The Japanese having captured Tarakan and Menado were ready in the last week of January 1942 to thrust their trident further south. One prong aimed at Kavieng and Rabaul, another towards Ambon and Timor, and one at Balikpapan and Bali. As the Japanese advanced down the Malaya Peninsula the allied bombing aircraft were forced to operate from Singapore Island and there the raiders took a heavy toll of them then were withdrawn to southern Sumatra. Wavell's orders for further withdraw of aircraft leaves only eight Hurricanes and six Buffalos on the Fortress Island. On the far right the Japanese also leapfrogged Singapore and landed on Sumatra. These advances by the Japanese carried them across the equator established bases in Dutch and Australian territory whence they would advance onto the final objectives, the New Guinea mainland and the isolation of Java. In the meantime while the political and military proposals and predictions were being deliberated over the lead vessel of the convoy the Ocrades, shipping 3,400 troops mostly Australian, had been ordered to Sumatra.
Air Marshal Sir Robert Brooke-Popham, the commanding officer of all British forces on Far East, had been ordered to consult the Dutch about land and air reinforcements for Java and Sumatra by the Chiefs of Staff, and on 16th December an AHQ team had been sent to reconnoiter the airfields in Sumatra, at that stage their value was mainly seen for a reinforcement route. Plans were made to stock Sabang, Medan and Pakan Baroe with supplies and to send in handling parties, but on 27th December Air Vice Marshal Pulford, the RAF commanding officer for Malaya, was ordered to prepare facilities for a substantial bomber force. Palembang was selected as the new headquarters, which had two nearby airfields, one of which was secret. This was despite the fact that Palembang would probably be the focal point of the initial Japanese attack, the town also had good road and rail links, a port and an oilfield nearby. Work began on the airfields on 31st December.
Within two weeks, the first Japanese troops had entered Johore, in front of the Singapore Fortress. Air Vice-Marshal Maltby ordered the formation of 225th RAF (Bomber) Group on 1th January, which moved to Palembang on 18th and was taken over on the 30th by Air Commodore H.J.F. Hunter who had just arrived directly from the United Kingdom. The group consisted of 1st and 78th RAAF and 62th RAF Squadrons, flying Hudsons, as well as 27th RAF and 84th RAF Squadrons Blenheims. In addition 84th RAF and 211st RAF Squadrons Blenheims had flown in from the Middle East without ground support, losing 11 aircraft en route. The Hurricanes of No.226 RAF (Fighter) Group under Air Commodore S.F. Vincent were based at the civilian airfield. Vincent was also a new arrival. It is interesting that Air Vice-Marshal Pulford had been told about neither of the new arrivals before they showed up.
The conditions at the airfields were primitive, the civilian airfield (P1) had hard concrete runways but no way to disperse the aircraft. The military airfield (P2) was a large jungle clearing where the aircraft could be dispersed under the trees, despite having upto one hundred aircraft at the site, the airfield was never found by the frequent Japanese overflights. There was insufficient time and shipping to bring the bases upto operational standard and a dearth of transport only compounded the problems. There were more airmen than could be properly accommodated or employed, many went onto Oosthaven and Java.
One main road ran north to south on the western end of the little developed Sumatra island and a railway ran from Palembang to the port of Oosthaven on the south west coast facing Sunda Strait. Japanese bombers operating from captured airfields in Malaya from early February had bombed Palembang airfield P1 in the south east of Sumatra but were unable to discover the second airfield at Palembang and even allied aircrew briefed on the whereabouts of P2 had trouble locating it. The airfields at Palembang were garrisoned by Dutch defence unit of 150 Indonesian troops, deployed in company or platoon size groups, and two "rather ancient" armoured vehicles plus British anti-aircraft detachments and small parties of RAF ground staff armed as infantry. Although never enough forces to go round vulnerable sectors were entirely undefended. Palembang town and P1 were both on the north side of the Musi River and the Dutch for the L-shaped hard surface runways at the aerodrome was developing a dispersal area. The Musi River to just below the town forked into a delta and the main channel could be navigable by ocean going ships for about 50 miles inland from Banka Strait. Schools and cinemas in Palembang housed some 2,500 redundant air personnel from Singapore with about 1,750 officers, maintenance and technical staff elsewhere. P2 previously an emergency landing strip was a huge natural field concealed from the road and extremely difficult to detect from the air. There was no bridge spanning the Musi to P2 from Palembang and the process of the few ferries with the capacity of a four to six vehicles across the river was slow. Although ABDAIR Command assumed operational control over all air units in Sumatra No.225 Bomber Group headquarters, formed 18 January 1942, was situated in a hotel in downtown Palembang controlling up to eight squadrons, No. 453 with Buffaloes, No.34 Squadron, No.62 and No.27 were in a poor state, No.84 and No.211 just flown in from the Middle East were seriously depleted, two RAAF reconnaissance Hudson squadrons No.1 and No.8. And a Malayan Volunteer Air Force formation based at P1 operating light aircraft for invaluable work making recon runs over the Musi River approaches twice daily and maintaining communications between P1, P2 and Lahat, plus locating crashed aircraft.
Close to Palembang, capital of Sumatra, were oilfields regarded as the best in South East Asia, which supplied two refineries in the adjacent area of the town. During the Malaya campaign priority in airfield improvement had been given to suitable sites in the north east of Sumatra for refuelling of reinforcement aircraft for Singapore by the trans India route. Sabang Island, Lhonga across from Malacca Passage, the Medan civil aerodrome and a military airfield was under construction, Pakanbaru central Sumatra, Padang midway on the southwest coast, P1 and P2, also at Lahat south of Palembang, and the building of an aerodrome at Oosthaven. These many aerodromes, airfields and airstrips under construction, upgrading or being expanded became vulnerable to Japanese aircraft operating from captured airfields on the Malay Peninsula. Only a primitive telephone system linked the principle towns. The Dutch were initially without AA guns protecting the airfields on Sumatra until ABDA Command provided six heavy and six Bofors anti-aircraft guns each for P1 and P2 plus four of each type for the two refineries. The only problem was the ships carrying the ammunition were sunk by the enemy resulting in a shortage throughout the campaign.
On February 6th, 1942 at 1100 the first Japanese air raids struck Palembang P1 airfield. The Japanese were still unaware of the existence of P2. By the end of the day the Allies had lost two Bristol Blenheims with the loss of all six aircrew shot down by Sargeant Major Hiroshi Onozaki of 59th Sentai. Two Hurricanes were shot down with one pilot killed and a further two Hurricanes remained missing. Two Hurricanes came in damaged. One of these BG678 was piloted by a South African Sargeant Dick Parr who came in with his severed little finger from his left hand in his shirt pocket after a 20mm shell exploded in his cockpit. Two Buffaloes were also destroyed on the ground as a result of the raids and by days end the airfield was covered in debris and burning aircraft. Of the two missing 258th Squadron Hurricanes the wreckage of the plane and the body of Pilot Officer Cardwell Kleckner and American was latter found in the jungle, Pilot Officer Campbell-White a New Zealander returned to base shaken and bedraggled four days latter, escorted by helpful natives. In return Pilot Officer Reg Bainbridge of 232nd Squadron claimed a single Ki 43 shot down.
Nightly air attacks from Sumatra began intensifying against Japanese line of communication concentrations on the Malay Peninsula. These long flights not only contented with enemy actions but violent monsoonal storms and the risky business of refuelling at Pakanbaru, Medan or Singapore, severely testing the skill and endurance of the bomber aircrews. The bomber force attacked Japanese airfields at far distant as Singora and covered the reinforcement and evacuation convoys for Singapore. The No.226 RAF Fighter Group was formed by Air Commodore S.F. Vincent on 1 February at Palembang P1, from the remnants of 224th RAF Fighter Group at Singapore and 226th RAF Fighter Group from Great Britain, and where lack of communication facilities delayed the interception of Japanese aircraft. There were also plans for an overall command of all British air forces, in Sumatra, in Headquarters, under command of RAF Air Commodore B.J. Silly. There were Hurricanes and Buffaloes from Singapore and about 50 Hurricanes arrived being flown off HMS Indomitable, five crashed on landing and fifteen flew onto Singapore. To improve the climb and manoeuvrability of the Hurricanes in the tropical climate the four outside Vickers machine-guns were removed. These defending Hurricanes hit unescorted enemy bombers but when high level air raids increased the Japanese included escort fighters and were able to destroy allied aircraft on the ground with quick low level attacks. All was much improvised. Few of the pilots had operational experienced, many had come straight from OTUs. Servicing was difficult with few spares, no toolkits and most of the ground crews were from the Buffalo squadrons. In addition, there were no radars to provide warning. On February 2nd headquarters for the RAF was established at Palembang, which was moved to Soekaboemi on Java exactley two weeks later.
On 13th February, a British reconnaissance plane found a large concentration of Japanese shipping north of Bangka Island, at the same time many boats, full of British and Australian troops, were fleeing Singapore and found themselves among the enemy vessels. The launch carrying Air Vice-Marshal Pulford and Rear-Admiral Spooner and some 40 others was attacked by Japanese aircraft and stranded on a small uninhabited island north of Bangka Island. Two months later disease and starvation forced the survivors to surrender, the two flag officers were not among them.
At 8.00am on 14 February the observer corps warned of "a large hostile formation of enemy aircraft" approaching. All available Hurricanes were on escort duty for the bombers and were out of range for radiotelephone communications. The Japanese bombers hit P1, then the large escort of fighters swept the aerodrome with machine-gun fire and almost immediately airborne carriers dropped two groups of parachutists. About 260 Japanese paratroopers were dropped around P1 originating from airfields in occupied Malaya. At the airfield P1 and nearby were stationed only 150 British soldiers manning the anti-aircraft batteries at Palembang and 110 Dutch soldiers drawn from the Sumatra garrison as well as 3 officers and 72 men of the RAF ground defence unit. The Japanese paratroopers were from 1st Airborne Division with the first wave originating from Kahang for the assault on P1, at the same time the second echelon from Kluang, the main southern most Japanese air base, of about 100 Japanese paratroopers were dropped at 600feet and descended over the refinery, several miles west of P1. After engaging in small fire fights and setting up a road block with over turned vehicles the Japanese paratroopers persistently attacked the aerodrome P1, defended under the command of Wing Commander H.G. Maguire. When some of 232nd RAF Squadron aircraft landed it was possible to refuel them and sent them onto P2. Worrying reports were coming from Palembang and the oil refinery so it was decided to evacuate the two Group HQs to P2 along with most of the support personnel. During the afternoon the situation was a stalemate, Maguire's men held the airfield but were short of supplies and blocked in by road. He was then advised, wrongly, of a further Japanese landing 15 miles away and decided to pull out from the town and the airfield. At the refinery the Japanese paratroopers used air raid shelters for entrenched resistance. The next day about 100 paratroops were dropped near the refineries instigating close combat against the enemy all day and being finally dislodged after fierce fighting but the fires started prevented effective demolition of the refinery. The refinery at Pladjoe was slightly damaged permitting immediate use also the other refinery, damaged by the battle, could still be quickly operational again and at Sungei Gerong demolition charges were completed by the defenders holding the enemy for the time required.
Enemy losses from anti-aircraft fire were slight and the Japanese airborne troops attempted to rush the aerodrome. But this improvised banzai charge was checked by 3.7inch guns and 40mm Bofors firing over open sights, the Dutch infantry force plus its two aged armoured cars and RAF ground defence units from No.258 and No.605 RAF Fighter Squadrons. The Hurricanes returned from escort duty, some were diverted to P2 and a few landed, refuelled, rearmed and back into the fray against the Japanese invasion force. The AA guns once they spent their meagre ammunition supply withdrew with excess RAF personnel and the Dutch remained with RAF ground troops to deny the enemy their objective. When the first echelon of paratroopers were reinforced by another airborne drop on the morning of 15 February a rearguard was posted on the aerodrome and the Japanese airborne force moving in combat formation occupied Palembang town later that afternoon.
The Japanese surface assault against Sumatra started from Hong Kong, the 229th Infantry Regiment, part of 38th Infantry Division, sailed to Cam Ranh Bay. This arm of the Western Force under Vice-Admiral Jisaburo Ozawa had been assigned the objectives of Bangka Island and the Palembang area. The advance elements, part of Japanese 229th Infantry Regiment, set out from Cam Ranh Bay (French Indochina) in 8 transports escorted by the cruiser Sendai and 4 destroyers. The main force, the Japanese 229th Infantry Regiment and one battalion of 230th Infantry Regiment in 14 transports followed after escorted by a heavy cruiser and 4 Destroyers. Vice-Admiral Ozawa in the cruiser Chokai led the covering force, the 7th Cruiser Squadron four 8 inch gun warships, one 5.5 inch gun armed cruiser.plus an aircraft carrier and 3 destroyers. At the entrance to Bangka Strait Ozawa fanned out his naval forces placing screening operations across the escape route for refugees and escapees from Singapore. The advance Japanese force invaded Bangka Island and the main force with the task of taking Palembang area. The air support was provided by the carrier Ryujo, land based naval air formations and the Japanese Army 3rd Air Division. The main Japanese invasion convoy had arrived off the mouth of the Musi River and an army amphibious element began the advance up the waterway. Japanese reconnaissance had sighted Doorman's squadron sailing northward through Gasper Strait. Admiral Doorman on orders from Wavell sailed westward to intercept the Japanese invasion convoy. His squadron was originally south of Bali and it took him till the 14 February to gather his forces and at dusk set a course for a point north of Sunda Strait with the Dutch cruisers De Ruyter, Java and Tromp and British cruiser Exeter and Australian light cruiser Hobart plus ten destroyers. The main Japanese convoy was diverted while the naval surface covering force prepared for action and the next day about midday Japanese carrier and land based aircraft attacked the Allied squadron, forcing Doorman's surface ships southward with his warships all accounted for. The main Japanese convoy returned to the mouth of the river and began moving up stream late in the evening on 16 February.
The officer commanding No.225 RAF Bomber Group, Air Commodore H.J.F. Hunter, instructed that it was imperative to continue the air attacks on the Japanese invasion convoy at first light and the aircraft available to do this task were 22 Hurricanes, 35 Blenheims and 3 Hudsons, assembled at P2 airfield, the air battles over Bangka Strait were extremely severe to all combatants. The news from P1 caused the airfield commander, Group Captain McCaley, to order the evacuation and preparatory destruction of the base, but better tidings from P1 caused this to be countermanded but serious damage had already been achieved. The night as spent getting the aircraft back to operational capability. A reconnaissance flight at dawn revealed through the morning tropical mist 20 warships, many transports and various vessels steaming through Bangka Strait and landing barges laden with troops coming down the Moesi estuary. The enemy fighter interception committee retired in the early stages of the battle and allied aircraft scored direct hits on transports, damaging others too and sinking at least twenty landing barges swarming up the separate channels of the river. The enemy amphibious force was like scattered matchsticks on the water surface and Japanese dead littered the shore banks of the river as thousands of Japanese troops on barges were caught in the open by machine gun fire. Allied naval forces were unavailable to follow up the temporary advantage gained by the air attacks the Japanese paid a high price for not locating the secondary airfield P2. On their last strike for the day Hurricane pilots destroyed enemy fighters reported parked on a beach on the south-west coast of Bangka Island, for whatever reason, and the Hurricanes avenged their own ground losses against the undefended targets.
Meanwhile Dutch high command orders were issued for the destruction of oil and rubber stocks, the refinery area and to embarrass the southward advance of the enemy "in one hours time" the ferries across the river will be wrecked. This definitely prompted the remaining garrison fighting for P1 to join the retreat. The general manager of the Sumatra railways, despite contrary orders, delayed the demolition of the rail link to Oosthaven until evacuation was completed. That night, 15 February, a scratch force of Japanese troops moved up the Musi River in landing craft, reached Palembang and relieved the paratroopers. The Dutch commander withdrew his forces to the southwest and on that day Wavell ordered the evacuation of Sumatra by way of Oosthaven where many small ships had been assembled. The Dutch had sent a few KNIL companies to reinforce the forces pulling back from Palembang and Brigadier Steele, the senior Australian officer on Sumatra, reconnoitring the territory as Chief Engineer of First Australian Corps, went to Oosthaven about seeing to the reception of the Ocrades. Now under new orders the fast liner was steaming far ahead of the AIF 7th Division convoy and carrying two battalions, the 2/3 Machine-Gun Lt-Col A.S. Blackburn and 2/2 Pioneer Lt-Col Williams. While at sea Blackburn was instructed on arrival to move his forces to Palembang, and at the same time to guard lines of communications. Senior Australian and British officers held a conference on the morning of 15 February and discovered there were no Dutch troops south of Prabumulih near P2. Steele formed a headquarters for the defence of Oosthaven and the evacuation of personnel and civilians with himself in command. His forces consisted of the 3rd Hussars, which had disembarked on the day before, also a British anti-aircraft battery and five improvised RAF companies, each of a hundred riflemen.
At midday the Ocrades arrived, Steele went aboard and discussed disembarkation with Blackburn then to carry out the instructions. And as this was proceeding the captain of the HMS destroyer Encounter signalled that Wavell orders no troops to be put ashore and that the 3rd Hussars were to embark on the Ocrades then sail immediately. Later in the day a Dutch liaison officer reported that Japanese seaborne troops had reached Palembang and the oil refineries had been destroyed except two small plants. The Japanese had moved upstream to Menggala in vessels laden with troops. At Mandah a rearguard force of British AA gunners and RAF riflemen under Major Webster, staff corps, defended a position where the road and railway crossed a river. In three days about 2,500 RAF men, 1,890 British troops, 700 Dutch soldiers and some 1,000 civilian refugees had embarked in twelve various sized vessels by the 17 February. The rearguard was put aboard the steamer Rosenbaum and at the harbour quay remained a K.P.A. steamer to pick up latecomers. The Australian corvette Burnie, covering the embarkation and having the task of demolishing oil tanks and quayside. On 16th all surviving aircraft were flown out to Java, all RAF and RAAF personnel were evacuated via Oosthaven apart from the care and maintenance parties at the airfield, mot of whom got away to India. The Japanese did not press on to Oosthaven and on 20 February the Australian corvette HMAS Ballarat, whose captain was familiar with the area, went in with an airforce salvage team, some 50 men led by Group Captain G.E. Nicholetts, and retrieved valuable aircraft spares and technical stores and destroyed what was left, including the harbor facilities. Once Sumatra had been neutralised the Japanese descended onto Bali at the opposite end of Java closing another door.
The escapees from Singapore fell into three types of fugitives, those officially evacuated, those that had become detached from their unit during the confusion of the conflict and those that had absconded after the declaration of surrender, possibly the dividing line between desertion and duty to escape being in some instances indefinite. The extent of those getting away from the island about 3,000 persons reached Java, Ceylon and India through Sumatra. Many escapees drowned, were killed by bombs and bullets, some died at the hands of brutal Japanese, or of starvation and disease but those that reached Sumatra were evacuated from the west coast port of Emmahaven, near Padang. The Dutch authorities in Sumatra generously supplied transport food and clothing.
The Mary Rose passed unmolested out of Singapore Harbour with the plan to escape to the Inderagiri River in Sumatra and presumably reach Padang and then Java. So instead the launch made for Palembang but at the entrance to Bunka Strait two Japanese patrol vessels shone lights and trained their guns on the stricken boat. Taken to Muntok Harbour, Banka Island, the launch was searched thoroughly. A passenger named Bowden asked to be allowed to speak to a Japanese officer in order to make known his diplomatic status. The elderly, white-haired man remonstrated and an altercation with a Japanese guard resulted. Then he was punched, had a bayonet pointed at him, and the guard tried to grab his gold wristwatch. A second Japanese guard came on the scene and gestured to accompany him from the hall of prisoners to outside. Half an hour later two shots were heard and the guards returned to their duties. Those aboard the Vyner Brooke also discovered what it meant to be at the mercy of the Japanese mentality at the time. On this vessel were sixty-four Australian nurses under the charge of Matron Drummond of the 2/13 Australian General Hospital. The vessel after evacuating Singapore on 12 February 1942, as the enemy closed in on the city, and was bombed then sunk off Banka Island two days later. There were two nurses killed, nine were drifting on a raft never to be seen or heard of again and twenty-two landed from a lifeboat on the north shore of Banka, near Muntok. Other survivors had arrived on the beach and lit a fire, the nurses looked after the wounded, some being casualties themselves, and it was discovered a couple of days later that the Japanese occupied the island. An officer and some women and children walked to Muntok to negotiate their surrender. About ten Japanese soldiers and an officer appeared, they marched the men around a small headland and returned wiping their bayonets. The nurses and capable walking wounded were next, they were ordered into the sea, when knee deep a Japanese machine-gun crew opened up a fusillade of fire and killed all but one. The survivor, Sister Vivian Bullwinkle, drifted not only in and out of consciousness but also found herself washed up on the beach surrounded by the dead bodies of those that had fallen with her. She had a flesh wound, was able to rest and recover from the shock of it all, found fresh water but by the third day hunger drove her to investigate the lifeboat. A voice called out, it was an Englishman, he told her that after machine-gunning the nurses the Japanese bayoneted the stretcher cases and he too had a flesh wound and was left for dead. Both were captured ten days later and the Englishman died in captivity, Sister Bullwinkle survived and returned to Australia at wars end.
The Netherlands Army used their Bofors 75-mm Model 1934 howitzers in the Netherlands East Indies, where they were carried into action in pack loads carried by mules. Note how brakes were applied to this carrier mule as it move down a steep slope carrying the wheels and part of the carriage trails
The airfields feeding Java were occupied by the 20 February and Wavell recommended his command not be transferred but dissolved, since the control of the forces in Java would be better exercised by overall Dutch command. Meanwhile Sumatra had been lost and ABDA command was terminated. On 24 February Japanese ground forces had advanced to and captured Gelumbang, 30 miles south west of Palembang, the 22nd Air Flotilla began ariel operations from this air base in strength and the combat depleted paratroopers went back to their base after fourteen days of operations.
In outline, the invasion plan for Northern Sumatra called for one element to attack Sabang Island and Koetaradja, another to land at Idi and secure Langsa and Pangkalanbrandan oilfields, and the main element to land at Laboehanroekoe and move rapidly to occupy Medan. The invasion fleet sailed in four different convoys, all departing from Singapore harbor in the following order:
- on the afternoon of 8 March the units which were to proceed to Sabang and Koetaradja sortied from West Harbor, Singapore on four transport ships escorted by 3rd Destroyer Squadron consisting of the 20th and 10th Destroyer Divisions and the 1st Minesweeper Division
- the force assigned for the invasion of Idi departed West Harbor on the morning of 9 March aboard two transport ships escorted by the escort patrol ship Shumushu and the 2nd Section of the 41st Minesweeper Division
- also on 9 March at 1000 hours, the main elements of the Northern Sumatra Invasion Force with the mission of general support to the entire invasion departed Seletar, Singapore. This force consisting of heavy cruiser Chokai (flagship), the 7th Cruiser Division, the 11th and 12th Destroyer Divisions, and the seaplane tender Sagara Maru, headed for the waters south of Great Nicobar Island
- the main body of Imperial Guard Division on board 8 transport ships left West Harbor on 10 March escorted by the Hatsutaka, the Nagoya Maru, sub-chaser No.7 and the 1st Section of the 44th Minesweeper Division
The Japanese Invasion Fleet consisted of:
Western Attack Force (after the fall of Java Island was Western Java Support Force renamed into Western Attack Force )
1st Southern Expeditionary Fleet
training cruiser Kashii
patrol escort ship Shumushu
seaplane tender Sagara Maru
9th Base Force
gunboat Eiko Maru
1st Minesweeper Division
minesweepers- W1, W3, W4
Choko Maru, Shonan Maru # 6, Shonan Maru # 7
12th Base Force
destroyer torpedo-boat (torpedo boat) Kari (only for "U" Operation)
gunboat Kosho Maru
12th Gunboat Division
units not indentified
41st Minesweeper Division
minesweepers- Kyo Maru # 1, Kyo Maru # ?, Reisui Maru, Takao Maru
The above Force covered the transports carrying the 3 Battalions of the Kobayashi Detachment (elements of the Japanese Imperial Guard Division)
Cort Unit 1
light cruiser Yura
5th Destroyer Division
destroyers- Asakaze, Harukaze, Matsukaze, Hatakaze
The above Force escorted the Transports
Destroyer Squadron 3
light cruiser Sendai (flagship)
19th Destroyer Division
destroyers- Isonami, Uranami, Ayanami
20th Destroyer Division
destroyers- Amagiri, Asagiri, Yugiri, Shirakumo
The above Force provided Close Cover
cruiser Chokai (flagship for the entire operation)
aircraft carrier Ryujo
7th Cruiser Division
cruisers- Chokai, Kumano, Suzuyu, Mikuma, Mogami
11th Destroyer Division
destroyers- Hatsuyuki, Fubuki, Shirayuki, Murakumo
These convoys proceed to their destinations under air cover provided by the 40th Naval Air Group from the Seletar airfield, seaplanes from seaplane tender Sagara Maru and the Bihoro Naval Air Group from Penang airfield.
The main elements, charged with general support, arrived in the area northwest of Sabang on the evening of 11 March. Beginning at dawn on 12 March unopposed landings were made at Sabang at 0235, Koetaradja at 0330, Idi at 0540 and Laboehanroekoe at 0700.
On 12 March 1942 at 0235 hours one Japanese battalion of the Kobayashi Detachment, covered by the 12th Base Force landed in Sabang (a town on the island of Weh), while other two battalions of the Kobayashi Detachment, covered by the 9th Base Force landed in Banda Atjeh (Kutaradja) on the same day (12 March 1942). Dutch forces in this area, officered by KNIL Colonel G.F.V. Gosenson (Dutch territorial commander for Banda Atjeh province) offered almost no resistance. In the meantime the 7th Cruiser Division laid off to the west while light cruiser Sendai and 19th and 20th Destroyer Divisions patrolled north in the "Great Channel". By 15 March 1942, all participating naval elements, with the exception of a small naval landing unit, which remained to occupy Sabang, Weh Island, had returned to bases at Penang and Singapore and began preparations for Andaman and Burma Invasions. The 5th Destroyer Divison scurried back to Singapore soon after Sabang operation in order to bring up the next convoy, while the other units after 3 days, retired to Penang to wait for the next convoy coming up from Singapore, escorted by 5th Destroyer Division. The 5th Destroyer Division then brought up the next convoy through Malacca Strait, picked up the escorts at Penang, and continued to Port Blair and Mergui. There again splitting their escorts. Then the 5th Destroyer Division raced back down to Singapore to pick up another convoy for the Rangoon operation, only this time, picking up the escorts at Mergui.
On 12 March 1942 the Imperial Japanese forces also reached the important inland town and airfield at Medan. In the meantime parts of the Japanese 38th Infantry Division also started to move from the Palembang area to link up with the elements of the Japanese Imperial Guard Division in order to complete the occupation of the Sumatra Island, which was than finally conquered by the Japanese Army on 28 March 1942 when KNIL Major-General R.T. Overakker (Dutch commander for Sumatra Island) surrendered with about 2000 men at Kutatjane, west of Kabanjahe (Northern Sumatra).
Koninklijk Nederlands Indisch Leger (KNIL Army)
- Territorial Command "West Sumatra Island and Tapanoeli", commander was KNIL Lieutenant Colonel J.H.M. Blogg.
West Sumatra and Tapanoeli (1st Garrison) Battalion in Fort de Kock
West Sumatra and Tapanoeli (2 nd Garrison) Battalion in Sibolga
Stadswacht Infantry Company in Padang
Artillery Detachment (4 x 75mm L/35 guns)
Mobile Auxiliary First Aid Platoon
- Territorial Command "North Sumatra Island", commander was KNIL Colonel G.F.V. Gosenson, with a headquarter in Medan.
North Sumatra (1st Garrison) Battalion in Medan
North Sumatra (22nd Garrison) Battalion in Pematangsiantar
KNIL Military Police Battalion
Stadswacht Infantry Company in Medan
Artillery Battery (3 x 75mm L/55, 2 x 75mm L/35, 2 x 7mm AA guns)
Artillery Battery (2 x 75mm L/35, 2 x 7mm AA guns) in Medan and Belawan
Coastal Artillery Detachment (2 x 75mm L/35 guns)
Mobile Auxiliary First Aid Platoon
Militaire Luchtvaart, KNIL (Air Force)
IIe Vliegtuiggroep (IInd Group)
1-V1.G.II (Bomber Squadron) at Palembang airfield
WH-1 Patrol Squadron, commanded by KNIL Air Force 1st Lieutenant L.J. Janssen at Palembang II airfield (attached from ML-KNIL)
Zeemacht Nederlands-Indiλ (Royal Dutch Navy)
In Palembang existed Battle Naval Command (Commandement Maritieme Middelen Palembang) under command of (local) Navy Commander J.F.W de Jong van Beek en Dong. In Palembang were stationed some Dutch Navy vessels:
minelayer Pro Patria under command of Lt.Cdr. L.F. Guiot
auxiliary patrol vessel P 37
auxiliary patrol vessel P 38
auxiliary patrol vessel P 39
auxiliary patrol vessel P 40
Naval Air Group GVT-8 with 3 flying boats Do-24K at Samboe Island
Nihon Rikugun (Imperial Japanese Army)
229th Infantry Regiment of 38th Japanese Infantry Division. The 229th Infantry Regiment was concetrated at Camranh Bay (French Indochina)
1st Parachute Force:
- Parachute Regiment (four companies with 425 men) under command of Colonel Seiichi Kume
Infantry Battalion of the 230th Infantry Regiment
elements of the Japanese Imperial Guard Division
Teikoku Kaigun (Imperial Japanese Navy)
The Western Force came under the command of Vice-Admiral Jisaburo Ozawa aboard the cruiser Chokai and was intended for the landings at Banka and Palembang and consisted of an Advance Force and a Main Force.
Convoy for Palembang numbered 8 transport ships carrying part of the 229th Infantry Regiment. Convoy escort was under command of Rear-Admiral Shintaro Hashimoto in the light cruiser Sendai (flagship) and the convoy was escorted by:
20th Destroyer Division
11th Destroyer Division
destroyers- Fubuki, Hatsuyuki, Shirayuki
1st Minesweeper Division
minesweepers- W 1, W 2, W 3, W 4, W 5
11th Submarine-chaser Division
submarine-chasers- Ch 7, Ch 8
Main Force was under command of Vice-Admiral Jisaburo Ozawa in the heavy cruiser Chokai. Convoy numbered 14 transport ships carrying the 229th Infantry Regiment (minus the part of the Advance Force) and a battalion of the 230th Infantry Regiment. Convoy was escorted by:
training ship Kashii
20th Destroyer Division
destroyers- Yugiri, Amagiri
escort vessel Shimushu
11th Submarine-chaser Division
submarine-chasers- Ch 9
minesweepers- W ?, W ?
transport ship Konyu Maru
Tanker Eikyo Maru
Covering Force was under command of Vice-Admiral Jisaburo Ozawa.
4th Cruiser Division
heavy cruiser Chokai (flagship)
7th Cruiser Division
heavy cruisers- Mogami, Mikuma, Suzuya, Kumano
12th Destroyer Division
19th Destroyer Division
destroyers- Isonami, Ayanami
Air Group was under command of Rear-Admiral Kakaji Kakuta.
4th Carrier Squadron
carrier Ryujo with the 3rd Air Group
19th Destroyer Division
- "T" Operation was Northern Sumatra and Sabang
- "D" Operation was the Andaman's
- "U" Operation was Rangoon (this was the ultimate objective)