Mutsuki class destroyers (1925)

Destroyers built 1924-26, Mutsuki, Kisaragi, Yayoi, Uzuki, Satsuki, Minazuki, Fumizuki, Nagatsuki, Kikuzuki, Mikazuki, Mochizuki, Yūzuki

WW2 IJN Destroyers:

Momi | Minekaze | Wakatake | Kamikaze | Mutsuki

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Fubuki | Akatsuki | Hatsuharu | Shiratsuyu | Asashio | Kagero | Yugumo | Shimakaze | Akizuki

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Matsu | Tachibana | Simushu | Erotofu | Ukuru | Type C | Type D

The Mutsuki-class destroyers were twelve destroyers built for the Imperial Japanese Navy (IJN) in the mid-1920s. They played a significant role in Japan’s naval strategy in World War II, together with all other “classic” destroyers of the “german type” cranked up since 1918. Produced through five classes, including two 2nd class ones, and in 1941 still accounted for a large part of the IJN destroyer force. The Mutsuki closely derived from the previous Kamikaze but received a new bow and new Type 8, 610 mm (24 in) torpedo tubes. All twelve were given traditional poetic names of the months of the year by the Lunar calendar or phases of the moon and were built at six different years from May 1924, the last being commissioned in 1927. Meanwhile a brand new design, the “special type” was worked out in secret, alongside the famous “long lance” torpedo. See this in December.

IJN Minazuki

The Mutsuki-class unlike previous ones were maintained in the first line and fought on many theaters of the Pacific, but as escorts of invasion and then supply convoys and ASW patrols. During the Guadalcanal Campaign some took part in the famous “Tokyo Express”, and were lost from air attacks or mainly from submarine actions, with the exception of IJN Mutsuki and Kisaragi sunk during the Battle of the Eastern Solomons in 1942.

Development

Launch of IJN Yuzuki

The Washington Naval Treaty signed by Japanese politicians suddenly stopped dead all extension projects and the latest naval plan of the IJN. This also capped, if not gutting capital warships, and redefining cruisers tonnage, but left a global tonnage and inidvidual tonnage also for destroyers, only putting more pressure on this type to compensate the two others. This was also counter the perceived growing threat from the United States Navy. The Mutsuki-class were thus now seen largely as unsufficient, but since its schedule went back before the treaty, the class was maintained, but it was agreed a new “special type” of destroyer was now needed. Thus, the Mutsuki was a continuation of the Kamikaze class ordered under the 1923 fiscal budget.

With the Minekaze and Kamikaze classes, the Mutsuki formed the backbone of IJN destroyer formations until 1936. The Minekaze and Kamikaze however were eventually withdrawn from front line service due to their age, reassigned to secondary duties, notably escort, towards that time and it was understood the new “special type” such as the Fubuki class and successor would be the new fleet destroyer. The lack of these through forced to a compromise and to keep the Mutsukis as first line destroyers.

Launch of IJN Nagatsuki

Indeed, gradual improvements on the same basic design allowed to enable extra range wuthout compromise top speed too much. But the real game change here was their powerful torpedo armament. At that stage indeed, the IJN was inflexing its traditional view given its now new limited tonnage, inferior globally to the US and Britain. It was decided to invest more in quality than quantity, and notably in the areas of protection, gunnery and torpedoes. In this field, the IJN took a very aggressive stance and decided it needed new models to outrange any model at the time, at greater speeds and payloads.

Given the progresses in ASW protection since the lessons of WWI had been digested, a new standard of 610 mm (the Type 8) was adopted. The first results were impressive with the model 2 which entered service in 1925. Thus, the Mutsuki were never completed with the initially planned 533 mmtorpedo tubes and were the only one of their generation to have these new models also keeping their 1st line status.

All saw combat during World War II, none survived, and they were in thick of the action, even so than their precedecessors. They were also completed with hull numbers dating back pre-Washington as it was believed a very large numbers would be built as part of the 8-8 fleet plan. When cancelled due to the treaty, and because this proved to be extremely unpopular with crews for communication and morale by August 1928 they were all reverted to names. In that case, after natural elements (like winds), they had either ancient months denominations or poetic evocations.

IJN Okikaze at Yokohama in 1932 – scr irootoko JR

Design of the class

Hull and general design

ONI depiction of the class
The Mutsuki-class destroyers had basically same hull design as the previous Kamikaze class. The only major change was the double curvature of their bow, a feature believed to improve seaworthiness, and which became standard on the special types and all later destroyers. It was also able to act as icebreaking bow. Like the previous classes, the Mutsuki had this caracteristic “toothbrush” shape inherited from the German destroyers they obtained as was reparation in 1919. The forecastle (supporting the forward main gun) ended with a recess in which was installed a torpeod tube bank, followed by the bridge, two raked funnels, two more TT banks and a rear structure supporting two main guns. The fourth was located between funnels and all were elevated out of reach of water spray.
Since the forecastle was short, this made of a light hull, making the best of a powerful powerplant, and speeds in excess of 36 knots. In the case of the Mutsukis, extra power gave an evern better top speed.

However the way these hulls were built, especially after the post-treaty rethinking of the IJN, which emphasised better armament and protection on lighter or more compromised hulls for tonnage economy, had dire consequences: The 4th Fleet Incident of September 1935 had many ships taking part in a large Imperial Japanese Navy exercise, hit by a typhoon. Two “Special Type” destroyers, Hatsuyuki and Yūgiri had their bows torn awayn the cruisers Myōkō, Mogami and submarine tender Taigei developed hull cracks, Hōshō and Ryūjō had their flight decks and superstructure badly damage, Ryūjō even had her hangar section flooded and the minelayer Itsukushima was also badly damage. All were stuck in several months for extensive repairs and then later it was decided to have them basically rebuild. Nearly all destroyers, including the Mutsukis, experience various levels of damage to their hulls and superstructures, in addition to 54 crewen lost, swept overboard.

Yuzuki as rebuilt in 1944

This revealed thus weaknesses in the Mutsuki-class construction. This was addressed by having them all strengthened. The hul receiced extra bracing to better support torsion without cracking, and the bridge were rebuilt as more compact and the raked smokestacks were lowered. They also had redesigned watertight shields on the new 610 mm torpedo mounts, which now could be worked in all weather conditions. This however precluded new training sessions before 1936-37.

Blueprints reconstituted of the class in 1944

Powerplant

IJN Uzuki full speed in 1926 in Tateyama Bay, colorized by Irootoko JR

The machinery was improved compared to the Kamikaze. There were still two shaft propellers driven by various types (see later) of geared turbines, fed in turn all by four improved Ro-Gō Kampon boilers for a total of 38,500 shp. Top speed was 37 knots (69 km/h) and from 37.25 kts for the Kamikaze on trials, it seems they achieved the same. However alterations and modifications, especially from 1933 and in 1936, increased their displacement, and reduced their top speed to 33 knots.
Mutsuki, Kisaragi, Uzuki, Satsuki and Fumizuki, Kikuzuki and Yuzuki were completed were sets of Parsons geared steam turbines.
Yayoi (Uraga) however had 2 sets Rateau geared steam turbines and Nagatsuki (Ishikawa) had 2 sets Zoelly geared steam turbines.
Range was 4000 nautical miles at 15 knots based on 420 tonnes of oil, same as the Kamikaze class.

In 1942, Mikazuki was modified as a fast attack transport, being the prototype for more to be converted (Satsuki, Mikazuki, Fumizuki, Nagatsuki, Kikuzuki, Uzuki became fast attacj transports, see below) and lost a boiler, aft stack reduced but she was the only one so modified. Yayoi also had her forward funnel reduced only in her class. Between September 1942 and December 1943 Uzuki received a new stern for the launching and recovery of landing barges, only ship one modified as destroyer transport.

Armament

The Mutsuki-class destroyers had the exact same main battery as the Kamikaze and Minekaze class: Four Type 3 120 mm/45 caliber (4.7 inches) naval guns in single open mounts protected with a small shield: One forward (forecastle), one amidship on a banstand between funnel, and two aft back-to-back. Anti aicraft pritection was an afterthought given the level of tech at the time, and was limited to two Type 92 7.7 mm machine guns with high angle mounts. There was one on either side of the bridge.

The great novelty was the adoption of two triple 24-inch (610 mm) torpedo tubes instead of the planned three double launchers. This newly developed Type 8 torpedoes had greater range, larger warhead but not performing as well as the next Type 93 “Long Lance” oxygen-propelled torpedoe that were later added. For the first time on a Japanese destroyer however, there was a reload for each tube.

12 cm/45 3rd Year Type naval gun

The 12 cm/45 gun was designed in 1895 as an indigenous variant of an Elswick Ordnance Pattern Y under the designation “Type 41”. In 1921 it was declined into an high-angle AA gun, the 12 cm/45 10th Year Type. The base model had a Single motion interrupted screw Welin breech block different from the Type 3 12 cm AA Gun used by the Army in 1943. On destroyers it was always shielded (photo), with the latter fitted with two opening panels.

From 1922 the gun evolved into the 12 cm 11th Year Type naval gun (Model 1922) with a shorter gun barrel and horizontal sliding breech-block but reserved for TBs and submarines only. Manually loaded it fired a 20.3 kg (45 lb) high-explosive or illumination shell. The patrol conversions from 1943 also received an anti-submarine shell.
Thuis gun was ubiquitous for early IJN destroyers, also found on the Momi, Kawakaze, Minekaze, Mutsuki, Wakatake class destroyer as well as the Chidori/Erotofu class TBs and the Shimushu and Tsukushi class escort/survey ships of the Hashidate class gunboats.

As for torpedoes, these ships had access to a wide variety of 533 mm models, the 21″ (53.3 cm) Type 43 and Type 44 No. 1/2 1911 models and still the trusted Type 6 (1917) which entered service in 1918. The Mutsukis were planned at first with the same three triple banks as previous classes, one in the recess between the forecastle and bridge, and two aft of the funnels, separated by a projector platform, and the Type 6 533 mm type.
However they adopted instead the Type 8, new 610 mm. In 1935-36 they were likely replaced by two triple banks for the new Type 90 or model 1 Type 93. Given their size and weight for the sake of stability, N°2 torpedo tubes bank was dropped in 1926. Instead of three banks indeed, constraints of weight and stability forced the adoption of two banks, one in the same location forward, but one only one aft, leaving extra space for spare torpedoes, also a novelty of the design. They were originally “naked” like previous banks. But after the 1935 4th fleet incident, they received a caracteristic cover to protect them from the weather and water spray. This is why it is hard to tell when they swapped on the Type 90 or direclty to the Type 93.

Type 8 (1920)

The “8th Year Type” was a brand new 61 cm (24 in)-diameter torpedo made for surface ships and later further developed into the more advanced Type 90 torpedo and Type 93 Long Lance. It was designed in 1919 already but not for destroyers, and adopted in 1920 with the model 1. Later in 1925 appeared the model 2 with a larger warhead. The 8th Year Type the first-ever 61 cm (24 in) diameter torpedo in service anywhere, and rounded as a 610 mm (exactly 609 mm (24.0 in)) and initially deployed for the Mutsuki-class destroyers, Fubuki-class “special type” and several light cruisers when refitted such as the Nagara class. This caliver soon became standard.
The Hatsuharu-class and rebuilt heavy cruiser had these also and soon swapped onto the better Type 90 torpedo replacing them all. The latter was developed from 1928 aznd adopted in 1932, replacing the Type 8, but its seems the Mutsuki swapped directly to the Type 93.
The Type 8 used a four-cylinder Schwarzkopff radial engine with wet-heater mising kerosene and compressed air. The Type 90 torpedo had an new 2-cylinder double action engine and was capable of reaching 46 knots (85 km/h). The launching mechanism was imporved as well.

Type 90 (1930)

This new type was adopted originally for heavy Cruisers and Fubuki destroyer classes only. Development started in 1928 and was completed in 1932, with introduction made in 1930 for tests and strict service adoption in 1933. It had a more powerful engine of the one used in the 53 cm Type 89. The starting point were the 46-knot (85 km/h) 21-inch (53 cm) Whitehead torpedoes and instead of a radial they used a new double-action two-cylinder engine. The compacity and extra power meant more speed but shorter range. Neither of the resulting 6th and 8th Year torpedoes were manufactured, but they led to the Type 90.
It’s thus not known if the Mutsuki were ever fitted with these or instead swapped directly to the Type 93.

Type 93 (1933)

The Type 93 entered service in 1933 (model 1) and the ships were possibly rearmed in 1935-36 or never, it’s not strictly confirmed. The Type 90 could have been installed instead when available.
61 cm Type 93 torpedo found on the Mutsuki, Fubuki, Akatsuki classes, and all oxygen fuelled from the Hatsuhara and beyond. The Designer was Rear Admiral Kaneji Kishimoto, and Captain Toshihide Asakuma, and this started in 1928 (just as the last Mutsuki class ships were completed), then went on until 1932. The Type 93 became the nororious “secret weapon” unleashed by IJN destroyers and cruisers in WW2, which caused extebsive damage during the Solomons campaign expecially. The defective US Type 14 torpedo was in stark contrast with this. The Type 93 torpedo was dangerous to its user however but its effectiveness outweighed the risks anyway, claiming 23 Allied warships, 11 cruisers, 11 destroyers, and a fleet aircraft carrier and among these, 13 hits were fatal.

AA Defence

After the start of the Pacific War, their poor anti-aircraft capabilities were enhanced, at the expense of surface warfare capabilities, and also speed. But there was no standard modification for the class (see later). They just discarded their 7.7 mm light AA machine guns for Type 93 13 mm AA Guns in front of the bridge and abaft the aft stack and from 1941-1942, amidships and aft guns were landed to carry extra triple 25 mm AA mounts and up to ten Type 96 25mm AA Guns in some cases.
The ones that survived in 1943, had their aft TT bank removed to reduce weight and storage extra cargo for fast supply missions, notably in the Carolines. The three that survived by late 1944 (Uzuki, Satsuki, Yūzuki), went up to sixteen 25 mm Type 96 guns and 13 mm HMGs in single, triple or dual mounts.

Depth Charges

The Mutsuki-class had two Type 81 depth charge launchers at the stern, with a total of 18 depth charges. This was augmented in wartime.
Standard Type 95, 30.5″ by 17.7″ (77.5cm by 45cm). 220 lb (100 kg) charge, Type 88 explosive (ammonium perchlorate and ferrosilicate). Fuse using a water inlet. 100 feet (30m) and 200 feet (60m) settings (after the revelations of a US Congressman).
Later increased to 324 lb (147kg), Type 97 explosive (70% TNA/30% HNDA), 300 foot (90m) setting.
-1944 Type 2: 230 lbs (105kg) Type 97 explosive settings 98, 197, 292, 390, 480 feet (30m, 60m, 89m, 120m, and 145m).
-1945 Type 2: 357 lbs (162kg) explosives.

Mines

20 mines on rails, no precision given. Can be any of the models here.
The ships were also given an optional mechanical minesweeping gear.

Sensors (WW2)

93-shiki (Type 93) sonar (1943):2 kW 4400 lbs (2000 kg) model, FRQ 17.5 kHz, receiver gain 120 decibels 2, 4, or 8 seconds pulse interval, range up to 1640-3300-6600 yards (1500m-3000m-6000m) at 3°/10° resolution.
3-shiki (Type 3) 1-go radar: Surviving destroyers in 1944. 2 arrays of 5 dipoles, 10 kW, wlg 20, PRF 500, range 150 km effective, 300 km max.
2-shiki (Type 2) 2-go radar: Probably the same as above, no data found yet.

Author’s 1944 camouflage depiction of IJN Mutsuki

Russian book description of the class in 2 views, pre-1935 (russian book, from pinterest)

Upgrades

As said before, in 1933-34 all these ships swapped their 533 mm tubes for 610 mm, and lost a torpedo bank to spare weight and keep stability. Still in 1935-36 following the 4th fleet incident they were all reinforced, strenghtened and partly rebuilt. Satsuki, Minazuki, Fumizuki, Nagatsuki, Kikuzuki, Mikazuki had their two 7.7mm/80 KMG replaced by a twin 25m/60 Type 96 AA mount. This was later done in 1941 to Mutsuki, Kisaragi, Yayoi, Uzuki, Mochizuki, Yuzuki.
In 1942, Satsuki, Mikazuki, Fumizuki, Nagatsuki, Kikuzuki and Uzuki were converted as fast attack transports wirth a larger displacement at 1590t sta,dard and 1913t fully loaded, a top speed down to 34kts. Two main guns, N°2 and 3 were removed, as well as their minesweeping gear, and mines rails. Instead they kept obtained two triple 25mm/60 Type 96 AA mounts as well as a twin one and two 2 depth charge throwers (36) as well as new accommodation for marines and a new cargo deck, albeit not slanted back. They also had the Type 93 sonar installed. They were used for night supply missions, notably in the Solomons.

In 1944, several ships were modified, Minazuki lost her N°2 120mm/45 gun and gained two triple Type 96 and a twin 25 mm mount, as well as a twin 13.2mm/76 Type 92 HMG mount. Uzuki “only” received an additional triple and two single 25mm/60 Type 96 AA mounts, while later in 1944 Yuzuki was modified like Minazuki less the twon 13.2 mm AA mount and Satsuki had an extra fove single 13.2mm/76 and the Type 3 1-go radar. Losses were heavy, early one, so no further modifications were mae after 1944. Satsuki also was the first fitted with a Type 13 radar in February 1944.

Career of the Mutsuki class

IJN Mutsuki (Dai-19) was laid down at Sasebo Naval Arsenal on 21 May 1924, launched on 23 Jul 1925 and completed on 25 Mar 1926. From Destroyer No. 19, she was assigned the name Mutsuki on 1 August 1928 and started by the campaign in China, First Shanghai Incident of 1932 and Second Sino-Japanese War.
On 7 December 1941, Mutsuki was flagship of DesDiv 30, DesRon 6, 4th Fleet. On december 1941 she headed for Kwajalein with the Wake Island invasion force and a SNLFl (Japanese Special Naval Landing Forces) on board. On 11 December the US garrison repulsed the first landing supported by Yūbari, Tenryū, and Tatsuta and Yayoi, Hayate, Kisaragi, Mutsuki, Oite, and Mochizuki, as well as two old Momi-class now patrol boats 32, 33. Theu also escorted two troop transports with 450 extra SNLF troops. Kisaragi and Hayate were badly mauled and the Japanese withdrew, first defeat of the war, mainly due to well concealed, powerful shore-based guns. Mutsuki was back on 23 December with the second Wake Island invasion force and her own SNLF advance landing party, but withdrew to Kwajalein.
She escorted a convoy from Kwajalein to Truk in January 1942, receiving two 13.2 mm Type 93 AA guns on the forward side of the bridge. She escorted a troop convoy from Truk to Guam later that month, and then joined the invasion of the Solomon Islands, covering the landings of Japanese forces during Operation R (the invasion of Rabaul and took part in Operation SR (Lae-Salamaua assault, January–March 42). From 28 March to 1 April she remained flagship for Rear Admiral Masao Kanazawa, 8th Special Base Force in the Shortland Islands and Bougainville assaults and later the Admiralty Islands.
She was in the thock of action at the Battle of the Coral Sea (7–8 May) assigned to Operation Mo invasion force at Port Moresby until cancelled and the returned to Rabaul, escorting convoys between Truk, Rabaul and Palau before a refit in Sasebo completed on 12 July. She was set to the 8th Fleet and took part in the raid on Henderson Field on 24-25 August 1942. She was sunk in the Battle of the Eastern Solomons on 25 August 1942 by USAAF B-17 which also sank the transport Kinryu Maru, 40 miles (64 km) northeast of Santa Isabel, with a direct bomb hit in her engineering space. 41 wznt down with her, 11 later, injured. Yayoi rescued the remainder including Captain, Lt. Cdr. Kenji Hatano. Frmally stricken on 1 October 1942.

IJN Kisaragi (Dai-21) “February” or Dai-21-Gō Kuchikukan was laid down on Maizuru Naval Arsenal on 3 Jun 1924, launched on 5 Jun 1925, completed on 21 Dec 1925. On 7 December 1941 she was assigned to DesDiv 30, DesRon 6, 4th Fleet and was in the same sortie from Kwajalein on 8 December with the later repelled Wake Island invasion force, carrying SNLF troops. Kisaragi was sailing away when attacked and sunk by Grumman F4F Wildcat fighters from VMF-211 armed with 100-pound (45 kg) bombs from the Island. US accounts attributed her loss to a bomb from Captain Henry Elrod which hit her depth charges or one that penetrated below decks, started a fire which spread to ammunitions and blew her stern. Japanese accounts related a bridge hit, and that she blew up five minutes later from amidships. In any case she lost 157 crewmembers, 30 miles (48 km) southwest of Wake Island, second major loss after Hayate. She was stricken on 15 January 1942. Elrod did later in the fight and was posthumously awarded the MoH for the sinking of the destroyer.

IJn Yayoi (Dai-23, later ‘March’) was laid down at Uraga Dock on 11 Jan 1924, launched on 11 Jul 1925 and completed on 28 Aug 1926. She took part in the Second Sino-Japanese War and Invasion of French Indochina in 1940.
On 7 December 1941, she was in the same DesDiv 30 as her sisters above and took part from Kwajalein to the Wake Island invasion force. Major James Devereux’s garrison commander ordered his shore guns to fire at the right moment from 4,100 meters (4,500 yd) and sank Hayate, damaged the flagship Yubari. Badly Shook, the admiral ordered a withdrawal. Yayoi was hit by a 5-inch shell, killing one, injuring 17. She was part of the second invasion force on 23 December which succeeded.
She escorted a convoy from Kwajalein to Truk in January 1942 and received extra AA, then a convoy from Truk to Guam and was part of the invasion of the Solomon Islands, covering landings in Operation R (Rabaul, New Ireland, New Britain) and Operation SR (Lae-Salamaua, New Guinea), the the Shortland Islands and Bougainville and occupation of the Admiralty. She was present as an escort in the Battle of the Coral Sea and after Operation Mo was cancelled, was refitted at Sasebo until mid-July. She joined the 8th Fleet for the bombardment of Henderson Field on Guadalcanal, 24 August 1942.and escape destruction at the Battle of the Eastern Solomons, rescuingd survivors from Mutsuki.
Late August saw her part of the “Tokyo Express” as troop transport to Milne in New Guinea. In September she was in Operation Ke, the evacuations from Guadalcanal. On 11 September she left Rabaul for Goodenough Island, when attack by Allied B-17 and B-25 some 8 nautical miles (15 km; 9 mi) northwest of Vakuta Island, killing Shiro Yasutake, the commander of DesDiv 30, Captain and staff. Lieutenant Commander Shizuka Kajimoto ordred to abandon ship as she lsted rapidly, 83 men were rescued by Mochizuki and Isokaze off Normanby Island. Stricken 20 October 1942.

Uzuki (Dai-25 later ‘April’) was laid down at Ishikawajima Shipyards on 11 Jan 1924, launched on 15 Oct 1925 and completed on 14 Sep 1926. In the late 1930s, Uzuki participated in the Second Sino-Japanese War, covered landings in central and southern China, and Invasion of French Indochina. In december 1941 she was part of Desron 23, CarDiv 2, 1st Air Fleet (Kido Butai) as escort. She sailed from Hahajima (Ogasawara) with the Guam invasion force. Later she sailed to Truk for the landings or “Operation R” (Rabaul-Kavieng) on 23 January and bac to Truk. In March she covered landings of Operation SR (northern Solomon, Lae-Salamaua) and Admiralty, then she was reassigned to the 4th Fleet on 10 April, escorting the tanker Hoyo Maru in the Shortlands during the Battle of the Coral Sea. She was refitted at Sasebo Naval from 28 May and in June she was in Truk, escorting convoys carrying airfield construction crews to Bougainville and Guadalcanal. She was present in the invasion of Buka on 21–22 July, strafed by Allied aircraft, loosing 16 crewmen. On 11 August she left Rabaul to rescue men from the sunken cruiser Kako. She took part in several “Tokyo Express” runs to Guadalcanal, and had a near miss by USAAF B-17. She was repaired in Sasebo from 14 September.
Back with the 8th Fleet on 1 December 1942 she escorted IJN Chūyō from Yokosuka to Truk, and a troop convoy from Truk to Rabaul. At Rabaul on 25 December she collided with the transport Nankai Maru, towed by Ariake and Urakaze back to Rabaul for emergency repairs and damaged in the raid on 5 January 1943. She was towed by Suzukaze to Truk for more repairs, and proceeded to Sasebo on 3 July, until mid-October, and back to Truk escorting the cruisers Kiso and Tama loaded with troops for Rabaul. On 23–24 October she rescued survivors from Mochizuki in Jacquinot Bay (New Britain). She went on with “Tokyo Express” runs in the Solomon and on 24–25 November, she met in battle Fletcher class destroyers (led by Captain Arleigh Burke) at the Battle of Cape St. George during the evacuation of Buka, remaining unscathed. In December she escorted tankers from Rabaul to Truk and Palau and back.
In January 1944 she escorted Nagara back to Japan and was refitted at Sasebo, then escorted troop convoys from Yokosuka to Palau, Yap, Saipan and Truk until late June 1944. During the Battle of the Philippine Sea she was in the Second Supply Force. On 20 June she rescued men from the oiler Genyo Maru, before sinking her by gunfire. She escorted ships from Kure to Manila and Singapore until November. On 18 July 1944 she was back in the Combined Fleet and from 20 November, the 5th Fleet. On 12 December underway from Manila to Ormoc, she was ambushed and torpedoed by PT-490 and PT-492, 50 miles (80 km) northeast of Cebu. 170 crewmen lost their lives, including Captain Watanabe, 59 survivors. She was stricken on 10 January 1945.

IJN Satsuki (Dai-27 later ‘May’) was laid down on Fujinagata Shipyards, on 1 Dec 1923, launched on 25 Mar 1925 and completed on 15 Nov 1925. In december 1941 she was in DesDiv 22, DesRon 5, 3rd Fleet, Mako Guard District, Pescadores and taking part in Operation M (Philippines invasion), screen landing zones at Lingayen Gulf and Aparri. Later she escorting troop convoys from French Indochina for Operation E (Malaya) and Operation J (Java) in February 1942. From 10 March she was sent to the Southwest Area Fleet, escoting convoys to Singapore and in occupied Netherlands East Indies. She was refitted at Sasebo from 9-24 June and ecorted the seaplane tender Kamikawa Maru from Sasebo via Truk and Rabaul in the Shortlands. By January 1943 she remained in the Solomon Islands of notably Operation KE (evacuations from Guadalcanal) and more escorts from Palau to Wewak and Kolombangara as part of the 8th Fleet. She was part of several “Tokyo Express” runs until late May 1943, being grounded on a reef southeast of Bougainville (24 May) and repaired in Rabaul. In June-July, she made a “Tokyo Express” to Tuluvu and Kolombangara and was present in the Battle of Kula Gulf and Battle of Kolombangara, no damage. On 17 July she was strafed and bombed in the Shortlands and had to return to Kure for repairs via Rabaul, Truk, and Yokosuka. When back at Rabaul she resumed “Tokyo Express” to Kolombangara, Gasmata, and Buka. She had another refit and was back in Rabaul in early December.

On 4 January 1944 Satsuki was damaged during the raid on Kavieng, taking many casualties including captain Tadao Iino. While underway to Japan she was diverted to Saipan to assist IJN Unyō. She emerged from Sasebo on 15 Marchn escorting several troop convoys from Tateyama to Palau and ended in the Central Pacific Area Fleet. She escorted troop convoys from Tateyama to Saipan and Guam and in July, from Kure via Manila to Lingga and from Singapore. On 20 August, she was in the Combined Fleet and on 21 September, after anotehr escort from Singapore via Miri and Brunei to Manila, she was attacked by a squadron frol TF 38 in Manila Bay and took three direct bomb hits: 52 killed, 15 injured, and sank.
She was stricke on 10 November 1944.

IJN Minazuki (Dai-28, later ‘June’) was laid down Uraga Dock Company on 24 Mar 1925, launched on 25 May 1926 and completed on 22 Mar 1927. In December 1941 she was with DesDiv 22 , DesRon 5, 3rd Fleet. She left the Mako Guard District for Operation M (Philippines invasion) in the Lingayen Gulf and Aparri. In early 1942, she escorted convoys from French Indochina for Operation E (Malaya) and Operation J (Java), reassigned to the Southwest Area Fleet znd escorted troop convoys from Singapore to the NL East Indies, then back to Sasebo for refit on 18 August-4 October.
Assigned to the 8th Fleet at Rabaul on 25 February 1943 she started a serie of “Tokyo Express” runs in the Solomons, notably the Battle of Kolombangara on 12 July and damaged in a raid near the Shortlands, withdrew to Kure (August- September). On 13 September back in Rabaul she evacuating troops from Kolombangara. On 2 October she met three US destroyers, was hit by three shells (duds) and later was damaged by a near miss in an air raid (lost No. 1 and No. 2 guns) on 12 October, but she made another “Tokyo Express” run to Buka and Kavieng and on 4 November, rescued 267 from Kiyozumi Maru.
Back to “Tokyo Express” missions to Rabaul after refit to the end of February 1943 she patrolled off Palau in March-April and in May, was reassigned to the Central Pacific Area Fleet, escorted troop convoys from Yokosuka to Saipan. On 6 June she left Tawitawi with a tanker convoy to Balikpapan (Borneo) when ambushed, torpedoed by USS Harder off Tawitawi. Wakatsuki rescued 45 survivors but captain Kieji Isobe went down with the ship. Stricken 10 August 1944.

Fumizuki (Dai-29, later ‘July’) was laid down at Fujinagata Shipyards on 20 Oct 1924, launched on 16 Feb 1926 and completed 3 Jul 1926. On 7 December 1941, Minazuki she was in desDiv 22 DesRon 5, 3rd Fleet, leaving the Mako Guard District (Pescadores) for Operation M, the invasion of the Philippines, in Lingayen Gulf and Aparri. Next she escorting troop convoys from French Indochina for the Malaya and Java operation, joined on 10 March 1942 the Southwest Area Fleet, escorted convoys from Singapore to Penang-Rangoon. She was refitted at Sasebo from 17 June to early September, and sailed to Mako but on the 16th she collided with the transport Kachidoki Maru in Formosa Strait, back to Sasebo for repairs until early 1943. Late January 1943 saw her escorting the seaplane tender Kamikawa Maru from Sasebo to Shortlands and wa sin Operation KE (evacuations from Guadalcanal). In February she joined the 8th Fleet and took part in several Tokyo Express runs in the Solomons until the end of April, dzmaged by strafing attacks at Finschhafen (March), Kavieng (April).
Back to Yokosuka on 4 May until August 20 for refit she escorted a convoy via Sasebo to Saipan, Truk and Rabaul. September 1943-January 1944 saw her committed to more “Tokyo Express” runs, evacuations from Kolombangara and Vella Lavella or landings at Buka (Bougainville) and others. On 2 November she was dalmaged in a raid off Rabaul, 6 killed, 4 injured, then same near Kavieng on the night of 4 January 1944. On 17 February 1944 in Truk, Fumizuki had a near miss from TBF Avengers in Operation Hailstone while at anchorage. Port amidships blast knocked out her corresponding but only usable turbine while flooding was soon out of control. She sank on 18 February with 29 crewmen, stricken 31 March 1944.

IJN Nagatsuki (Dai-30, later ‘September’) was laid down at Ishikawajima Shipyards on 16 Apr 1925, launched on 6 Oct 1926 and completed on 30 Apr 1927. She took part in the Second Sino-Japanese War in the central and southern China, plus Invasion of French Indochina in 1940. By December 1941 she was in desDiv 22, DesRon 5, 3rd Fleet, Mako Guard District, taking part in Operation M (invasion of the Philippines) but while at Lingayen Gulf, she was damaged by strafing attacks (USAAF aircraft) with one killed, five injured. In early 1942 she escorted troop convoys from French Indochina to Java and from 10 March 1942 joined the Southwest Area Fleet, escorted ships from Singapore to Penang, and Rangoon before a refit at Sasebo from 19 September to 9 November.
By late January 1943, IJN Nagatsuki escorted the seaplane tender Kamikawa Maru from Sasebo to Shortlands an remained for Operation KE (evacuations from Guadalcanal) and escort ships to Palau, Wewak and Rabaul before being reassigned to the 8th Fleet. She had her share of Tokyo Express transport missions until late June, Kolombangara and Tuluvu. On 4–5 July, she met the US destroyer USS Strong, and torpedoed her. In the next Battle of Kula Gulf however she was in the thick of action, badly damaged by gunfire. She had her hull holed by mukltiple 6-inch shots and captain Tameo Furukawa, managed to have her grounded near Bambari Harbor to land troops bu she could not refloated even with assistance of Satsuki. She was spotted and finished off in a air raid on 6 July with 8 dead and 13 injured, survivors walking to the IJA base at Vila, Kolombangara, on foot. Stricken 1 October 1943.

IJN Kikuzuki (Dai-31 later ‘Chrysanthemum Moon’) was laid down at Maizuru Naval Arsenal on 15 Jun 1925, launched on 15 May 1926 and completed on 20 Nov 1926. Sje was present in the Second Sino-Japanese War and French Indochina. In december 1941 she was in Desron 23, CarDiv 2, 1st Air Fleet, saiking from Hahajima (Ogasawara Islands) to support the invasion of Guam and back to Truk in early January 1942 for Operation R (Kavieng in New Ireland) on 23 January. In March this was Operation SR (northern Solomons, Lae, Admiralty Islands) until reassigned to the 4th Fleet on 10 April. She took part in Operation Mo, and invasion of Tulagi on 3-4 May 1942 but she was torpedoed here by Douglas Devastators from USS Yorktown on 4 May, killing 12, injuring 22. She listed but held, towed by the submarine chaser Toshi Maru No.3 to a beach at Gavutu Island, and embarked the survivors. Kikuzuki slid back into the water on 5 May 1942 in high tide and sank, stricken 25 May 1942. Her rusting hulk was photographed in August 1943 after she was dragged back to the beach after the capture of Tulagi. She was partially restored to navugation by the repair ship USS Prometheus and became a treasure trove of intel. Her partially-dismantled hulk still is rusting away at Ghovana Bay, Nggela Sule.

Mikazuki (Dai-32 later ‘Crescent Moon’) ws laid down at Sasebo Naval Arsenal on 21 Aug 1925, laid down on 12 Jul 1926 and completed on 5 May 1927. She fought in the Second Sino-Japanese War, central and southern China and in December 1941 assigned ti CarDiv 3, 1st Fleet, as escort for the fleet aircraft carriers Hōshō and Zuihō. Thus she took part in the Battle of Midway under Admiral Nobutake Kondō’s occupation force, not involved in combat. She was reassigned to the Southwest Area Fleet and from July 1942 to March 1943 she escorted convoys between Moji, Kyūshū and Taiwan. Until 10 June 1943 she was refitted at Sasebo and joined DesDiv 30, DesRon 3, IJN 8th Fleet in Rabaul. In June-July 1943 she was part of Tokyo Express runs to Kolombangara. She was present at the Battle of Kula Gulf on 5–6 July, landing SNLF troops (Special Naval Landing Forces) under fire. She was in cover during the Battle of Kolombangara on 12 July. On 27 July she grounded on a reef underway to Tuluvu in New Britain and a day later, attacked and destroyed by USAAF B-25 Mitchell (8 killed, many more wounded) and abandoned as a total constructive loss, stricken 15 October 1943.

Mochizuki (Dai-33, later ‘Full Moon’) was laid down at Uraga Dock on 23 Mar 1926, launched on 28 Apr 1927, completed on 31 Oct 1927. She took part in the Second Sino-Japanese War, central and southern China and on 7 December 1941 was in DesDiv 30, DesRon 6, 4th Fleet. She took part in the first Wake Island invasion force, repelled and in the second from December 23 via Kwajalein. She escorted a covoy to Truk in January 1942 ad in Feb. March participated in the invasion of the Solomon Islands, covering landings of Operation R (Rabaul-New Ireland-New Britain) and Operation SR (Lae-Salamaua) and in April, the Admiralty Islands. At the time of the Battle of Coral Sea she wa sin the escort for the invasion force for Operation Mo to Port Moresby, cancelled. She escorted vessels from Truk, Lae and Guadalcanal and refitted in Japan from July to early september, and reassigned to the 8th Fleet.

Late September saw Mochizuki sand Isokaze rescuing survivors from Yayoi on Normanby Island. On 14–15 October she escorted Kinugasa and Chōkai shelling Henderson Field. In November she made several “Tokyo Express” runs but on 8 November she was hit by a dud torpedo from PT-61 and on 13–15 November), assisted Amagiri, rescuing 1500 survivors from Nagara Maru and Canberra Maru. On 1 December 1942 she was reassigned to the 8th Fleet and escorted the cruisers Kumano and Suzuya in the Admiralty Islands for landings at Buna and Finschhafen and took minor damage durjng air attacks.
She made two more Tokyo Express runs from Rabaul to Kolombangara and Rekata Bay in January 1943 and retruend to Sasebo for overhaul, back to Rabaul in March, assisting Florida Maru. Until late June 1943 she made a Tokyo Express to Rekata, Buna, Tuluvu and Kolombangara. She took part in the Battle of Kula Gulf on 5–6 July, engaging by gunfore and torpedo USS Radford and USS Nicholas, taking minor damage from shell hits (No. 1 gun) and torpedo tubes forcing her back to Sasebo by late August and back to Rabaul in late September for other Tokyo Express runs.
On 24 October 1943 while underway Jacquinot Bay she was attacked by night by “black cats” PBY Catalinas 90 mi (140 km) south-southwest of Rabaul and took a direct bomb hit in her engine rooms. Her crew was rescued by Uzuki and she was scuttled, stricken 5 January 1944.

Yuzuki (Dai-34, later ‘Evening Moon’) was laid down at Fujinagata on 27 Nov 1926, launched on 4 Mar 1927 and completed on 25 Jul 1927. She took part in the Second Sino-Japanese War and Invasion of French Indochina. In december 1941 she was in desDiv 23, CarDiv 2, 1st Air Fleet. She left Hahajima (Ogasawara Islands) for the invasion of Guam and back to Truk in early January 1942 for Operation R (Kavieng) and in In March, covered landings in the northern Solomons, Lae and Admiralty Islands, then reassigned to the 4th Fleet (10 April).
She was overhauled at Sasebo and reassigned to DesDiv 29 in June as flagship based at Truk, and escorting convoys with airfield construction crews to Bougainville and Guadalcanal. She patrolled around Rabaul until late August and on the 31st, August, screened the Nauru and Ocean Island invasions (Operation RY), central Pacific.
After refit at Sasebo in January 1943, back to Truk she resumed patrols in the central Pacific until November 1943, rescuing crews of torpedoed transports and on 30 November, reassigned to DesDiv 30, DesRon 3, 8th Fleet in Rabaul by February 1944 for the final Tokyo Express run to New Britain and final evacuation of Rabaul. Until May 1944 she remained based on Palau, rescuing survivors from Yūbari on 27 April. On 1st May she was sent to the Central Pacific Area and on 18 July, Combined Fleet. In September-October she escorted convoys from Japan to Taiwan, the aircraft carrier Jun’yō to Brunei and Manila. On 21 November she is reassigned to the 5th Fleet and on 12 December, while escorting a convoy from Manila to Ormoc she is spotted and attacked by a squadron of USMC aircraft, 65 miles (105 km) north-northeast of Cebu. She sank, with 20 killed and 217 survivors rescued by IJN Kiri. Stricken 10 January 1945.

The refloated wreck of IJN Kikuzuki in 1944

Gallery

IJN Yukaze in Yokohama

IJN Shimakaze

IJN Minekaze in Yokohama

IJN Minekaze in Maizuru

IJN Kisaragi as completed in Feb. 1927. Note the weak early open bridge type, later rebuilt in all ships.

Read More/Src

Books

Evans, David (1979). Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941. US Naval Institute Press. ISBN 0-87021-192-7.
Brown, David (1990). Warship Losses of World War Two. Naval Institute Press. ISBN 1-55750-914-X.
Howarth, Stephen (1983). The Fighting Ships of the Rising Sun: The Drama of the Imperial Japanese Navy, 1895–1945. Atheneum. ISBN 0-689-11402-8.
Jentsura, Hansgeorg (1976). Warships of the Imperial Japanese Navy, 1869–1945. US Naval Institute Press. ISBN 0-87021-893-X.
Morison, Samuel Eliot (1958). The Struggle for Guadalcanal, August 1942 – February 1943, vol. 5 of History of United States Naval Operations in World War II. Boston: Little, Brown and Company. ISBN 0-316-58305-7.
Nelson, Andrew N. (1967). Japanese–English Character Dictionary. Tuttle. ISBN 0-8048-0408-7.
Watts, Anthony J (1967). Japanese Warships of World War II. Doubleday. ISBN 978-0-3850-9189-3.
Whitley, M J (2000). Destroyers of World War Two: An International Encyclopedia. London: Arms and Armour Press. ISBN 1-85409-521-8.

Links

Mutsuki clas son combinedfleet.com
https://www.globalsecurity.org/military/world/japan/mutsuki-dd.htm
on navypedia.org/
combinedfleet.com TROM mutsuki
combinedfleet.com TROM kikuzuki
combinedfleet.com TROM nagatsuki
combinedfleet.com TROM mikazuki
navweaps.com/ early interwar IJN torpedoes
navweaps.com/ torpedoes
taietsu-shigoku.com/sansogyorai/
combinedfleet.com/torps.htm
navweaps.com/ 13mm/76
on ww2db.com/
on en.wikipedia.org/
CC photos on commons.wikimedia.org/
archive.ph
all colorized photos of the class by Hirootoko Jr.

Videos

Model Kits

3D

IJN Mutsuki details on WoW, 1944 configuration