Japanese submarine chaser CH-7

History
Empire of Japan
Name	CH-7
Builder	Tsurumi Iron Works, Yokohama
Laid down	30 October 1937
Launched	10 June 1938
Completed	15 November 1938
Commissioned	15 November 1938
Stricken	25 May 1945
Fate	Sunk by aircraft, 11 April 1945
Notes	Call sign: JUUD; ;
General characteristics
Type	Submarine 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;
Beam	5.6 m (18 ft 4 in)
Draught	2.1 m (6 ft 11 in)
Propulsion	2 × Kampon Mk.22 Model 6 diesels, 2 shafts, 2,600 bhp
Speed	20.0 knots (23.0 mph; 37.0 km/h)
Range	2,000 nmi (3,700 km) at 14 kn (16 mph; 26 km/h)
Complement	59
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;

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

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

In November 1941, she was assigned to the Borneo Invasion Group (under Rear Admiral

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

On 9 February 1942, she departed

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

On 10 March 1942, she departed Singapore as part of

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

On 19 March 1942, she departed

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

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

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

On 11 April 1945 while conducting escort duty for auxiliary transport Agata Maru in the

Navy list on 25 May 1945.^[2]^[5]

Notes

^ ^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).
^ ^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.
^ ^a ^b ^c ^d ^e Hackett, Bob; Kingsepp, Sander (2012). "Zatsuyosen: IJN Hokkai Maru: Tabular Record of Movement". combinedfleet.com. Retrieved 5 November 2019.
^ ^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. Archived from the original on 21 June 2023. Retrieved 30 March 2021.
^ "Japanese Auxiliary Netlayers". Combinedfleet.com. Retrieved 27 February 2023.

References

L, Klemen (2000). "Forgotten Campaign: The Dutch East Indies Campaign 1941–1942". Archived from the original on 26 July 2011. Retrieved 30 March 2021.