This was the US occupation of Kiriwina island in the Trobriand islands group and also of Woodlark island off the south-eastern corner of Papua to protect the right flank of the ‘Cartwheel’ advance by General Douglas MacArthur’s South-West Pacific Area forces in the south-western component of the ‘Elkton’ plan, and otherwise known initially as ‘Coronet’ (i) and then as ‘Operation I’ (30 June 1943).
Kiriwina is the largest of the Trobriand islands group to the north of the eastern tip of New Guinea. The island is shaped something like a tadpole, with a round upper part and a long peninsula to the south. It is about 25 miles (40 km) long and 7 miles (11.25 km) across its head. Kiriwina is very flat, with a maximum elevation of just 180 ft (55 m) near its northern end, and is covered with jungle. Its population in the World War II was about 7,500 persons. The island had numerous trails and its flat terrain was suitable for the construction of airfields, but it lacked landing beaches suitable for amphibious operations.
Woodlark is an island to the north-east of the eastern tip of New Guinea, and is some 44 miles (71 km) long and 20 miles (32 km) wide. Although ringed by reefs, it has a number of anchorages along its south coast, including Guasopa Harbour in the south-east, which could be approached only by two channels through the reef. Though relatively flat, there is some hilly terrain in the south, rising to a maximum elevation of 790 ft (240 m), and most of the south coast is lined with cliffs. The island is covered with jungle, and in the World War II period had few inhabitants.
The Japanese did not occupy the islands in their great advance to the south-east through the South-West Pacific region in the first four months of 1942.
The RAAF had established a radar station on Kiriwina island by March 1943, and the radar crews were alarmed to see Japanese survivors of the Battle of the Bismarck Sea coming ashore on 7 March. The next day, Australian troops killed 34 survivors and captured three, with eight other escaping into the jungle. Survivors continued to come ashore for some time thereafter, and the pro-Allied native population delivered many of these to the Australians.
In ‘Chronicle’, the ‘Leatherback’ elements of Lieutenant General Walter C. Krueger’s ‘Alamo’ Force (6th Army designated thus in order that it remained under the direct control of MacArthur rather than of General Sir Thomas Blamey’s combined Australian and US land forces command) were moved by sea from the base at Milne Bay at the extreme south-eastern tip of New Guinea for the first Allied amphibious operation of any real size in the South-West Pacific Area.
Initial planning for the seizure of Woodlark and Kiriwina islands was undertaken in May 1943 at Krueger’s headquarters in Brisbane, Australia, and the responsibility for the landings and for the co-ordination of the ground, air and naval planning was entrusted to Krueger by MacArthur. At the time the plans were being developed, Woodlark and Kiriwina islands were each required as future airfield sites to support operations in New Guinea, New Britain and the Solomon islands group.
The operation was the first amphibious landing undertaken in the South-West Pacific Area, and the thorough and comprehensive nature of the operation’s planning meant that it became the blueprint for the SWPA’s future landings.
Air support for the operation was split between Brigadier General Roger M. Ramey’s V Bomber Command of Major General George C. Kenney’s US 5th AAF, and two Australian operational groups. The V Bomber Command was to attack the Japanese airfields round Rabaul on each night from 25 to 30 June, and also to be ready to support the invasion fleet and provide close air support as and when required. The RAAF was to provide fighter cover as requested.
Reconnaissance parties landed on Woodlark and Kiriwina islands during May and reported that they were not occupied by Japanese troops. As a result of a delay in gathering the units assigned to the operation, these being spread across the north of Australia and New Guinea, the operation was scheduled for 30 June. An Australian radar unit, No. 305 Radar Station, arrived on Kiriwina island on 17 May and became operational on the following day to provide early warning of air threats.
The landings took place in conjunction with a landing at Nassau Bay in North-East New Guinea and the 'Toenails' landing on Rendova, New Georgia.
An advance party of the 112th Cavalry, under the command of Major D. M. McMains, left Milne Bay at the south-eastern tip of Papua at 16.00 on 22 June on board the destroyer transports Brooks and Humphreys to reach Woodlark island. Arriving at Guasopa Harbour at 00.32 on 23 June, the advance party landed in six ramped personnel landing craft. At 04.00 the destroyer transports departed for Milne Bay. An Australian coastwatcher, not having been informed of the landing, almost attacked the landing force with his islander guerrilla force, but then heard the troops’ voices and desisted. The advance party reconnoitred, established defences and facilities for the invasion force, and cleared obstructions from the designated landing beaches.
The 158th Infantry’s advance party, with a detachment of the 59th Combat Engineer Company and the 158th Infantry’s communication platoon, under the command of Lieutenant Colonel Floyd G. Powell, departed Milne Bay at 18.10 on 23 June on board the returned Brooks and Humphreys and, reaching Kiriwina island at midnight on 24 June landed along a channel winding through the reef to the beach at Losuia. The ships had not been emptied before departing, returning three nights later to unload heavy communication and engineer equipment left in their holds. The advance party built a coral causeway across the reef to facilitate direct landing.
On 25 June 2,600 troops of Colonel Julian W. Cunningham’s Woodlark Force (elements of the 112th Cavalry, 134th Field Artillery Battalion, 12th Marine Defense Battalion and quartermaster, port, ordnance, medical, and engineer units, a naval base unit and a construction battalion) departed Townsville on the north-east coast of Australia on six tank landing craft escorted by the destroyers Bagley and Henley, and the submarine chaser SC-749. The force arrived off Woodlark island, and the landing began at 21.00 on 30 June. Carrying more troops from Milne Bay, Brooks and Humphreys arrived at 01.00 on 1 July, and further supply echelons arrive in tank landing ships and infantry landing craft.
On 30 June the 2,250 men of Colonel J. Prugh Herndon’s Kiriwina Force (158th Infantry less its 2nd Battalion, 148th Field Artillery Battalion with other artillery, engineer, ordnance, medical, anti-aircraft, and quartermaster troops) departed Milne Bay in six infantry landing craft escorted by six destroyers, and arrived off Red beach near Losuia at 21.00. A supply echelon arrived on 30 June on 12 tank landing craft and seven mechanised landing craft.
The 16,800 or so men of the two landing forces were transported and escorted by the ships and craft of Rear Admiral Daniel E. Barbey’s Task Force 76 (7th Amphibious Force) with the destroyers Mugford, Bagley, Henley, Helm and Conyngham, and the transport group comprising Humphreys, Brooks, LST-447 and LST-454. Cover was provided by Rear Admiral V. A. C. Crutchley’s Australian Task Force 74, which comprised the heavy cruiser Australia, light cruiser Hobart and destroyers Arunta and Warramunga.
These two successes completed the Allied domination of the Solomon Sea, and allowed the construction of airfields. With the ‘Quadrant’ conference’s decision that New Britain and New Ireland would be isolated rather than reduced, the islands lost their raison d’ętre as fighter bases from which Rabaul on New Britain could be dominated, so aircraft based on the islands were used instead to help in the neutralisation of Japanese air power over New Britain and the north-western end of the Solomon islands group.
Except for reconnaissance flights and two small bombing attacks against Woodlark island, the Japanese took no action in relation to the occupation of the islands.
On Woodlark island the construction of an airfield was started by the 20th and 60th US Naval Construction Battalions on 2 July, and by 14 July the airfield consisted of one runway 3,000 ft (915 m) long and 150 ft (46 m) wide, and able to accommodate aircraft up to the size and weight of the Douglas C-47 transport. By 21 July the runway had been extended to a length of 5,200 ft (1585 m) with a crushed coral surface, and the 67th Fighter Squadron landed on this during 23 July. The airfield was ultimately extended to 6,500 ft (1980 m) in length and 225 ft (69 m) in width, together with a parallel runway 6,000 ft (1830 m) long and 60 ft (18.3 m) wide, and included hardstanding for 110 aircraft. The airfield was used as a stop-over and refuelling point.
Defensive positions were set up around Woodlark island with the anti-aircraft and coast-defence guns of the 12th Defense Battalion, and on the beach there were also machine guns and 37-mm light guns to deter assault landings.
A PT-boat and landing craft repair base was also constructed at Guasopa Bay, and the island was used as a supply base.
On Kiriwina island the difficulty of landing heavy engineering equipment meant that the construction of an airfield was delayed. Heavy rain further slowed construction, and unhappy with the progress, Krueger replaced Herndon in command of the Kiriwina Force with Colonel John T. Murray.
By 20 July a single runway 1,500 ft (460 m) long and 150 ft (45 m) wide had been cleared and roughly graded. By the end of July the runway had been lengthened to 5,000 ft (1525 m) and was ready to be surfaced with crushed coral. The RAAF’s No. 79 began operations from this surface on 18 August.
A seaplane base (anchorage and jetty) was also constructed at Losuia, where a PT-boat was also constructed in October 1943. This facility was closed as superfluous to requirement in February 1944. Kiriwina island was also used as a supply base.