Attack on Yokosuka

What Happened

On 18 July 1945, aircraft of the United States Navy struck the Japanese port city of Yokosuka, at the mouth of Tokyo Bay. The raid came in the final weeks of the Pacific War, and its principal target was the battleship Nagato, the largest surviving unit of the Imperial Japanese Navy. Carrier aircraft also attacked anti-aircraft batteries and other warships lying at the Yokosuka Naval Arsenal, the navy's main shipbuilding and repair complex.

Nagato came through the attack only lightly damaged. The cost to the Japanese navy fell instead on smaller vessels: the American aircraft sank a destroyer, a submarine and two escort vessels, and damaged five small vessels. Allied pilots claimed the destruction of several locomotives and 43 Japanese aircraft, with a further 77 aircraft claimed as damaged.

The raid was not an exclusively American operation. Aircraft of the Royal Navy took part, and British planes joined strikes on airfields around Tokyo. Japanese anti-aircraft fire answered the attackers: guns ashore and afloat shot down twelve American aircraft and two British aircraft.

Background

By the summer of 1945 the Japanese fleet had been reduced to a handful of surviving ships, and Nagato was the most significant of them. The battleship had been laid down before the war and had served as the flagship of the Combined Fleet at the time of the attack on Pearl Harbor. By July 1945 she lay at Yokosuka, moored in home waters and largely immobilised for want of fuel and escorts.

Yokosuka itself was the natural focus of a raid aimed at the remnants of the navy. The town on the western shore of Tokyo Bay housed the Yokosuka Naval Arsenal, the principal yard where the Imperial Japanese Navy built, converted and repaired its warships. Attacking the arsenal meant striking both the ships and the industrial base that kept them in service.

The raid belonged to a wider campaign. In the last months of the war, American carrier task forces ranged along the Japanese coast, striking ports, airfields and industrial targets almost at will. The attack on Yokosuka formed part of the bombing of Yokosuka, a series of raids on the city, and it fell in the twentieth year of the Shōwa era (昭和, Shōwa, the reign name of Emperor Hirohito, 1926–1989).

Why It Mattered

The attack demonstrated how little remained of Japanese naval power. A battleship that had once symbolised the fleet's reach could be found at its home yard, protected by anti-aircraft guns rather than by a fleet at sea, and the raiders could single it out with near impunity. That Nagato survived with light damage mattered less than the fact that the raid could be mounted at all.

The material losses were real but modest in the scale of the wider war: a destroyer, a submarine, two escort vessels and five small vessels damaged, alongside the aircraft and locomotives claimed by Allied pilots. The raid's importance lies in what it signalled. Japan's harbours, shipyards and airfields were now within reach of carrier aircraft operating off the coast, and the navy that Yokosuka had been built to supply could no longer defend its own base.

The exchange of losses tells its own story. Japanese guns brought down twelve American and two British aircraft, a reminder that the defences were still dangerous. Yet the attackers pressed home their strikes on the arsenal and the airfields around Tokyo, and the surviving Japanese ships could do nothing to stop them.

The Name in Japanese

The event is called 横須賀空襲, read よこすかくうしゅう (Yokosuka kūshū). The word divides into a place name and a compound noun for an air raid.

横 — read yoko here. The kanji means "sideways" or "horizontal", and it appears in many everyday words as the element yoko.

須 — read su here. In this name it functions as a phonetic element rather than carrying its own meaning; the character is otherwise read su or shu in other contexts.

賀 — read ka here. The kanji means "congratulation" or "felicitation", and it is common in personal names and place names.

Together, 横須賀 (Yokosuka) is the name of the city on Tokyo Bay. The reading is not predictable from the individual characters, which is typical of Japanese place names: the three kanji are read as a single unit, Yokosuka.

空 — read kū here. The kanji means "sky" or "empty". It is the first element of 空襲 and points to the raid coming from the air.

襲 — read shū here. The kanji means "attack" or "strike", and it carries the sense of falling upon something suddenly.

The compound 空襲 (kūshū) therefore means "air raid" — an attack delivered from the sky. The full name 横須賀空襲 follows a common Japanese pattern for naming wartime events: the place name comes first, and the type of action follows. The same 空襲 appears in the names of many raids of 1945, and a reader who knows the compound can recognise them at a glance.

Key Figures

The raid was carried out by the United States Navy, with aircraft of the Royal Navy also taking part and British planes joining the strikes on airfields in the Tokyo area. No individual commander is recorded in the surviving account of the operation.

The central figure in the story is not a person but a ship: the battleship Nagato, the raid's main target, which lay at Yokosuka Naval Arsenal and came through the attack lightly damaged. Around her were the anti-aircraft positions and smaller warships that bore the weight of the assault, and the Japanese gunners who shot down twelve American and two British aircraft.