The battle for Enogai Inlet (5-11 July 1943) was the first and most successful operation carried out by the Northern Landing Group on New Georgia and saw them capture a Japanese coastal gun battery as well as block the important trail from Bairoko to Munda.
The Japanese had two important bases on the north-western coast of New Georgia. The barge base at Bairoko was an important link in the route between the major base at Vila on Kolombangara, at the northern end of a trail from Munda. A little further to the east, at Enogai, they had a battery of 140mm guns that helped dominate Kula Gulf, between Kolombangara and New Georgia. The area between Bairoko and Enogai, known as the Dragons Peninsula, would be the main battlefield for the Northern Landing Group.
The Americans decided to land at Rice Anchorage, east of Enogai. This meant that they would have a difficult cross-country march before they could attack the Japanese positions. The battery at Enogai was on the western side of a deep inlet, and difficult terrain at the southern end of the inlet forced the Americans to move even further inland to find a suitable crossing point.
The attack on Enogai would be made by the Northern Landing Group (Colonel Liversedge). He had three battalions under his command - the 3rd Battalions from the 145th and 148th Infantry Regiments, 37th Infantry Division and the 1st Raider Battalion, 1st Marine Raider Regiment. His men were lightly equipped in order to allow them to pass through the jungle, and their heaviest weapons were mortars.
The convoy carrying Liversedge's force left Guadalcanal on 4 July. It was escorted by a naval force of three cruisers and nine destroyers under Rear Admiral Ainsworth, which was to both protect the troop transports and bombard nearby Japanese bases. On the night of 4-5 July Ainsworth's ships bombarded Vila on Kolombangara and Bairoko, while the invasion convoy landed the Northern Landing Group at Rice Anchorage. The destroyer USS Strong was sunk by a torpedo during this operation, but otherwise the American ships were left alone (on the following day they were involved in the battle of Kula Gulf, 6 July 1943, where the cruiser Helena was sunk in an attempt to prevent fresh Japanese troops from reaching the New Georgia islands).
This was a rather unusual landing, in that the landing area was already under Allied control. Flight Lieutenant J.A. Corrigan (RAAF), an Australian coastwatcher, and Captain Clay A. Boyd, a Marine raider, along with around 200 natives, were waiting for the invaders. They had cleared a landing area 550 yards upstream from the mouth of Rice Inlet and even cut two new trails from Rice towards Enogai alongside an existing trail.
The landing began at 1.30am on 5 July and was largely complete by 3.30am. At dawn the naval force withdrew, with 72 men and 2% of the cargo still onboard, in order to avoid more accurate fire from the Japanese coastal guns. The landing had gone well, although 200 men were landed a short distance to the north, on the wrong side of the anchorage, and took several days to catch up.
The American troops were quickly established at Rice, and at 6.00am on 5 July Colonel Liversedge ordered the start of the cross-country march. The Marine Raiders, 3rd Battalion 148th Infantry and two companies from the 145th Infantry were to advance along the three trails towards Enogai. Once they were across the swamps south of the Enogai Inlet the 148th was to head west to block the Munda-Bairoko trail, while the rest of the force turned north to advance along the western side of the inlet.
The first few days of the advance were slow and difficult but unopposed and by the morning of 7 July the Americans were around the tip of Enogai Inlet. The force split into two, with Lt. Col Delbert E. Schultz's 3rd Battalion 148th Infantry heading towards the Munda-Bairoko Trail, while the rest of the first advanced up the inlet.
The Japanese were finally found at Triri, half way up the western shore of the Enogai Inlet, on 7 July. The advancing Marines clashed with a small patrol, alerting the Japanese to their presence. The Marines seized Triri after a short fight, and by 4pm the entire attacking force had reached the village. A bonus of this fight was the discovery of a map showing the position of all of the Japanese guns at Enogai.
8 July saw the Marines engaged in a fierce fight to the south-west of Triri, while a force sent toward Enogai found no Japanese but also ran into a mangrove swamp that blocked their first line of advance. They returned to Triri just in time to defeat a Japanese counterattack.
During the day two companies from the 145th Infantry replaced the Marines in the south, and by the end of the day the Japanese force had been dispersed.
On 9 July most of the 1st Raider Battalion advanced along a different trail towards Enogai. By 11am the Marines could see the coast west of Enogai, and were in a position to trap the Japanese defenders on a peninsula of higher ground. The Americans began an advance towards Enogai Point, but ran into Japanese machine guns. A four-company-strong assault was repulsed, and the American advance stopped for the day.
Overnight the Americans sent out a number of patrols and soon had a clear idea of the Japanese positions. The Japanese were strongest in their centre and right but B Company, on the American right, was unopposed.
The Americans resumed their attack at 7am on 10 July. A Company on their left and C Company in the centre made slow progress, but B Company advanced rapidly and got around the Japanese left. A Company was then able to make progress and by 3pm most resistance was over. A couple of Japanese strongholds held out until 11 July but the area was now secured. The Marines had lost 47 dead, 4 mussing and 74 wounded in the battle. Japanese casualties were estimated at 150-350, although Japanese accounts suggest that the area was defended by one infantry platoon (perhaps 60 men) and 81 naval soldiers.
The hardest fighting took place around the 3rd Battalion, 148th Infantry (Schultz) and its road-block on the trail from Bairoko to Munda. By the morning of 8th July this roadblock was in place. I Company was facing Bairoko, K Company Munda, L Company covered their flanks and M Company formed a reserve.
The first combat came at around 13.00 when a small Japanese force came down the trail from Bairoko. After a short fire fight this squad fled. A larger attack, by 40-50 Japanese troops, was launched two hours later and forced the outposts to pull back, but got no further.
9 July was quiet, with no contact with the Japanese. The main fighting began on 10 July. It started with a small probing attack by 50 men on the American right, followed by a second probing attack, this time by 80 men against the American left. This was followed by a heavy attack on the American right, which hit the junction between I and L Companies. The Americans were forced to withdraw in the face of this attack, by the Japanese 13th Infantry Regiment. The Japanese captured a small ridge and set up a strong defensive position.
Schultz ordered Company K to make an immediate counter-attack, but this was repulsed. American mortar fire helped prevent the Japanese from advancing any further, but a second attack by Company K on 11 July also failed. On the night of 11-12 July the Japanese launched a banzai attack against Company K's positions, but this was repulsed easily.
On 11 July Company I, 145th Infantry, arrived to reinforce Schultz. The new company was used to make a fresh attack on the Japanese position on the ridge on the morning of 12 July, only to discover that the Japanese had retreated. This ended the main fighting around the road block, and it appears that the Japanese simply moved to a different trail. The road block was held until 17 July when Schultz was ordered back to Triri to prepare for the attack on Bairoko.