Japanese submarine chaser CH-7

CH-7 or No. 7 (jp: 第七号駆潜艇) was a No.4-class submarine chaser of the Imperial Japanese Navy during World War II.

History
Empire of Japan
NameCH-7
BuilderTsurumi Iron Works, Yokohama
Laid down30 October 1937
Launched10 June 1938
Completed15 November 1938
Commissioned15 November 1938
Stricken25 May 1945
FateSunk by aircraft, 11 April 1945
Notes
General characteristics
TypeSubmarine chaser
Displacement
  • 291 long tons (296 t) standard
  • 309 long tons (314 t) trial
Length
  • 56.2 m (184 ft 5 in) overall
  • 55.5 m (182 ft 1 in) waterline
Beam5.6 m (18 ft 4 in)
Draught2.1 m (6 ft 11 in)
Propulsion2 × Kampon Mk.22 Model 6 diesels, 2 shafts, 2,600 bhp
Speed20.0 knots (23.0 mph; 37.0 km/h)
Range2,000 nmi (3,700 km) at 14 kn (16 mph; 26 km/h)
Complement59
Armament
  • 2 × 40 mm heavy machine guns
  • 36 × depth charges
  • 2 × Type 94 depth charge projectors
  • 1 × depth charge thrower
  • 1 × Type 93 active sonar
  • 1 × Type 93 hydrophone
  • No.4, November 1944
  • 2 × 40 mm heavy machine guns
  • 3 × Type 96 25 mm AA guns
  • 36 × depth charges
  • 2 × Type 94 depth charge projectors
  • 2 × depth charge throwers (estimate)
  • 1 × 13-Gō surface search radar
  • 1 × Type 3 active sonar
  • 1 × Type 93 hydrophone

History edit

CH-7 was laid down on 30 October 1937 at the Yokohama shipyard of Tsurumi Iron Works, launched on 10 June 1938, and completed and commissioned on 15 November 1938.[1][2] On 8 December 1941, she was assigned to Sub Chaser Division 11 (SCD 11) under Commandeer Hayashi Risaku, 9th Base Force, Southern Expeditionary Fleet.[2] CH-8 and CH-9 were also assigned to the squadron.[2]

Invasion of Borneo edit

In November 1941, she was assigned to the Borneo Invasion Group (under Rear Admiral Kurita Takeo), code-named "Operation B" (the invasion of British Borneo).[3] The force consisted of five Imperial Japanese Army transports carrying the 25th Army (Katori Maru, Hiyoshi Maru, Myoho Maru, Kenkon Maru, and Nichiran Maru); and five Imperial Japanese Navy transports (Hokkai Maru carrying the No.2 Yokosuka Special Naval Landing Force, Tonan Maru No 3 carrying the 4th Naval Construction Unit, and three transports carrying equipment and supplies, Unyo Maru No. 2, Kamikawa Maru, and Mitakesan Maru).[3] The force was escorted by CH-7 along with and two minesweepers (W-3 and W-6) while two heavy cruisers (Kumano, Suzuya), two light cruisers (Yura and Kinu), six destroyers (Fubuki, Murakumo, Shinonome, Shirakumo, Usugumo, Sagiri), provided distant cover; and a seaplane tender (Kamikawa Maru) provided air support.[3] On 13 December 1941, the convoy left Cam Ranh Bay, Indochina (Mitakesan Maru is later detached to deliver supplies to the Philippines). On 15 December 1941, the transports arrived and disembarked their troops unopposed at Seria, Miri, and Lutong, successfully occupying the airfields and oil wells. On 17 December 1941, the destroyer Shinonome was sunk by a Dutch Dornier Do 24 flying-boat flying from Tarakan.[3] CH-7 remained at Miri[1] with one battalion of the 25th Army while the rest of the force departed on 22 December 1941 to occupy Kuching.[3] On 25 December 1941, CH-7 left Miri arriving at Kuching on 26 December 1941.[2]

Invasion of Palembang and Banka Island edit

On 9 February 1942, she departed Camranh Bay as part of "Operation L" tasked with the invasion and occupation of Palembang and Banka Island, Sumatra.[2] The invasion force consisted of eight transports escorted by subchasers, CH-7 and CH-8; light cruiser Sendai; destroyers Fubuki, Hatsuyuki, Shirayuki, and Asagiri; and minesweepers W-1, W-2, W-3, W-4 and W-5.[2]

Invasion of Northern Sumatra edit

On 10 March 1942, she departed Singapore as part of "Operation T" tasked with the invasion and occupation of Northern Sumatra.[2] The invasion force consisted of 4 convoys carrying 22,000 soldiers including the Imperial Guards Division.[4] CH-7 served as escort along with section 1 of Minesweeper Division 44 for one of the convoys consisting of the minelayer Hatsutaka, submarine tender Nagoya Maru, and eight transports.[2] The force reached Sumatra unmolested on 12 March 1942 as Allied air and naval power had been severely reduced after the Battle of the Java Sea and the Dutch East Indies campaign.[4]

Reinforcement of Burma edit

On 19 March 1942, she departed Camranh Bay as part of "Operation U" tasked with the reinforcement of Japanese troops in Burma.[2] The convoy is escorted by subchasers CH-7 and CH-8 along with a light cruiser Kashii (which serves as flagship), five destroyers (Shikinami, Asakaze, Harukaze, Hatakaze, and Matsukaze); an escort ship (Shimushu); a minelayer (Hatsutaka), 3 minesweepers (W-1, W-3, W-4); the 91st Subchaser Division (AN Choko Maru, PC Shonan Maru No. 5, PC Shonan Maru No. 7); a gunboat (Eiko Maru); an Ōtori-class torpedo boat (Kari), and an auxiliary gunboat (Kosho Maru).[2] The warships escorted the First Burma Transport Convoy consisting of 32 transports carrying the main body of the Imperial Japanese Army's 56th Division.[2]

Interim edit

On 14 July 1942, CH-7 is assigned along with CH-8 and CH-9 to Submarine Chaser Division 11, 10th Special Base Force, 1st Southern Expeditionary Fleet, Southwest Area Fleet.[2] She conducts various escort duties throughout southeast Asia primarily in the waters surrounding Vietnam, Indonesia, Singapore, and Malaysia.[2]

Convoy Mashi-03 edit

On 7 November 1944, she departed Manila for Singapore with CH-8 as escort for convoy MASHI-03 consisting of tankers Nichinan Maru No. 2 and Shimotsu Maru. On 8 November 1944, Nichinan Maru No. 2 was torpedoed and sunk by the USS Redfin (killing 86).[2] On 9 November 1944, Shimotsu Maru was torpedoed and sunk by the USS Barbero (killing 39).[2] The convoy was dissolved.[2]

Fate edit

On 11 April 1945 while conducting escort duty for auxiliary transport Agata Maru in the Andaman Sea 11 miles north east of the Nicobar Islands, she was attacked by Consolidated B-24 Liberator bombers of the Royal Air Force's No. 203 Squadron.[2] Both ships were sunk at 09°21′N 93°00′E / 9.350°N 93.000°E / 9.350; 93.000.[2] CH-7 was removed from the Navy list on 25 May 1945.[2][5]

Notes edit

  1. ^ a b c Toda, Gengoro S. "第七號驅潜艇の艇歴 (No. 7 submarine chaser - Ship History)". Imperial Japanese Navy -Tokusetsu Kansen (in Japanese).
  2. ^ a b c d e f g h i j k l m n o p q r s Hackett, Bob; Kingsepp, Sander; Cundall, Peter; Mcilveen, Hans; Casse, Gilbert. "IJN Subchaser CH-7". combinedfleet.com. Retrieved 6 June 2020.
  3. ^ a b c d e Hackett, Bob; Kingsepp, Sander (2012). "Zatsuyosen: IJN Hokkai Maru: Tabular Record of Movement". combinedfleet.com. Retrieved 5 November 2019.
  4. ^ a b Womack, Tom (1999–2000). "An Abandoned Army - The KNIL and The Japanese Invasion of Northern Dutch Sumatra". Forgotten Campaign: The Dutch East Indies Campaign 1941-1942.
  5. ^ "Japanese Auxiliary Netlayers". Combinedfleet.com. Retrieved 27 February 2023.

References edit

Further reading edit

  • "Escort Vessels of the Imperial Japanese Navy special issue". Ships of the World (in Japanese). Vol. 45. Kaijinsha. February 1996.
  • Model Art Extra No.340, Drawings of Imperial Japanese Naval Vessels Part-1 (in Japanese). Model Art Co. Ltd. October 1989.
  • The Maru Special, Japanese Naval Vessels No.49, Japanese submarine chasers and patrol boats (in Japanese). Ushio Shobō. March 1981.