page_title: Operation Transom
section_title: Aftermath
hierarchical_section_title: Operation Transom / Aftermath
caption_attribution_description: The British Royal Navy aircraft carrier HMS Illustrious (87) steaming past the U.S. carrier USS Saratoga (CV-3) in the Indian Ocean, 18 May 1944. Note the crews of both ships assembled on deck to pay farewell.
context_page_description: Operation Transom was an attack made by Allied forces against the Japanese-held city of Surabaya on 17 May 1944 during World War II. It was conducted by the British-led Eastern Fleet, and involved aircraft launched from American and British aircraft carriers striking the city's docks and an oil refinery. One American torpedo bomber was shot down.
  The attack on Surabaya was the second, and final, joint American-British aircraft carrier raid in the Indian Ocean during 1944. It was undertaken as a diversion from an Allied landing on an island off New Guinea on the same day, and to make use of the American aircraft carrier on its return voyage to the Pacific. Estimates of the extent of the damage inflicted by the Allies differ between sources; some describe the results as modest while others state that they were significant. There is consensus that the operation provided the British Royal Navy with useful exposure to superior United States Navy carrier tactics. The attack had no effect on Japanese military deployments.
context_section_description: Saratoga and her three escorting American destroyers detached from the Eastern Fleet shortly before sunset on 18 March, and proceeded to Fremantle. The remainder of the Eastern Fleet reached Exmouth Gulf the next morning, and sailed for Ceylon before sunset after refuelling again. It arrived back at Ceylon on 27 May.
   
  Accounts of the damage inflicted during Operation Transom differ. Writing in 1960, the official historian of the Royal Navy's role in World War II Stephen Roskill stated that the Allied pilots had over-estimated the damage caused, as  Japanese records "do not confirm that either their shipping or the shore facilities suffered at all heavily" and indicate that only a single small ship was sunk. The Australian naval official historian G. Hermon Gill reached an identical conclusion in 1968. He also noted that Admiral Guy Royle, the head of the Royal Australian Navy, told the Australian Advisory War Council on 23 May that operation Transom had been of dubious value on military grounds as similar results could have been achieved by land-based aircraft without a need to risk warships to attack. In contrast, the official historian of the British effort in South East Asia Stanley Woodburn Kirby wrote in 1962 that the Wonokromo oil refinery and other industrial facilities were set on fire, the naval dockyard and two other docks were bombed and twelve Japanese aircraft destroyed on the ground. More recently, historian Jürgen Rohwer stated in 2005 that twelve Japanese aircraft were destroyed on the ground, a small freighter was sunk and a patrol boat damaged beyond repair. In 2011 David Hobbs judged that the operation was successful, with the Wonokromo oil refinery being "burnt out", naval dock installations damaged and a merchant ship sunk. Marcus Faulkner wrote in 2012 that Operation Transom "inflicted considerable damage".
  Both Roskill and Hobbs agree that the attack provided the Royal Navy with important experience of carrier strike operations and exposure to superior American carrier tactics. Roskill observed that Somerville decided to copy the way in which Saratoga's crew conducted flight operations. Hobbs identifies a number of other lessons the Royal Navy took away from the operation, including the need to plan to conduct at least two strikes against  targets and the desirability of obtaining photo reconnaissance aircraft which could be flown from carriers.
  As was also the case with Operation Cockpit and the several other carrier raids the Eastern Fleet conducted in 1944, Operation Transom did not have any effect on Japanese deployments. This was because the Combined Fleet did not regard the Eastern Fleet as a threat, and was under orders to preserve its strength to contest a major American offensive which was expected to take place in the central Pacific.
caption: Saratoga's crew farewelling Illustrious on 18 May 1944
exif: {}