Operation S (i)

'S' (i) was the Japanese seizure of Lombok island in the Dutch East Indies (8/9 March 1942).

Lombok is part of the chain of the Lesser Sunda islands group, with the Lombok and Alas Straits separating it from the islands of Bali to the west and Sumbawa to the east. The island is approximately circular, with a the small tail of the Sekotong peninsula jutting out to the south-west, and is about 43.5 miles (70 km) across with an area of about 1,825 sq miles (4514 km˛).

The island is dominated by a central volcano, Mt Rinjani, which rises to a height of 12,224 ft (3726 m) and is the second highest volcano in what is now Indonesia. Lombok’s highlands are covered with forest and were mostly undeveloped, while the very fertile lowlands were highly cultivated for rice, soybeans, coffee, tobacco, cotton, cinnamon, cacao, cloves, cassava, corn, coconuts, copra, bananas and vanilla. The southern part of the island is fertile but drier, especially toward the southern coast.

The Lesser Sunda Islands Invasion Force, commanded by Rear Admiral Kenzaburo Hara, departed Soerabaja in south-eastern Java with the light cruiser Isuzu, torpedo boat Tomozuru, minesweeper W-12 and submarine chaser Wakataka escorting the two army transport vessels carrying the 1st Yokosuka Special Naval Landing Force. The naval infantry of this force landed at Mataram on Lombok island in the face of fire from the local detachment of Dutch troops, but moved rapidly to occupy the entire island. Two companies (less three platoons), a communications unit, an engineer unit, a transport unit, a medical unit, and a paymaster unit were left to occupy the territory, and the rest of the Japanese force departed Mataram on the following day.

The Japanese seizure of the Lesser Sunda islands group was completed on 9 March when the minelayer Shinko Maru and 2,745-ton army transport Shingu Maru, each carrying elements of the 3/47th Regiment, departed Soerabaja for Lombok island as the core of Hara’s Lesser Sunda Islands Invasion Force escorted by the submarine chasers Ch-6 and Ch-19. The light cruiser Isuzu and torpedo boat Tomozuru, auxiliary seaplane tender Sanyo Maru (carrying a contingent of the 1st Yokosuka Special Naval Landing Force) escorted by the submarine chaser Ch-20 carried the 1st Air Unit and 2nd Air Unit, which were detachments of the 33rd Air Group at Soerabaja. The minelayer Wakataka (carrying the balance of the 1st Yokosuka Special Naval Landing Force) escorted by minesweeper W-12 departed Soerabaja with the occupation forces.

The Japanese forces landed on Lombok, Soembawa, Flores and Bali islands, and encountered no more than token resistance.