Type C class Escorts (1944) – Naval Encyclopedia

Japan, 56 Escort (kaibōkan)/300 planned, 28 lost, 79 cancelled.

The Imperial Japanese Navy Type C and D constituted the last and massive effort to stem the US Navy submarine and air-sea campaign to strangle japan, cut it from all its supply lines and forced it to surrender. These were Kaibōkan, light versatile escorts for AA and ASW convoy protection, and the 5th class of escorts, decided in April 1943 to protect the convoy. This was also for Japan, its largest industrial effort, with 300 ships for the Type C and 200 for the Type D so 500 in all, which was half as much destroyer escorts built in the US. Technically, they were essentially scaled down and even more simplified versions of the Ukuru class to be made as fast as possible. Thanks to this, the seven naval yards awarded contract managed to put out together 56 of these ships, whereas the remainder 79 were cancelled (as the next order for 150) as the war ended. Most survived the war and ended as war prizes under other flags in the cold war. The C class were also called “1-Go” escorts.

Type C N°17 on trials – colorized by Irootoko Jr.

Development

April 1943: The development starts

The Type C escort ships (丙型海防艦, Hei-gata kaibōkan for Kai = sea, ocean, Bo = defense, Kan = ship) were an emergency class of escort ships initiated by the Imperial Japanese Navy staff as the “Type C” ocean defense ships, 5th class of Kaibōkan multi-purpose vessels, and like the Ukuru and Mikura classes, were designed priarily as anti-aircraft and anti-submarine ships, having no use for A/S armament.
Indeed on 22 April 1943, the Navy General Staff was now acutely aware of the reverses of fortunes in the South Pacific. The Guadalcanal campaign was then still fought, as New Guinea, bu after Midway and early battles in Guadalcanal the situation was dire for communication lines witrh the recently created Empire.

Convoys were more and more the prey of submarine attacks, that had been underestimated, and the use of smaller, cheap sub-hunters for short convoy lines proved not useful enough. In April it was alo realized that US naval Air presence would really only grow, so the mass production of escort ships became a priority for the stretched capabilities of Japanse shipyards and industry. Because of the urgent need to better protect convoys, a plan was to build an even more basic, barebone escort ship of around 800 tons, both simple in design and construction was now at a premium. The first designs of “Type A” Etorofu class and “Type B” Mikura class were reported still tt long to build. By June 1943, the Navy General Staff planned for an even more simplified design, the Ukuru class, and alongside, a scaled-down version of the previous Mikura class. This latter ship became the “Type C” and “Type D” escort classes, with a few differences between them.

June 1943: The Type C is finalized

Following the Etorofu class, efforts were made to build coastal defense prioritizingd anti-submarine and anti-aircraft defence with ease of mass production and for this, the Hiburi and Ukuru classes showed how much shipyards could do with simplified designs. However as the war situation further deteriorated, the need for a further expansion of this escort fleet with limited resources led to a smaller, more simplified design, even better suited for mass production. Already by May 1943 it was decided for propulsion to use the Navy-designed Type 23 Model B diesel, relatively easy to manufacture. Two would be installed for a combined output of 1,900 horsepower and 16.5 knots, which would be slower than for the Ukuru class but still enough for escort work, and the reduction in size was a cost-cutting measure but also partially linked to the pair of diesels which occupied now a reduced space. But led to a significant decline in habitability, with nearly absent partitions or any conmfort creatures, in service they were even less popular. Nevertheless wherever Spartan these ships were, they were still well-equipped for anti-submarine warfare with a total depth charge capacity of 120.

September 1943: Production Starts

The lead ship of the Type C was named “Kaibōkan No. 1” (Coastal Defense Ship No. 1), and subsequent ships were assigned odd-numbered designations intermingled with those allocated to the next Type D coastal defense ships given sometimes crossed production orders. Construction started primarily under the supervision of the Naval Ship Administration Headquarters, and the design was a mix of Mitsubishi Heavy Industries engineers, and and Nippon Kokan (NKK) for the naval architecture. Later, to further boost production, contracts were also awarded to mid-sized manufacturers such as Niigata Iron Works. Frm the start it was decided they would be constructed using prefabricated sections, enabling them to be built in as little as three to four months. In 1944-45, German methodology to mass-built the Type XXI and XXIV was also likely passed on to the japanese. Three months was the absolute best result in 1945. The modularity also allowed to build sections in anonymous workshops, to be later shipped for final assembly to heavily bombed shipyards. Construction started at the same time as the Ukuru class.

Nippon Kokan, in particular, achieved outstanding results, surpassing all other shipyards for mass-production capacity, while preserving quality. This was due to the dedicated efforts of Naval Technical Commander Koichi Toyama from Section 4, Naval Ship Administration Headquarters. Later her became Vice President of Nippon Kokan. The production was also watched over by Naval Commander Junji Uozumi from Section 5, later Vice Admiral in the Maritime Self-Defense Force and advisor to Nippon Kokan. The same team behind Nippon Kokan also included Naval Lieutenant Toshio Ishii, chief engineer at Nippon Kokan and its Tsurumi Shipyard.

The Naval Ship Administration HQ placed large-scale orders in which Nippon Kokan played a major role for the construction of the Type C. Hpwever other yards took part as well: Maizuru Naval Arsenal, Kyōwa Zōsen Corporation, Mitsubishi Heavy Industries (master yard), Naniwa Dock Company, Nihonkai Dock Company, and Niigata Iron Works. The lead ship was laid down in September 1943 and completed in February 1944, so about 6 months. It was planned to reduce this to three months in 1945 and it was achieved. Although a construction plan for 133 ships was established, only 53 were completed, 26 lost in action, three additional ones were completed postwar for repatriation. Mitsubishi completed its last Type C, No.3 (CD-3) on 29 February 1944. These all three were basically pre-production prototypes. Under the Wartime Naval Armaments Supplement Programme, the 300 Type C and 200 Type D proposed was ludicrous given the state of Japanese industry at the time. These ships were assigned the Programme numbers #2401-#2700 for the Type C, #2701-#2900 for the Type D, no names allocated (esprit de corps be damned) only numbers from No.1 upwards but No.2 and foll-up alternated for the Type D escorts. The first 132 Type C were authorised under the 1943 Fiscal Year. The remaining 168 Type C were authorised under the 1944 Fiscal Year, no contracts issued. Cancellations were massive and ships were broken up for scrap metal as they were in their slipways, wit three ships nearly completed by August 1945 and used unarmed in the cold war for utility roles.

Design of the class

The the Type C was a further simplification of the Ukuru, shorter, smaller by 200 tons, with a pair or simplified diesels that were also smaller. Only two 4.7-inch (119 mm) guns were installed also to spare the overall quantity manufactured, unlikle previous escorts, but the depth charges aboard remained identical albeit with less depth charge throwers and just a single depth charge chute, both to lower pressure of these equipments being manufactured en masse as well. One simplfication that was not made however, was to go for a single shaft. It was likely believed easier to keep the two diesels in direct drive to the shaft to avoid using a common gearbox and its connections. This choice preserved agility, as one diesel could run full and the other low to make an even tighter tun in combination with the rudder, and so both dodge torpedoes or keep pace with a submarine manoeuvers underwater.

Hull and general design

The Type C escorts were small indeed, at just 745 long tons (757 t) standard and 810 tonnes fully loaded, for a hull 67.5 meters (221 ft) long overall (63 between pp, 66.0 waterline, 67.5m overall), shorter than the Ukuru (940t standard for 77.7 x 9.1 x 3.05 m (10 ft) and they were also significantly narrower with a beam of 8.4 m (27 ft 7 in) making for a hull ratio of 1:9 and a draught of 2.9 m (10 ft), also reduced. This enabled them service on the Yang Tse and shallow waters at large. Now for the general outlook, it was very similar to the Ukuru, with simplified shapes for the bridge, a squarish funnel amidship aft. The forecastle was made with simplified shapes, apart the nose of the bow, which had still a rounded top.

The upper plates were flat and mounted at an angle with the lower plates, making a split whic traduced visually in a hard shadow that looked like a camouflage. In reality the paint was the same top and bottom, it was only a light play. The transom stern was also simplified and completely squat. Like for the Ukuru class, internal spaces were no longer compartimentalized to save material, so the sailors had to make due with large, noisy rooms. There was no insulation either and equipment in general was simplified with lany systems existing in double units omitted and if a simper design existed, swapped. The Type C still had the essential in the bridge, notably a repeater or chadburn, a compass, two signal lamps, the usual red and green navigation lamps, three anchors (two main forward, one smaller aft), two small boats under davist for their crew of 136 officers and men. They stall a main light projector, on a platform just behind the tripod mast. The overall shape of the hull seen from above had a very progressive beam, identical fore and aft to reduce the waterline footprint without making complex shapes. So hydrodynamic properties could be kept. Just as much engineering went into simplifying the design than more complex ships of 1943.

Powerplant

The new diesels were rated as seen above for 1,900 shaft horsepower (1,400 kW) versus 4,200 shaft horsepower (3,100 kW) for the Ukuru class. That decrease in engine power, despite a smaller hull, traduced into a to speed decreased from 19.5 knots (36.1 km/h; 22.4 mph) to 16.5 knots (30.6 km/h; 19.0 mph). The range remained the same at 6,500 nautical miles (12,000 km; 7,500 mi) however, at 14 knots (26 km/h; 16 mph) based on an unknown fuel oil quantity, lilely lower than for the Ukuru.

Armament

Instead of three 4.7-inch (119 mm) they now had just two. The twin mount aft was replaced by a single, which also streamlined production. The number of depth charges remained the same at 120, but now 12 depht charges instead of 18, and one depth charge chute instead of two. The AA armament remained the same, but it was revised as the design was ready in the spring of 1943, and reinforced during production, as well as modified for earlier ships (see below).

12 cm/45 10-shiki (Type 10) naval gun

The Type 10 found on these ships, one forward and one aft, were high-angle AA gun, called the 12 cm/45 10th Year Type. It 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 with the latter fitted with two opening panels. The ones fitted were not the 12 cm 11th Year Type naval gun (Model 1922) of TBs and the previous class, but the more advanced DP version found both on the Chidori and Etorofu class. It was said “dual-purpose” but in reality the mount limited them to 33° elevation only in the previous class, but this one might have the new HA mount that brought that elevation to 75° making for a maximum surface range of 22,430 yards (20,500 m) and a maximum AA Ceiling of 42,660 feet (13,000 m). Model 1922

⚙ specifications 12 cm/45 3rd Year

Weight 3,240 kg (7,140 lb), Barrel length 5.4 m (18 ft) bore
Elevation/Traverse -7° +75° and 120°/120°
Loading system: Welin breech block, Hydro-pneumatic recoil for 5–6 rpm
Muzzle velocity 825 m/s (2,710 ft/s), range 16 km (10 mi) at 33°
Crew: 6. Round 20.3 kg (45 lb) 120 x 550 mm.R., sep. loading cased charge

25 mm Type 96

These two triple Type 96 25-millimeter (1in) anti-aircraft guns were placed in standard triple-gun mounts abreast the funnel amidship. For the ships commissioned later in 1944 and 1945, they obtained in addition up to six single 25mm/60 Type 96, and for the ships commissioned in 1945, the two triple amidship were completed by two twin mounts abreast the bridge and four single ones.
The type 96 25 mm AT/AA gun became the standard of the IJA and IJN, automatic cannon developed as variant of the French Hotchkiss 25 mm, dual-purpose and developed as AA on single, twin and triple mounts. Development worked on 1935. 25 mm Hotchkiss design evaluated and order placed for several mounts types for evaluation at Yokosuka Naval Arsenal. Led to the Type 94 and Type 95 and then the main model produced at Yokosuka Arsenal, the Type 96. Elements made with castings and not forging for larger production, Rheinmetall supressor, new mounts designed. Air-cooled gas operated with multiple rings (Hotchkiss patent).

Twin-mount in 1939, followed by triple mount in 1941 and single mount in 1943. Issues of the designed revealed in combat:
Slow elevation and traverse, ineffective sights, excessive vibration, limited magazine cap., blinding Flashes.
The 1944 single mount needed a single operator and a loader but had a better spiderweb sight.

⚙ specifications 25 mm Type 96

Barrel Lenght 1.5 m (4 ft 11 in) L/60
Barrel weights: Single 785 kg (1,731 lb)
Barrel weights: Twin 1,100 kg (2,400 lb)
Barrel weights: Triple 1,800 kg (4,000 lb)
Crew: 3, 7 and 9 respectively
Shell 25×163mm
Exact caliber 25 mm (0.98 in)
Action Gas operated
Elevation/Traverse -10°/+85° – 360°, manual
Rate of fire 200–260 rpm (cyclic)
Muzzle velocity 820 m/s (2,700 ft/s)
Effective range 6.8 km (4.2 mi) at 45° with HE shell
Maximum firing range 85° 3 km (9,800 ft) effective, 5.5 km (18,000 ft) max.
Feed system 15-round box magazine

Depth Charges

The Type C Kaibonan were all armed with the same 81mm/12 Type 97 ASW mortar, but also twelve Depht Charge Throwers for a grand total of 120, a single rack, but no mechanical minesweeping gear. Initially these were Type 95 depth charges racks, and Type 94 depth charge launchers.
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.

81mm Type 91 Mortar

A 15 cm (5.9″) ASW mortar was developed for transports and merchant ships in a cradle mounting that could fire a 60 lbs. (27 kg) charge at 4,500 yards (4,100 m) but it was too heavy for the esscorts, so instead, a modified Navy 81 mm mortar was carried by many escorts, firing standard projectiles. This modified version used by Imperial Japanese Navy with the designation Type 3 mortar was impromptu anti-submarine weapon designed for escort ships that was introduced in early 1943. This mortar was installed in front of the bridge and was some sort of “Japanese hedgehehog”.
The original Type 97 was a copy of the French Brandt mortar going back to 1936, produced from 1938 to the end of the war to 3892 units. It was fixed to the deck and weighted 66 kg (145 lb), but could fire at +85 degrees elevation a 6.5 kg (14 lb 5 oz) direct percussion charge at up to 1.2 km (0.75 mi). For longer range, they would use the Light HE: 3.3 kg (7 lb 4 oz) reaching 3 km (1.9 mi). Each of these were essentially grenades, to “clean up” the submarine deck from personal, especially gun crews. In theory it could also burst into the air or underwater at very short depth thanks to its delay pellet inserted in the fuze nose prior to firing.

Sensors

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.
They also all kept their Type 93 Hydrophones in complement.

Type 22 Radar

The early Type 22 General Purpose Radar looks like characteristically like a 2910 lb (1320 kg) drum topped with a twin cornet amplificators, mounted mid-way top the mast.
Specs: Wavelength 10 cm, pwd 10 microsecond, PRF 2500 Hz, scan rate 5 rpm, PP 2 kW.
Range: 20 nautical miles (35 km) aircraft group, 10 nm (17 km) single, 13 nm(24 km) battleship.
Subject to land clutter. Horn and A scope display, accuracy 220 yards (200m)/3 degrees res. 1600 yards (1500 m)/40 degrees
300 sets produced installed on destroyers from the summer 1942. Generalized in 1944.

Type 13 Radar

Vertical 240 lb(110 kg) bedframe antenna, developed 1941, introduced mi-1943, with vertical dipole transmitter and Yagi mattress receiver. 1000 sets produced. Air defense, range 100 km (group), and single aircraft 50km. Specs: Wavelength 200 cm, pw 10 ms, PRF 500 Hz PP 10 kW, Range: 30-60 nautical miles (50-100 km).

Modernization

In 1944-1945 early ships were refitted with the 3-shiki 1-go radar and by early 1945, the new standard in AA was six single 25mm/60 96-shiki installed whever possible and by mid-1945, for those still around the singles were replaced by 25mm/60 Type 96, notably abaft the bridge.

⚙ Type C class specifications
Displacement	745t standard, 810t FL
Dimensions	67.5 x 8.4 x 2.9 m ()
Propulsion	2 shafts geared Kampon diesel (1,900 bhp)
Speed	16.5 knots ()
Range	6,500 nautical miles at 14 knots
Armament	2x 120m/45 Type 10, 2×3 25mm/60 Type 96, 1x 81mm/12 ASW mortar, 12 DCT1, 2 DCR (120)
Sensors	Type 22 radar and Type 93 sonar
Crew	136 (1944)

WW2 and Postwar Service

The Type C were commissioned in 1944 in time still for critical convoys but suffered heavy losses to air and sea attacks. They were assigned to Destroyer and Escort Divisions for convoy escort operations but from mid-1944 protection of the Japanese merchant fleet became a true challenge. Of the 53 completed during the war 26 were sunk in action, mostly by submarines, for which the Mark XIV torpedo defaults had been worked out and new models were available. The usual tactic was a magnetic proximity fuse and the torpedo exploded right behind the hull. This was devastated for any ship, let alone for a frail, small Type C. With their large internal open spaces and compromise contruction for which protection were scondary and compartimentation optional, this was a death sentence each time. There was nothing to stop the flooding.
But they were not only victims. They also took their fair share of kills:
On October 30, 194: off Cape Toi, No. 29, No. 33, and No. 22 badly damaged the American submarine USS Salmon (SS-182), she became a total constructive loss.
On November 8, 1944 off Mindoro Island, No. 19 and the destroyer Shigure, escort Chiburi are believed to have sunk USS Growler (SS-215).
On March 28, 1945 fff the Nansei Islands, No. 33 and No. 59 with Mikura are believed to have sunk the American submarine USS Trigger (SS-237).
On June 19, 1945 In Toyama Bay, No. 63, No. 75, No. 207, No. 158, and Okinawa are believed to have sunk USS Bonefish (SS-223).
Postwar, the were redesignated as minesweepers or special transport vessels under the generic “Kai-dai-nango” (“Sea vessel No. X”) engaged in their respective missions. They proved useful indeed, especially the first, since Japan in 1945 had been heavily mines, expecting an invasion, especially the Kyushu coastline.

N°1

#2401 N°1 sunk on 6 April 1945 south of Xiamen, South China Sea, USAAF photo from Rekishi Gunzo, Vol.51. Just hit, and capsizing, note the airborne torpedo coming for her in the second photo.
Ordered under program #2401, IJN No.1 was laid down at Mitsubishi, Kōbe Shipyard on 15 September 1943 as class prototype, launched on 29 December 1943 and completed on 29 February 1944 so in six months. The section construction was just getting started on organizational level, and took a further year to perfect. N°1 was under command of LtCdr Ebihara Yoshiichiro and on 1 April she departed Saiki, being assigned to the General Escort Command’s First Surface Escort Division, to Moji. She departed on the 5th, with the torpedo boat HATSUKARI and other small vessels, with convoy TE-03 (KINREI, SHORYU, DAIBU, YULIN, DAIYOKU and TOYOHI MARU) and convoy ASO (JINJU, NARUO, SORACHI, BRAZIL MARUs, YOSHIDA MARU No. 3 and five others.

On 14 April she arrived at Takao and departed on the 19th with convoys TASA-17, TE-03 and No. 82. On 21st the convoys split. She headed for Yulin, Hainan, arrived on the 23st. On 30 April she departed for Yawata with convoy TE-04. On 4 May USS TINOSA (SS-283) torpedoed and sank TOYOHI MARU under her watch, USS BANG (SS-385) the KINREI MARU. Then USS TINOSA sank DAIBU MARU and USS PARCHE (SS-384) SHORYU and DAIYOKU MARUs. On the 6th she arrived at Takao and a day later departed with the convoy TE-04, later joined by the destroyer ASAGAO with convoy MI-03. Later the destroyer SHIOKAZE joined in. They departed off Saei near Takao (convoy MI-03), and back on the 9th. On 14 May she was at Yulin.
On 19 May she departed Yulin in convoy HO-01 to Singapore (26th), departing on 3 June with the escorts CD-8, CD-15 and CD-20 (bauxite convoy HO-02). They were ambushed on 6 June 160 miles off Cape St. Jacques by USS RATON (SS-270). CD-15 is hit and sank. CD-8 and CD-20 rescued 34 survivors and counter-attacked. On 11 June they arrived at Manila and departed on the 14th for Takao. On 20 June CD-1 departs Takao with convoy HO-02 for Kirun but on 24 June in Koshiki Straits (SW of Nagasaki, Kyushu) they are attacked by USS TANG (SS-306), looing the NASUSAN, TAMAHOKO, KENNICHI and TAINAN MARUs. CD-1 counterattacked.
On 26 June they arrived at Moji whereas CD-1 continued to Kure alone for a short refit. She departed on 6 July with convoy MOMA-02 for Takao (6 days later).

On 14 July she departed with convoy TAMA-21C and on 16 July they were ambushed by USS PIRANHA (SS-389) snking SEATTLE MARU. Later they fell upon the wolfpack comprising USS THRESHER, GUARDFISH and PIRANHA, sinking SAINEI MARU, then JINZAN MARU and MANTAI MARU. On 17 July this is HIYAMA MARU, then SHOZAN MARU. At least the remainder made it to Manila on 19 July. On the 23th all departs (CD-1 with CD-18, CD-28, the TB IJN SAGI, a minelayer, a minesweeper, a subchaser) for Moji (convoy MI-08) and on the 24 July stopped to open a mine path. They arrived on the 27th departing a day later (convoy HI-68) but on the 29th CD-1 is detached to Kirun and returns to Takao. She departed on 30 July to Keelung and on 4 August to the Ryukyu Islands and Kyushu. But on 9 August they are ambushed by USS BARBEL (SS-316), sinking YAGI MARU. USS BARBEL is depht charged and damaged. On 11 August they arrived and departed Amami-O-Shima and arrived at Moji on 13 August, then Sasebo for maintenance. She left on 24 August for Arikawa Wan and convoy HI-73 for Singapore with the escort carrier UNYO, light cruiser KASHII and escorts CHIBURI, CD-3, CD-13, CD-19, CD-21 and CD-27 with a large military and civilian convoy.

When on 26 August MANEI MARU had issues, CD1 is detached with her back to Sasebo. She departed on the 30th for the Terajima Straits, joining convoy MOTA-25 to Kirun (Keelung), then Takao. On 5 September she departed with MOTA-23 for Keelung and to the Philippine Islands. One folds bac due to breakdown, and EIJI MARU hit a mine and returns to Takao but is abandoned, struck another mine and sank. On 7 September she departed Tungchiang with convoy TAMA-25 but on 9 September off Calayan Island, TOYOOKA MARU is torpedoed by USS QUEENFISH (SS-393) as later MANSHU MARU. They amde it to San Fernando and on 12 September TAMA-25 arrived at Santa Cruz.
On the 13th they departed for Subic Bay and because of the danger to Manila, the convoy sails to the north for Santa Cruz, depating on the 17th for Subic Bay, then Manila, Cebu (convoy MATA-27A) but on the 21st they are attacked at 10:28 in the Masinloc Sea, by 40 carrier-based aircraft from Mitscher’s TF 38. HOFUKU MARU in sank. On 10:56 was aa second raid, OGURA MARU No. 1 is sank. At 1515, third raid claiming YUKI, SHICHIYO and NANSEI MARUs and later SURAKARUTA MARU. The remainder arrive at Santa Cruz.

On 22 September they left for San Fernando, Lapoc Bay, Bangui, and Takao on the 25th.
On 26 September CD-1 sails for Saei, and departed a day later with convoy TAMO-26 for Moji via Keelung on 1 October and she is detached and arrives on 3 October to Nagasaki for maintenanace and command change to Reserve LtCdr Arima Kunio. She sailed to Moji, then Sasebo for a refit until 17 October. She returned to Moji and on 22 October departed with convoy MOMA-06. On 23 October they are attacked by USS CROAKER (SS-246) which hit and damaged GASSAN MARU (towed to Saishu Island and beached). On the 24th, the same submarine sinks MIKAGE MARU. On the 27th they made it into Keelung, then Takao. On the 31st she escorts MOMA-06 for Manila but on 2 November they are ambushed by USS POMFRET (SS-391): ATLAS MARU damaged as well as HAMBURG MARU a day later. They arrived at Sabtang Island, and on 8 November offf Cape Bolinao USS GUNNEL (SS-253) sank SAGI. The made it to Santa Cruz, then Manila Bay and its harbor taken shelter from a typhoon.

On 12 November they departs for Takao (convoy MATA-32) but on the 14th off Cape Bolinao they are attacked by USS RAY (SS-271) sinking CD-7, then USS RATON (SS-270) UNKAI MARU No. 5 and a day later KURASAKI. On 17 November they arrives at Takao, departing 2 days later (TAMA-32) but are recalled and on 20 November are back at Takao. On the 23rd TAMA-32A departs and sails along the Formosan coast to Musa Bay, Fuga Island, Lapoc Bay, San Fernando and on 30 November Manila. On 5 December CD-1 left with TAMA-35 for Chechung, then San Pio Quinto (Camiguin Island), Calayan Island and Manila. On 19 December she sails with SAMA-14 for Cap Padaranin Indochina, then Nha Trang, Qui Sande Bay, and on Xmas day, Qui Nhon. On 30 December alone B-24 bombed them and misses.
On 1 January 1945 they proceed to Saei (Tsoying) and on the 3rd left for Nanao Tao, then Hong Kong and with convoy HOTA-02 to Mako and Takao. On 14 January she joins convoy TAMO-37 to Saei, for Ssu Chiao Shan but on 23 January they have a suspected submarine contact, DCs are dropped, no result.

On 24 January CD1 strts a refit at Kure until 5 February. She left for Moji, Singaore (convoy HI-97) via Qui Sande Bay in Indochina. On 26 February she joins convoy HI-94 and on 3 March they sails past Cap St. Jacques to join convoy HI-98 from Singapore to Moji. On 4 March USS BAYA (SS-318) torpedoed PALEMBANG. A day later off Tourane RYOEI MARU is torpedoed by USS BASHAW (SS-241). The others made it into Yulin, departs for Hong Kong, then back to Yulin and Singapore. On the 19th they departs with the destroyer AMATSUKAZE, escorts CD-18, CD-26, CD-33, CD-84, CD-130, CD-134 for convoy HI-88-I but on 20 March off Camranh Bay, USS BAYA (SS-318) sank KAINAN MARU. Later USS BLENNY (SS-324) sinks NANSHIN MARU No.21.
On 21 March off Nha Trang (Indochina) she Convoy HI-88-J she tried to protect is assaulted by 5th Air Force B-25 “Mitchell” bombers (345 Bomb Group) and sank or savaged the MOTOYAMA MARU No. 1, FUSHIMI MARU No.2, damage CH-9, the TAKASAGO MARU NO. 6, cable-layer TATEISHI. Only one bomber is shot down. On the 27th the convoy went off Nha Trang Bay and convoy HI- 88I is merged with HI-88J. On 28 March she sailed off Nha Trang Bay. An air attack led to the sinking ASOKAWA MARU and later USS BLUEGILL (SS-242) sank HONAN MARU. On 29 March USS HAMMERHEAD (SS-364) sank CD-84 and there was air attack in which KAIKO MARU is bombed and sunk, and CD-134 is badly damaged.

On 30 March the escorts arrive at Samah but air attacks damaged CD-26. This is the end of the Singapore Convoys. On 31 March CD-1 departs Samah for Hong Kong but on 3 April there, USAAF Far East Air Force B-24 “Liberators” bombed the harbor, sinking HEIKAI MARU and SHOZAN MARU, badly damaged MANJU. A day later she sails to Shanghai en route to Moji with convoy HOMO-03 and a day later joins Pinghai Bay. That day, the convoy is attacked by a lone PBM-5 Mariner, sinking TOKAI MARU No. 2. Later they are attacked by 5th Air Force B-24 Liberators, B-26 Marauders escorted by P-38 Lightning which sank KINE MARU and the convoy is disbanded, all ships sailed to Hong Kong. Far East Air Force B-24s damaged CD-1, as well as the tanker KAMOI, CD-52 and subchasers CH-9 and CH-20.
On 6 April SSW of Amo. Next 24 USAAF B-25 Mitchell bombers (345th Bombardment Group) attack convoy HOMO-03 and sank the already damaged CD-1 as well as CD-134. She lost 159 officers and sailors with 19 more later dying at the Hong Kong Naval Hospital. That included CO LtCdr Arima. AMATSUKAZE was also savaged and forged to beach herself at the entrance to Amoy harbor. She is stricken on 25 May 1945.

N°3

#2402 No.3 was laid down at Mitsubishi, Kōbe Shipyard on 15 September 1943, launched on 29 December 1943 and completed on 29 February 1944. She was sunk by USN aircraft northwest of Keelung, 9 January 1945.
on combinedfleet.com

N°5

#2403 No.5 was laid down at Nihon Kōkan, Tsurumi Shipyard on 23 October 1943, launched on 29 15 January 1944 and completed on 19 March 1944. Sunk by USN aircraft west of Masinloc, 21 September 1944.
on combinedfleet.com

N°7

#2404 No.7 was laid down at Nihon Kōkan, Tsurumi Shipyard on 23 October 1943, launched on 29 18 January 1944 and completed on 10 March 1944. Sunk by USS Ray west of Vigan City, 14 November 1944. Rebuilt in Jiangnan Shipyard, recommissioned as PLAN FFG Nanning. Decommissioned 1979.
on combinedfleet.com

N°9

#2405 No.9 was laid down at Mitsubishi, Kōbe Shipyard on 15 October 1943, launched on 29 15 January 1944 and completed on 10 March 1944. Sunk by USS Gato in Yellow Sea , 14 February 1945.
on combinedfleet.com

N°11

#2406 No.11 was laid down at Mitsubishi, Kōbe Shipyard on 15 October 1943, launched on 29 15 January 1944 and completed on 15 March 1944. Heavy damaged by USAAF aircraft in Ormoc Bay, 10 November 1944. Later scuttled.
on combinedfleet.com

N°13

#2407 No.13 was laid down at Nihon Kōkan, Tsurumi Shipyard on 18 November 1943, launched on 9 February 1944 and completed on 3 April 1944. Sunk by USS Torsk at south of Hyōgo, 14 August 1945.
on combinedfleet.com

N°15

#2408 No.15 was laid down at Nihon Kōkan, Tsurumi Shipyard on 18 November 1943, launched on 29 21 February 1944 and completed on 8 April 1944. Sunk by USS Raton to west of Spratly Island, 6 June 1944.
on combinedfleet.com

N°17

#2409 No.17 was laid down at Nihon Kōkan, Tsurumi Shipyard on 15 December 1943, launched on 29 26 February 1944 and completed on 13 April 1944. Sunk by USN aircraft off Saint Jacques, 12 January 1945.
on combinedfleet.com

N°19

#2410 No.19 was laid down at Nihon Kōkan, Tsurumi Shipyard on 15 December 1943, launched on 29 28 February 1944 and completed on 28 April 1944. Sunk by USN aircraft off Saint Jacques, 12 January 1945.
on combinedfleet.com

N°21

#2411 No.21 was laid down at Nihonkai Dock Company on 1 December 1943, launched on 29 31 March 1944 and completed on 18 July 1944. Sunk by USS Seahorse to east of Pratas Island, 6 October 1944.
on combinedfleet.com

N°23

#2412 No.23 was laid down at Nihonkai Dock Company on 10 February 1944, launched on 20 May 1944 and completed on 15 September 1944. Sunk by USN aircraft at north of Qui Nhon Bay, 12 January 1945.
on combinedfleet.com

N°25

#2413 No.25 was laid down at Nihon Kōkan, Tsurumi Shipyard on 1 February 1944, launched on 14 May 1944 and completed on 2 July 1944. Sunk by USS Springer in Yellow Sea, 3 May 1945.
on combinedfleet.com

N°28

#2414 No.27 was laid down at Nihon Kōkan, Tsurumi Shipyard on 16 February 1944, launched on 29 3 June 1944 and completed on 20 July 1944. Decommissioned on 20 November 1945. Surrendered to United Kingdom, 14 August 1947. Later scrapped.
on combinedfleet.com

N°29

#2415 No.29 was laid down at Nihon Kōkan, Tsurumi Shipyard on 2 March 1944, launched on 29 26 June 1944 and completed on 8 August 1944. Decommissioned on 20 November 1945. Scrapped on 1 March 1948.
on combinedfleet.com

N°31

#2416 No.31 was laid down at Nihon Kōkan, Tsurumi Shipyard on 3 March 1944, launched on 29 4 July 1944 and completed on 21 August 1944. Sunk by USS Tirante in Yellow Sea, 14 April 1945.
on combinedfleet.com

N°33

#2417 No.33 was laid down at Nihon Kōkan, Tsurumi Shipyard on 26 May 1944, launched on 29 22 July 1944 and completed on 31 August 1944. Sunk by USN aircraft to east of Aoshima, 28 March 1945.
on combinedfleet.com

N°35

#2418 No.35 was laid down at Nihon Kōkan, Tsurumi Shipyard on 30 May 1944, launched on 29 3 September 1944 and completed on 11 October 1944. Sunk by USN aircraft at south of French Indochina, 12 January 1945.
on combinedfleet.com

N°37

#2419 No.37 was laid down at Nihonkai Dock Company on 5 April 1944, launched on 29 5 August 1944 and completed on 3 November 1944. Decommissioned on 15 September 1945. Surrendered to United States, 4 September 1947. Scrapped on 30 November 1947.
on combinedfleet.com

N°39

#2420 No.39 was laid down at Nihon Kōkan, Tsurumi Shipyard on 10 June 1944, launched on 29 and completed on 13 August 1944, commissioned on 27 September 1944. Sunk by USAAF aircraft off Geoje Island, 7 August 1945.
on combinedfleet.com

N°41

#2421 No.41 was laid down at Nihon Kōkan, Tsurumi Shipyard on 1 July 1944, launched on 29 September 1944 and completed on 16 October 1944. Sunk by USS Sea Owl at Tsushima Strait, 9 June 1945.
on combinedfleet.com

N°43

#2422 No.43 was laid down at Mitsubishi, Kōbe Shipyard on 10 April 1944, launched on 29 and completed on 22 June 1944 and commissioned on 31 July 1944. Sunk by USN aircraft off Cape Padaran, 12 January 1945.
on combinedfleet.com

N°45

#2423 No.45 was laid down at Nihonkai Dock Company on 25 May 1944, launched on 29 and completed on 5 October 1944 and commissioned on 23 December 1944. Decommissioned on 30 November 1945. Scrapped on 30 April 1948.
on combinedfleet.com

N°47

#2424 No.47 was laid down at Nihon Kōkan, Tsurumi Shipyard on 15 July 1944, launched on 29 and completed on 29 September 1944 and commissioned on 2 November 1944. Sunk by USS Torsk at south of Hyōgo, 14 August 1945.
on combinedfleet.com

N°49

#2425 No.49 was laid down at Nihon Kōkan, Tsurumi Shipyard on 31 July 1944, launched on 15 October 1944 and completed on 16 November 1944. Decommissioned on 30 November 1945. Surrendered to United States, 1 September 1947. Scrapped on 1 February 1948.
on combinedfleet.com

N°51

#2426 No.51 was laid down at Mitsubishi, Kōbe Shipyard on 1 May 1944, launched on 20 August 1944 and completed on 21 September 1944. Sunk by USN aircraft to north of Qui Nhon Bay, 12 January 1945.
on combinedfleet.com

N°53

#2427 No.53 was laid down at Nihon Kōkan, Tsurumi Shipyard on 15 August 1944, launched on completed on 29 October 1944 and completed on 28 November 1944. Sunk by USS Bergall east of Cam Ranh Bay, 7 February 1945.
on combinedfleet.com

N°55

#2428 No.55 was laid down at Nihon Kōkan, Tsurumi Shipyard on 20 August 1944, launched on 29 4 November 1944 and completed on 20 December 1944. Decommissioned on 5 October 1945. Surrendered to United Kingdom, 16 July 1947. Later scrapped.
on combinedfleet.com

N°57

#2429 No.57 was laid down at Nihon Kōkan, Tsurumi Shipyard on 10 September 1944, launched on 29 and completed on 15 November 1944, commissioned on 13 January 1945. Decommissioned on 5 October 1945. Converted to breakwater at Ube, May 1948.
on combinedfleet.com

N°59

#2430 No.59 was laid down at Nihon Kōkan, Tsurumi Shipyard on 25 September 1944, launched on 22 November 1944 and completed on 2 February 1945. Decommissioned on 5 October 1945. Collided with Hyūga and sunk at Kure, 30 July 1946. Salvaged and scrapped on 9 November 1947.
on combinedfleet.com

N°61

#2431 No.61 was laid down at Maizuru Naval Arsenal on 1 April 1944, launched on 25 July 1944 and completed on 15 September 1944. Decommissioned on 3 May 1947. Later scrapped.
on combinedfleet.com

N°63

#2432 No.63 was laid down at Mitsubishi, Kōbe Shipyard on 1 July 1944, launched on 20 September 1944 and completed on 15 October 1944. Decommissioned on 30 September 1945. Scrapped on 30 April 1948.
on combinedfleet.com

N°65

#2433 No.65 was laid down at Nihonkai Dock Company on 10 August 1944, launched on 30 November 1944 and completed on 13 February 1945. Sunk by USN aircraft at Muroran, 14 July 1945. Salvaged and scrapped in July 1947.
on combinedfleet.com

N°67

#2434 No.67 was laid down at Maizuru Naval Arsenal on 15 June 1944, launched on 15 September 1944 and completed on 12 November 1944. Decommissioned on 25 October 1945. Surrendered to Republic of China, 6 July 1947, and renamed Yingkan. Renamed Rui’an (PF-73) 1952. Decommissioned 1963.
on combinedfleet.com

N°69

#2435 No.69 was laid down at Mitsubishi, Kōbe Shipyard on 24 August 1944, launched on 28 November 1944 and completed on 20 December 1944. Heavy damaged by USAAF aircraft off Hainan Island, 9 March 1945. Sank on 16 March 1945.
on combinedfleet.com

N°71

#2436 No.71 was laid down at Nihon Kōkan, Tsurumi Shipyard on 5 October 1944, launched on 3 December 1944 and completed on 12 March 1945. Decommissioned on 5 October 1945. Surrendered to Soviet Union, 28 August 1947. Served in Soviet Pacific Ocean Fleet as patrol ship EK-43 (1947), oceanographic research ship West (1948), renamed Ostrovnoy (1953). Decommissioned on 31 January 1964 and scrapped.
on combinedfleet.com

N°73

#2437 No.73 was laid down at Nihon Kōkan, Tsurumi Shipyardon 8 October 1944, launched on 10 December 1944 and completed on 5 April 1945. Sunk by USS Sunfish at southeast of Iwate, 16 April 1945.
on combinedfleet.com

N°75

#2438 No.75 was laid down at Nihonkai Dock Company on 18 October 1944, launched on 20 February 1945 and completed on 21 April 1945. Sunk (probably by mine) off Nō 10 August 1945.
on combinedfleet.com

N°77

#2439 No.77 was laid down at Nihon Kōkan, Tsurumi Shipyard on 2 November 1944, launched on 18 December 1944 and completed on 31 March 1945. Decommissioned on 30 November 1945. Surrendered to Soviet Union, 28 August 1947. Served in Soviet Pacific Ocean Fleet as patrol ship EK-45 (1947), target ship TsL-45 (1948), repair ship PM-63 (1955). Decommissioned on 25 January 1969 and scrapped.
on combinedfleet.com

N°79

#2440 No.79 was laid down at Nihon Kōkan, Tsurumi Shipyard on 6 November 1944, launched on 30 December 1944 and completed on 6 May 1945. Decommissioned on 5 October 1945. Surrendered to Soviet Union, 29 July 1947. Served in Soviet Pacific Ocean Fleet as patrol ship EK-39 (1947), target ship TsL-39 (1948), oceanographic research ship Sozh (1949). Decommissioned on 30 August 1960 and scrapped.
on combinedfleet.com

N°81

#2441 No.81 was laid down at Maizuru Naval Arsenal on 7 August 1944, launched on 15 October 1944 and completed on 15 December 1944. Decommissioned on 5 October 1945. Surrendered to Republic of China, 29 August 1947, and renamed Yuan. Escape to People’s Liberation Army 13 February 1949, and renamed Shengyang. Decommissioned 1980.
on combinedfleet.com

N°83

#2442 No.83 was laid down at Kyōwa Zōsen and Naniwa Dock Company on 1944, launched on 16 January 1945. Still incomplete at the end of war (85%). Scrapped on 17 March 1948.
on combinedfleet.com

N°85

#2443 No.85 was laid down at Nihon Kōkan, Tsurumi Shipyard on 20 November 1944, launched on 27 January 1945 and completed on 31 May 1945. Decommissioned on 25 October 1945. Surrendered to Republic of China 6 July 1947, and renamed Shian. Escape to People’s Liberation Army 23 April 1949. Sunk by aircraft at Yanziji, 28 April 1949.
on combinedfleet.com

N°87

#2444 No.87 was laid down at Nihon Kōkan, Tsurumi Shipyard on 27 November 1944, launched on 15 February 1945 and completed on 20 May 1945. Decommissioned on 5 October 1945. Surrendered to United States, 29 July 1947. Scrapped on 1 March 1948.
on combinedfleet.com

N°88

#2445 No.89 was laid down at Nihonkai Dock Company on 1944 , launched on 29 3 May 1945 but scrapped incomplete until the end of war (95%). Scrapped in November 1947.
on combinedfleet.com

N°93

#2447 No.93 was laid down at Kyōwa Zōsen on 20 May 1944, never launched. Company was closed and construction stopped in May 1945. Later scrapped.
on combinedfleet.com

N°95

#2448 No.95 was laid down at Nihon Kōkan, Tsurumi Shipyard on 27 November 1944, launched on 14 April 1945 and completed on 4 July 1945. Decommissioned on 15 September 1945. Scrapped on 20 July 1948.
on combinedfleet.com

N°97

#2449 No.97 Nihon Kōkan, Tsurumi Shipyard on 5 October 1944, launched on 25 May 1945 and completed on 16 December 1945. Surrendered incomplete in August 1945. Decommissioned on 1 April 1946. Scrapped on 27 October 1947.
on combinedfleet.com

N°101

#2451 No.101 was laid down at Kyōwa Zōsen on 8 September 1944, never launched. Company was closed and construction stopped in May 1945. Later scrapped.
on combinedfleet.com

N°105

#2453 No.105 was laid down at Nihon Kōkan, Tsurumi Shipyard on 24 December 1944, launched on 29 January 1946 and completed on 15 April 1946. Surrendered to Soviet Union, 5 July 1947. Served in Soviet Pacific Ocean Fleet as patrol ship EK-34 (1947), target ship TsL-34 (1948), oceanographic research ship Khersones (1949). Decommissioned on 3 December 1960 and scrapped.
on combinedfleet.com

N°107

#2454 No.107 was laid down at Nihon Kōkan, Tsurumi Shipyard on 3 January 1945, launched on 16 March 1946 and completed on 30 May 1946. Surrendered to Republic of China 29 August 1947, and renamed Chaoan (PF-74). Decommissioned 1963.
on combinedfleet.com

N°205

#2503 No.205 was laid down at Nihonkai Dock Company on 10 May 1944, launched on 15 August 1944 and completed on 30 October 1944. Decommissioned on 5 October 1945. Surrendered to Republic of China 31 July 1947, and renamed Chinan (PF-75). Decommissioned 1960.
on combinedfleet.com

N°207

#2504 No.207 was laid down at Naniwa Dock Company on 17 May 1944, launched on 24 August 1944 and completed on 15 October 1944. Decommissioned on 5 October 1945. Surrendered to United States, 4 July 1947. Sunk as target at, 13 August 1947.
on combinedfleet.com

N°213

#2507 No.213 was laid down at Mitsubishi, Kōbe Shipyard on 24 September 1944, launched on 29 and completed on 15 January 1945, commissioned 12 February 1945. Sunk by naval mine at Busan, 18 August 1945.
on combinedfleet.com

N°215

#2508 No.215 was laid down at Niigata Iron Works on 20 July 1944, launched on 10 November 1944 and completed on 30 December 1944. Decommissioned on 5 October 1945. Surrendered to Republic of China 6 July 1947, and renamed Liaohai. Transferred to Army, 1948. Returned to Navy, 1953. Decommissioned 1960.
on combinedfleet.com

N°217

#2509 No.217 was laid down at Mitsubishi, Kōbe Shipyard on 1 December 1944, launched on 26 February 1945 and completed on 17 July 1945. Decommissioned on 30 November 1945. Surrendered to United Kingdom, 5 September 1947. Scrapped on 10 February 1948.
on combinedfleet.com

N°219

#2510 No.219 was laid down at Naniwa Dock Company on 2 September 1944, launched on 30 November 1944 and completed on 25 January 1945. Sunk by USAAF aircraft at Hakodate, 12 July 1945.
on combinedfleet.com

N°221

#2511 No.221 was laid down at Niigata Iron Works, Osaka on 11 September 1944, launched on 26 December 1944 and completed on 2 April 1945. Decommissioned on 30 November 1945. Surrendered to Soviet Union, 29 July 1947. Served in Soviet Pacific Ocean Fleet as patrol ship EK-40 (1947), target ship TsL-40 (1948), rescue ship Zhiguli (1949). Decommissioned on 11 March 1958 and scrapped.
on combinedfleet.com

N°223

#2512 No.223 was laid down at Mitsubishi, Kōbe Shipyard on 1944, launched on 4 July 1945. Construction stopped on 23 May 1945 (50%). Scrapped on 23 October 1947.
on combinedfleet.com

N°225

#2513 No.225 was laid down at Niigata Iron Works on 22 November 1944, launched on 29 26 March 1945 and completed on 28 May 1945. Decommissioned on 5 October 1945. Scrapped on 30 April 1948.
on combinedfleet.com

N°227

#2514 No.227 was laid down at Naniwa Dock Company, Osaka on 5 December 1944, launched on 10 February 1945 and completed on 15 June 1945. Decommissioned on 5 October 1945. Surrendered to Soviet Union, 5 July 1947. Served in Soviet Pacific Ocean Fleet as patrol ship EK-35 (1947), target ship TsL-35 (1948), oceanographic research ship Siurkum (1949)/ Decommissioned on 11 March 1958 and scrapped.
on combinedfleet.com

N°229

#2515 No.229 was laid down at Mitsubishi, Kōbe Shipyard on 16 January 1945, never launched, Construction stopped in January 1945. Later scrapped.
on combinedfleet.com

Never completed or Cancelled

Also, #2505, #2506 No.209, No.211 Cancelled in August 1944.
#2446 No.91: Cancelled in August 1944.
#2450 No.99: Cancelled in August 1944.
#2452 No.103: Cancelled in August 1944.
#2455 No.109 Nihon Kōkan, Tsurumi Shipyard, laid down 26 January 1945: Construction stopped on 1 April 1945. Later scrapped.
+#2456, #2457, #2458 No.111, No.113, No.115 Cancelled in August 1944.
#2459, No.117 Nihon Kōkan, Tsurumi Shipyard, laid down 1 February 1945. Construction stopped in March 1945. Later scrapped.
#2460 to #2502 Odd numbers from No.119 to No.203: Cancelled in August 1944.
#2516, #2517 (No.231), No.233 Cancelled in August 1944.
#2518 No.235. Niigata Iron Works 15 February 1945: Construction stopped in February 1945. Later scrapped.
#2519 to #2532. Odd numbers from No.237 to No.263: Cancelled between August 1944 and March 1945.