Japanese aircraft carrier Sōryū

Coordinates: Click the blue globe to open an interactive map. 30°38′N 179°13′W﻿ / ﻿30.633°N 179.217°W ﻿ / 30.633; -179.217

Soryu (蒼龍, Sōryū ?, meaning "Blue (or Green) Dragon") was an aircraft carrier of the Imperial Japanese Navy. During the Second World War, she took part in the attack on Pearl Harbor, Wake Island, Port Darwin and raids in the Indian Ocean before being sunk at the Battle of Midway.[1] {| class="toc" id="toc"

Contents
[hide] *1 Design
 * 1.1 Hull
 * 1.2 Machinery
 * 1.3 Flight Deck & Hangars
 * 1.4 AA Armament
 * 2 Operational history
 * 2.1 Pearl Harbor
 * 2.2 Wake Island / Port Darwin
 * 2.3 Indian Ocean
 * 2.4 Midway
 * 3 References
 * 4 Bibliography
 * 5 External links
 * }

Design
Sōryū was one of two large carriers approved for construction under the 1931-32 Supplementary Programme (the other being her sister-ship Hiryū). She was laid down at Kaigun Kosho, Kure, Japan on 20 November 1934, launched on 21 December 1935 and finally commissioned on 29 December 1937.[1] As opposed to some earlier Japanese carriers, which were conversions of battlecruiser ( Akagi ) or battleship ( Kaga ) hulls, Sōryū was designed from the keel up as an aircraft carrier and incorporated lessons learned from the light carrier Ryujo.[2]

Hull
Sōryū featured a slim cruiser-type hull with a length-to-beam ratio of 10:1. Primary protection from horizontal fire came from a 46 mm (1.8 in) waterline armor belt of Ducol Steel plate along with a separate internal anti-splinter bulkhead. Vertical protection consisted of 25 mm (0.98 in) of armor over the ship's machinery and 55 mm (2.2 in) over the fore and aft magazines and aviation fuel tanks. There were no bulges on the hull for anti-torpedo defense.[3]

Machinery
Sōryū's machinery was similar to that of the Mogami-class heavy cruisers and consisted of four sets of geared turbines, developing 152,000 shp (113,000 kW), connected to four propeller shafts. Steam power was generated from eight oil-fired Kampon boilers. With a maximum bunkerage capacity of 3670 tons of fuel oil, Sōryū could cruise 7,750 nautical miles (14,350 km; 8,920 mi) at 18 knots (33 km/h; 21 mph).

Corrosive exhaust gases were trunked upward through the ship and vented out a pair of downward-curving horizontal funnels located amidships on the starboard side, just abaft the carrier's island. This arrangement prevented smoke from interfering with flight operations in most wind conditions.[4]

The carrier's slender hull and powerful machinery resulted in a high maximum speed. Reaching close to 65 km/h (35 kts)[1] during initial sea trials, Sōryūwas the fastest carrier in the world at the time of her commissioning. Sōryū under construction at Kure Naval Arsenal, 1937.Sōryūmaking 35 knots on speed trials, November 1937.=== Flight Deck & Hangars=== The carrier's 217 m (712 ft) long flight deck overhung both ends of the hangar box but stopped short of the bow and stern. It was supported fore and aft by steel girders. Sōryū's diminutive island sat atop a starboard-side extension jutting beyond the side of the hull and therefore did not encroach on the width of the flight deck.

Nine Type 4 electrically operated arrester wires were capable of stopping a 6,000 kg (13,000 lb) aircraft at speeds of 60-78 knots.[3]

To facilitate rapid transfer of aircraft from hangar to flight deck and back, Sōryū was designed with three elevators. The largest of these was located along the ship's center line abreast the island. Two somewhat smaller elevators were offset to starboard, one just abaft the ship's funnels and one located further aft. They were capable of transferring aircraft weighing up to 5,000 kg (11,000 lb).[3]

Sōryū had two fully enclosed aircraft hangars, arranged one atop the other, with the 160 m (520 ft) upper hangar being approximately 30.5 m (100 ft) longer than the lower. Overhead clearance was limited to 4.5 m (15 ft) in the upper hangar (where the wings of a Nakajima B5N Kate torpedo bomber could therefore not be spread for maintenance purposes) and less than 4.25 m (13.9 ft) in the lower one where the top of the engine cowling of a Mitsubishi A6M Zero fighter came within 1.2 m (3.9 ft) of the deck-head.[4] [5]

AA Armament
Heavy AA armament consisted of six twin batteries of 127 mm (5.0 in) dual-purpose guns mounted below flight deck level on either side of the ship (three sited forward and three aft). Each was controlled by a Type 94 fire-control director. A seventh director was mounted atop the island and could control all six batteries if necessary though at a reduced rate of fire.[4]

Close-in AA armament consisted of fourteen twin 25 mm (0.98 in) AA guns distributed along the sides of the ship, again below flight deck level. Three of them were sited on a platform just below the bow end of the flight deck.[4] [5]

Pearl Harbor
At the outbreak of the Pacific War, commanded by Captain Ryusaku Yanagimoto, Sōryū, in Carrier Division 2, was one of six carriers comprising the Kido Butai (Striking Force) that attacked Pearl Harbor on 7 December 1941. She launched two waves of air strikes against the U.S. naval base. Her first wave targeted  Nevada ,  Tennessee , and  West Virginia  with armour-piercing bombs and  Utah ,  Helena ,  California , and  Raleigh  with torpedoes, and also attacked parked aircraft at Barbers Point. Her second wave targeted California, Raleigh, Kaneohe and Navy Yard installations.

Wake Island / Port Darwin
From 21 December to 23 December 1941 Sōryū launched air strikes against Wake Island. In January 1942 she supported the invasion of the Palau Islands and the Battle of Ambon. On 19 February 1942 Sōryū launched air strikes against Darwin, Australia. In March 1942 she took part in the Battle of the Java Sea, helping sink the US tanker  Pecos .

Indian Ocean
In April 1942 Sōryū took part in the Indian Ocean raid, launching air strikes against the Royal Navy base at Ceylon on 5 April 1942, and assisted in sinking the Royal Navy cruisers  Cornwall  and  Dorsetshire . On 9 April her aircraft contributed to torpedoes that sank the British carrier  Hermes  and the escorting Australian destroyer HMAS Vampire.

On 19 April 1942 she pursued the American carriers  Hornet  and  Enterprise  after they launched the Doolittle Raid, but without success.

Midway
In June 1942 Sōryū was one of four carriers with Vice Admiral Chuichi Nagumo's First Carrier Striking Force in the battle of Midway. Her aircraft complement consisted of 21 Mitsubishi A6M "Zero" fighters, 21 Aichi D3A "Val" dive bombers, and 21 Nakajima B5N "Kate" torpedo bombers. [1] On 4 June 1942 she launched her first wave of planes against the American base on Midway Island. At 10:25 AM while preparing to launch a second strike against an American carrier group, she was attacked by thirteen SBD Dauntless dive bombers from the American carrier  Yorktown . Sōryū received three direct hits from 454 kg (1000 lb) bombs: one penetrated to the lower hangar deck, and the other two exploded in the upper hangar deck. The hangars contained armed and fueled aircraft preparing for the upcoming strike, resulting in secondary explosions. Within a very short time the fires on the ship were out of control. At 10:40 AM she stopped and her crew were taken off by the destroyers  Isokaze  and  Hamakaze . Sōryūsank at 7:13 PM at position WikiMiniAtlas 30°38′N 179°13′W﻿ / ﻿30.633°N 179.217°W ﻿ / 30.633; -179.217. Losses were 711 crew of her nominal complement of 1103, including Captain Yanagimoto, who chose to remain on board. This was the highest mortality percentage of all the Japanese carriers lost at Midway, due largely to the devastation in both hangar decks.[1]

The official record (the Nagumo Report) implies that Sōryū sank of her own accord. Later research has revealed she was scuttled with torpedoes by Isokaze.