The was a class

Ship class

A ship class is a group of ships of a similar design. This is distinct from a ship-type, which might reflect a similarity of tonnage or intended use. For example, the is a nuclear aircraft carrier of the Nimitz class....

 of twelve destroyer

Destroyer

In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

. All were given traditional poetic names of the months of the year by the Lunar calendar

Lunar calendar

A lunar calendar is a calendar that is based on cycles of the lunar phase. A common purely lunar calendar is the Islamic calendar or Hijri calendar. A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to...

 or phases of the moon. Some authors consider the Kamikaze and Mutsuki class destroyers to be extensions of the earlier .

Background

With the imposition of the Washington Naval Treaty

Washington Naval Treaty

The Washington Naval Treaty, also known as the Five-Power Treaty, was an attempt to cap and limit, and "prevent 'further' costly escalation" of the naval arms race that had begun after World War I between various International powers, each of which had significant naval fleets. The treaty was...

 limiting the number and size of capital warships

Capital ship

The capital ships of a navy are its most important warships; they generally possess the heaviest firepower and armor and are traditionally much larger than other naval vessels...

, increased emphasis was placed by the Imperial Japanese Navy on the quantity and firepower of its destroyer fleet to counter what was perceived to be the growing threat from the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

. The Mutsuki class destroyers were an improved version of the Kamikaze class destroyers and were ordered under the 1923 fiscal budget.

Along with the Minekaze and Kamikaze classes, the Mutsuki class ships formed the backbone of Japanese destroyer formations throughout the twenties and thirties. The Minekaze and Kamikaze classes were withdrawn from front line service and reassigned to secondary duties towards the end of the 1930s, but the Mutsuki were retained as first line destroyers due to their range and their more powerful torpedo armament. All saw combat during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, and none survived the war.

Initially, the Mutsuki class ships had only hull numbers due to the projected large number of warships the Japanese navy expected to build through the Eight-eight fleet

Eight-eight fleet

The was a Japanese naval strategy formulated for the development of the Imperial Japanese Navy in the first quarter of the 20th century, which laid down that the Japanese navy should include eight first-class battleships and eight armoured cruisers or battlecruisers.-History and development:The...

 plan. This proved to be extremely unpopular with the crews and was a constant source of confusion in communications. In August 1928, names were assigned.

Design

The Mutsuki class destroyers were based on the same hull design as the previous Kamikaze class, except with a double curvature configuration of the bow

Bow (ship)

The bow is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is most forward when the vessel is underway. Both of the adjectives fore and forward mean towards the bow...

, a feature which became a standard in all later Japanese destroyers.

The Mutsuki class was the first to be fitted with the newly developed 24 inch torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

es, with greater range and larger warhead than previous torpedoes in the Japanese inventory. Originally Type 8 torpedoes were carried, arranged in two triple mountings. These were later replaced with the famous Type 93 "Long Lance"

Type 93 torpedo

The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

 oxygen-propelled torpedoes during World War II.

In September 1935, many ships in the navy were severely damaged by a typhoon while on training exercises, in what was later termed the "Fourth Fleet Incident", including a number of the Mutsuki class destroyers, which had several plates buckled and bridges wrecked. During 1936-37 the Mutsuki class ships were retrofitted with a strengthened, more compact, bridge

Bridge (ship)

The bridge of a ship is the room or platform from which the ship can be commanded. When a ship is underway the bridge is manned by an OOW aided usually by an AB acting as lookout...

, with redesigned watertight shields on the torpedo mounts. With the new shields the torpedoes could be worked in all weather conditions thus extending the useful life of the class.

From 1941-1942 the Mutsuki class destroyers were refitted with the 4.7"/45 main guns reduced to two single mounts and ten Type 96 25 mm AT/AA Guns added. The minesweeping

Minesweeper (ship)

A minesweeper is a small naval warship designed to counter the threat posed by naval mines. Minesweepers generally detect then neutralize mines in advance of other naval operations.-History:...

 and minelaying equipment was removed and replaced with four depth charge

Depth charge

A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

 launchers, with 36 depth charges.

In June 1944, the surviving vessels were again refit, with the number of Type 96 25 mm antiaircraft guns increased to twenty, and an additional five Type 93 13 mm AA Guns

13.2 mm Hotchkiss machine gun

The 13.2 mm Hotchkiss machine gun was a heavy machine gun designed and manufactured by Hotchkiss et Cie from the late 1920s until World War II where it saw service with various nation's forces, including Japan where the gun was built under licence....

s also installed.

Operational history

The Mutsuki class formed the 5th and 6th Destroyer Squadrons. Mutsuki and Kisaragi participated in the Battle of Wake Island

Battle of Wake Island

The Battle of Wake Island began simultaneously with the Attack on Pearl Harbor and ended on 23 December 1941, with the surrender of the American forces to the Empire of Japan...

 at the start of the war, during which time Kisaragi was lost due to aircraft bombardment. The remaining eleven vessels participated in the invasions of the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

 and Netherlands East Indies. In the subsequent Solomon Islands campaign

Solomon Islands campaign

The Solomon Islands campaign was a major campaign of the Pacific War of World War II. The campaign began with Japanese landings and occupation of several areas in the British Solomon Islands and Bougainville, in the Territory of New Guinea, during the first six months of 1942...

 surviving ships were exposed to considerable danger as fast transports in “Tokyo Express

Tokyo Express

The Tokyo Express was the name given by Allied forces to the use of Imperial Japanese Navy ships at night to deliver personnel, supplies, and equipment to Japanese forces operating in and around New Guinea and the Solomon Islands during the Pacific campaign of World War II...

” missions in trying to re-supply island garrisons. Mutsuki, Nagatsuki, Kikuzuki, Mikazuki and Mochizuki were lost due to air attack in various battles in the Solomons.

Surviving vessels participated in the New Guinea campaign

New Guinea campaign

The New Guinea campaign was one of the major military campaigns of World War II.Before the war, the island of New Guinea was split between:...

, mostly in the role of “Tokyo Express” transports. Yayoi was lost in an air attack off New Guinea and Fumizuki in Operation Hailstone

Operation Hailstone

Operation Hailstone was a massive naval air and surface attack launched on February 17–18, 1944, during World War II by the United States Navy against the Japanese naval and air base at Truk in the Caroline Islands, a pre-war Japanese territory.-Background:Truk was a major Japanese logistical base...

 at Truk. In the final stages of the war, Uzuki was lost to US PT-boats and Satsuki and Yūzuki to an attacks and Minazuki to submarine torpedoes in the Philippines.

None of the Mutsuki class destroyers survived the war.

List of Ships

Kanji	Name	Builder	Laid down	Launched	Completed	Fate
睦月	Mutsuki Japanese destroyer Mutsuki was the lead ship of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-19	Sasebo Naval Arsenal Sasebo Naval Arsenal was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy. -History:The Sasebo Naval District was established at Sasebo, Nagasaki in 1886, as the third of the naval districts responsible for the defense of the Japanese home islands. After the establishment of the... , Japan Japan Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...	21 May 1924	23 July 1925	25 March 1926	; renamed Mutsuki ("January") on 1 August 1928; sunk in air attack in Solomon Islands [07.47S, 160.13E] on 25 August 1942; struck 1 October 1942
如月	Kisaragi  DD-21	Maizuru Naval Arsenal Maizuru Naval Arsenal was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy. -History:The Maizuru Naval District was established at Maizuru, Kyoto in 1889, as the fourth of the naval districts responsible for the defense of the Japanese home islands. After the establishment of the... , Japan	3 June 1924	5 June 1925	21 December 1925	; renamed Kisaragi (“February”) on 1 August 1928; combat loss off Wake Island [18.55N, 166.17E] on 11 December 1941; struck 15 January 1942
彌生	Yayoi Japanese destroyer Yayoi (1925) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War...   DD-23	Uraga Dock Company Uraga Dock Company was a major privately owned shipyard in Uraga, Japan, which built numerous warships for the Imperial Japanese Navy.-History:Uraga Dock Company was founded by Enomoto Takeaki in 1869. A shipyard had already existed in Uraga from the end of the Edo period... , Japan	11 January 1924	11 July 1925	28 August 1926	; renamed Yayoi on 1 August 1928; sunk in air attack in Solomon Islands [08.45S, 151.25E] on 11 September 1942; struck 20 October 1942
卯月	Uzuki Japanese destroyer Uzuki (1925) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-25	Ishikawajima Shipyards IHI The acronym IHI can refer to:* Ishikawajima-Harima Heavy Industries, a Japanese company which produces ships, aero-engines, and other transport-related machinery* Information Holdings Inc., part of The Thomson Corporation since 2004... , Japan	11 January 1924	15 October 1925	14 September 1926	; renamed Uzuki (“April”) on 1 August 1928; Sunk Ormoc Bay [11.03N, 124.23E] on 12 December 1944; struck 10 January 1945
皐月	Satsuki Japanese destroyer Satsuki (1925) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-27	Fujinagata Shipyards Fujinagata Shipyards was a shipyard and railroad car manufacturer in Osaka, Japan.-History:Fujinagata claimed to have been founded in 1689, making it one of the oldest shipbuilders in Japan. Originally called Hyōgo-ya, and located in central Osaka, it was contracted in 1854 by officials representing the Tokugawa... , Japan	1 December 1924	25 March 1925	15 November 1925	renamed Satsuki (“May”) on 1 August 1928; sunk in air attack at Manila Bay [15.35N, 120.55E] on 21 September 1944; struck 10 November 1944
水無月	Minazuki Japanese destroyer Minazuki (1926) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-28	Uraga Dock Company Uraga Dock Company was a major privately owned shipyard in Uraga, Japan, which built numerous warships for the Imperial Japanese Navy.-History:Uraga Dock Company was founded by Enomoto Takeaki in 1869. A shipyard had already existed in Uraga from the end of the Edo period... , Japan	24 March 1924	25 March 1926	22 March 1927	; renamed Minatsuki (“June”) on 1 August 1928; Torpedoed in Celebes Sea [04.05N, 119.30E] on 6 June 1944; struck 10 August 1944
文月	Fumizuki Japanese destroyer Fumizuki (1926) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-29	Fujinagata Shipyards, Japan	20 October 1924	16 February 1926	3 July 1926	; renamed Fumizuki (“July”) on 1 August 1928; sunk in air attack at Truk [07.24N, 151.44E] on 18 February 1944; struck 31 March 1944
長月	Nagatsuki Japanese destroyer Nagatsuki (1926) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-30	Ishikawajima Shipyards IHI The acronym IHI can refer to:* Ishikawajima-Harima Heavy Industries, a Japanese company which produces ships, aero-engines, and other transport-related machinery* Information Holdings Inc., part of The Thomson Corporation since 2004... , Japan	16 April 1925	6 October 1926	30 April 1927	; renamed Nagatsuki (“September”) on 1 August 1928; combat loss in central Solomons [08.02S, 157.12E] on 6 July 1943; struck 1 November 1943
菊月	Kikuzuki Japanese destroyer Kikuzuki (1926) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War.-History:... DD-31	Maizuru Naval Arsenal, Japan	15 June 1925	15 May 1926	20 November 1926	; renamed Kikuzuki (“October”) on 1 August 1928; sunk in air attack at Tulagi [09.07S, 160.12E] on 4 May 1942; struck 25 May 1942. Later salvaged by USS Menominee (AT-73), 6 October 1943.
三日月	Mikazuki Japanese destroyer Mikazuki (1926) was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War... DD-32	Sasebo Naval Arsenal, Japan	21 August 1925	12 July 1926	5 May 1927	;renamed Mikazuki (“Crescent Moon”) on 1 August 1928; sunk in air attack at Cape Gloucester [05.27S, 148.25E] on 29 July 1943; struck 15 October 1943
望月	Mochizuki Japanese destroyer Mochizuki was one of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War... DD-33	Uraga Dock Company, Japan	23 March 1926	28 April 1927	31 October 1927	; renamed Mochizuki (“Full Moon”) on 1 August 1928; sunk in air attack in central Solomons [05.42S, 151.40E] on 24 October 1943; stuck 5 January 1944
夕月	Yūzuki Japanese destroyer Yuzuki was the final of twelve destroyers, built for the Imperial Japanese Navy following World War I. Advanced for their time, these ships served as first-line destroyers through the 1930s, but were considered obsolescent by the start of the Pacific War... DD-34	Fujinagata Shipyards, Japan	27 November 1926	4 March 1927	25 July 1927	renamed Yūzuki (“Evening Moon”) on 1 August 1928; sunk in air attack at Cebu [11.20N, 124.10E] on 12 December 1944; struck 10 January 1945