Myōkō

Background

Myōkō was approved under the 1922–1929 Fleet Modernization Program, as the first heavy cruiser to be built by Japan within the design constraints imposed by the Washington Naval Treaty, and was the first of the "10,000 ton" cruisers built by any nation. Naval architect Vice Admiral Yuzuru Hiraga was able to keep the design from becoming dangerously top-heavy in its early years by continually rejecting demands from the Imperial Japanese Navy General Staff for additional equipment to the upper decks. During modifications and rebuildings in the 1930s, though, the final displacement rose to 15,933 tons, well over the treaty limits.

Design

The Myōkō class displaced 13,500 t (13,300 long tons), with a hull design based on an enlarged version of the Aoba-class cruiser. Myōkō was 203.8 metres (669 ft) long, with a beam of 19.5 metres (64 ft) and draft of 6.36 metres (20.9 ft), and was capable of 35.5 knots (65.7 km/h; 40.9 mph).

Propulsion was by 12 Kampon boilers driving four sets of single-impulse, geared-turbine engines, with four shafts turning three-bladed propellers. The ship was armored with a 102 mm (4 in) side belt, and 35 mm (1 in) armored deck, but the bridge was not armored.

Myōkō’s main battery was ten 20 cm/50 3rd Year Type naval guns, the heaviest armament of any heavy cruiser in the world at the time, mounted in five twin turrets. Her secondary armament included eight 12.7 cm/40 Type 89 naval guns in four twin mounts on each side, and 12 Type 93 Long Lance torpedoes in four triple launchers positioned below the aircraft deck. Myōkō was also equipped with an aircraft catapult and carried up to three floatplanes for scouting purposes.

Myōkō was laid down at the Yokosuka Naval Arsenal on 25 October 1924 and launched and named on 16 April 1927 in a ceremony attended by Emperor Hirohito, and was commissioned into the Imperial Japanese Navy on 31 July 1929. Although the first ship in her class to be laid down, she was the third to be completed.

Myōkō was repeatedly modernized and upgraded throughout her career to counter the growing threat of air strikes. She eventually mounted 52 Type 96 25 mm AT/AA Gun guns and two 13.2 mm (0.52 in) antiaircraft guns after her final upgrade.

Operational history

Early service

All of the Myōkō-class cruisers were assigned to the Sasebo Naval District, forming Sentai-4 of the IJN 3rd Fleet, and trained as a unit during the 1930s. During a naval review off Kobe on 26 October 1930, stack gases caused problems on the bridge, resulting in a lengthening of the forward smokestack by 2.0 m.

During the First Shanghai Incident of February 1932, the cruisers escorted the transports conveying elements of the Imperial Japanese Army (IJA) to the continent. In December 1932, the Myōkō-class ships were placed in reserve as the new Takao-class cruisers were commissioned, becoming the new Sentai-4, whereas the Myōkō-class ships were shifted to Sentai-5. Between 1933 and 1935, all Myōkō-class cruisers were retrofitted with their fixed triple torpedo launchers replaced by two quadruple rotatable launchers, and their secondary guns upgraded from 12 cm/45 10th Year Type naval guns to 12.7 cm/40 Type 89 naval guns. In 1935, Myōkō was damaged in a typhoon as part of the Fourth Fleet incident.

During the Second Sino-Japanese War, Myōkō participated in the Amoy Operation from 10–12 May 1938 as flagship of Sentai-9 of the IJN 5th Fleet along with the Hainan Island Operation in February 1939.

A second reconstruction and retrofit was completed in April 1941, doubling the number of torpedoes to 16, adding another eight Type 96 25 mm AT/AA guns, and bulges to the hull to improve stability.

Pacific War

At the time of the attack on Pearl Harbor, Myōkō and Nachi formed Sentai-5 of the IJN 3rd Fleet. Sentai-5 was commanded by Rear Admiral Takeo Takagi and deployed from Palau cover for the landings of Japanese forces under "Operation M" — the invasion of the southern Philippine Islands. After covering the landings of Japanese forces at Legaspi on 11 December 1941, Myōkō and Nachi returned to Palau and were then reassigned to the Rear Admiral Raizō Tanaka, whose attack force covered landings at Davao on 19 December and Jolo on 24 December.

On 4 January 1942, Myōkō and the other vessels of Admiral Tanaka’s invasion force were attacked by United States Army Air Forces (USAAF) B-17 Flying Fortress bombers while at anchor at Davao. Myōkō was hit by one 500-pound (227 kg) bomb, causing only superficial damage, but she was drydocked at Sasebo Naval Arsenal for repairs.

In the Battle of the Java Sea on 1 March 1942 Myōkō, Nachi, and Haguro participated in the destruction of the last remaining Allied fleet units in the Netherlands East Indies. At 11:50, Myōkō, Ashigara and destroyers Akebono and Inazuma opened fire on the damaged British heavy cruiser Exeter and her escort of two destroyers. During the engagement, the 8-inch guns of Myōkō combined fire with Ashigara to sink the destroyer HMS Encounter, while Nachi and Haguro combined fire to finish off Exeter.

Later in March, Myōkō received a refit at Sasebo Naval Arsenal. In April, she participated in the unsuccessful pursuit of the Doolittle Raid task force.

In May, Myōkō was part of the carrier strike force during the Operation Mo that resulted in the Tulagi invasion force and subsequently the Battle of the Coral Sea. She served as a flagship of Vice Admiral Takagi, who was in the overall command of the carrier strike force, which consisted of the aircraft carriers Shōkaku and Zuikaku, which were under a tactical command of Rear Admiral Chūichi Hara, the heavy cruisers Myōkō and Haguro, and five destroyers. Shōkaku was damaged by American aircraft and Zuikaku lost most of her aircraft in the Battle of the Coral Sea, forcing the flotilla to withdraw without invading Port Moresby.

In June, Myōkō was part of Vice Admiral Nobutake Kondō's support force in the Battle of Midway, which included the battleships Kongō and Hiei, the heavy cruisers Haguro, Atago and Chōkai, the light cruiser Yura, the light aircraft carrier Zuihō, and seven destroyers. The support force returned to Sendai in northern Japan on 23 June without engaging the enemy in this battle, and Myōkō was sent out on 28 June as escort for the reinforcement convoy in the Aleutian Islands Campaign. This force included the aircraft carrier Zuikaku, the light aircraft carriers Zuihō, Jun'yō, and Ryūjō, the heavy cruisers Maya, Takao, Myōkō, Haguro, and Nachi, and the light cruisers Abukuma, Kiso, and Tama. Myōkō returned to Hashirajima on 12 July 1942.