Balikpapan.
1 July 1945

The assault went ahead. For two weeks before the invasion Allied mine sweepers cleared huge numbers of mines placed in Balikpapan harbour by both sides. A convoy of 100 ships landed the 18th and 21st Brigades south of Balikpapan township.

First ashore at Klandasan, just south of Balikpapan, were the 16th and 27th Battalions. Their advances differed considerably: the latter found the going easy while the former pushed forward in the face of considerable opposition.

The day after the Australians took command of Mount Malang the Sepinggang airfield fell to the 14th Battalion without opposition. Tough opposition from Japanese entrenched in the hills was encountered by the 25 Brigade.

On 4 July, although hampered by Japanese in the surrounding hills, Australian troops captured the Manggar airfield. Several heavy naval guns possessed by the enemy did considerable damage to Australian tanks, so that night Australian patrols attacked and took the gun positions. In the north the 25th Brigade was advancing along the Milford Highway against violent resistance. Australian units suffered considerable losses between 4 July and 9 July.

By 21 July the enemy had withdrawn through the village of Batuchampar, fighting doggedly all the way. When the enemy pulled back into the hills the Australians opted not to follow.

The other front in the Balikpapan operation opened on the western side of Balikpapan Bay on 5 July. Its aim was to neutralise any Japanese action which might threaten ships crowded in Bay. Real resistance was not encountered until 7 July, and even that was half-hearted. The 9th Battalion advanced easily against only sporadic battles with the enemy.

During May and June I945, Australian bombing -which had begun in October 1944-was intensified to become the softening up for a seaborne assault by the  Australian Seventh Division under the command of Maj-General E J Milford. The object of the operation was to capture and hold the Balikpapan-Manggar area of eastern Borneo for the establishment of air and naval facilities in the area and to conserve the petroleum producing and processing installations. The Japanese had had plenty of time to fortify Balikpapan-they had held it since January 1942 The 9th Division landings at Tarakan, Brunei and Labuan had warned them of the type of assault to expect. Aerial photographs and information through intelligence channels showed powerful defences. An offshore underwater obstacle of coconut logs laced together, three deep, starting north of Manggar, had been extended westward along the coast to include Klandasan. Extensive anti-tank ditches had been constructed. Trench networks on the ridges north of the beaches had been extended and improved. In the Klandasan area alone fifty tunnel entrances had been detected. Extensive land mines and booby-traps were expected. Several heavy coast defence guns had been located. Japanese anti-aircraft defences-described by Australian Air Force as the heaviest yet encountered in the South-west Pacific area-had already taken toll of Australian bombers. The majority of the weapons were of a dual-purpose type, capable also of being used for coastal defence.

There was a strong possibility of the Japanese using a burning-oil defence on the beaches. The pipeline from Sambodja to Balikpapan runs parallel to and within 300 yards of the beach. Flows of oil from points along this pipeline, and from the refineries themselves, could be ignited and directed to the beaches with devastating effect. To counter this Australian bombers were directed to destroy large sections of the pipeline before the landing. A triple minefield protected the harbour and sea approaches. The latest Allied acoustic mines had been dropped from the air to complicate the existing Dutch and Japanese fields. It meant a long and hazardous job for the mine sweepers because Australian mines are particularly difficult to sweep. Japanese strength in the Balikpapan area was estimated to be 3900 with reinforcements of another l500 at Samarinda, sixty miles to the north-east. In addition to these troops 4500 civilian labourers, made up of Japanese, Formosans and Indonesians, were thought to be in the Balikpapan-Samarinda localities.

The initial planning for the operations was carried out at Kairi on the Atherton Tableland. Here, during April and May 1945, a small team, under the direction of Major General Milford, made plans for the initial assault. Four possible landing beaches were in the area. Of these Manggar and Klandasan were the most suitable.

There were two ideas about how Balikpapan should be taken. One was to land on the coast at Manggar and advance along twelve miles of narrow coastal plain to the main objective, the other to land right in the thick of the Japanese defences at Klandasan, two miles from Balikpapan. Less resistance was expected in the first stages at Manggar, but the Japanese would then adjust his defences against a threat from a known direction, thus prolonging the campaign. The more daring alternative-to land in the heart of the Japanese defences at Klandasan-was chosen, while an alternative plan allowed for a landing at Manggar should Klandasan prove to be too powerfully defended. At Klandasan it was hoped to achieve quick results by seizing the key point of the Japanese defences in the initial assault, thus disorganising his force, shortening the campaign and saving lives.

Three brigade groups of the 7th Division were to be committed-the first time in its history that the complete division had fought as one force. 18th Brigade, Brigadier F O Chilton) and 21st Brigade, Brigadier I N Dougherty) were to land side by side in the initial beach assault, while 25th Brigade, Brigadier K W Eather) was to remain offshore as a floating reserve. These Brigades were commanded by, and respectively. The target date for the landing was fixed for the1 July-F-day.

The 7th Division staged at Morotai during June where the planning for the invasion was finalised. Almost on arrival, troops began to re-embark on ships of the assault convoy. Day by day thousands of soldiers went on to diesel-driven barges which scurried across the bay to the three LSI's, HMAS Manoora, Kanimbla and Westralia, or to LST's or the many other types of craft. Heavy field guns, flame-thrower tanks, Matilda tanks, motor vehicles, heavy engineering equipment all went the same way. On 24 June, two days before setting off for Borneo, the assault convoy steamed a short way up the coast from Morotai to rehearse on a smaller scale the amphibious landing. About midday on 26 June the largest convoy to carry an Australian invasion force left Morotai and sailed due west for the coast of Borneo. There were more than 200 ships sailing in battle formation.

The troops were told about the strength and weight of Australian assault, armour, support, even the number of rounds of shellfire to be laid down on the objectives before the landing. They were kept informed of the progress made by the mine sweepers and the underwater demolition teams. Sixteen days before the target date mine sweepers had begun the hazardous task of sweeping a passage through the triple minefield off Balikpapan. They came under constant fire from the Japanese heavy guns. Australian destroyers engaged the Japanese shore guns and the mine sweepers carried out their task successfully, but not without loss.

Although Australian sappers had been trained in underwater demolition tasks, the Navy had taken over responsibility for all obstacles below high-water mark. Two days before F-day specially trained US underwater demolition teams blasted a gap 800 yards wide and another 600 yards to 650 yards in the three rows of the offshore timber obstacle. This was accomplished by approaching in a landing craft, transferring to rubber boats and then swimming the last 300 yards to the obstacle, taking explosives and other equipment with them. The explosives were attached to the timber barricade and detonated electrically. The same day Australian engineer parties ensured that the beach was free of mines. At 3 am on the1 July a dull red glow on the horizon a few points to starboard could be seen. from the armada-it was Balikpapan on fire-a result of the rapidly increasing tempo of Australian air and naval bombardment. A few miles to go and action stations sounded-day was breaking. Before dawn the thunder of guns from combined Australian, American and Dutch warships and the drone of heavy bombers overhead told of the opening of Australian assault.

Dawn unveiled a terrifying scene. The whole shoreline was blanketed in smoke patterned with tongues of flame shooting hundreds of feet upwards. The beachhead and rolling inland hills were erupting and rocking under the impact of hundreds of tons of high explosive shells and aerial bombs. H-hour for the beach assault was set for 9 am. At 7 am the assault troops descended to the landing craft by rope nets. They were eight and a half miles from the shore at the entrance to a 500-yard-wide channel through the minefields. For two hours the sea was a congested mass of small craft manoeuvring into their respective assault waves. Then rocket ships went into action. In two sweeps along the waterfront they plastered 2000 yards of landing beach. As H-hour drew closer Australian barrage increased. To every 230 square yards of the actual landing beach the Navy hurled an average of one shell or rocket. Never before in the Pacific had Australians seen such a tremendous and spectacular display. There was some ineffectual reply to Australian shellfire. Flak from Japanese anti-aircraft fire patterned the smoke shrouded sky.

Five minutes before 9 am the first assault wave of three infantry Battalions hit the beach, 2/10th and 2/12th Battalions of the 18th Brigade on the left, and beside them 2/27th Battalion of 21st Brigade. Ramps of the assault craft banged down on a bewildering scene of desolation. Against a background of black smoke and burning oil stood shell-splintered coconut Palms and the rubble of brick buildings, while native huts were burning fiercely. A few scattered shots harassed the beachhead but the landing was practically unopposed. The Japanese had withdrawn to his tunnels, pillboxes and entrenchments which pockmarked the dominating features some hundreds of yards inland. Troops and heavy mechanical equipment poured on to the narrow beachhead. Every man knew his job, every vehicle and piece of heavy equipment had its allotted place. Engineers were looking for and delousing mines; signallers were running telephone wire; wireless sets were in operation. Matildas and flame-thrower tanks ploughed across the beach and inland to support the infantry.

Bridge laying tanks and bridging equipment capable of spanning I 60-foot gaps were brought ashore in early waves. Bulldozers cleared passages from the beach to the main highway which runs parallel to the beach from the town proper to the airstrips, and on to the oil fields of Sambodja. The late Maj-General George Alan Vasey, loved by every man who had fought with him, was remembered here. The highway was given his name -Vasey Highway. For the first time Australian short 25-pounders complete with ammunition and gun crews were landed in DUKWs (amphibious craft) which rapidly moved to the areas already selected for gun positions. AD hour after landing, shells from eight 25-pounders were whistling over the heads of Australian advancing infantry to thicken up the naval fire. In direct wireless communication with the warships were Naval Bombardment Shore Fire (Control Parties. From vantage points with Australian forward troops these parties accurately directed broadsides from cruisers and destroyers on to the Japanese defensive positions.

Six-pounder tank attack guns and 4.2-inch. mortars, manned by gunners of 2/2nd Tank Attack Regiment, were brought ashore in LVT's which hit the beach with the assaulting infantry. They were in action forty minutes later. The 4.2-inch mortars blasted the Japanese on dominating features farther inland while the 6-pounders closely supported the infantry in knocking out bunker positions at a few hundred yards' range. To protect the rapidly expanding mass of equipment in this confined area the infantry. The advance was advancing faster against opposition which was lighter than expected. Only fifteen minutes after landing the three assaulting infantry Battalions had penetrated 800 yards across the beach plain to the pipeline running parallel to the beach. This marked the first phase of the operation: the beachhead had been secured. On the left flank nearer the town proper and the oil refineries, 2/10th Battalion swung to the west, advancing through the rubble of houses on the outskirts of the residential area, Klandasan. The objective was an abrupt feature named Parramatta-a ridge 300 feet high, running IS00 yards due north, on which the Japanese defences commanded the entire Klandasan beach.

Parramatta Ridge was a Japanese fortress. At the top was a cunning trench system, while a hundred feet below were vast intercommunicating honeycomb tunnels. On the seaward side, sheltered in concrete and armoured emplacements, were two I 20-mm. naval guns. Australian shells had shaken the Japanese out of this fortress, razed every vestige of forest, pitted it from top to bottom with craters, and made the way easy for the infantry. At the southernmost point of Parramatta Ridge was Hill 87. C Company of the 2/10th Battalion launched an attack against the Japanese on this feature. With tank support the advance would have been difficult enough, but the tanks of 2/1st Armoured Regiment had bogged down near the beach and could not be brought forward in time. With heavy support of 25 pounders and 4.2-inch mortars, C Company captured Hill 87 by I pm The Japanese had been strongly emplaced in tunnels on this hill and their sniper fire was accurate.

By this time the tanks had passed the boggy ground near the coast by moving along Vasey Highway through Petersham Junction, reaching Hill 87 in time to support C Company's further advance north along Parramatta Ridge. While the infantry were mopping up around Japanese bunker positions and native huts, two tanks-a Matilda and a flame-thrower-moved forward I00 yards in front of a platoon of C' Company. The Matilda blasted open bunker positions with its 2-pounder gun and through the openings the second tank shot jets of flame. Infantry cleaned up what was left. Japanese opposition was determined, but by 2.20 pm Parramatta Ridge was completely in Australian hands.

During the afternoon 2/9th Battalion progressively relieved the remainder of 2/10th in the initial beachhead area, allowing them to concentrate on Parramatta Ridge with C Company. Meanwhile, in the centre between 2/10th and 2/27th Battalions, 2/12th Battalion had cleared the firmly entrenched Japanese from prominent features to a depth of 1500 yards. On the right flank the 2/27th Battalion had advanced forward of the pipeline to capture features Romilly and Rottnest, which menaced the beachhead. One company then swung to the east dealing with isolated bunker positions, while patrols cleared the area to the Klandasan Besar River. 2/16th Battalion landed on the heels of 2/27th Battalion and passing through the captured Romilly feature occupied ridges to the north and east of Rottnest against mortar and machine-gun fire. Stray Japanese with rifles scattered throughout the area had to be dug out before the advance could continue. From these captured features 2/16th launched attacks against firmly entrenched Japanese on Malang feature, 2000 yards north of the beachhead. Malang was in Australian hands by 4 pm.

During this time 2/14th Battalion and 2/7th Cavalry Commando Regiment had landed and passed through 2/27th Battalion, swinging east to cross the Klandasan Besar River. A high feature on the far bank was captured by 2/14th against light opposition, while 2/7th Commando Regiment advanced to the north-east occupying the same ridge I000 yards farther inland. Sappers moved with the attacking infantry, marking minefields to allow the infantry to advance freely. Behind the advancing troops more engineers were finding and delousing numerous heavy mines and booby-traps. So thorough was their work that these Japanese defences caused few casualties among Australian troops. When night fell on the battlefields at Balikpapan after that first day's fighting the 7th Division had over-run numerous heavily defended localities, captured many Japanese antiaircraft and machine guns, denied him the high ground from which serious interference could have been caused to the unloading of stores, and split open the crust of defences protecting the town itself and the docks area. Only spasmodic shells and mortar bombs harassed the beachhead and few found their mark. The bold strategy had been eminently successful, and careful planning had saved casualties during that vital first day. Australian casualties were twenty-two killed and seventy-four wounded. The Japanese had suffered ten times that number, and more.

Then followed a thunderous night of naval and artillery shelling, night bombing, mortar and machine-gun fire to which the Japanese sporadically replied. The whole northern half of the sky was bright, then brilliant red. Star shells illuminated the battle areas, revealing infiltrating parties of Japanese which clashed with Australian patrols. As dawn broke more than 300 Japanese dead lay scattered about Parramatta Ridge many as the result of the night's patrol clashes. Beside some of the bodies were long wooden spears with sharp points of metal-a primitive weapon, but efficient in the dark. Below Parramatta nestles the former lovely Dutch suburb, Klandasan, with street upon street of neat brick villas, now shell-splintered ruins. It was thought that the Japanese would fight house-to-house and street-to-street, but less than a dozen remained with a few natives in ruined Klandasan that morning. The natives, pitifully emaciated from starvation, lay exhausted among their own dead, too weak to move. The few stray Japanese were mopped up by 2/9th Battalion, which had advanced through the Santosa barracks area. Many tunnel entrances led into the hills near Santosa barracks and Klandasan. Some of these tunnels, particularly those of the Japanese commanders, were comfortably furnished. The bypassing of these tunnels would have left Australian rear open to attack. Matildas and a flame-throwing frog, supporting 2/9th's advance, supplied the answer: fierce jets of flame from the frog roared into the dark openings, while the Matildas demolished the entrances with 2-pounder shells, bottling up the occupants. Silhouetted on a ridge against an oil-blackened sky to the west of Parramatta were the blasted and tangled installations of the oil-cracking plant. Along this ridge to the right, large squat oil storage tanks were set on a tabletop feature: Tank Plateau. Not one of these tanks had escaped Australian bombardment.

During the second morning's fighting a large storage tank burst. A great sea of blazing oil roared down the valley between Tank Plateau and Parramatta Ridge, where Australian patrols were active. The whole valley became an inferno. So terrific was the heat that Australian men on the ridge threw themselves on the ground, pressing their faces against the earth and escaping the fire. Following a heavy artillery and mortar concentration that afternoon a company of 2/10th Battalion skirted the valley and mounted the southern slopes of the cracking-plant feature. A 6-pounder tank-attack gun supporting this attack accurately sniped four machine-gun posts, destroying them with direct hits. North of Parramatta two companies of 2/10th Battalion had pushed the Japanese from a high feature overlooking ! the town and harbour: Newcastle feature. The division was now well placed to launch an attack on Balikpapan itself.

Morning of 2 July had seen the reserve infantry brigade 25th-beaching and moving inland to relieve units of the two assault brigades in the central sector. This enabled 18th to concentrate its entire force for an attack on the town, and 21st to make a successful thrust east along Vasey Highway. With 2/7th Commando Regiment protecting its left flank, 2/14th Sepmggang Battalion rapidly advanced along Vasey Highway against scattered opposition. On the left flank Australian dismounted cavalry was held up by strongly entrenched Japanese in the foothills about I000 yards north of the highway, but 2/14th continued to advance, enveloping Sepinggang airstrip by 11 am on 2 July. The airstrip was soon secured. It was badly cratered, but work began immediately and it was serviceable for Auster scout planes by midday the following day. Back on the Klandasan beach and for some distance inland huge ordnance and engineer dumps were rapidly expanding. Vehicles of all descriptions-bulldozers, Alligators, graders, heavy trucks and jeeps-cluttered the roads awaiting movement to the dispersal areas.

Large floating docks which had been brought 800 miles in the assault convoy, now spanned the shallow water between the beach and the landing ships. All day and most of the night landing craft ferried equipment ashore, while LSTs and LCTs disgorged hundreds of tons of cargo. On the 18th Brigade front, 2/12th Battalion had relieved 2/10th's companies on Newcastle feature-our foremost point to Balikpapan township. From this 300-foot eminence, through gaps in the smoke on the morning of that third day's fighting, one could look down on the devastated thoroughfares and built-up areas less than half a mile away. In the left foreground was the thousand-yard-long Tank Plateau, smoking after its terrific pounding. Across the town the harbour front with its many broken piers; rising above the outrunning tide were the funnels and masts of a Japanese warship and the broken hulls of many small craft. To the right, beside a muddy inner harbour, was old Kerosene Tank Farm. On the far right, two miles away, the old Dutch Barracks, and on the far left, Cape Toekoeng and Signal Hill.

At 9 am the 18th Brigade launched a three pronged attack on Balikpapan. On the left, supported by a troop of Matildas and a flame throwing frog, 2/9th Battalion captured a Japanese radar station on Signal Hill, and advancing around Cape Toekoeng, cleared the harbour front north to the old oil refinery. Advancing through the twisted, white-hot refining installations, and across Tank Plateau, 2/10th Battalion occupied the town area at the power-house, north of 2/9th. To complete the occupation of Balikpapan 2/12th Battalion had pushed north-west from Newcastle to clear the industrial area, Pandansari. Heavy mortaring and shelling from dual-purpose anti-aircraft guns on two nearby features, Nail and Nurse, delayed 2/l2th's advance to Pandansari. The Japanese fire was quickly silenced by naval fire and the 25 pounders of 2/4th Field Regiment. A company of 2/12th Battalion with tank 6upport then attacked Nail feature, securing it during the late afternoon.

Except for a few scattered Japanese snipers in bunker positions, who were routed by flame-throwers and mopped up by the infantry, Balikpapan had been evacuated by the Japanese. All that remained was an eerie, deserted mass of crumbling mortar and the charred skeletons of power plants, factories and business houses. Huge storage tanks had collapsed centrally and lay flattened. Telephone posts and broken wires drunkenly lined the main highway along the waterfront and there were many damaged motor cars; locomotives used for hauling long lines of coal to the wharves had been brought to a standstill. Beside the road were shattered oil-pipes from which oil still dribbled to feed the diminishing flames.

With Auster scout planes using the Sepinggang strip, 21st Brigade's next objective lay six miles to the north-east Advance to Manggar airfield, the second largest in Borneo. Relieved by 2/27th Battalion at Sepinggang on 3 July, 2/l4th Battalion advanced farther along Vasey Highway. The bitumen surface of this coastal road was badly cratered and bridges over the many small streams had been blown. The area between the road and the coast had been heavily mined and booby-trapped. As the infantry advanced these were deloused by engineers, who immediately began to repair the bridges and road. On the far bank of Batakan-ketjil 2/14th Battalion encountered a small Japanese force in two pillboxes. With naval-fire support C Company of 2/l4th quickly drove the Japanese from their pillboxes, and the following morning Australian advance continued. Based at Sepinggang with 2/27th Battalion, 2/7th Cavalry Commando Regiment was patrolling vigorously inland to a depth of 2000 yards giving left flank protection to 2/l4th.The 2/14th Battalion met little opposition approaching the Manggar Besar River during late afternoon of the 4 July. On the northern bank of this river the airstrip runs parallel to the coast and beside the Vasey Highway. The bridge spanning Manggar Besar had been demolished at both ends, but two companies of 2/14th Battalion pushed across the river. B Company secured the bridgehead on the northern bank while A Company advanced to the far end of the airstrip, quickly setting up a road block.

Then the Japanese staged his first determined stand in this sector. From many gun emplacements, set in a group of ridges overlooking the northern end of the airstrip, he opened fire on the Australians. .

A Company had established a perimeter at the northern end of the for strip, and held it despite the shrapnel bursting low over their heads, fired from an Japanese anti-aircraft gun only 800 yards away. B Company moved back across the Manggar Besar and established a firm block on the southern side of the river.  The guns of a small naval unit, standing offshore, quickly countered the Japanese artillery. A naval bombardment officer, in direct wireless communication with the warships, had climbed a rickety I00foot control tower on the airstrip and, from this vantage point, accurately directed the gunfire.  Meantime 25-pounders of 2/5th Field Regiment had been hauled forward and joined in the fierce duel between the Navy and the Japanese heavy shore guns

At nightfall B Company of 2/14th was able to move forward again to occupy the western side of the strip, protecting Australian left flank. For five days the battle raged-five days of heavy shelling and counter-shelling, both the Japanese and Australian guns firing over open sights. Three Matilda tanks, put ashore from LCMs on the beach east of the Manggar Besar, during the second day of the battle, were hit by the Japanese heaviest gun, a 155-mm, at point-blank range. One Matilda was badly damaged while the other two were destroyed in flames. This 155-mm coastal defence gun was set into the hillside and protected by heavy steel doors, against which Australian shells were at first ineffective. But Australian artillery were not to be beaten. During the night they moved a 25-pounder forward to within 800 yards of the Japanese gun. At first light they opened fire, placing direct hits through the steel doors of the emplacement and destroying the gun and crew.

Then D Company of 2/14th Battalion, relieving A Company at the far edge of the airstrip, assaulted and captured the gun emplacement. Twice during the night that followed the Japanese counter-attacked the newly won gun position, one attack lasting an hour and a half. Twice he was repulsed by the Australians. Five minutes after midnight the Japanese vainly counter-attacked Australian other forward company, C Company, which had advanced 1000 yards along Vasey Highway to the end of the strip during the day. Even more formidable were the Japanese counter-attacks during the following night between 8 pm and 1 am. Torrential rain had filled the fox-holes and shell-holes. Australian infantry beat off these attacks although many Japanese got to within a few yards of Australian fox-holes. The Japanese heavy shelling had prevented repair work on the bridge over the Manggar Besar. With some ingenuity the sappers had partly solved the problem by building a wire-mesh foot-bridge underneath the actual bridge, slung from girders between the pylons.

On 9 July the Navy and artillery continued to hammer the Japanese positions. Then, guided by mortar smoke bombs, Liberators blasted their defences with 1000-pound bombs. The planes were scarcely off the area when Australian mortars and artillery opened up again, quickly followed by fire from a cruiser and two destroyers. After a brief lull six Lightnings flashed over the ridge in a trial run, circled and then returned, diving steeply. Belly tanks of Napalm tumbled down. There was a vivid flash and a deluge of fire enveloped the Japanese held area. The Lightnings came back at treetop level in a strafing run. The Japanese resistance at Manggar had been overcome and a patrol of 2/14th Battalion went in without firing a shot.

While the battle for Manggar strip had raged, the other two Battalions of 21st Brigade-2/16th and 2/27th-made further advances to the north-east of Sepinggang, and with 2/7th Cavalry Commando Regiment had patrolled vigorously north of Vasey Highway.

A mile and a half across the harbour from Balikpapan lies Cape Penadjam, a swampy area with a ruined sawmill, forty to fifty houses, and an oriental theatre. Penadjam was not important commercially, but it posed a threat to shipping in Balikpapan Bay. It 's strategic value to the Japanese as an antiaircraft centre to protect Balikpapan was lost when the Australians captured the oil refineries. Although it was reported that the Japanese had evacuated Penadjam two days previously no chances were taken, and it was subjected to a terrific pounding before the landing. Seaplanes strafed the township and the Navy bombarded the beach. Artillery from Balikpapan laid down a heavy creeping barrage as 2/9th Battalion and men of 2/7th Cavalry Commando Regiment in Alligators streamed across the bay in single file a mile long. About 200 yards from the shore the Alligators wheeled and sped towards the beach in waves at two to three minute intervals. Tank support had been given to 2/9th Battalion, but two Matildas bogged down in twelve feet of mud in the swampy beach area. The troops landed at 1 pm and the town was occupied without loss. Within an hour the infantry had fanned out, securing all initial objectives. The Japanese had not been sighted, but a 5-inch coastal gun opened up on Australian forces. This gun was knocked out by naval fire and captured by C Company of 2/9th Battalion that afternoon. Patrols pushed a mile to the north and south without contacting the Japanese.

Patrols south of the Sesoempoe River during the following day located deserted machine guns, while patrols to the west captured a single Japanese. In this area the Japanese were withdrawing by launch and barge along the Riko River. By now the Japanese had been ousted from all positions menacing the harbour. He had been pushed out of the town and had lost the two airstrips. in action It was apparent that he was trying to withdraw the remnants of his force to the Batochampar area on the road to Samarinda-Milford Highway.

Milford Highway was a road of craters and shattered houses, lined with burnt-out cars and trucks. On the features beside the road were knocked-out heavy guns and searchlights. Cultivation frequently lined the sides of the low hills and spurs of this terrain but many were bald from mortaring, bombing and shellfire. 

The Japanese were strongly entrenched on these hills and spurs. Here 25th Brigade struck and kept on striking, day after day. Australian tactics were hit and probe, hit hard with the full weight of Australian artillery and air strength, then probe with infantry and dismounted cavalry patrols to ascertain Japanese strength and positions. Australian artillery fired at the rate of 5000 shells a day, while 2/25th, 2/31stand 2/33rd Battalions of 25th Brigade were closely supported by 6-pounder tank attack guns and heavy mortars.

The Japanese stayed in their bunker positions during the day, but at night small parties infiltrated through Australian lines. During the night of 17/18 July a party of Japanese approached the headquarters of 2/33rd Battalion by creeping down Milford Highway. As they entered the area they fired a flare to give them visibility. A sharp hand-to-hand skirmish developed. Here again the Japanese used their long spears, but to no effect. Dawn disclosed thirteen Japanese bodies. Japanese infiltration in another Battalion area met a similar fate that night.

For three days the Japanese stood in his strong positions running across Milford Highway. Then they cracked and 9 July saw one of the biggest advances since first Australian assault. Probing slowly forward in the morning the advance gathered momentum and by 4 pm 3000 yards had been covered on a 2000-yard front, placing Australian forward troops some five and a half miles north of Balikpapan. Faster than the advance was the Japanese retreat. By nightfall they was moving so fast that contact had been lost. Large quantities of food and equipment were captured in the day's advance. Two heavy anti-aircraft guns which had been hurling shells at Australian forces were captured. They had been knocked out by direct hits in a duel with 25 pounders of 2/4th Field Regiment. Results of the accuracy and weight of the artillery barrage were borne out by the number of Japanese dead throughout the captured area.

Milford Highway was extensively mined and booby-trapped. On the evening of 9 July three 1000 pound bombs were exploded simultaneously in the middle of the road as an infantry platoon of 2/3Ist Battalion was advancing. Many other heavy bombs lay beside the road but the Japanese did not get a chance to use them against us. The engineers hastily repaired the section of Milford Highway captured and their tireless work sappers kept the road open to jeeps and tracked vehicles at all times. Not once were the rations and stores held up.

On the left flank a squadron of 2/7th Cavalry Commando Regiment patrolled east to harass the Japanese s lines of communication. Farther to the left Netherlands East Indies troops were unopposed in a 3000-yard advance to a position four miles north of Pandansari. 25th Brigade pressed its advantage the following morning. Set on a jungle-clad hill, to the left of the road, were the Cello barracks. Supported by Matilda tanks and a flame-throwing frog, D Company of the 2/3lst Battalion stormed this hill killing fifty Japanese without suffering a fatality. Right of Milford Highway C Company of the same battalion occupied another high feature. That afternoon artillery, mortars and tanks paved the way for a further half-mile advance by D Company. In the day's advances two tanks had knocked out three gun positions, and Japanese in six bunkers had been ousted by the flame-throwing frog.

Later in the afternoon A Company was to attack another dominating feature, Coke Spur. A two and a half hours' barrage by 25 pounders and a close supporting 6-pounder tank attack gun, combined with 4.2 and 3 inch mortars, opened the attack. On a lower explosive key crackled the 2-pounders and machine guns of two Matilda tanks, lined up on the highway with the flame-thrower. The barrage cut out and the three tanks crawled forward. Bunched close behind them were three infantry sections. A short distance ahead the road turned to the left, went down through a small cutting and on to a level at the bottom of Coke Spur. From both sides of the jungle and from Coke Spur itself the road was swept by Japanese machine-gun fire. The infantry could not advance. To retreat meant being caught and hemmed in by the cutting, through which the Japanese had allowed them to advance. The artillery re-opened and the tanks blazed away at close range, but the Japanese were strongly emplaced. The battle continued for an hour and a half. Practically the whole infantry platoon was wiped out in that confined ambush area. One tank stood by giving covering fire, while one Matilda, and then the other, crawled back, each carrying three wounded men on the deck. Back on the other side of the cutting the tank commander had been killed. The Australian attack was brought to a standstill and the dead were left where they lay on the road. Lives were not wasted in another assault against Coke Spur and the artillery were given the job to blast the Japanese from his bunkers.

On Milford Highway The Australian northerly advance was held up. For twelve days the Japanese clung tenaciously to his strong pillbox and bunker positions strategically placed between the commanding features Chair and Coke, on either side of the highway. It was twelve days of heavy shelling, constant patrolling and nerve-racking infiltration at night. A slow grinding-down process was involved. The infantry could have pushed the Japanese from his pillboxes and bunkers days before they eventually over-ran them, but were not prepared to waste lives in doing it. While the artillery and mortars pounded the Japanese defences and lines of communication, the infantry began to outflank him in preparation for a general squeeze. On 14 July the 2/25th Battalion, after relieving the 2/31st as point battalion astride Milford Highway, pushed two companies around the Japanese flanks on both sides of the road. The envelopment continued during the following day with the two companies firmly established on Cart and Calm features, to the outside and slightly in rear of the Japanese on Chair and Coke.

The 2/33rd Battalion moved forward on 16 July taking over responsibility for the east side of the highway, allowing the 2/25th to concentrate on its outflanking movement to the west. To the rear of the Japanese defences the Australian commandos were active. Pushing through the thick rain forest and tangled vegetation on the 13 July a commando patrol had skirted the Japanese right flank and reached a point overlooking his line of communication on Milford Highway. Late that afternoon a Japanese patrol twenty strong approached the position. The Australians withdrew and ambushed the Japanese, killing nine without loss. Day after day the Australian ambush parties took toll of the Japanese along his lines of communication. Farther west and nine miles north of Balikpapan, Netherlands East Indies troops were steadily moving along a water pipeline to a pumping station on the Wain Besar River. No Japanese had been contacted in this area.

The Japanese reacted violently to the Australian encircling pressure on his positions astride Milford Highway. By day he sent out strong fighting patrols; by night suicide parties charged the forward companies with swords and spears. All attacks were repulsed with heavy casualties to the Japanese. The night of 17/18 July saw the fiercest night attack. Two 2/25th Battalion company fronts and the headquarters of the 2/33rd Battalion were scenes of bloody hand-to-hand clashes. The Japanese succeeded in knocking out one 4.2-inch mortar and inflicted some casualties, but the count of Japanese dead the following morning showed no fewer than fifty-three, with an estimated additional sixteen.

The Australian pressure on the Japanese gradually increased. Slowly an encircling movement squeezed them from there bunkers and pillboxes astride the highway. Pockets of resistance were cleared. One of these pockets on the left flank contained ten Japanese in a cave. Infantry of the 2/25th Battalion quickly cleared this with a flame-thrower. Then on the 22 July after a twelve day stand, the Japanese broke contact. Patrols from the 2/25th and 2/33rd Battalions found their positions unoccupied and the 2/31st Battalion advanced 2000 yards north along Milford Highway. This placed the battalion outside the perimeter which had been laid down in the original order: to capture and hold Balikpapan area. Though no further advances were ordered, the only means of securing this perimeter was by constant offensive patrolling. The Japanese had not evacuated the area. Every day there were patrol clashes, and at night continued their infiltration tactics.

North of Manggar the 21st Brigade had pushed farther along Vasey Highway on the way to Sambodja, the third largest oil field in Borneo. Covered by a smoke screen, three more Matildas tanks had been landed at Manggar to support the advance. When the Japanese guns had been silenced, engineers quickly repaired the demolished portions of the Manggar Bridge and supplies were brought forward by jeeps.

In the area north-west of the Sepinggang airstrip the 2/16th Battalion had advanced 1000 yards against heavy opposition. An interesting series of moves and counter-moves preceded this advance. Two miles from the airstrip in a maze of steep hills the Japanese had held a feature called Gate. After a heavy concentration of mortars and machine guns the Japanese had withdrawn on the evening of 8 July.

An Japanese counter-attack forced the 2/16th to retire, but soon after the Australian artillery brought down heavy fire on the feature, ousting the Japanese. The battalion again occupied Gate the following morning and probed forward.

The Japanese were encountered on many other features in this area, but artillery was directed on his positions and infantry cleared the remaining Japanese. The Australian advance in this area had forced back the left flank of the Japanese retreating on Batochampar.

On Vasey Highway the 2/27th Battalion had relieved the 2/14th as point battalion and had advanced beyond the Adjiraden River. Only native refugees flocking to the Australian lines were met by the 2/27th. Many had come from Sambodja, fifteen miles from Manggar. A number of them were suffering from gunshot wounds and burnt feet-a Japanese method of preventing them from being of use to us.

The 2/27th continued their unopposed advance during the following days, reaching the village of Bangsal and patrolling forward to Amborawang, eleven miles along the coast from Manggar and twenty-three miles from Balikpapan. Patrols inland from Vasey Highway failed to find the Japanese.

A special reconnaissance party penetrated the heart of Sambodja on the 14 July and observed a party of Japanese supervising the burning of the village by pro-Japanese police-boys.

Four days later a patrol in strength occupied Sambodja, while another strong patrol cut their way through the jungle west of Amborawang to build a road block on a track leading from Sambodja to the Batochampar area.

Long-range patrols secured the Australian perimeter in the Sambodja area and parties of Japanese were mopped up behind the Australian lines in the vicinity of Manggar. The Japanese continued to infiltrate at night and harass the Australian lines of communication, but caused little damage and invariably suffered losses.

Based on Penadjam, across the bay from Balikpapan, the 2/9th Battalion and elements of the 2/7th Commando Regiment were patrolling extensively to secure the harbour for shipping. Overland patrols probed south to the Bandjermasin Road, while water patrols scoured the Riko River and upper reaches of Balikpapan Bay.

Supplied by barge along the river and waterways leading into it, scattered parties of Japanese still resisted in the Riko area. LCM gunboats carrying out river patrols were successful in sinking many Japanese barges, and his water activities were confined to the hours of darkness.

One river patrol set an unusual ambush for the Japanese river movement by night. The patrol had captured a 300-ton ship, laden with a cargo of coal and oil, where it had run aground some six miles up the Riko River. An armed party was left aboard the captured vessel that night. The ruse worked-a large Japanese barge carrying about forty Japanese and towing five prahus approached the stranded vessel, and at close range the Australian patrol opened up. Bombs from a Pita gun gutted the barge and the Japanese craft was swept by small-arms fire.

On the northern point of the Riko River mouth elements of the 2/8th Battalion landed a Djinabora during 8 July. Some 600 natives and Chinese were reported in this area but no Japanese. This force was withdrawn to Penadjam on the 14 July.

Opposite Djinabora, on the Balikpapan side of the bay, a company of the 2/8th Battalion made another unopposed landing at a small settlement about 1500 yards north of Cape Teloktebang. One platoon was left to occupy the area and the remainder of the company returned to Penadjam. From these positions, eight and a half miles north of the harbour entrance, any Japanese attempt to penetrate Balikpapan Bay by launch or barge from the rivers to the north could be forestalled.

Upper Balikpapan Bay is a network of waterways, which the Japanese were using as evacuation and supply routes for his scattered force in the Penadjam and Riko area. He had also appreciated their value to us as a potential line of advance to outflank his force astride Milford Highway. To prevent the Australian use of the area the Japanese had established a block near Tempadoeng at the mouth of the Balikpapan River where it flows into the upper reaches of the bay.

A force known as Buckforce, which consisted of a tactical headquarters and two companies from the 2/1st Pioneer Battalion, and elements of supporting arms, occupied Djinabora on the 20 July. This force moved to Tempadoeng the next day. From this forward base? patrols operated throughout the area, particularly to the east towards Milford Highway, to harass the Japanese lines of communication in front of the 25th Brigade.

In an area called Tandjoeng Batoe a scout plane checking a report about Indian prisoners saw a white sheet stretched on the ground bearing the inscription: `Indian PW'. A patrol of the Pioneers was sent out. Guided by the plane they found sixty-three Indian prisoners, who had suffered badly in Japanese hands for three and a half years.

It became increasingly evident that the Japanese were withdrawing its entire force north from the Balikpapan-Manggar area to a concentration area in the vicinity of Sepakoe. The Japanese had fallen back on the Manggar and Batochampar fronts and were evacuating the remnants of its Penadjam force via the Sepakoe and Semai rivers. An evacuation route to Samarinda, farther north, had been prepared, and under pressure he would, perhaps, have made full use of it. The Australian long-range patrols throughout the area constantly clashed with delaying parties of the Japanese which were covering the main withdrawal. It was not the Australians' intention to advance farther or to extend their perimeter. Long-range patrols operated to gain information and to maintain offensive action against the Japanese so that the perimeter would be secure. This was the situation when hostilities ceased.