New Guinea WW2 - A Maritime Campaign

To most Australians the campaign fought against the Japanese in New Guinea during WW2 is typified by images of Australian diggers and ‘Fuzzy Wuzzy Angels’ struggling along the Kokoda Track or fighting hand to hand at Milne Bay. Very few would consider this to have been a maritime campaign, yet this is exactly what it was, for the final arbiter of victory or defeat in the jungles of New Guinea was maritime power.

Following Japan’s attack on the United States Pacific Fleet at Pearl Harbor on 7 December 1941, the sinking of Force Z (HMS Prince of Wales and HMS Repulse), and the subsequent defeat of Allied naval forces in the Battles of the Java Sea and Sunda Strait, the Imperial Japanese Navy had achieved control of the seas in the South Pacific. This enabled her to project her military forces into the islands north of Australia. By 23 January 1942 Rabaul had fallen and became the location of the Japanese forward headquarters. In order to protect Rabaul the Japanese occupied Lae and Salamaua on 8 March. However, the Japanese were soon to find that the capture of Lae did not ensure the security of Rabaul from air attacks, and they decided to capture Port Moresby by amphibious assault.

That the Japanese intended to conduct an amphibious assault on Port Moresby (Operation MO) had become known to the Commander-in-Chief Pacific Fleet through the work of USN and RAN code breakers. As a result of this intelligence Task Force 17, built around the aircraft carriers USS Lexington and USS Yorktown, was sent to the Coral Sea to engage the Japanese. Also assigned to Task Force 17 was a cruiser squadron under command of RADM J Crace RN, which included HMAS Australia and HMAS Hobart. Prior to the battle RADM FJ Fletcher, USN directed Admiral Crace to patrol the Jomard Passage at the eastern tip of New Guinea. The Port Moresby Invasion Force, which included the light carrier Shoho, was provided with distant cover by the aircraft carriers Shokaku and Zuikaku. As it approached the Jomard Passage the Invasion Force learnt of the presence of Admiral Crace’s cruisers and halted awaiting the outcome of the impending carrier battle further to the south. Although in the ensuing Battle of the Coral Sea the Americans lost the Lexington, the Japanese carriers were in no condition to support the further advance of the Port Moresby Invasion Force, which by this time had lost the Shoho. Rather than fight their way through the cruiser blocking force, the Japanese retired to Rabaul.

Failure to take Port Moresby by amphibious assault did not deter the Japanese. They immediately commenced planning to take Port Moresby by assault from the land. This would entail a landing at Buna, which was undertaken on 21 July, and an advance across the Owen Stanley Ranges. All the logistics required by the Japanese to support this assault, and the Allies to oppose it, had to be carried by ships. So began the struggle for control of the sea-lanes.

Coastal convoy routes.

From May 1942 Japanese submarine operations off Australia’s east coast began to take a toll on shipping. By August seven ships had been sunk and a further six damaged. Convoys were organised to protect this vital shipping and the First Naval Member was designated the Commander South West Pacific Sea Frontiers. Fortunately for the Allies the Japanese failed to allocate sufficient resources to the submarine campaign and this, coupled with a lack of strategic intelligence, ensured that losses were never of such a magnitude as to disrupt the flow of supplies north. By the end of 1943 over 60 warships were allocated for convoy escort duties. Figure 1 shows the convoy route along eastern Australia. By contrast, in the interdiction campaign against the Japanese sea lines of communications USN submarines effectively destroyed the Japanese merchant marine. An example of the fate of Japanese convoys is the January 1943 patrol by the USS Wahoo. During the course of a ten hour running battle off New Guinea, she reported sinking an entire convoy of two Japanese freighters, one transport and one tanker.

The Japanese losses of merchant shipping ensured that only a trickle of logistics and reinforcements reached the Japanese in New Guinea. By contrast Allied forces were receiving more and more supplies and equipment. As an indication, from the opening of the campaign until September 1943, 7261 vehicles, 306 guns, 596,033 tons of stores, and 75 surface craft were shipped to New Guinea. By mid-1943 the Japanese attack on shipping was coming to an end as their submarines and light forces were being increasingly used to supply cut off island garrisons. During the course of the war in excess of 1100 coastal convoys were escorted by units of the RAN, not including a number of special convoys or troop convoys.

Air power contributed to the maritime interdiction campaign, attacking Japanese shipping, airfields and port facilities. The first Japanese defeat at Milne Bay was assisted by the destruction of an enemy convoy on 25 August 1942 by 75 Squadron RAAF. In the most notable example, intelligence warned of the last major Japanese resupply operation, a reinforcement convoy from Rabaul to Lae. Termed the Battle of the Bismarck Sea, continuous coordinated attacks by RAAF and US aircraft on 3 March 1943 resulted in the sinking of all eight transports, four out of eight destroyers, and the loss of at least one third of the Japanese troops. This action was untypical because weeks of advance warning was provided, which allowed for intensive, coordinated training and rehearsal - most shipping interdiction actions were ad hoc at short notice. From mid-1943 RAAF Catalinas mined Japanese ports, sinking or damaging 40% of all shipping entering the Balikpapan-Surabaya area.

As the Americans and Australians went over to the offensive in New Guinea the inherent advantages of sea power, in the context of flexibility and manoeuvre, became apparent. The Seventh Fleet Amphibious Force was established under command of RADM Daniel E Barbey, USN. From October 1942 through to July 1944 this force conducted a series of amphibious assaults from Goodenough Island in the east through to Sansapor on the western tip of New Guinea (see Figure 2). These assaults, when combined with the central Pacific advance, were a demonstration of manoeuvre warfare on a grand scale. Strong enemy forces were bypassed, while captured areas became advanced bases, airfields and logistic depots for the continuing maritime offensive against the Japanese. After Kokoda there were no other northern advances across New Guinea. The movement of Allied forces was in a westerly direction in a series of amphibious assaults.

RAN ships, in particular the Infantry Landing Ships HMAS Kanimbla, HMAS Westralia and HMAS Manoora, cruisers, destroyers and the Bathurst Class corvettes played an important part in the naval campaign for New Guinea providing escorts, fire support, amphibious sea lift, minesweeping, survey and logistic support. The smaller craft of the RAN, Fairmiles, HDMLs and other motor launches, also played an important role in patrol work, convoy escorts, hydrographic surveys and clandestine operations. Supporting these ships were a number of logistics and other specialist ships that ensured the Allied ground and air forces had the required equipment and support to conduct and sustain operations in a very hostile environment. Had the Allies been unable secure the sea lines of communications the final outcome in the jungles of New Guinea may have been very different. It was not the stalwart efforts of the Australian and US ground forces alone, but the combination with the maritime interdiction campaign against Japanese supply lines, amphibious movements to outflank and bypass defensive positions, and the successful convoying of ‘troopers, beans and bullets in greater and greater numbers’ that forced the Imperial Japanese forces back from Port Moresby to their final defeat.