A newcomer in destroyer design

WW2 Japanese destroyers were certainly among the world's most powerful since the Fubuki in 1926. Just like Russia showed the way in 1910 with the Novik, Japan was at the forefront in destroyer design, with speed, firepower, and aggressive tactics matching over-the-top torpedoes like the deadly "long-lance". The prewar models were rather small, high seas TBs, while from 1917, Japan launched in a frenzy dozens of large oceanic destroyers. This story started very early on, like many other nations, with torpedo-boats. In August 1914, 62 destroyers were in service, all classes confounded.


Isokaze class destroyers


Destroyer Momo in the Mediterranean, 1917. src: Roads to the Great War - blogger

From 1879 to 1895

The first contract on behalf of the IJN was awarded as early as 1879. Because of previous events, little funds, only small series of modest ships could be ordered at a time. The first four were built at Yarrow, dismantled, shipped and reconstructed at Yokosuka, and retired in 1899. What followed was the experimental armoured TB Kotaka in 1885 and about 40 TBs followed from 1885, coastal Yarrow types (50t and 25t), then Japan turned to France and ordered 35m types and Normand 34m types (1894). All has been discarded prior to ww1. Larger Schichau types were later also ordered. The 54t type, 3rd class TBs were the first Japanese-designed ones, in all 26 boats all operational when WW1 began, for coastal defence.


Destroyer Katsura at Brindisi, 1917. Colorized by Irootoko Jr. alias Atsushi Yamashita

Japanese early destroyer design

At last in 1900 the Ten Years Programme put a plan for dozens of new TBs but also ordered 23 destroyers. The following classes consisted in the Ikazuchi (6), Murakumo (6), Akatsuki (2), Shirakumo (2), Harusame (7), Asakaze (32), Umikaze (2), Sakura (2), and three ex-Russians. These ships were 275 to 375 tonnes, 63 to 69m long, 5.96 to 6.57m of width, 1.56 to 1.83m of draught, 29 to 31 knots and the same armament of 2x 12 pdr, 4x 6pdr and 2 18 in TTs (450 mm).

Ikazuchi were basically Yarrow ships (like the Akatsuki), Murakumo were from Thornycroft, while the Harusame were all Japanese, after a modified Shikarumo design. Their machinery was still very Thornycroft-esque in style. These 1st generation destroyers were all scrapped in 1920. But the second generation was far more interesting and for the most, was in service in the whole interwar and for many, WW2 as well.

Ikazuchi class (6 ships, 1899)

Yarrow-built, completed 1898-1900. Comprised the Akebono, Ikazuchi, Inazuma, Niji, Oboro and Sazanami. 305 tons, 6000 hp, 31 knots. Few participated in the great war: the Niji, scarcely received and perhaps badly manoeuvred by her crew was carried by her own speed and ran aground on a reef. She was salvaged and broken up in 1900, following her only sortie. Ikazuchi was in Tsushima and survived the Russian fire, saw his boiler explode in 1913 and was lost. The Inazuma crashed into a schooner near Hakodate in 1909 and sank it. The Sazanami was also the victim of an accident in 1913. Only the Akebono and Oboro participated in the great war. They became tankers in 1918 and were removed from the lists in 1921.

Murakumo class (6 ships, 1898)

Thornycroft boats, 275 tons (63 x 5.9 x 1.7m), fitted with more powerful machinery to reach 30 knots for 5800 hp. The class Comprised the Murakumo, Shinonome, Shiranu, Usugumo, Yugiri and Kagero.
They were practically built at the same time as the Ikazuchi at Yarrow. They were differentiated by smaller dimensions and a reduced displacement of 305 to 275 tons, and less power available. The Shinonome was hit hard by the first typhoon that almost caused its destruction, but was repaired and lost in another typhoon in 1913. The Murakumo survived the same typhoon in 1909. The Yugiri was almost destroyed in Tsushima, but all participated in the Great War and were removed from the lists between 1921 and 1927.

Akatsuki class (2 ships, 1899)

Virtually repeats of the Ikazuchi, but with boilers giving extra pressure, for 6500 hp (500 hp gain) and 31 knots. 363t boats, same lenght and width but greater draught. Akatsuki and Kasumi were launched and completed 1901-1902.

Shirakumo class (2 ships, 1901)

Japanese design, slimmer and lighter (thus faster) than the following design (see below). Comprised the Shirakumo and Asashio.

Harusame class (7 ships, 1901)

These first 100% Japanese destroyers were derived from the Shirakumo class, which only counted two ships. The class comprised the Shirakumo and Asashio. Both were Japanese-designed, still with some British influence. The Shirakumo were 342 tonnes, 65.8m long 6.34 m wide, whereas the Harusame were substantially larger and wider, while keeping the same draught and different engines. However performances of the former were better, their VTE engines (extra boiler) being able to develop 7000 hp for a reduced weight (33 tons less).


Externally they shared the same silhouette: Long, slim hull with a front turtleback, small platform above the armoured conning tower with the 12 pdr gun and backup bar, command and observation devices. The two single tubes were behind the serie of four funnels squared by the four 57 mm guns while the 75 mm was at the rear end;
Armament comprised the standard two 60mm (12 pdr, four QF 47 mm (6pdr) and two 457 mm torpedo tubes. The class launched 1902-1905 and completed from 1093 to 1905 comprised the Arare, Ariake, Fubuki, Harusame, Hayatori, and Murasame.

In 1905 they all fought in Tsushima. The Harusame was severely damaged by Russian fire and managed to survive. She was lost in 1911 in a typhoon. Hayatori was blown up on a mine during the blockade of Port Arthur. So 5 the units left participated in the Great War, being subsequently deleted from active lists in 1922-24-25.


2nd class destroyer Isononome.

All these 24 ships were active (home waters) and retired from service in 1920. They mostly built knowledge and expertise from these different designs that help creating a larger, second generation destroyers.

Harusame specifications
Dimensions	69.2 x6.57 x1.83 m
Displacement	375 T FL
Crew	55
Propulsion	2 shafts VTE engines 6000 hp
Speed	29 knots (55.58 km/h; 34.53 mph)
Armament	2x 12 pdr, 4x 6pdr, 2x 18 in TTs (457 mm).

Asakaze class (32 ships, 1905-1907)

IJN Ushio at Vladivostok

Still 1st generation destroyers, they were the first mass-produced Japanese destroyers. They looked very much like copies of the previous Harusame, as part of an "emergency plan", 1904 special war programme ordered in June, September 1904 and 1905. Following this, there were attempts to devise oceanic types, but budget and time constraints had the Navy adopting a double standard, with medium (2nd class types) like these ones, fit for coastal water. They indeed participated in WW1 as a defence fleet and were all broken up in 1923-1930, some being converted as minesweepers in between.



The Asakaze were substantially larger than the previous ships, displacing 381 tonnes for 450 at full load, 72 m long, but only lightly larger (4 cm), and the same draught. They derived from a previous Thornycroft design. They had two shafts with 4-cylinder vertical watertubes engines, four Kampon boilers which produced a total of 6000 hp, and the same 29 knots as above. Armament was heavier, with improved guns, two 3.1 in/40 (80 mm), and four 3.1/28 calibers, and like previous classes, two single 457 mm (18 in) centerline torpedo tubes. Complement was also larger, 70 men.

For the first time, Yokosuka could not fulfill the order, which was passed to civilian yards, gaining experience in that area. But because this was a first, some yards had troubles getting the construction right in time, and meny of these ships were launched in 1906, as the design was already obsolete. Ships that were rearmed as minesweepers get two 4.7 in/45 guns and two 3.1in/40 guns for earlier classes.

Asakaze specifications
Dimensions	72 x6.6 x1.83 m
Displacement	381 T FL
Crew	70
Propulsion	2 shafts VTE engines 6000 hp
Speed	29 knots
Armament	2x 3.1/40, 4x 3.1/28 in, 2x 18 in TTs (457 mm).

Umikaze class (2 ships, 1911)

Umikaze class - ww1 Japanese destroyer, 1911

This was the first oceanic class of destroyers designed and built in Japan, at Maizuru NyD and Mitsubishi (Nagazaki) Naval yard. This design call D-9 were ordered in 1907 as a "proof of concept" in modern standards, but they were only launched in 1909, their blueprints being redrawn and modified in between. First, they were given powerful turbines, Parsons designs built by Mitsubishi, three of them, each one connected to a single shaft, the lot fed by 8 Kampon boilers, for a whooping total of 22,500 hp, enough to reach 33 knots. These were mixed boilers, so 250 tons of coil and 178 tons of oil were stored on board, which gave a range of about 2700 nautical miles at 15 knots.



Complement was double than previous ships, and armament comprise two light cruiser size 4.7 in guns (120 mm) of 40 calibers, and five 3.1 in (80 mm)/40, and two twin 457 mm (18 in) TTs on the Umikaze, whereas Yamakaze had three single tubes. They were delivered only in March 1910 and January 1911 due to delays or delivering the turbines. Their armament was reduced when converted as minesweepers in 1930. Both were stricken in 1936 and broken up. The design was expensive and the next oceanic class was scaled down.

Umikaze specifications
Dimensions	98.5 x8.5 x2.7 m
Displacement	1030/1150 T FL
Crew	140
Propulsion	3 shafts Turbines, 8 boilers 20500 hp
Speed	33 knots
Armament	2x 4.7in, 5x 3.1 in, 4x 18 in TTs (457 mm).

Wartime Production

The war production was not at the level of those of the RN and the USA: In the 10 Kaba, succeeded the 4 Momo, the 6 Enoki, the 4 Isokaze, the 2 Urakaze, the 2 Tanikaze. 28 destroyers in total. All saw the conflict. On the other hand, the 1918 plan tried to catch up with the allied navies, seeing the construction from 1919 to 1924 of the Minekaze, Momi, Wakatake and Kyokaze/Kamikaze classes, all impressive oceanic destroyers that will actively participate in WW2.

Sakura class (2 ships, 1914)

Sakura at Sasebo, Taisho, 1918

The Sakura inaugurated a new category of "second class" destroyers, more economical than the "first class". They were clearly out of the initial program, including only ocean-going ships of the Umikaze type (1910), and were commissioned mainly for budgetary reasons. The Sakura and the Tachibana were thus lighter than 400 tons, but also less slower.
They were good compromises between the coastal destroyers of the Asakaze type and previous ones coming from Yarrow and the ambitious Umikaze. They were followed by the Kaba class in 1915, 10 heavier units of 60 tons with a larger draft.

Sakura specifications
Dimensions	83,6 x 7,3 x 2,3 m
Displacement	665t - 850t T FL
Crew	92
Propulsion	3 shafts, 3 VTE, 4 kampon boilers, 9500 hp.
Speed	30 knots
Armament	1x 4.7in, 4x 3.1in, 4x 18 in TTs (457 mm).

---

Colorized photos by irootoko jr.

IJN Shiranui(I) in yokosuka. This early generation was hardly more than a torpedo boat.


Momo-class destroyer, Hinoki, on sea trials at Miyazu Bay, February, 1917.


IJN Kawakaze class leader on sea trials at Tateyama, October, 1918. With Tanikaze she was the first to use the Type 3 12cm/45 naval gun and triple 21 inch torpedo launchers.

Kaba class (11 ships, 1915)

Kaba departing departing Ryojun, 1925

When the was broke out, Japan had only two modern destroyers for oceanic deployment, the Sakura and Tachibana, so the government approved the Emergency Naval Expansion Budget FY1914 and ten more destroyers had to be built in 8 different civilian yards with conventional coil boilers and VTE engines (also to speed up things) rather than turbines. They were indeed laid down in the end of 1914 and launched in early 1915, completed just 1-2 month after and all named after trees. This Kaba class was so successful that the French ordered 10 more for their own fleet in the Mediterranean, the "Arabe", all named after peoples living in French colonies. All the Kaba were all removed from service in the 1932.


Arabe type destroyer, 1917

Kaba specifications
Dimensions	83,6 x 7,3 x 2,3 m
Displacement	665t - 850t T FL
Crew	92
Propulsion	3 shafts, 3 VTE, 4 kampon boilers, 9500 hp.
Speed	30 knots
Armament	1x 4.7in, 4x 3.1in, 4x 18 in TTs (457 mm).

Urakaze class (2 ships, 1915)

Urakaze at Wuhan, China in 1930-1933

Urakaze and Kawakaze were built in Yarrow, a first since the beginning of the century. They were designed to test new 533 mm torpedo tubes and oil-fired turbines. The kawakaze was, however, awarded by the British government to the Italians even before its completion. The name will be carried by the second building of the Tanikaze class in 1918. The Urakaze, ordered in 1912, saw its construction delayed and it will be finally delivered only in 1919. It will serve a long service until 1936, and its hull will be cast by a US Navy aircraft in 1945.

Urakaze specifications
Dimensions	87,2 x 8,4 x 2,4 m
Displacement	907t - 1089t FL
Crew	120
Propulsion	2 shafts, 2 Curtis turbines, 3 Yarrow boilers, 22 000 hp
Speed	30 knots
Armament	2x 4.7in (120), 4x 3.1in (80), 4x 21 in TTs (533 mm).

Isokaze class (4 ships, 1916)

Japanese destroyer Amatsukaze on patrol in Yangzi River, China

The Isokaze class included the Isokaze, Amatsukaze, Hamakaze and Tokitsukaze. They were launched and completed in 1916-17. They were ranked first-class destroyers, and derived from the 1910 Umikaze, as "squadron leaders." They were much heavier (400 tons) and larger, and gave up their secondary artillery for two additional TTs. In 1935, they were all removed from the lists and broken up in 1936.



Hinoki at Wuhan

Isokaze specifications
Dimensions	96,9 x 8,5 x 2,8 m
Displacement	1227t - 1570t FL
Crew	128
Propulsion	3 shafts, 3 Parsons/Curtis turbines, 5 kampon boilers, 30 000 hp
Speed	33 knots
Armament	4x 4.7in (120), 6x 18 in TTs (457 mm).

Momo class

The four Momo (Kashi, Hinoki, Yanagi, Momo), completed in 1916-17 were built in parallel to the Isokaze, with some specific characteristics for the second-class destroyers they were, compared to the Kaba and Sakura. They were the first to showcase an inverted curved bow, specifically Japanese, whose ice-breaking vocation is not an obvious fact, especially turbines and triple torpedo tubes.They were sent to the Mediterranean until 1919 and then served until 1935.

The Kashi was transferred to the marine epoch of the Mandchuko under the name of hai Waei in 1937 and returned to service in Japan in 1943 under the name Kali, before being blasted in Okinawa. The Yanagi was used for training and was broken up only in 1947. The six Enoki (Enoki, Nara, Kuwa, Tsubaki, Maki and Keyaki) were derived from it closely and were launched and finished in 1918. They were slightly heavier and more powerful. They were removed from the lists in 1932 and 1938 for two of them, transformed into minesweepers.



Momo specifications

Dimensions	58,8 x 7,7 x 2,3 m
Displacement	875t-1080t T FL
Crew	110
Propulsion	2 shafts, 3 Curtis turbines, 4 kampon boilers, 16 000 hp
Speed	31.5 knots
Armament	3x 4.7in, 3x 7.7mm MGs, 6x 18 in TTs (457 mm).

Enoki class (6 ships, 1918)

Kuwa in trials in 1918 off Yokosuka

All named after trees, these six destroyers were part of the FY1917 emergency procurement budget, bound to operate in the Mediterranean. They were all laid down in 1917 and completed in 1918, built in Yokosuka Naval Arsenal, but also Kure, Sasebo and Maizuru naval arsenals. They were virtually repeates of the previous Momo (same blueprints) but were modified with a new bow and better armour. In general experience dictated their hull to be strengthened to handle heavy seas.

For propulsion their relied on proven Brown-Curtis geared steam turbine engines coupled with mixed-fired boilers. Armament was also identical to the Kaba, with three QF 4.7 inch Gun Mk I – IV guns and triple TT banks. Due to their very late arrival, these ships were never deployed in their intended destination and instead spent their career near the Japanese home islands. Two were converted as minesweepers in 1930. They were all retired in 1934-36. Specs are near-identical to the Kaba.

Kawakaze class (2 ships, 1918)

Tanikaze (谷風 "Valley Wind")

The large destroyer leaders (Kawakaze, Tanikaze, named after winds) were built in Maizuru and Yokosuka, as part the IJN '8-4 Fleet Program' FY1915. Basically they were escort vessels for the new Nagato class battleships and Tenryū class cruisers. One of the two was funded by the Italian government after reception of the Kawakaze (now Audace). These were large ships (1600 tons fully loaded), roomy enough to fit a set of two large shaft steam turbine fed by 4 boilers producing 34,000 ihp (25,000 kW) total, enough to reach a blazing 37.5 knots (69.5 km/h) speed. Armament also comprised the new new Type 3 120 mm 45 caliber naval guns and also new 533 mm three double launchers and AA armament of two 6.5 mm machine guns. Both missed ww1 as Kawakaze was completed in November, 11, 1918 and the second 30 January 1919. They served in the interwar until 1934-35.

Minekaze class (16 ships, 1919-22)

Minekaze, Sawakaze, Okikaze, Yakaze, Hakaze, Nadakaze, Shimakaze, Akikaze, Shiokaze, Yukaze, Hokaze, Tachikaze, Nokaze, Namikaze, Numakaze.

Design

First class destroyers (1,400 tonnes) belong to this section as the were designed in 1917 and the first laid down in January 1918. Others followed in Feb., April and August that year; None of course was completed before the war ended. Called design 1941, 1345 tonnes type, they were designed for high speed in rough weather and represented a break in previous Japanese practice (following the 1914 British Practice), in favor of German destroyers practice: The forecastle was extended, the bridge pushed backwards and a TT bank installed in the break. The guns were raised well above the main deck, amidhips and aft, to avoid the effect of water spray in heavy weather. Also, geared turbines were adopted for better speed. In the end, the Minekaze clas constituted a total of 36 ships, making up several DD squadrons, first class combined destroyers flotillas before the arrival of the Fubuki class a few years later. They parralleled the second rate destroyers of the Momi class built alongside.

Modifications

On trials, they proved quite fast: Shimakaze ('island wind') made 40;652 knots on trials at 1379 tonnes,in October 1920. Sawakaze made 42,742 shp for 38.13 knotsn Nadakaze 40,511 shp for 39,81 knots. In general they were maintained to 36 knots in service. The last three were much improved, called design F-41A: The gun arrangement was modified to make ammunition supplies faster: N°3 gun and N°4 were mounted close together on the after deck house abaft the second funnel. IJN Yakaze was later reconfigured as a radio control ship for the ex-battleship Settsu reformed after the treaty of Washingon as guided target and air bombing target in September 1944. From 1937 to 1938 some of these destroyers had their hull strenghtened and the funnels raised, with rain-proof caps. Fuel capacity was lowered but displacement rose to 1552 tonnes, top speed down to 36 knots. In 1939, four ships were refitted: Kamakaze, Nokaze, Numakaze, and Namikaze had ballasts added in addition to the 1937 additions, displacement going up to 1692 tonnes, top speed down to 34.5 knots. Kamikaze was the heaviest at 1784 tonnes, and all were recommissioned in May 1940.

Minekaze and Okikaze were removed from the list in 1938, rearmed in 1941 as escort vessels and others will follow: Nadakaze and Shimakaze in 1939. Modifications consisted in removing two boilers, making them 19,250 shp vessels able to 20 knots. The space freed was used for extra fuel and ammunitions (notably depht charges). The armament was modified, down to two Dual-Purpose 4.7 in/50 guns and their aft TT banks removed making room for ten 25 mm AA guns and 16 depht charges aft. By the end of 1941 they were all reconverted as destroyer transports, with a modified aft section, making room to launch two Daihatsu landing crafts, a single DP gun forward, more DCS (18) and facilities to carry 250 troops. Remaining vessels were also converted as escorts in 1941-42 but without removing boilers. In 1944 all received a significant increase in 25 mm AA guns it was ranging from thirteen to fifteen 25 mm AA and five 13 mm HMGs. They carried also four depht charge throwers and two racks for 36 DCs in all.

But this history of modifications was not over yet. IJN Sawakaze was reconstructed as aicraft rescue ship in 1940 but was converted back to escort vessel without TTs and in 1944 her only remaining 4.7 in DP gun forward was replaced by an experimental ASW, nine-barreled 5.9 in rocket launched not unlike the Hedgehog. Namikaze was torpedoed in Sept. 1944 but survived, was retrieved and rebuilt at Maizuru as a kaiten carrier, carrying two. Her aft deck and stern were rebuilt, one boiler removed, 22,000 shp for 28 knots, single 4.7 in fwd, twenty 25 mm AA and eight 13 mm AA. This was the case of Shiokaze in January 1945, this time carrying four human torpedoes and modification to carry no less than seven Kaitens in her former boiler room, but light battery reduced to eleven 25 mm AA.


Minekaze as a Kaiten carrier

Service

Minekaze was stricken in 1938, but commissioned again 1940 as escort and sunk 10.2.1944. Sawakaze was surrendered in 8.1945. Okikaze was also stricken 1938 and recommissioned as escort in 1940, sunk 10.1.1943. Yakaze became a target 7.1942, a patrol escort 1.1945 and surrendered 8.1945. Hakaze was sunk in 23.1.1943. Nadakaze became a patrol escort in 1939 and was sunk on25.7.1945. Shimakaze became also a patrol escort in 1939, and was sunk 21.1.1943. Akikaze was sunk 3.11.1944. Shiokaze was badly damaged 31.1.1945 and never repaired. Yukaze was also hit on damaged 18.7.1945, and never repaired. Hokaze was sunk on 6.7.1944. Tachikaze was sunk on 17.2.1944. Nokaze was sunk on 20.2.1945, Namikaze surrendered on 8.1945, and was sent as war reparations to China on 10.1947 as Shen Yang. Numakaze was sunk on 19.12.1943.

Minekaze specifications
Dimensions	97,5/102.6m x 9m x 2,9m (337 x 30 x 9.5ft)
Displacement	1,345-1,650 T FL
Crew	148
Propulsion	2-shaft Mitsubishi-Parsons GST, 4 OF boilers, 38,500 ihp
Speed	39 knots (72 km/h)
Range	3600 nm at 14 knots
Armament	4x 4.7in/45, 2 × 7.7mm, 6 533mm TTs, 20 mines

MOMI class (21 ships, 1919-21)

Momi, Kaya, Nire, Nashi, Take, Kaki, Kuri, Tsuga, Fuji, Kiku, Aoin, Hagi, Susuki, Ashi, Tsuta, Warabi, Hasu, Hishi, Sumire, Yomogi, Tade

Design of the Momi class

They were virtually repeats of the cheap and simple Enoki second-class destroyers, comparable in some ways to Royal Navy corvettes. Their main trade feature like German destroyers was a lengthened forecastle with a break forming immediately forward of the bridge giving protection to the forward bank of torpedo tubes. They used three Kampon oil-fired boilers, and light turbines of the Parsons, Brown-Curtis, Escher Wyss & Cie Zoelly, Mitsubishi, but Kampon turbines for most Consequentely these ships developed 21,500 hp (16,000 kW), enough for their 800 tonnes to reach 36 knots. Their career will be seen in detail in ww2 IJN destroyer post, but in short, 11 were lost in action.

Second class destroyers, F-37 design, 21 in all ordered, under the Programmes of 1918 (8 ships), 1919 (5 ships) and 1920 (8 ships). They were a further development of the Momo class, but significantly modified. The designers upgraded their triple 450mm TTs (18 in) to twin 533 mm (21) to match supplies of standard torpedoes. Also, No.1 Torpedo tube Bank was placed forward from the bridge. Their machinery was both better balanced and more powerful wit various geared steam turbines. They diverged indeed for their powerplants: Kaki, Tsuga, Nire, Hagi, Susuki, Hishi and Hasu had two sets Parsons geared steam turbines, and 3 Kampon boilers. Sumire, Yomogi had two sets of Zoelly geared steam turbines and same 3 Kampon boilers. Momi, Kaya, Nashi, Take, Kuri, Fuji, Kiku, Aoi, Ashi, Tsuta, Warabi, Tade had two sets of Curtis geared steam turbines. Also they transitioned to pure oil-firing boilers, gaining in range. They were considered good for 31 kts in service at a regular basis.

Artillery did not changed much, with the same three 120mm/45 guns in single masked mounts: One forward, one aft and one between funnels amidship. They had a minesweeping equipment and demountable mine rails to act as minelayers and minesweepers if needed ad carried 20 mines. AA defene was weak consisting of two single 7.7mm/80 machine guns. They were heavily modified and were mostly relegated to patrol in 1939, but apart those lost of disacrded, all participated to WW2. The F-37A modified concerned the Kiku group, and they had a larger and longer bridge, a searchlight abaft the second funnel, atop the bridge, and their foremast separated from it. The Tsuta group was later separated and called F-37B.


Blueprint of the Momi class

Modifications

-In 1937, Fuji, Susuki, Hishi, Hasu, Tusta and Yomogi, had their funnels raised and capped. These were the same later converted as transport.
-In 1939, they were converted into patrol escorts (-go): One boiler was removed, with an output down to 12,000 hp and top speed 18kts while their displacement increased to 935 tonnes standard and 1,162t fully loaded (instead of 850/1020 tonnes) - their armament was reduced to a single 4.7 in/45 (120mm) the No 3 aft gun, they kept their two single 7.7 mm/80 AA MGs, kept their two twin 533 TTs but received three twin 25mm/60 96-shiki, and four DCT (60 in reserved) for ASW warfare as well as a 93-shiki sonar.

-In 1940, IJN Nire, Taki, Kaki, Ashi, and Sumire were converted to tenders, fast depot ships. They had one more boiler removed to make room and top speed was down to 14kts, based on an output of 9,000hp. Standard displacement was much lighter, at 735tonnes standard. Their armament was reduced to a single 120mm/45, and single bank of 533mm TTs. Their facilities made them also repurposed as Training ships.
-In 1941, One of the transports, 31-go received an additional twin 25mm/60 96-shiki
-In 1942-1943, other transports were modified: 34-go, 36-go, 38-go, and 39-go: They became fast attack transports with fasr less depht charges, only 18, but they had their aft and section and stern modified to launch a single 14m Daihatsu landing craft, plus they were given accommodation for 150 marines.
-Also in 1942-1943, Tsuga, Kuri, and Hasu were reconverted as fast minesweepers. Their minesweeping gear was reinstalled, mine rails and 20 mines plus their four DCT (36 in all) and they kept their 93-shiki sonar.
-In 1944-1945 the survivors were giiven the 3-shiki 1-go radar.

Momi class specifications
Dimensions	85.3 x 7.9m x 2,4m (280 x 26 x 8ft)
Displacement	850m/1020 tonnes FL
Crew	110
Propulsion	2-shaft GST*, 3 Kampon OF boilers, 21,500 ihp
Speed	36 knots (65 km/h)
Range	240 tonnes oil, 3000 nm at 15 knots
Armament	3x 4.7in/45, 2×7.7mm, 2x2 533mm TTs

Tsuta as converted as a fast landing ship transport in 1943, notice the Daihatsu barge and modified stem.

The Momi in service

Since the concept was of a second class DD, not all were still active in WW2. Momi for example was hulked on 4.1932, Kaya was stricken 1939. Nire became a Tomariura 1-go transport on 12.1944. She was previously a depot ship in 1940 and training ship in 12.1944. She surrendered on 8.1945. Nashi was also stricken in 1939. Take became a tender in 1940. Kaki was also a tender in 1940, TS 2.1945 and was surrendered 8.1945. Kuri surrendered on 9.1945. Tsuga was sunk on 15.1.1945. Fuji became a patrol escort in 1939, was damaged on 17.5.1945 and never repaired.

Kiku was a patrol escort in 1939, and sunk 30.3.1944. Aoi was a patrol escort in 1939, sunk 23.12.1941, repaired and converted as 32-go in 1944. Hagi was also a patrol escort in 1939, she was sunk on 23.12.1941. Susuki became the transport 34-go in 1941 after being used as patrol escort from 1939, and sunk 3.7.1944. Ashi became the Tomariura 2-go in Dec. 1944 after being used a tender from 1940, TS in late 1944. She surrendered on 8.1945. Tsuta became the transport 35-go in 1942. She was a patrol escort from 1939, sunk on 2.9.1943.

Warabi was lost in a collision on 24.8.1927. She was a total constructive loss. Hasu was badly damaged 16.1.1945 and never repaired. Hishi was the transport 37-go from 1939. She was a patrol escort and destroyed on 24.1.1942. Sumire became the 1944 transport Mitaka. She was a tender in 1940 and TS in 1944, and surrendered on 8.1945. Yomogi became the transport 38-go in 1939, after being a patrol escort 1939. She was sunk on 25.11.1944. Tade became in 1939 the transport 39-go, also a patrol escort and sunk on 23.4.1943. More details about the conditions of their loss will be developed in a dedicated post.

Wakatake/Kiyokaze class (17 ships, 1922-24)

Wakatake second class (900 tons) of the IJN. This one is too distant from WW1 and will be seen in the WW2 (interwar) destroyer section, as the nine Kiyokaze class (1922-24).

Links

Specs Conway's all the world fighting ships 1921-1947.
navypedia.com
Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships: 1906–1921. Annapolis, Maryland: Naval Institute Press.
Evans, David (1979). Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941. US Naval Institute Press.
Howarth, Stephen (1983). The Fighting Ships of the Rising Sun: The Drama of the Imperial Japanese Navy, 1895–1945. Atheneum.
Jentschura, Hansgeorg; Jung, Dieter & Mickel, Peter (1977). Warships of the Imperial Japanese Navy, 1869–1945. Annapolis, Maryland: United States Naval Institute.
Watts, Anthony J. & Gordon, Brian G. (1971). The Imperial Japanese Navy. Garden City, New York: Doubleday.
Jentsura, Warships of the Imperial Japanese Navy, 1869-1945
Howarth, The Fighting Ships of the Rising Sun
Globalsecurity.org, IJN Momi class destroyers
Stille, Mark (2017). Imperial Japanese Navy Antisubmarine Escorts 1941–45. Oxford, UK: Osprey Publishing. pp. 12–14.
Destroyers of World War Two: An International Encyclopedia. pp.188/189
https://www.naval-encyclopedia.com/ww1/pages/japan/asakaze.html
https://www.naval-encyclopedia.com/ww1/images/ships/japan/
https://www.naval-encyclopedia.com/ww1/pages/japan/marine_jap1914c.htm