the United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
transport ship Portmar and damaging USS LST-469
USS LST-469
USS LST-469 was a Landing Ship, Tank operated by the United States Navy during World War II. She was commissioned in 1943 and decomissionsed in 1946.- Service history :...
. Two of the corvettes subsequently counter-attacked I-174, but only lightly damaged her.
The Australian military conducted an intensive search for I-174 in the days after the attack in the mistaken belief that she had been significantly damaged. This search was not successful and highlighted the unsatisfactory communications between the 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...
(RAN) and Royal Australian Air Force
Royal Australian Air Force
The Royal Australian Air Force is the air force branch of the Australian Defence Force. The RAAF was formed in March 1921. It continues the traditions of the Australian Flying Corps , which was formed on 22 October 1912. The RAAF has taken part in many of the 20th century's major conflicts...
(RAAF). Because of Japan's deteriorating strategic situation, I-174 was the last 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...
(IJN) submarine to operate off the Australian east coast.
Background
During 1942 and 1943, Japanese submarines periodically operated in the waters surrounding Australia. A force of midget submarineMidget 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 raided Sydney Harbour
Attack on Sydney Harbour
In late May and early June 1942, during World War II, submarines belonging to the Imperial Japanese Navy made a series of attacks on the cities of Sydney and Newcastle in New South Wales, Australia...
on the night of 31 May – 1 June 1942 and attacks on merchant shipping travelling off the east coast began several days later. These attacks continued until August 1942, when the Japanese submarine force was redeployed. The I-174 made a 24-day patrol off Australia in July and August 1942, but did not attack any ships. In response to the Japanese attacks, the Australian naval authorities ordered that all ships with a displacement of more than 1,200 tons and a maximum speed of less than 12 knots travel in escorted convoys from 8 June. These convoys were successful in minimising losses, and no escorted ships were sunk off Australia during 1942.
Japanese submarine I-21
was a Japanese Type B1 submarine which saw service during World War II in the Imperial Japanese Navy. She displaced 1,950 tons and had a speed of . I-21 was the most successful Japanese submarine to operate in Australian waters, participating in the attack on Sydney Harbour in 1942 and sinking...
made a highly successful patrol in January and February, during which she sank five ships, and two other submarines operated off Sydney and Brisbane in March. A force of five boats from the IJN's 3rd Submarine Squadron subsequently attacked shipping along the full length of the Australian east coast during April and May in an attempt to disrupt the Allied supply line to New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
. This marked the peak of the Japanese submarine offensive against Australia and nine ships were sunk off the east coast within a month. In contrast with 1942, several successful attacks were made against ships travelling in convoys.
The large number of Japanese attacks in 1943 put great strain on the Allied forces responsible for protecting shipping off eastern Australia. The Australian naval authorities were forced in April to reduce the number of convoys that sailed so their escort could be increased to at least four warships. The RAAF also greatly increased the number of aircraft allocated to escort convoys and ships sailing independently. Further ships and aircraft fitted for anti-submarine warfare
Anti-submarine warfare
Anti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....
(ASW) became available in May, but were still not adequate to counter the Japanese attacks.
The sinking of the hospital ship AHS Centaur
AHS Centaur
Australian Hospital Ship Centaur was a hospital ship which was attacked and sunk by a Japanese submarine off the coast of Queensland, Australia, on 14 May 1943...
on 14 May 1943 with heavy loss of life led the Advisory War Council
Advisory War Council (Australia)
The Advisory War Council was an Australian Government body during World War II. The AWC was established on 28 October 1940 to draw all the major political parties in the Parliament of Australia into the process of making decisions on Australia's war effort and was disbanded on 30 August...
to seek information from the RAN and RAAF on the actions being taken to protect shipping. While the RAN acknowledged that the Bathurst-class corvettes
Bathurst class corvette
The Bathurst class corvettes were a class of general purpose vessels produced in Australia during World War II. Originally classified as minesweepers, but widely referred to as corvettes, the Bathurst class vessels fulfilled a broad anti-submarine, anti-mine, and convoy escort role.Sixty Bathurst...
that made up most of its escort force were too slow, it argued that the losses suffered by escorted convoys were no worse than those in other parts of the world. Despite the Navy's assurances, Australia's anti-submarine forces were constrained by a shortage of training opportunities and poor coordination between the RAN, RAAF and 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...
. The Australian military had also not kept pace with improvements to British and United States ASW doctrine by fully implementing the tactics that had proven most successful in other theatres of the war.
Attack
I-174 departed from the major Japanese naval base at TrukChuuk
Chuuk — formerly Truk, Ruk, Hogoleu, Torres, Ugulat, and Lugulus — is an island group in the south western part of the Pacific Ocean. It comprises one of the four states of the Federated States of Micronesia , along with Kosrae, Pohnpei, and Yap. Chuuk is the most populous of the FSM's...
on 16 May 1943 under the command of Lieutenant Nobukiyo Nanbu and arrived off Sandy Cape, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
on 27 May. She was the only Japanese boat operating off Australia at the time, as all other available submarines were deployed to counter Allied advances in the Solomon Islands
Solomon Islands
Solomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
. She made an unsuccessful torpedo attack on the American ship Point San Pedro on 1 June, exchanged gunfire with U.S. Army transport Edward Chambers three days later, and on 5 June was driven off by convoy PG 53's escorts. On 7 June, I-174 fired four torpedoes at the American Liberty ship John Bartram, all of which missed. She sighted another convoy on 13 June, too far away to attack. During this period, she was repeatedly attacked by Allied aircraft and warships, but did not sustain any damage.
Convoy GP55 was assembled in mid-June 1943 as one of at least 69 convoys that sailed from Sydney to Brisbane during 1943. It comprised ten cargo ships and three U.S. Navy Landing Ships, Tank (LST), and was escorted by the Bathurst-class corvettes (which embarked the convoy's senior officer), , , and . After departing Sydney at 8.45 am on 15 June the convoy maneuvered into five columns, with three ships in each of the centre columns and two in those at the edges. The escorts surrounded the convoy, with four sailing ahead of it and Deloraine to the stern. RAAF Anson
Avro Anson
The Avro Anson is a British twin-engine, multi-role aircraft that served with the Royal Air Force, Fleet Air Arm and numerous other air forces prior to, during, and after the Second World War. Named for British Admiral George Anson, it was originally designed for maritime reconnaissance, but was...
and Beaufort
Bristol Beaufort
The Bristol Beaufort was a British twin-engined torpedo bomber designed by the Bristol Aeroplane Company, and developed from experience gained designing and building the earlier Blenheim light bomber....
aircraft also patrolled over the convoy at all times. U.S. Army transport Portmar, which had been badly damaged in the Bombing of Darwin on 19 February 1942, had difficulty maintaining her position in the convoy and at times straggled behind the other ships.
I-174 sighted Convoy GP55 about 35 nautical miles (64.8 km) east of Smoky Cape
Smoky Cape
Smoky Cape is a headland in Australia on the New South Wales Mid-North Coast. It lies just east of the town of South West Rocks, and within the Hat Head National Park.- Cape :...
at 4.37 pm on 16 June. The submarine immediately began preparations to attack the Allied ships and easily penetrated the escort screen. At this time Portmar was trying to return to her station and was passing to the port of USS LST-469. This made the ships an ideal target for Nanbu as they overlapped from the viewpoint of his periscope. Accordingly, he fired two torpedoes at them at 5.20 pm. A single torpedo struck the LST near her stern two minutes later, resulting in severe damage and the loss of 26 lives and 17 wounded. Portmar spotted the second torpedo and attempted to evade it but was also struck on her starboard side. The transport's cargo of petrol and ammunition quickly caught fire and she sank within ten minutes. One of her crew and a passenger were killed, and 71 survivors, including four who were injured, were rescued by Deloraine. Despite losing steerage LST-469 remained afloat and was taken under tow by the corvette. I-174s attack on Convoy GP55 was probably the most successful made by a Japanese submarine off Australia.
While Deloraine attended to the torpedoed ships, the other four escorts attempted to locate the Japanese submarine. I-174 had not been detected approaching the convoy, and after the attack the Australian corvettes reversed their courses to conduct a sonar sweep of the area from where she was presumed to have attacked. This was in accordance with tactics that had recently been adopted by the RAN after they proved successful in the Battle of the Atlantic. Warrnambool detected the submarine 23 minutes after the attack, and she and Kalgoorlie subjected I-174 to four 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...
attacks over two hours until contact was lost. An Anson from No. 71 Squadron
No. 71 Squadron RAAF
No. 71 Squadron was a Royal Australian Air Force maritime patrol squadron of World War II. It was formed in January 1943 and conducted patrols off the east coast of Australia until it was disbanded in August 1944.-History:...
was escorting the convoy at the time the two ships were torpedoed but was low on fuel and returned to base shortly after the attack. While the corvettes believed that they had sunk I-174, she was only lightly damaged and withdrew to the east. The Australian failure to sink the submarine was due to a lack of practice and too few ships being available to create an adequate search scheme.
After breaking off their attack Warrnambool rejoined the convoy while Kalgoorlie assisted Deloraine in protecting the damaged LST. Deteriorating weather broke the tow-line between Deloraine and LST-469, and instead the corvette proceeded to the nearby town of Coffs Harbour
Coffs Harbour, New South Wales
-History:By the early 1900s, the Coffs Harbour area had become an important timber production centre. Before the opening of the North Coast Railway Line, the only way to transport large items of heavy but low value, such as timber, was by coastal shipping. This meant sawmillers on the North Coast...
with Portmars survivors and the LST's wounded personnel. The tugboat
Tugboat
A tugboat is a boat that maneuvers vessels by pushing or towing them. Tugs move vessels that either should not move themselves, such as ships in a crowded harbor or a narrow canal,or those that cannot move by themselves, such as barges, disabled ships, or oil platforms. Tugboats are powerful for...
was dispatched from Brisbane on 16 June to recover the LST and towed her to Sydney, where they arrived on 20 June. LST-469 had been carrying troops and supplies for Operation Chronicle
Operation Chronicle
Operation Chronicle was the Allied invasion of Woodlark and Kiriwina Islands during World War II, in the South West Pacific as part of Operation Cartwheel. An early planning name for this operation was Operation Coronet...
, an amphibious landing at Woodlark
Woodlark Island
Woodlark Island, known to its inhabitants simply as Woodlark or Muyua, is an island in Milne Bay Province, Papua New Guinea. It is called Murua by the inhabitants of some other islands in the province...
and Kiriwina
Kiriwina
Kiriwina is the largest of the Trobriand Islands, with an area of 290.5 km². It is part of the Milne Bay Province of Papua New Guinea. Most of the 12,000 people who live in the Trobriands live on Kiriwina. The Kilivila language, also known as Kiriwina, is spoken on the island...
islands on 30 June, and this operation was hindered by her unavailability.
Aftermath
Following the attack, the Australian Chief of Naval StaffChief of Navy (Australia)
The Chief of Navy is the most senior appointment in the Royal Australian Navy, responsible to the Chief of the Defence Force and the Secretary of Defence...
, Admiral Sir Guy Royle, judged that the submarine had been damaged and ordered that "special measures" be taken to search for it. The RAAF commenced air searches of an 80 sqnmi box south-east of Coffs Harbour on the night of 16/17 June, while Deloraine, Kalgoorlie and the recently arrived 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...
patrolled the area. On 17 June, Anson aircraft were assigned to patrol the submarine's most likely escape routes in the hope that this would force her to remain submerged during the day and surface at night. Radar-equipped Beauforts relieved the Ansons after dusk and continued the search.
No. 32 Squadron RAAF
No. 32 Squadron is a Royal Australian Air Force unit based at RAAF East Sale in Victoria. It currently flies training and transport operations.- World War II :...
Beauforts attacked with bombs and gunfire what they took to be a submarine. Deloraine was less than 6 miles (9.7 km) from the area of the RAAF attack, but did not acknowledge repeated attempts by the aircraft to communicate with her. The Beauforts reported that they had damaged the submarine and intensive efforts were made on 19 June to locate and sink her, with twelve Ansons continuously sweeping the area while six Vengeance dive bombers were held in readiness nearby. No further sightings were made and it was assumed that the submarine had been damaged by a No. 32 Squadron aircraft but escaped. The sighting made on 18 June appears to have been mistaken, as I-174 was at least 60 miles (96.6 km) to the east of where the RAAF attack took place and it was not recorded in her war diary. I-174 was ordered to depart from Australian waters on 20 June, and returned to Truk
Truk Lagoon
Truk Lagoon, also known as Chuuk, is a sheltered body of water in the central Pacific. North of New Guinea, it is located mid-ocean at 7 degrees North latitude. The atoll consists of a protective reef, around, enclosing a natural harbour 79 by 50 kilometres , with an area of . It has a land...
on 1 July. She did not make contact with any Allied ships or aircraft after attacking GP55.
The seeming failure of the RAAF and RAN to cooperate to finish off a damaged submarine led Royle to order an inquiry into the attack. This found that a breakdown in communication between the two services was the main cause of the failure, with both the aircraft and the naval signal room in Sydney making procedural errors. Rear Admiral Gerard Muirhead-Gould
Gerard Muirhead-Gould
Rear Admiral Gerard Charles Muirhead-Gould DSC was an officer of the Royal Navy.Muirhead-Gould was born in London. He was the son of Arthur Lewis Gould and Emily Gertrude Lilias Muirhead. He joined the Royal Naval Cadets in January 1904...
, the naval officer in command of the Sydney region, also noted that communications between the RAN and RAAF were unsatisfactory at higher levels, and that the communication procedures to be used in anti-submarine operations were not well known or understood. In response, he suggested that the RAN establish the position of Commander Escort Vessels Group to organise and command escorts and coordinate their tactics.
The attack on Convoy GP55 was the last attack made by a Japanese submarine on the east coast of Australia. Two submarines were dispatched to operate off Australia in July 1943, but were diverted to the Solomon Islands shortly before reaching the east coast. Following this, the Japanese submarines were fully occupied responding to Allied offensives and transporting supplies to isolated garrisons. As the threat to shipping declined, the RAN ceased running convoys in waters south of Newcastle
Newcastle, New South Wales
The Newcastle metropolitan area is the second most populated area in the Australian state of New South Wales and includes most of the Newcastle and Lake Macquarie Local Government Areas...
on 7 December 1943 and Sydney–Brisbane convoys ended on 10 February 1944.