Invasion of Sumatra

Background

After the Japanese conquest of the Malay Peninsula , the Allies began transferring troops to Sumatra in December 1941. The first British and Australian bombers took turns south of the island to evacuate troops on the Malay Peninsula. The operations brought about 3,400 Australian soldiers to Sumatra.

At a joint conference on 16 December, the Netherlands asked for help to strengthen the defense of Sumatra and Java . In addition, plans were made in Sabang to set up supply camps in Medan and Pekanbaru . However, these plans were revised on 27 December, and P1 (Pangkalanbenteng) and P2 ( Praboemoelih ) airfields were selected as new headquarters locations to station an operational bomber relay. Due to the poor condition of the aerodromes, resettlement began on December 31st and available ground staff arrived in early January. Another aerodrome was located in Oosthaven. Roads between Medan and Pekanbaru were constructed and six heavy and light Bofors 40 mm antiaircraft guns were delivered to each Palembang aerodrome, while eight other antiaircraft guns were placed in the refineries. However, the Allies faced a shortage of ammunition because ammunition delivery ships were sunk by the Japanese during the crossing.

Operation L

The first Japanese airstrike began on 6 February, striking Palembang’s P1 airfield, where two Blenheims bombers and four Hurricanes were destroyed and two more Hurricanes were damaged. On the ground, the Japanese destroy two Buffalo while the Allies kill only one Japanese Nakajima Ki-43 . As a countermeasure, the Allies launched nocturnal raids against Japanese lines on the Malay Peninsula and provided air protection for convoys of refugees from Singapore .

For the “L” operation, the Japanese Army alignment was the 229 ^th Regiment of the 38 ^th Infantry Division of Hong Kong to Cam Ranh Bay in Indochina . Eight transports departed on February 9 , 1942escorted by the 7th ^Cruise Division, including a cruiser , four destroyers , five minesweepers and two submarine hunters under Commodore Shintarō Hashimoto’s command to invade Bangka and Palembang . The following day, Rear Admiral Jisaburō Ozawa’s force followed with the Western Coverage Fleet, consisting of the Ryūjō aircraft carrier , the Chōkai flagship , five other cruisers, four destroyers and an air group, under the command of Admiral Kakuji Kakuta. Most of the invasion force was flown in thirteen transports on February 11, being accompanied by a heavy cruiser , a frigate , four destroyers and a submarine fighter.

The Dutch tanker Manvantara is sunk by Japanese planes on February 13 , 1942in the Java Sea . Four Dutch submarines are deployed from the Anambas Islands , too far away to reach the Japanese fleet. The transports reach Singapore as Allied refugee cargo ships moving towards Java and Sumatra are attacked by Ryūjō planes . These same planes damaged the British light cruiser Durban, who had to turn away from Colombo and attack Genzan’s air unit with Japanese land bombers. Two allied tankers, a steamboat and many smaller ships were sunk, and one tanker and two transports were badly damaged.

On February 14 at 8 am, the anti-aircraft guards warn Palembang that a large wave of Japanese attack is en route to the city. However, all available Allied air forces were on mission to protect maritime convoys and were not in radio range. The wave of Japanese bombers bombarded P1 airfield, strafing all resistance. Soon after, 260 Japanese paratroopers of the first Japanese Airborne Division Kahang  (in) landed on P1. The second wave, composed of 100 paratroopers from Kluang  (in) , soon after landed a few kilometers west of P1 near the refinery.

In front of them, 150 British antiaircraftmen, 110 Dutch soldiers and 75 men of the British territorial defense of P1 were opposed. As the Japanese stacked vehicles for roadblocks, many skirmishes broke out as planes landed to refuel them. In the face of the anti-aircraft fire, the planes headed for the P2 airfield. In the afternoon, the British still held the airfield, but they were soon out of ammunition. After a false report announcing other Japanese landings about 25 kilometers away, the British commander, HG Maguire, decided to evacuate the airfield and the city. The next day, another 100 Japanese paratroopers reached the refinery. After heavy fighting that lasted all day, the Allies managed to repulse the Japanese, but the refinery was heavily damaged by machine gun fire and before firing. Other small surrounding facilities were also damaged.

Meanwhile, Vice Admiral Ozawa’s escort fleet passed north of Bangka to form a large-scale cover for the Japanese landings that took place shortly thereafter. An advance guard arrived at Bangka, while the main units that had landed near Palembang, at the mouth of the Musi River , were advancing along the river to the city.

At the same time, Japanese reconnaissance aircraft sighted the ABDACOM fleet , under the command of Rear-Admiral Karel Doorman . By order of Wavell, Doorman had assembled the fleet south of Bali , consisting of the Dutch cruisers De Ruyter , Java and Tromp , accompanied by the British cruiser Exeter , the Australian light cruiser Hobart and ten destroyers, en route to Sumatra since February 14th. Japanese fighters from the Ryūjō and a Malaysianbase attacked the ABDACOM fleet at noon the next day and pushed all their ships southward.

The invasion fleet in Bangka Strait is also spotted by British P2 reconnaissance aircraft. In the morning 22 Hurricanes, 35 Blenheims and three Hudsons , launch an attack against the ships, immediately engaged by Japanese planes which gives rise to violent aerial battles.

At P2, the news of the landing of Japanese parachutists on P1 is known. The commander then initiates preparations for the evacuation of the aerodrome. However, the command learns that the P1 airfield is not abandoned, preparing a night attack. In the morning fog, the Allied aircraft launched violent attacks against the Japanese beginning their landing at the mouth of the river. The Japanese planes withdrew shortly after the start of the battle, then taking advantage of the Allies who attacked the carriers. Twenty landing craft were sunk by Hurricanes and hundreds of Japanese were killed on the beach southwest of Bangka.

Meanwhile, the Dutch command ordered the destruction of oil depots and rubber dumps. The ferries in the Musi River were destroyed in the next hour so that they could not be used by the Japanese while the defenders of P1 began a quick retreat. On the night of February 15, Japanese units that had survived the air strike in the mouth of Musi reached Palembang and supported the parachutists who landed on P1 and at the refinery.

Marshal Archibald Percival Wavell was the supreme commander of ABDACOM forces. On the morning of February 15th, Wavell organized a regular retreat at Oosthaven, where several small ships lay in the harbor. On February 17, 2,500 British RAF members , 1,890 British infantrymen, 700 Dutch soldiers and about 1,000 civilians were evacuated by twelve ships. The corvette Australian Burnie covering the retreat destroyed the port facilities and oil tanks. A smaller steamboat remained at the port to accommodate refugees arriving later.

Meanwhile, the Japanese had completely taken Palembang and destroyed the oil refineries of two smaller stations. Small troop carriers went up the river to Menggala  (in) .

All remaining Allied combat aircraft leave the area no later than 16 February, while aerodrome personnel are evacuated by boat to India . The city Oosthaven still has not fallen, an operational force goes to earth February 20 to seize spare parts planes while destroying the latest facilities still usable.

On February 24, the Japanese reached Gelumbang.

Operation T

Allied units remaining in Sumatra, mainly KNIL, retreat to the central and northern provinces of the island. The Dutch are planning a recapture of Palembang to try to expel the Japanese from the island. This plan was of short duration in the face of the aggressive Japanese pursuit of Palembang led by a motorized reconnaissance regiment of about 750 men. The forces in numerical inferiority and in continuous retirement commanded by Major CF Hazenberg had only 350 KNIL regulars divided into two companies. The equally dispersed forces allowed the better trained and better equipped Japanese to advance quickly. After three weeks, the Japanese are finally confined to Moearatebo on March 2nd. Padangpandjang’s Dutch reinforcements were able to recover when heavy rains made the rivers virtually impassable.

On 3 and 7 March, many ambushes took place as Japanese units attempted to cross the river. At the end of the offensive, Dutch spies returned with reports of many dead and wounded, noting that the regiment had only 200 men. Still, Major Hazenberg decided to counter-attack on the night of March 8-9. On the 7th and 8th, several native boats were collected out of sight and loaded with food and ammunition during the formation of the assault groups. However, on March 8, the news of the surrender of Javaarrived, and all the offensive efforts had to be interrupted because Sumatra was dependent on deliveries from Java. It was decided to take a defensive direction. Western Sumatra was to be left to the Japanese, and only a small part of the north would be defended with all available forces for as long as possible, until an evacuation by sea could be organized.

During the retreat, KNIL units destroy all aerodromes and all port facilities. They retreated into defensive positions at the southern entrance to Alice’s Valley, where it is planned to hold the position as long as possible. If the positions fall, a guerrilla war in the vicinity is planned. But this option proved difficult because of the hostility of the population of Sumatra to the Dutch, due to colonization .

Operation “T” begins on February 28, when 27 transports carrying 22,000 Imperial Guard soldiers leave Singapore. They are divided into four convoys and are accompanied by three cruisers, ten destroyers, several patrol boats and submarine defense units. The Japanese force reached North Sumatra without any problem, the Allies having at that time no air or sea support.

On 12 March, the Kobayashi Detachment captured Sabang Island and Koetaradja Airfield without encountering opposition. The Yoshida Detachment landed south of Idi with one infantry battalion, to seize the oil fields Lantja and Pangkalan Brandan  (in) . They then head south towards Medan, where they exert pressure on the Dutch positions. The main force landed about four miles northwest of Tandjoengtiram, along Highway Pematang- Siantar – Balige  (in) – Tarutung  (in) by cutting all the forces of KNIL tempting to withdraw fromMedan , while going north by entering the airfield of the city.

Sumatra falls on March 28 when Dutch Major General RT Overakker and 2,000 soldiers go near the town of Kutatjane, north of Sumatra.

Many Allied prisoners of war were forced to build a railway line between Pekanbaru and Moera  (in) . Overakker and other KNIL officers in captivity were shot in 1945 for the impending Japanese defeat.

Notes and references

• ( In ) This article is partially or entirely from the article in English entitled ” Invasion of Sumatra (1942) ” ( see the list of authors ) .