The naval campaigns for New Guinea

Author:  Dr David Stevens

{1} This essay briefly examines some of the major issues surrounding the operations of Allied and Japanese naval forces during the war in New Guinea from 1942 to 1944. The most important point to keep in mind is that the naval campaigns were not concerned simply with the defeat of the enemy fleet at sea. Although often taken for granted, the sustained and successful involvement of maritime power had a direct influence on operations ashore. There may not have been a single decisive battle for command, but there was a continuous struggle by both the Allies and Japanese to keep the sea for their own use while denying it to their adversary.

Early manoeuvres

{2} By early 1942, Allied authorities could be in no doubt that the Japanese held the initiative in the Pacific War. After a series of unbroken victories stretching from Pearl Harbor to Java, the Imperial Japanese Navy (IJN) held undisputed command of the sea in the eastern Pacific Ocean. This achievement enabled Japanese commanders to maintain their control on the course of the conflict. Having decided on a particular objective it became a relatively simple matter to muster superior forces and overwhelm the defenders in a combined operation. Lae and Salamaua on the north-east coast of New Guinea were occupied on 7 March when the Japanese landed a force of 3,000 men. With the enemy seemingly unstoppable, many Australians believed that their own homeland might be the ultimate objective. The Australian Government turned to the United States for assurance and President Roosevelt recalled General Douglas MacArthur from the Philippines to take charge. MacArthur knew that it must be some time before the United States would be capable of launching a counterattack but, on assuming supreme command of the South West Pacific Area (SWPA), he also found that he had very few resources available for defence.

{3} The Japanese, however, had already rejected the invasion of Australia as being beyond their ability. Instead, before the United States could muster a significant response, they aimed to occupy Port Moresby and the southern Solomons, followed by Fiji, Samoa and New Caledonia. Having secured their resource base, the Japanese expected these additional operations to shore up their defensive perimeter while simultaneously cutting Australia's vital communications with America.¹ Isolated from its allies, Australia would thereafter be prevented from acting as a staging area for manpower and matériel. Subsequently, Australia would either be forced out of the war, or rendered harmless until a Japanese invasion could proceed at a more favourable time in the future.

{4} Assisted by an efficient intelligence system, MacArthur had an accurate understanding of Japanese intentions, and soon made it clear that he considered Australia's security lay in Port Moresby rather than on the mainland. Unfortunately, garrison forces at Port Moresby amounted to only one militia brigade group, and reinforcement would not be easy. A great mountainous and undeveloped island, New Guinea had virtually no land routes of communication. Airfields were few and equally undeveloped, and there was no intermediate air base closer than Townsville. In essence, Port Moresby (and indeed New Guinea as a whole) was solely dependent upon sea lines of communication and their control by friendly air and naval forces.²

{5} On 25 April 1942, the Combined Operational Intelligence Centre in Melbourne, linking information from locally-based signals intelligence units, coastwatchers and aerial reconnaissance, issued an assessment that a Japanese assault on Port Moresby was imminent. On 1 May the cruisers HMAS Australia and Hobart, and USS Chicago, escorted by three American destroyers, sailed from Hervey Bay in Queensland under the command of Rear Admiral John Crace, RN, commander of the Australian Squadron. The formation was ordered to rendezvous with an American force built around the aircraft carriers USS Yorktown and Lexington.

{6} Three days later the Japanese Port Moresby Attack Force carrying some 6000 troops and supported by aircraft carriers, cruisers and destroyers, sailed from Rabaul. Crace's force was detached on 7 May to block the movement of any Japanese ships through the Jomard Passage. Here it came under heavy air attack, although it did not encounter Japanese surface units. Indeed, the Battle of the Coral Sea, which extended over 7-8 May, was the first naval battle in history in which the opposing ships did not sight each other. The aircraft carriers and their close escorts played the key role and the battle resulted in each side having one carrier sunk and another damaged. Their losses might not have been huge, but the encounter was a strategic defeat for the Japanese. The IJN had failed to establish control of the Coral Sea and, with the covering force depleted and air cover reduced, the Port Moresby operation was postponed.

{7} In the breathing space provided, MacArthur reinforced the troops in New Guinea and ordered the construction of additional air bases at the south-eastern tip of New Guinea and on the Cape York peninsula. Meanwhile the IJN turned its attention to the major operation against the American base at Midway; this time there were no doubts about the outcome. For the Japanese Combined Fleet, the Battle of Midway was a major disaster. Four fleet carriers were sunk and the naval air arm received a blow from which it never completely recovered. The Japanese had lost not only their capacity to contest command of the sea, but also the strategic initiative for the remainder of the Pacific War.

{8} Although Coral Sea and Midway checked Japanese ambitions, they had not been curbed, and the occupation of Port Moresby remained a priority. However, since a direct amphibious assault was still impractical, the Japanese instead accelerated studies for an overland advance from their bases on the northern New Guinea coast.³ The operation commenced in July and soon led to the prolonged and vicious fighting along the length of the Kokoda Trail. In August, the struggle expanded to include Milne Bay where the Allies were attempting to establish a forward air base.

{9} For the remainder of 1942 the pattern of fighting in New Guinea was characterised by a series of slow and costly engagements ashore and, for the Allies, there were few incentives to commit major naval forces. United States Navy (USN) commanders regarded MacArthur's area as predominantly army and concentrated their efforts in the Central and South Pacific. Moreover, warships of all types were scarce and, with the profusion of reefs, and lack of accurate hydrographic information, operations close to the New Guinea coast were inherently unsafe. The proximity of Japanese air bases and the lack of Allied air superiority added further difficulties to surface operations. As a result, for the initial stages of the New Guinea campaign and at least till the capture of Buna, direct naval assistance was limited to that provided by American motor torpedo boats and the ubiquitous corvettes of the Royal Australian Navy (RAN).

{10} In fact, for both antagonists, the prime focus of offensive naval activity had moved to the area around the Solomon Islands. Here they waged the struggle over Guadalcanal, as both the Japanese and Allies attempted to establish forward air bases. Yet, though for the public New Guinea had become a purely land campaign, and major offensive action by naval forces was not contemplated, maritime activity had certainly not ceased. The relatively small RAN had already begun the massive task of surveying the inadequately-charted areas of the New Guinea coast, while both sides began operations in support of, or against sea communications. Most important from the Allied perspective were the regular patrols of a small fleet of USN submarines which, operating from Australian bases, formed the core of what soon became known as "MacArthur's Navy".

The Allied view

{11} Once the land campaign in New Guinea was underway, Australia's role as a rearward support base came to the fore, and Allied shipping movements along the East Australian Coast and up to forward areas increased rapidly. After Coral Sea, the Japanese no longer risked surface ships south of New Guinea, and so their attempts to disrupt Allied communications were generally limited to what could be achieved by their aircraft and submarines. Nevertheless, there were occasional sorties by warships, including some bombardments of Allied shipping in Milne Bay. In September 1942 the Japanese cruiser Tenryu and destroyer Arashi sank the supply ship Anshun. The Australian hospital ship Manunda was illuminated by searchlight, but not otherwise troubled.

{12} The first serious Japanese anti-shipping offensive had begun four months earlier with a sortie by five fleet submarines to the east coast, and the midget submarine attack on Sydney on the night of 31 May-1 June. A Japanese campaign of this type was not unexpected, but Australian reactions were initially hampered by a lack of suitable assets. To its credit, the RAN was quick to introduce coastal convoys and, by early 1943, there existed a complete system that stretched from Melbourne to Darwin and advanced New Guinea bases. Allied naval forces in the SWPA were under the overall command of MacArthur's naval deputy, Vice-Admiral Arthur S. Carpender, USN, but the convoy system was ultimately the responsibility of the Australian Chief of Naval Staff, Admiral Sir Guy Royle, RN. As Commander Southwest Pacific Sea Frontiers (CSWPSF), Royle was charged with the safe conduct and routing of all coastal shipping, shipping to and from contiguous areas, and routine shipping in support of military operations.

{13} Despite the protective effort, in the period to August 1942, enemy submarines sank seven merchant ships and damaged another six. A few of these vessels were carrying purely commercial cargoes, but most carried at least some military equipment. The Greek steamer G.S. Livanos, torpedoed by I-11 on 20 July, went down with 87 army motor vehicles. SS William Dawes, sunk two days later by the same submarine, included in her cargo manifest:

• 82 x ton jeeps
• 33 x ton CSR
• 72 x ton pickups
• 60 x 1 ton trailers
• 2 x 1 ton cargo trucks
• 12 x 2 ton cargo trucks
• 12 x ambulances
• 13 x half-track vehicles

Explosives and other sundry army stores in William Dawes brought her total service cargo to 5,576 tons.⁴

{14} Ship losses off Australia were comparatively small on a world-wide scale and, backed by American industrial might, the destruction of cargo was not great enough to stop the Allied build-up. Local losses were not insignificant, however, and their impact was magnified by the absolute dependence of Australian trade on shipping, the increasing supply needs of Allied forces in New Guinea, and the severe shortage of ships everywhere. The sea-lanes, after all, were interconnecting and even events in the Atlantic had repercussions in Australia. At a meeting with the State Premiers on 10 August 1942, Prime Minister John Curtin remarked how the increasing efficiency of Allied anti-submarine measures in the North Atlantic had driven German U-boats further south. The result had been "increased attacks on ships bound for Australia through the Panama Canal" and the loss of "some valuable cargoes of war materials".⁵

{15} While the protection of all shipping was important, military cargoes always took priority and special convoys to New Guinea had begun as early as January 1942. Initially these arrangements had been conducted in an ad hoc manner under the broad direction of the Australian Naval Board but, as the land campaign continued, such a situation could not be sustained. In December 1942, regular routine convoys from the mainland (ex-Townsville) to New Guinea began. Designated TN/NT, these supply convoys continued to operate until 23 March 1944. Over fifteen months, 1,148 merchant vessels made the journey in 254 separate convoys.⁶ These figures though do not represent all New Guinea convoys, for there were also many special and troop convoys. Records are imprecise, but Table 1 provides some idea of the equipment successfully shipped to New Guinea in Australian vessels:

Source: Review of RAN War Effort, on NAA(VIC), file IT 296B.

{16} CSWPSF arranged maximum protection for the transport of personnel, and thankfully no troop ships were ever lost. In all, 189,128 Australian military personnel were safely transported to New Guinea between 1941 and 1943.⁷ There were, however, some close escapes. On 23 August 1942, MV Malaita reached Port Moresby with a load of troops and supplies. On sailing for Cairns six days later, she was torpedoed and severely damaged by the Japanese submarine RO-33. The escorting destroyer, HMAS Arunta, counter-attacked and destroyed the submarine, but Malaita did not return to service until 1947.

{17} The Japanese continued their campaigns of disruption in 1943. Enemy aircraft maintained frequent attacks against the supply lines around New Guinea and across northern Australia, while submarines tended to operate further south. With fighting ashore concentrated along the north coast of New Guinea, the Allied northern supply line, and in particular, the run from Milne Bay to Oro Bay, assumed the greatest importance. Insufficient friendly aircraft were available to cover all ships on this passage and, because of the navigational dangers, smaller warships such as the RAN's corvettes shouldered most of the escort burden. For example, "Operation LILLIPUT" (December 1942 to June 1943) involved fifteen corvettes and two USN sub-chasers in the close escort of convoys that carried 60,000 tons of supplies and 3,802 troops to Oro Bay. The tonnage of stores and equipment carried was some seven times greater than that carried by air.⁸ Losses to enemy air attack amounted to two merchant ships sunk and two badly damaged, while several corvettes also sustained damage and casualties.⁹

{18} Attacks by Japanese submarines off the east coast continued, but were generally kept under control, primarily because the number of submarines allocated was always too small for the area involved. This in turn owed much to the inadequacies of Japanese doctrine. The IJN considered attacks on trade and shipping to be merely one, and not the most important, of the functions of their submarine fleet and never gave the anti-shipping campaign the priority it deserved. Nevertheless, enemy submarines continued to achieve the occasional success. SS Starr King, sunk off Sydney on 10 February 1943, was designated by Allied authorities as a Special Ship and carried 7000 tons of army supplies. SS Lydia M. Childs, sunk off Newcastle a month later, carried a cargo of tanks.

{19} Moreover, the requirement to protect shipping continued to place a heavy strain on Allied air and naval resources. In May 1943, Admiral Royle noted that the main naval activity in the SWPA remained the provision of escorts for coastal convoys, and shipping carrying troops, stores and equipment to New Guinea ports.¹⁰ By the end of 1943, naval authorities had allocated over sixty warships for convoy escort duties, while other formations remained available to provide cover. These vessels included Australian and Allied destroyers, corvettes and a wide assortment of smaller anti-submarine vessels. The period May-June 1943 saw the Japanese campaign peak with nine ships torpedoed over four weeks. The scale of the attack forced Admiral Royle to reduce the number of convoy sailings by half so that the number of escort vessels allocated to each convoy could be doubled.¹¹ Meanwhile, the Royal Australian Air Force pressed all possible reconnaissance aircraft into service, employed three reserve squadrons on the escort task, and ordered training aircraft to carry weapons and keep a sharp lookout for submarines.¹²

{20} The Japanese, though, were also feeling the strain and could not maintain even a minimum effort. By the end of June, all their submarines had been withdrawn from Australian waters for defensive operations closer to home. Strangely, however, it was the final attack of the enemy campaign that was to be among the most effective. On 16 June, with two torpedoes, the submarine I-174 sank the US Army Transport Portmar, fully loaded with fuel and ammunition, and severely damaged a tank landing ship (LST). The LST belonged to MacArthur's Seventh Amphibious Force, which had been formed only in January and was still short of ships. Loss of the vessel forced the last minute elimination of troops and cargo from the assault convoy destined for MacArthur's first amphibious operation, the occupation of Kiriwina and Woodlark Islands.¹³

{21} The establishment of the Seventh Amphibious Force under Rear Admiral Daniel E. Barbey, USN, marked the turning point for MacArthur's Navy and heralded a return to the offensive by Allied naval forces in New Guinea. Supported by ever increasing strength at sea and in the air, Allied troops were for the first time able to take full advantage of amphibious mobility and naval gunfire support. The first opposed amphibious landing by Australian troops took place at Lae at the beginning of September 1943. It was followed by a successful assault on Finschhafen a few weeks later.

{22} In contrast to the earlier overland campaigns, amphibious operations reduced losses and increased the speed of advance. Troops no longer had to make frontal assaults against prepared enemy positions. By relying on amphibious movement, strongly-garrisoned points could be bypassed and troops landed on lightly or undefended beaches. The Allies, the Japanese admitted, had at Lae "inflicted an annihilating blow on us without engaging in direct combat".¹⁴ The example set at Lae was subsequently repeated many times as MacArthur's forces "coast hopped" up the northern New Guinea coast through Hollandia, Wakde and Numfor Island. By March 1944 MacArthur had recaptured the Admiralty Islands, and at Manus he formed an advanced naval base from which he could launch his great amphibious operation for the liberation of the Philippines.

{23} Fully integrated into Barbey's Seventh Amphibious Force, Australian warships were involved in many of these operations. The RAN's three armed merchant cruisers, Manoora, Kanimbla and Westralia, were converted to infantry landing ships, while Australian cruisers and destroyers were tasked to provide shore bombardments and seaward cover. That such cover was needed was apparent in late May 1944 during the Allied assault on the island of Biak, north of New Guinea. The IJN soon responded with a force of three destroyers towing landing barges, escorted by three more destroyers with distant support from two cruisers. The Allied covering forces under Rear Admiral Victor Crutchley, RN, were ready and eager for an encounter. The Japanese, however, had been warned of the presence of Crutchley's force by shadowing aircraft and were wary in their approach to Biak. Detected by radar late on the evening of 8 June, the Japanese destroyers shortly afterwards turned away and increased speed. The Allied ships gave chase, but were unable to catch the Japanese ships, which escaped with only limited damage.

The Japanese view

{24} The Japanese armed forces, and the IJN in particular, had been designed around the need to maximise battle strength. The navy paid only minimal attention to the problem of maintaining and protecting supply services. This was a critical weakness, for although Japan's industrial development had rendered the nation increasingly dependent on shipping, her merchant marine was inadequate even for peacetime needs. Japan could not match American shipbuilding capacity, and an initial shortage of suitable transports and cargo vessels, combined with wartime attrition, soon caused major breakdowns in Japanese logistics. To compensate, sea movement by warships rapidly became the norm for men and equipment.

{25} Despite these limitations, the Japanese in New Guinea could rely on adequate reinforcement by surface transport from Palau and Rabaul for most of 1942, and as a result were able to maintain an offensive posture. However, by the end of the year they were faced by Allied victories at Milne Bay, Kokoda, and Buna, and attention had turned towards strengthening and consolidating their position along the northern coast of New Guinea. Hampering this objective, Allied air and submarine attacks on their poorly-defended convoys were becoming increasingly effective. Heavy equipment, food and ammunition were soon in short supply, while difficulty in maintaining an adequate supply of spare parts severely reduced Japanese air strength. Meanwhile, the Combined Fleet - reflecting the change in IJN strategic policy to the defensive - had by mid-November 1942 suspended all offensive operations and ordered its light forces to operate chiefly in fulfilling the constant requirement for supplies.¹⁵ The major units based at Truk were held back in preparation for a decisive action against the US Pacific Fleet at some time in the future.

{26} The Allies continued to improve their interdiction and maritime strike capability. In January 1943, the submarine USS Wahoo reported that after a ten-hour running battle off New Guinea, she had sunk an entire convoy of two Japanese freighters, one transport and one tanker. In early March, in what was to be their last major resupply operation, the Japanese attempted to run a large reinforcement convoy from Rabaul to Lae. Good intelligence allowed the Allies to mount a massive air attack, and in what became known as the Battle of the Bismarck Sea, the Japanese lost all eight transports, four out of eight destroyers, and at least a third of their troops. Smaller convoys were sometimes seen after this time, but shipping available for operations had fallen dramatically. The Japanese recognised that their continued losses by surface transport could no longer be maintained and they removed eastern New Guinea from their vital area. A new strategic plan, drawn up in May 1943, established a defensive perimeter on a line joining Wake, the Marshall and Gilbert Islands, Nauru and Ocean Islands and the Bismarck Archipelago. Thereafter the Japanese abandoned hope of further offensive operations in New Guinea, and isolated areas became almost totally reliant on submarines and small barges for resupply.

{27} While Allied air and submarine attacks harassed Japanese supply lines during the day, fast motor torpedo boats took over at sunset. The torpedo boats only caught the occasional enemy submarine but, well suited to the coastal conditions, they wreaked havoc on the poorly-defended supply barges. Sinkings were so frequent that one Japanese diarist at Finschhafen wrote thankfully on 29 August 1943 that his was the only trip in July or August "when barges were not attacked by torpedo boats".¹⁶ His barge was sunk on its return passage.

{28} Japanese submarines began their supply missions to New Guinea in December 1942 and, with the attrition of other transport assets, it was soon usual for most of the Japanese submarine service to be dedicated to transport. Although safer than other methods, supply by submarine was hardly more efficient. Stripped of all unnecessary equipment, submarines were then incapable of offensive operations and still only able to transport a very small load. Even the largest 2000-ton submarines were estimated to have a cargo capacity of only 20 tons below decks and another 40 tons above, or alternatively 50 troops and 15 tons of cargo.¹⁷ The usual load, however, was much less and nearly half the early missions failed after the submarine was unable to establish communications with forces ashore.¹⁸ Despite the introduction of several ingenious devices to increase cargo capacity and reduce unloading time, such measures could not make up for the lack of a fully functional transport service.

{29} In May 1943, supply submarines took 400 tons of cargo from Rabaul to the Huon Gulf area.¹⁹ In July, the Japanese managed to mount seven submarine transport missions that landed 195 men and 238 tons of supplies. The following month, seven submarines made a total of eighteen trips to Lae.²⁰ According to a Japanese submarine commander who took part, submarines completed 95 trips to New Guinea between December 1942 and September 1943, in all transporting 3,500 tons of cargo.²¹ By contrast, in June 1943 alone, the Allies moved 55,305 tons from Milne Bay and Port Moresby to forward areas, increasing to 200,246 tons in September.²²

{30} Despite often possessing the advantages of position and preparedness, the majority of Japanese troops in New Guinea were never to come to grips with Allied forces. Subjected to what was in effect, an extremely effective blockade, enemy troops suffered terribly from illness and malnutrition. Claims have since been made that deaths in combat account for only 3 per cent of the 100,000 Japanese who died in New Guinea.²³ Those on the ground were under no illusions. One of the few Japanese survivors of Buna was later to admit that "We lost ... because we could not supply our troops, and because our navy and airforce could not disrupt the enemy supply line".²⁴

Conclusions

{31} To say that the Allied navies supported the actions of land forces in New Guinea would be an understatement. Although Allied maritime power could not ultimately remove the Japanese from New Guinea, it did directly affect the course of events ashore. Throughout the operations, the protection and maintenance of the sea lines of communication were vital to the successful progress of MacArthur's campaign. The simultaneous denial to the Japanese of their own supply lines meant that the enemy had no hope of competing with Allied "troopers, beans and bullets in greater and greater numbers".²⁵ Later, when the Allies had clearly established the capability to establish local superiority on the sea and in the air, it was possible to exploit this control for combined operations. Compared to overland assault, power could thereafter be projected at times and places chosen by the Allies and with remarkable speed and economy.

{32} The Japanese, on the other hand, consistently failed to allocate sufficient priority to either a concentrated offensive against Allied shipping, or protection of their own lines of communication. Once they had lost control of the sea and air off the New Guinea coastline, any Japanese local superiority ashore could never be effectively applied. Starved of reinforcements and supplies, Japanese strong points were consistently neutralised, and either disposed of piecemeal or left to waste away. Though often ignored by historians, the operations of naval forces around New Guinea were vital to the war's outcome, providing the "enabling factor" that allowed the campaign to be fought to its successful conclusion.

© Dr David Stevens

The author

Dr David Stevens is a former RAN officer and has been Director of Naval Historical Studies at the Sea Power Centre, Department of Defence (Navy), since 1994. He is the author of U-Boat Far From Home (1997) and has edited several books on maritime strategy and power, including The Royal Australian Navy, vol.3 in the Australian Centenary History of Defence series (2001).

Notes

¹ Tanaka H., "The Japanese Navy's operations against Australia in the Second World War", Journal of the Australian War Memorial, no.30, April 1997, p.1.

² See "Appreciation by Australian Chiefs of Staff" in D. MacArthur, Reports of General MacArthur (Washington: Department of the Army, 1966), p.26.

³ A message detailing revised Japanese plans for Port Moresby was decrypted 18 May even before the Japanese defeat at Midway in June. See E. Drea, MacArthur's ULTRA (Lawrence: University Press of Kansas, 1992), p.37.

⁴ National Archives of Australia (NAA) (VIC) file MP 1587/1 155A.

⁵ Prime Minister's War Conference Agendum 6/42, NAA (ACT), file A5954/1, Box 669.

⁶ Papers of G. Hermon Gill, Australian War Memorial, AWM 69, no.82.

⁷ 'Review of RAN War Effort, NAA (VIC), file IT 296B.

⁸ Naval History Directorate, Canberra, file 69.

⁹ G. Hermon Gill, Royal Australian Navy 1942-1945, The Official History of Australia in the War of 1939-1945 (Sydney: Collins, 1985), pp.268-9.

¹⁰ Minutes of Advisory War Council Meeting, 13 May 1943, "Report by CNS on Operations", NAA (ACT), file A2682, vol.VI.

¹¹ "Report by CNS on Operations".

¹² G. Odgers, Air War Against Japan 1943-1945, The Official History of Australia in the War of 1939-1945 (Canberra: Australian War Memorial, 1968), pp.140, 144, 148.

¹³ D. Barbey, MacArthur's Amphibious Navy (Annapolis: United States Naval Institute, 1966), p.55.

¹⁴ S.E. Morison, Breaking the Bismarks Barrier, History of USN Operations in World War II, vol.VI (Boston: Little, Brown and Company, 1950), p.268.

¹⁵ Japanese monograph, "Submarine Operations in Second Phase Operations, April 1942 to March 1943", GHQ Far East Command, Military Intelligence Section, ATIS, 24 July 1950, p.39.

¹⁶ Morison, Breaking the Bismarks Barrier, p.257.

¹⁷ "Advanced Intelligence Center Report 927-43", 19 December 1943, on file AWM 54, 423/11/194, and "Characteristics of Japanese Submarines", 22 January 1944, on file AWM 54, 917/7/2.

¹⁸ "Submarine Operations in Second Phase Operations.", p.45.

¹⁹ "New Zealand Naval Intelligence Memoranda" in NAA (VIC), file IT 1587/1 155U.

²⁰ "New Zealand Naval Intelligence Memoranda".

²¹ Z. Orita, I-Boat Captain (California: Major Books, 1976), p.146.

²² "CSWPSF summary of shipping movements in forward area", file held by Naval History Directorate, Canberra.

²³ M. Parillo, "The Imperial Japanese Navy in WWII", in S. Sadkovich (ed.), Re-evaluating Major Naval Combatants of WWII (New York: Greenwood Press, 1990), p.65.

²⁴ Major Mitsuo Koiwai, commanding officer 2nd Battalion, 41st Infantry, quoted in S. Milner, Victory in Papua, United States Army in World War II (Washington: Office of the Chief of Military History, Department of the Army, 1957), p.374.

²⁵ Morison, Breaking the Bismarks Barrier, p.448.