No.251-class auxiliary submarine chaser
 Auxiliary Submarine Chaser No.251 in 1938 | |
| Class overview | |
|---|---|
| Name: |
No.251-class aux. submarine chasers • No.251-class (Project number K5A) • No.253-class (Project number K5B) |
| Builders: |
Nihon Kōkan Corporation Ōsaka Iron Works |
| Operators: |
 Imperial Japanese Navy |
| Built: | 1936 – 1939 |
| In commission: | 1937 – 1945 |
| Planned: | 3 |
| Completed: | 3 |
| Retired: | 3 |
 Auxiliary Submarine Chaser No.253 in 1937 | |
| General characteristics | |
| Type: | Submarine chaser |
| Displacement: | 170 long tons (173 t) standard |
| Length: | 45.0 m (147 ft 8 in) overall |
| Beam: | 4.80 m (15 ft 9 in) |
| Draught: | No.251 and No.252 1.70 m (5 ft 7 in) No.253 1.73 m (5 ft 8 in) |
| Propulsion: | No.251 2 × original MAN Mk.1 diesels 2 shafts, 3,000 bhp No.252 2 × copied MAN Mk.1 diesels 2 shafts No.253 1 × Kampon geared turbine 2 × Kampon water tube boilers 2 shafts, 3,000 shp |
| Speed: | 23.0 knots (26.5 mph; 42.6 km/h) |
| Range: | 800 nmi (1,500 km) at 14 kn (16 mph; 26 km/h) |
| Complement: | 41 |
| Armament: | • 1 × 40 mm heavy machine gun • 18 × Type 95 depth charges • 2 × Type 94 depth charge projectors • 1 × depth charge rack • 1 × Type 93 active sonar • 1 × Type 93 hydrophone |
The No.251 class auxiliary submarine chaser (第二百五十一号型駆潜特務艇, Dai 251 Gō-gata Kusen-Tokumutei)[1] was a class of submarine chasers of the Imperial Japanese Navy (IJN), serving during World War II. 3 vessels were built in 1936 – 1939 under the Maru 2 Programme. They have two sub classes, this article handles them collectively.
Background
- In 1934, the IJN planned an experimental model of high-speed coast defense submarine chaser. The IJN wanted over 20 kn (23 mph; 37 km/h), however the Navy Technical Department (Kampon) have not designed such a small-sized and high-powered diesels yet.
- The IJN ordered hull design to the Thornycroft, and high-powered diesel design to the MAN, for study a small-sized high-speed boat.
Design
- The Thornycroft drawings were not able to satisfy the IJN, because their designs center of gravity was too high, and bad drainage. The Kampon made a based on the Hayabusa class torpedo boat and finished hull designs.
- The IJN was satisfied with MAN diesel specifications, however their designs were very complicated and very high-prices. The IJN bought two diesels and named MAN Mk.1 diesel (マ式1号ディーゼル, Ma-Shiki 1 Gō diesel). Furthermore, the IJN ordered a copy of this diesel to the Kawasaki Heavy Industries and Mitsubishi Heavy Industries.
- Also, 1 vessel was equipped with a Kampon turbine, because diesel engine was unsuitable for a mass production.
Service
- The IJN deployed them to a mine warfare school after having finished their examination, because they were too small.
- They became a training ship of the mine warfare school, and they acted in Tokyo Bay.
Ships in classes
No.251-class
- Project number K5A. 2 vessels were completed. They were equipped with MAN design diesels. The No.252 was equipped the copied MAN diesels by Kawasaki and Mitsubishi.
No.251
- 14 December 1936: Laid down as the Submarine Chaser No.51 (第51号駆潜艇, Dai 51 Gō Kusentei) at Nihon Kōkan, Tsurumi Shipyard.
- 9 June 1937: Launched.
- 30 September 1937: Completed.
- 15 November 1940: Classified to the Auxiliary submarine chaser, and renamed Auxiliary Submarine Chaser No.51 (第51号駆潜特務艇, Dai 51 Gō Kusen-Tokumutei).
- (after): Assigned to the mine warfare school (Kurihama).
- 30 April 1943: Renamed Auxiliary Submarine Chaser No.251 (第251号駆潜特務艇, Dai 251 Gō Kusen-Tokumutei).
- 28 August 1944: Classified to the Support vessel (tugboat), and renamed No.1658 (公称第1658号, Kōshō-Dai 1658 Gō).
- August 1945: The end of war at Uraga, later nothing more was heard.
No.252
- 14 December 1936: Laid down as the Submarine Chaser No.52 (第52号駆潜艇, Dai 52 Gō Kusentei) at Nihon Kōkan, Tsurumi Shipyard.
- 25 August 1937: Launched.
- 25 July 1939: Completed.
- 15 November 1940: Classified to the Auxiliary submarine chaser, and renamed Auxiliary Submarine Chaser No.52 (第52号駆潜特務艇, Dai 52 Gō Kusen-Tokumutei).
- (after): Assigned to the mine warfare school (Kurihama).
- 30 April 1943: Renamed Auxiliary Submarine Chaser No.252 (第252号駆潜特務艇, Dai 252 Gō Kusen-Tokumutei).
- 15 February 1944: Classified to the Support vessel (tugboat), and renamed No.1650 (公称第1650号, Kōshō-Dai 1650 Gō).
- August 1945: The end of war at Uraga, later nothing more was heard.
No.253-class
- Project number K5B. 1 vessels was completed. She was equipped with Kampon turbine. She was classed in the No.251-class in the IJN official documents.
No.253
- 9 January 1937: Laid down as the Submarine Chaser No.53 (第53号駆潜艇, Dai 53 Gō Kusentei) at Ōsaka Iron Works, Sakurajima Factory.
- 15 July 1937: Launched.
- 31 October 1937: Completed.
- 15 November 1940: Classified to the Auxiliary submarine chaser, and renamed Auxiliary Submarine Chaser No.53 (第53号駆潜特務艇, Dai 53 Gō Kusen-Tokumutei).
- (after): Assigned to the mine warfare school (Kurihama).
- 30 April 1943: Renamed Auxiliary Submarine Chaser No.253 (第253号駆潜特務艇, Dai 253 Gō Kusen-Tokumutei).
- 15 February 1944: Classified to the Support vessel (tugboat), and renamed No.1651 (公称第1651号, Kōshō-Dai 1651 Gō).
- August 1945: The end of war at Uraga.
- August 1946: Sink by unknown effect.
Footnotes
- ↑ At first No.51 class submarine chaser (第五十一号型駆潜艇, Dai 51 Gō-gata Kusentei), until 15 November 1940.
Bibliography
- Ships of the World special issue Vol.45, Escort Vessels of the Imperial Japanese Navy, "Kaijinsha"., (Japan), February 1996
- The Maru Special, Japanese Naval Vessels No.49, Japanese submarine chasers and patrol boats, "Ushio Shobō". (Japan), March 1981
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