CHAPTER 2 1 THE SEIZURE OF BALIKPAPA N HILE the 9th Division was finishing its task in north Borneo, th e W 7th was preparing for the attack on Balikpapan, the last large- scale Allied operation of the six years' war . The re-conquest of Luzon was now virtually completed; organised resistance had ceased on Okinawa ; for nearly three months United States aircraft had been raining explosiv e and incendiary bombs on the major cities of Japan ; in Burma, Rangoon had fallen on 3rd May . Balikpapan was distant 2,500 miles and more from Rangoon an d Okinawa, and was 1,200 miles south of Manila . Even as early as April General Blarney could see no justification for attacking Balikpapan, but the operation had been ordered by the Combined Chiefs of Staff, an d the Australian Prime Minister, after having informed General MacArthu r of General Blarney's opinion, had not objected . Balikpapan, which, after Palembang in Sumatra, was the most pro- ductive oil port in east Asia, was built round the eastern headland o f Balikpapan Bay . The port, with its seven piers and its warehouses, la y within the bay; the European suburb of Klandasan faced the open sea ; on the steep-sided ridge in between, forming the backbone of the headland , towered the cracking plant and about 40 storage tanks . The oil wa s piped to the Balikpapan refinery from Sambodja and Sangasanga, 2 5 and 55 miles to the north-east respectively, and, in peace, oil was shippe d to Balikpapan also from Java, Tarakan and Ceram . Before the war Balik- papan exported about 1,800,000 tons of cargo a year, almost all of i t fuel oil and other petroleum products. The airfields were to the east of the town on the narrow coastal plains : at Sepinggang, five miles from Balikpapan, and Manggar, about 12 mile s away. The hills rose steeply from the coast to about 700 feet in the area to be covered by the troops . The country was open for several miles round Balikpapan, but farther inland, and several miles to th e north along the coast, the jungle began . There was a motor road alon g the shore and thence inland to Sambodja, an uncompleted road to Samarinda, and a track to Bandjermasin . The Australian staffs name d the coast road the Vasey Highway and the Samarinda Road the Milford Highway, and, as at Tarakan, they gave names to every hilltop in the area, thus greatly simplifying signalling, written and oral orders, and reports by reducing the use of map references . The Japanese had assembled a fairly large force of troops and civilian workers of several nationalities in the Balikpapan-Samarinda area . In June it was estimated that there were, round Balikpapan, about 3,900 troops, of whom 1,500 were in mobile units and 2,400 in anti-aircraft, ai r force and base units ; also 1,100 Japanese workers, 2,400 Indonesians 1945 FORMIDABLE COAST DEFENCES 503 and 1,000 Formosans . Round Samarinda there were believed to be abou t 1,500 troops, plus possibly a battalion recently arrived from Tarakan . Experience had taught that, in estimating the strength of the enemy's resistance, every Japanese and Formosan, whether in a fighting unit, bas e unit or a civilian labour group, had to be regarded as a fighting man . It was known that at least 18 coast-defence guns were mounted round Balikpapan, principally on the ridges overlooking the sea, and there wer e at least 26 heavy dual-purpose and 78 medium and light anti-aircraf t guns. Off shore between Klandasan and Manggar rows of stout poles had been driven into the bed of the sea and horizontally braced with timbe r and protected with barbed wire. An almost continuous anti-tank ditch from 12 to 14 feet wide lay above the beach from Stalkudo to Sepinggang, and extensive trench systems with many tunnel openings had been detected on the ridges overlooking Klandasan . There were also many concrete strong-posts and a continuous line of bunkers along the fringe of the beach. The area was as strongly fortified as any that the Australians had encountered anywhere in the war . Indeed Air Vice-Marshal Bostock,1 who was in control of air support of the landing, in a letter to the Prime Minister, warned him that these carefully-prepared defences might lead t o A.I.F. casualties comparable with those at the landing on Gallipoli . The enemy appeared to have established his main defences on th e slopes overlooking the beaches from Klandasan to Stalkudo . The Aus- tralian staffs considered that the Japanese would try to contain the invaders within their beach-head area as long as they could and then withdra w inland and either south to Bandjermasin or overland to Bintulu i n Sarawak . It was expected that the enemy would direct burning oil dow n 1 AVM W . D. Bostock, CB, DSO, OBE. (1st AIF, 1914-17 ; 48 Sqn RFC 1917-18 .) Director o f Operations and Intelligence RAAF HQ 1938-39 ; Deputy Chief of the Air Staff 1939-41 ; Chie f of Staff AAF SWPA 1942 ; AOC RAAF Cd 1942-46 . MHR 1949-58 . Regular air force officer ; b. Sydney, 5 Feb 1892 . 504 SEIZURE OF BALIKPAPAN Apr-May on to the beach unless the oil tanks were destroyed in the preliminar y bombardment . As mentioned, the decision to employ the 7th Division instead of th e 9th at Balikpapan was not made until 17th April, when G .H.Q. authorised the movement of the division less a brigade from Australia to Morotai, where, it was expected, the concentration of the force would be complete by 16th June. The 7th Division like the 9th had had a long period of training in combined operations . On 30th April G.H.Q. issued a staff study which said that the pre- paratory naval and air bombardment would destroy enemy defences an d any oil tanks whose contents might be used in the defence ; in the next stage a landing would be made with the object of destroying the garriso n and seizing the port and airfields ; in the final stage the remaining enemy forces were to be destroyed, the N .E.I. Government re-established, and the remaining oil-producing and oil-processing installations protected . On 7th May the date of the landing was fixed at 28th June, but the dela y in beginning the Brunei Bay operation caused a corresponding postpone- ment of the landing at Balikpapan, and on 8th May this was fixed a t 10th July . Nine days later, however, G .H.Q. decided that, because of the expected concentration of the force at Morotai by 19th June, the dat e of the landing would be 1st July. G.H.Q. provided 25 L .S.T's, in addition to ships already allotted, to hurry units from Cairns to Morotai. The 7th Division was now going into action for the first time since i t had been withdrawn from the Ramu Valley operations early in 1944 . This would be its first opposed landing, the first operation since Syri a in 1941 in which it would have a full array of supporting weapons, an d the first operation in which it had fought as a complete formation . The division's commander, Major-General E . J. Milford, had joined it in Jul y 1944. Milford had led the 5th Division in the final operations roun d Salamaua and later had been chief of staff of New Guinea Force . He was a firm leader, learned and shrewd. Primarily a gunner, he wa s determined to make the most of the opportunity presented by this rela- tively open country to use artillery . All his brigade commanders and all but two of the infantry battalion commanders had led their formation s or units in the Ramu Valley. Although it was a tried and experienced division it now contained, in the infantry, a fairly high percentage of subalterns who had come fro m disbanded artillery and other units and had not been in action before . Consequently, when briefing began, great emphasis was placed on the nee d to push on and gain ground . Major-General Milford and his staff had begun planning the operation on 26th April and by 5th May Milford had decided to make an assaul t on a two-brigade front between the Klandasan Besar River and Klandasan . The infantry brigadiers, F . O. Chilton of the 18th and I . N. Dougherty of the 21st, were not informed about the operation until 11th May, and then in great secrecy. Milford told them what resources were likely to May 1945 LANDING PLACE CHOSEN 505 be available and that the object was to capture the town and port area. He asked the brigadiers to study the problem independently and sugges t an outline plan. They studied the maps and models at divisional head - quarters on the Atherton Tableland and on 18th May, in conference with Milford, each said that he favoured making the landing at Klandasa n and not farther east. Milford told them that that was his plan and, afte r arriving at it, he had examined the appreciation already made by th e 9th Division and discovered that it also had favoured Klandasan . On Chilton's representations Milford agreed to make the assault 1,000 yard s east of where he had originally intended. Three possible landing places had been considered: Manggar, Seping- gang and Klandasan, the only places where the water was deep enough , the beach long enough and the approaches suitable .