Landing at Nassau Bay

The Landing at Nassau Bay was an amphibious landing by Allied forces at Nassau Bay during the New Guinea campaign of World War II that took place between 30 June and 6 July 1943. The landing was undertaken so that Allies could secure a beachhead to establish a supply point to shorten their supply lines for the proposed attack on Salamaua as part of the Salamaua-Lae campaign.

Background
Upon the recommendation of Commander Morton C. Mumma, the Allied South West Pacific Area GHQ determined that a beachhead at Nassau Bay would greatly shorten the supply line for Australian and American troops for the proposed attack against Salamaua.

During the night of 28 June 1943, the 162nd Infantry Regiment's Intelligence and Reconnaissance Platoon placed lights upon islands lying offshore between Nassau Bay and Mageri Point to guide the invasion flotilla. Colonel Archibald R. MacKechnie flew to the Bulolo Valley for a conference with General Stanley Savige to discuss the proposed landings. 'D' Company of the 2/6th Australian Infantry Battalion from Lababia Ridge was required to march to the mouth of the Bitoi River to divert Japanese attention from Nassau Bay. Also, one platoon of 'D' Company 2/6th Australian Infantry Battalion was sent to the landing beach to set up lights to guide the landing craft. 'A' Company of the Papuan Infantry Battalion, reconnoitered to Cape Dinga just south of Nassau Bay for the southern flank.

Prior to the landing the USAAF Fifth Air Force's B-25s bombed Imperial Japanese strong points along the Bitoi River, and A-20s pounded a supply dump on the southern side of Nassau Bay on 29 June. The amphibious landing force was known as MacKechnie Force.

Landing
Consisting of the combined elements of Colonel MacKechnie's American 162d Regiment as well as Australian units, MacKechnie Force embarked from Mort Bay at dusk on 29 June 1943. PT boats PT-142, PT-143, PT-120 of the Seventh Fleet took aboard 210 men of the 1st Battalion, 162nd Infantry Regiment, with PT-68 providing escorted. Twenty-nine LCVPs, two requisitioned Japanese barges of the 2nd Engineer Special Brigade, and one Landing Craft Mechanized of the 532nd Engineer Boat and Shore Regiment took the other 770 men of the 1st Battalion, 162nd Infantry Regiment on board at Mageri Point. The landing force was organized into three waves.

With rough seas, heavy rain, and poor visibility the landing force lost escort PT-68 after leaving Mort Bay. PT-142 with Lieutenant Commander Barry K. Atkins led the first wave of landing craft out of Mort Bay and due to poor visibility obscuring the offshore island guide lights the first wave overshot Nassau Bay by up to 3 mi. Time was taken turning around and finding the convoy again.

At Nassau Bay, a platoon of 'D' Company, 2/6th Australian Infantry Battalion of the 17th Brigade, from Mubo set landing markers to guide the landing craft into the beachhead. As the first wave with PT-142 arrived at Nassau Bay, PT-143 arrived with the second wave landing craft. The landing craft intermingled and landed on the same stretch of beach in 10 - 12 ft pounding surf. The landing craft were pushed far up on the beach, with seventeen unable to get off the beach which became broached and filled with water. The Landing Craft Mechanized, after unloading a bulldozer was able to proceed back out to sea and retrieved the troops off PT 142 and then returned to the beach, where it became swamped. The landing had been unopposed with 770 men landed at Nassau Bay. The landing craft breached were wrecked and most of the radios were damaged by salt water. PT-143 returned to the advanced PT Base at Morobe, while PT-142 and PT-68 provided seaward protection.

The garrison of 300 Imperial Japanese troops had retreated after Commander Torashige Tsukiokare was killed by a bomb in his Headquarters that day and fled into the jungle, believing that the bulldozer was a tank.

The third wave of landing craft with PT-120 arrived hours after the first two waves and decided not to land until the surf abated. They took shelter in a cove down the coast, until the storm had subsided and returned to Nassau Bay but failed to find the beachhead. The wave returned to Mageri Point.

During the first night 'A' and C Companies, 162nd Infantry Regiment, established defence lines 300 yd north and south, respectively, of the landing beach. A platoon of 'D' Company, 2/6th Australian Infantry Battalion defended the western flank. No contact was made with the Imperial Japanese that night.

At dawn on 30 June, the beach was cleared of all ammunition, equipment, and supplies. Machine guns salvaged from the wrecked landing craft were set up in the beach defences. 'C' Company marched south to the Tabali River just west of Cape Dinga to try to link up with the Papuan Infantry Battalion which was located to the south of Cape Dinga. 'A' Company patrolled north to the south arm of the Bitoi River and ran into enemy mortar and machine gun fire and was halted. Patrols reported the enemy present in some strength. 'A' Company with ' D' Company of 2/16th Australian Infantry Battalion attempted to strike the Japanese western flank but was stopped. 'D' Company of 2/6th Australian Infantry Battalion ran out of ammunition and was relieved by a detachment of engineers from the crews of the wrecked landing craft. Two platoons of 'C' Company rushed up from the south to join 'A' Company and at 15:00 started forward and by 16:50 had moved past the scattered Japanese opposition to reach the south arm of the Bitoi River.

Upon receiving word of the invasion in Lae, General Hatazō Adachi, ordered 150 men of III/66th Battalion south from Salamua. The Papuan Infantry Battalion began attacking the rear of the Japanese detachment of III/102nd Battalion at Cape Dinga and began moving toward the Nassau Bay beachhead. At 16:30 on 30 June, the remainder of 'C' Company defending the southern flank reported that Japanese troops were crossing the Tabali River just south of its position, and was ordered to withdraw to the southern densive flank of the beachhead and hold a line between the beach and a swamp a short distance inland. Before the remainder of 'C' Company could withdraw, Japanese troops attacked its rear and flank and fought its way north, losing the commander and four men on the way.

The beachhead defence line at the beach, utilising engineers, part of Australian 'D' Company, and headquarters were hastily prepared. At dusk one of 'C' Company's platoons reached the southern perimeter of the beachhead defence line. The Imperial Japanese attacked the defensive line in a series of attacks lasting all night, with machine gun, mortar, rifle and grenade fire against the beachhead defensive positions. Small parties of Japanese soldiers attempted to infiltrate the positions, but were beaten off. The Japanese withdrew before sunrise on 1 July. Patrols hunted down straggling Japanese during the morning.

The eastern most company of the 2/6th Australian Infantry Battalion advanced to the coast near the southern arm of the Bitoi River, driving off a company of Japanese. Further patrols found that the Japanese defenders north of Nassau Bay had withdrawn.

On 2 July, the third wave of landing craft with PT-120 reached Nassau Bay. PT-120 also strafed two Japanese held villages to the south of Nassau Bay near Cape Dinga. Further landing craft hauled by trawlers also arrived at Nassau Bay. The eastern most company of 2/6th Australian Infantry Battalion made contact with the northern perimeter of American troops at the south arm of the Bitoi River. Patrols by C Company, 162nd Infantry Regiment found Japanese defenders at Cape Dinga had been evacuated.

Four 75mm Pack Howitzer M1 artillery guns were unloaded on 3 July, together with reinforcements. MacKechnie Force patrols were then sent out towards Napier. By 4 July, more than 1,400 troops were ashore. PT-120 and PT-152 carried 140 troops to Nassau Bay, which were transferred to shore by landing craft. On 6 July, PT-120 & PT-149 transfer another 135 troops and escort 11 landing craft to Nassau Bay.

Aftermath
The Allied forces gained a supply point for the attack against Salamaua. Heavy artillery landed at Nassau Bay was able to shell Salamaua. The Papuan Infantry Battalion advanced along the coast ahead of the 162nd Infantry Regiment and reached Lake Salus on 9 July and then pushed on to Tambu Bay.