'Broccoli' was a US subsidiary landing and subsequent operations in the Munda area of New Georgia island of the Solomon islands group as a follow-on to 'Toenails' (5/11 July 1943).
New Georgia lies about mid-way along the Solomon islands chain. At 45 miles (72.5 km) in length along its north-west/south-east axis with an area of 786 sq miles (2037 km˛), it is the largest of the New Georgia islands group, which also includes Kolombangara, Rendova and Vella Lavella islands. New Georgia’s north coast is protected by an almost continuous coral reef, but there are passes through the southern reef into Blanche Channel, an unusually deep protected body of water some 3,600 ft (1100 m) deep in places. Blanche Bay itself is accessible only from the south-east, its western entrance being blocked by reefs and islets. There are good anchorages on the north-west coast, facing Kolombangara across Kula Gulf, at Bairoko Harbour, Enogai Inlet, and Rice Anchorage. There are also anchorages on the south-east coast at Segi Point and Viru Harbour. There is also a good anchorage at Wickham Anchorage on the east coast of Vangunu island just to the east of New Georgia. However, the best natural anchorage in the group is Rendova Harbour to the south-west of the island.
New Georgia’s terrain comprises rugged, jungle-clad hills for the most part. The climate is still hotter and more humid than that of Guadalcanal, and malaria is rampant.
When the Pacific War of World War II began, the only Western settlement was the Lambeti copra plantation at Munda Point, across from Rendova island, where there was also a methodist mission. The local tribes were on good terms with the British colonials and sided with the Allies during the war. There was no transport network more sophisticated than native trails and most travel between settlements was by boat or canoe. The British administration of the area was based on Gizo island to the west of Kolombangara island, and had been selected for its relatively healthy climate and low incidence of malaria.
The Japanese undertook a reconnaissance of New Georgia in October 1942, and two rifle companies and two anti-aircraft battalions arrived to occupy Munda Point on 13 November. On 21 November there followed the first construction troops, who began work on the construction of an airfield, whose 4,700-ft (1430-m) runway was completed on 17 December. This airfield was used as a staging point during the Guadalcanal campaign, which was fought some 175 miles (280 km) to the south-east: Mitsubishi A6M Reisen 'Zero' fighters operating from this new airfield had the range and endurance for a useful loiter time over Henderson Field on Guadalcanal, and thus posed a serious threat to the US warplanes using this captured airfield. The defences of the New Georgia group were placed under the command of Major General Minoru Sasaki’s South-East Detachment at Vila on 31 May 1943, and comprised the 8th Combined Special Naval Landing Force and Sasaki’s infantry group of Lieutenant General Tadayoshi Sano’s 38th Division, and an integrated army and navy command was created right down to the smallest units. The forces actually located on New Georgia included the 6th Kure Special Naval Landing Force and the 229th Regiment.
Munda lies on the south coast of New Georgia’s north-western tip, and is protected by the reefs of the Munda Bar, which made direct amphibious assault impractical with the landing craft available in 1943. Thus the US campaign against Munda required landings at some remove from the target area and a long advance through the jungle.
In an effort to prevent Allied detection of their new airfield, the Japanese replaced each coconut palm as it was removed with fronds suspended from wires, but this ruse failed in the face of Allied intelligence efforts. By 28 November coastwatchers had reported that the Japanese were landing concrete and other construction materials on New Georgia for the airfield. On 3 December a photo-reconnaissance mission detected the ruse, and by 5 December the photographic interpreters had located gun emplacements and a 2,000-ft (1830-m) runway under the fronds. On 9 December Boring B-17 Flying Fortress heavy bombers made their first raid on this new facility, but neither this nor subsequent raids was able to prevent the Japanese from basing A6M fighters on the airfield after the first runway had been completed on 15 December. The Americans were, in short, now discovering for themselves what they had already demonstrated to the Japanese, namely the difficulty of permanently destroying an airfield with bombing. However, the US bombing did have the useful effect of making it impossible for the 'Zero' fighters, so hard-pressed defending their own base, to attempt to secure and maintain air superiority over Henderson Field. Moreover, Japanese convoys to New Georgia also came under heavy US air attack.
Munda was heavily bombarded by Rear Admiral Robert L. Ainsworth’s Task Force 67 (the light cruisers Nashville, St Louis and Helena, and the destroyers Fletcher and O’Bannon) during the night of 4-5 January 1943. The operation was notable as the first time that Consolidated PBY Catalina 'Black Cat' flying boats were used in such an operation, providing effective spotting for the bombardment force in concert with the submarine Grayback.
It was the continued serviceability of the airfield which led to the 'Broccoli' assault by Colonel Harry B. Liversedge’s Northern Landing Force (1st Marine Raider Battalion and the 3/145th Infantry and 3/148th Infantry of Major General Robert S. Beightler’s 37th Division). The Americans came ashore at Rice Anchorage on the north-western end of New Georgia some 16 miles (26 km) to the north-west of Munda, where 'Toenails' had been committed. The Northern Landing Force had departed Guadalcanal on 4 July to proceed up 'The Slot' and pass round the north-western end of New Georgia to make an unopposed landing at 02.00 on 5 July, though a Japanese battery at Enogai Inlet to the south-west fired on the transports.
The troops were carried in the troop-carrying destroyer conversions Dent, Talbot, McKean, Waters, Kilty, Crosby and Schley, and cover for the operation was provided by Rear Admiral Walden L. Ainsworth’s Task Force 36.1 comprising the light cruisers Honolulu and St Louis, and the destroyers Nicholas, Strong, O’Bannon, Chevalier and Taylor. The cruisers and destroyers bombarded the Japanese positions at Vila and Bairoko Harbour to cover the landing. At much the same time Captain Orita’s Japanese force, comprising the destroyers Mochitsuki, Mikatsuki and Hamakaze landed 1,200 troops near Vila in the Kula Gulf, and torpedoed and sank Strong. The subsequent detonation of the destroyer’s depth charges damaged Chevalier.
Once ashore, the men of the Northern Landing Force moved 6 miles (10 km) to the south-east to bivouac for its first night on the island in the southern end of the swampy area on each side of the small river debouching into the Enogai Inlet, and then began to fight its way to the north along the western side of the river and onto the western side of the Enogai Inlet, with the 3/145th Infantry holding the southern end of the inlet, so that the 1st Marine Raider Battalion could pen part of the Japanese defence against the inlet at Triri and then advance onto the Dragons Peninsula to secure the flanking Enogai Inlet and Bairoko Harbour on 10 July. By the following day the Northern Landing Force had cleared the peninsula of its last Japanese defenders. A roadblock on the trail to Munda had been established on 8 July, and this was held by the 3/148th Infantry until 17 July to block the approach of any Japanese reinforcements from the south and prevent the escape of any Japanese on the Dragons Peninsula to the south.
The US casualties were light, but the Japanese lost some 500 men, but even so the Americans to rethink their strategy for the Solomon islands campaign. Admiral William H. Halsey’s South Pacific Area forces would leapfrog Kolombangara island, between New Guinea and Vela Lavella islands, to land on the latter, which was only weakly defended Vella Lavella, in 'Dogeared'. This initiated the concept of leapfrogging Japanese strongpoints, a concept which characterised US amphibious operations in the Pacific and South-West Pacific theatres for the rest of the war.