No.1 class submarine chaser

Class overview
(left to right) No.1, No.2 and No.3 in 1938
Name:	No.1 class submarine chasers • No.1 class • No.3 class
Builders:	Uraga Dock Company Tōkyō Ishikawajima Shipyard Asano Shipyard
Operators:	Imperial Japanese Navy
Succeeded by:	No.4 class
Cost:	1,525,700 JPY (No.1 class) 1,530,000 JPY (No.3 class)
Built:	1933 – 1936
In commission:	1934 – 1946
Planned:	3
Completed:	3
Lost:	1
Retired:	2
General characteristics No.1 class
Displacement:	266 long tons (270 t) standard 280 long tons (284 t) trial and after late 1934 377 long tons (383 t) trial
Length:	65.30 m (214 ft 3 in) overall 64.00 m (210 ft 0 in) waterline
Beam:	5.90 m (19 ft 4 in)
Draught:	1.43 m (4 ft 8 in)
Propulsion:	2 × Kampon Mk.22 Model 8 diesels 2 shafts, 3,400 bhp
Speed:	24.0 knots (27.6 mph; 44.4 km/h) and after late 1934 21.1 knots (24.3 mph; 39.1 km/h)
Range:	1,500 nmi (2,800 km) at 14 kn (16 mph; 26 km/h)
Complement:	65
Armament:	• 2 × 40 mm heavy machine guns • 36 × depth charges • 1 × depth charge thrower • 1 × Type 93 active sonar • 1 × MV hydrophone
General characteristics No.3 class
Displacement:	270 long tons (274 t) standard 285 long tons (290 t) trial
Length:	56.10 m (184 ft 1 in) overall 55.00 m (180 ft 5 in) waterline
Beam:	5.60 m (18 ft 4 in)
Draught:	2.10 m (6 ft 11 in)
Propulsion:	2 × Kampon Mk.22 Model 6 diesels 2 shafts, 2,500 bhp
Speed:	20.0 knots (23.0 mph; 37.0 km/h)
Range:	1,500 nmi (2,800 km) at 14 kn (16 mph; 26 km/h)
Complement:	60
Armament:	• 2 × 40 mm heavy machine guns • 36 × depth charges • 2 × Type 94 depth charge projectors • 1 × depth charge thrower • 1 × French SCAM active sonar • 1 × Type 93 hydrophone

The No.1 class submarine chaser (第一号型駆潜艇,, Dai 1 Gō-gata Kusentei^?) was a class of submarine chasers of the Imperial Japanese Navy (IJN), serving during World War II. 3 vessels were built in 1933-36 under the Maru 1 Programme and the Maru 2 Programme. They have two sub classes, this article handles them collectively.

1 Background
2 Design
3 Service
4 Ships in classes
- 4.1 No.1 class
- 4.2 No.3 class
5 Photos
6 Footnotes
7 Bibliography

Background

In World War I, German U-boat raged. The IJN began maintenance of an anti-submarine boat as a lesson in this, because Japanese shoreline and sea-lanes were very long. The IJN had some submarine chaser type tugboats and yard ferries. However, they were small and their speed was low.
The IJN wanted to give the anti-submarine boats a speed of more than 20 knots, because their Kaidai III submarine already achieved a 20kt surfaced.

Design

The Naval Technical Department (Kampon) made draft shallow to give them high speed. They achieved 24 kt speed hereby.
The No.1 and the No.2 were completed in March 1934, and they were assigned to the 1st Subchaser Division, Yokosuka Naval Defence Squadron.
However, because of their very shallow draft they lacked the rolling performance. This fact become evident after the Tomozuru incident.
The Tomozuru incident affected the No.1 class. The No.1 and the No.2 were sent to the Uraga Dock Company in July 1934, and repairs were started. They were equipped 80 tons ballast and mounted a ballast keel. The drawings for the No.3 type boats were also revised.

Service

Late 1934, Repairs were completed.
October 1936, The No.3 assigned to 1st SchDiv. They always shared an action afterward.
In 1938, the 1st SchDiv was transferred to the No.1 Base Force (Shanghai).
On 5 September 1941, the No.1 Base Force was transferred to the 2nd Fleet.
In December 1941 – March 1942, the 1st SchDiv engaged to the Battle of the Philippines and Dutch East Indies campaign.
On 10 March 1942, the 1st SchDiv was transferred to the No.21 Special Base Force (Surabaya), 2nd Southern Expeditionary Fleet, Southwest Area Fleet.
On 1 May 1942: The 1st SchDiv was dissolved. They spent all their time for escort operations in the Java Area.

Ships in classes

No.1 class

Project number was K3. 2 vessels were built under the Maru 1 Programme. They equipped the MV hydrophone by Submarine signal company and latest active sonar the Type 93.

Ship	Builder	Laid down	Launched	Completed	Fate
No.1^[1]	Uraga Dock Company	19 June 1933	23 December 1933	24 March 1934	Scuttled by Royal Navy off Singapore on 11 July 1946. Decommissioned on 10 August 1946.
No.2	Tōkyō Ishikawajima Shipyard	9 June 1933	20 December 1933	25 March 1934	Sunk by USS Blueback at north of Lombok on 27 June 1945.

No.3 class

Project number was K4. Only 1 vessel was built under the Maru 2 Programme. They equipped the Frech SCAM active sonar and latest hydrophone the Type 93. The No.3 was classed in the No.1 class in the IJN official documents.

Ship	Builder	Laid down	Launched	Completed	Fate
No.3	Asano Shipyard	17 April 1935	6 June 1936	5 October 1936	Scuttled by Royal Navy off Singapore on 11 July 1946. Decommissioned on 10 August 1946.

Photos

Footnotes

^ Submairne chaser No.1 (第1号駆潜艇, Dai 1 Gō Kusentei^?). The same shall apply hereinafter.

Bibliography

Ships of the World special issue Vol.45, Escort Vessels of the Imperial Japanese Navy, "Kaijinsha". http://www.ships-net.co.jp/. , (Japan), February 1996
The Maru Special, Japanese Naval Vessels No.49, Japanese submarine chasers and patrol boats, "Ushio Shobō". http://www.kojinsha.co.jp/. (Japan), March 1981

Japanese auxiliary ship classes of World War II

Colliers and Oilers	Notoro · Ondo · Sunosaki · Ashizuri · Kazahaya ^S · Hayasui ^S · Hario ^S · Muroto · Ōse (ex-Dutch tanker Genota) ^SC

Food supply ships	Mamiya ^S · Nosaki ^S · Kinesaki · Irako ^S · Kurasaki ^SC

Landing ships	No.1 · No.101 · Shinshū Maru ^S (Army) · SS (Army)

Minelayers and Cable layer	Tokiwa ^SC · Itsukushima ^S · Yaeyama ^S · Okinoshima ^S · Tsugaru ^S · Minoo ^SC · Shirataka ^S · Hatsutaka · Tsubame · Natsushima (1933) · Sokuten (1938) · Hirashima · Ajiro ^S · Kamishima · Hashima · Sokuten (1913) · Aux. No.1 · Aux. No.101 (ex-HMS Barlight) ^SC

Minesweepers	No.1 (1923) · No.5 (1928) · No.13 · No.17 · No.7 (1938) · No.19 · No.101 (ex-HMS Taitam and Waglan) ^C · Aux. No.1 · Aux. No.101 (ex-HNLMS DEFG class) · Aux. No.104 (ex-HNLMS DEFG class)

Patrol boats	No.1 ^C · No.31 ^C · No.46 ^SC · No.101 (ex-HMS Thracian) ^SC · No.102 (ex-USS Stewart) ^SC · No.103 (ex-USS Finch) ^SC · No.104 (ex-Dutch East Indies Valk and Arend) ^C · No.105 (ex-Philippine customs Arayat) ^SC · No.106 (ex-HNLMS Banckert) ^SCI · No.107 (ex-USS Genesee) ^SC · No.109 (ex-Dutch East Indies Fazant) ^SC · Aux. No.1

Repair ships	Asahi ^SC · Akashi ^S · Hayase (ex-Chinese passenger Chin Kiang)^SC · Hitonose (ex-ROCN Min Sheng)^SC

Seaplane tenders	Notoro ^SC · Kamoi ^SC · Chitose · Mizuho ^S · Nisshin ^S · Akitsushima ^S

Submarine chasers	No.1 · No.3 ^S · No.4 · No.13 · No.28 · No.60 · Aux. No.1 · Aux. No.101 (ex-HNLMS Tjerimai) ^SC · Aux. No.102 (ex-HNLMS Ardjoeno class) ^C · Aux. No.103 (ex-HNLMS B1 class) ^C · Aux. No.111 (ex-HNLMS P13 or P14) ^SC · Aux. No.112 (ex-HNLMS A class) ^C · Aux. No.117 (ex-HNLMS Bantam) ^C · Aux. No.251 · Aux. No.253 ^S

Submarine tenders	Komahashi ^SC · Jingei · Taigei ^S

Survey ships	Tsukushi ^S · Katsuriki ^SC · Hakusa (ex-China customs Fu Hsing)^SC

Target ships	Settsu ^SC · Yakaze ^SC · Hakachi ^S · Ōhama ^S

Training ships	Fuji ^SC · Shikishima ^SC · Asama ^SC · Azuma ^SC · Kasuga ^SC · Atada (ex-ROCN Yat Sen) ^SC

Others	Sōya (freighter)^SC · Kashino (turret transporter)^S · Ōtomari (icebreaker)^S · Tategami (salvage tug) · Kasashima (salvage tug) · Miura (salvage tug) · Kaiyō No.1 (oceanographic research ship) · Asuka (traffic ship, ex-ROCN Yung Chien) ^SC

^S - Single ship of class • ^C - Converted to ship type • ^I - Incomplete until the end of war