W-7 class

from Wikipedia, the free encyclopedia
W-7 class
Mine sweeper number 7 in September 1942
Mine sweeper number 7 in September 1942
Ship data
country JapanJapan (naval war flag) Japan
Ship type Minesweeper
draft I-4
Construction period 1937 to 1939
Launch of the type ship June 16, 1938
Units built 6th
period of service 1938 to 1945
Ship dimensions and crew
length
72.27 m ( Lüa )
71.05 m ( KWL )
67.09 m ( Lpp )
width 7.89 m
Draft Max. 2.60 m
displacement Standard : 630 ts / 640 t
Use: 750 ts / 762 t
 
crew 88
Machine system
machine 2 Kampon boilers,
2 geared turbine sets
Machine
performance 		3,850 hp (2,832 kW)
Top
speed 		20 kn (37 km / h)
propeller 2
Armament

When commissioned

  • 3 × 12 cm
  • 2 × 2.5 cm type 96
  • 18 depth charges
  • Mine clearance equipment

From 1944

  • 2 × 12 cm
  • 9 × 2.5 cm type 96
  • 36 depth charges

The W-7 class ( Jap. 第七号型掃海艇 , Dai Nana GO-gata Sōkaitei , dt "No.7 class minesweeper.") Was a class of six minesweepers the Imperial Japanese Navy , which in World War II for Use came.

List of ships

Construction no. Surname Shipyard Keel laying Launch Commissioning Whereabouts
49 Dai-7-go Sōkaitei
( 第七号掃海艇 )
minesweeper No.7 		Mitsui Zosen ,
Tamano 		October 27, 1937 June 16, 1938 December 15, 1938 sunk on April 15, 1944 by the British submarine HMS Storm ,
off the Andamans
50 Dai-8-GO Sōkaitei
( 第八号掃海艇 )
minesweeper No.8 		Uraga shipyard,
Yokosuka 		December 11, 1937 May 28, 1938 February 15, 1939 Spoils of war Great Britain, sunk on July 13, 1946
in the Strait of Malacca
51 Dai-9-Gō Sōkaitei
( 第九号掃海艇 )
minesweeper No.9 		Maizuru naval shipyard February 7, 1938 September 10, 1938 February 15, 1939 sunk after being hit by a mine on February 1, 1942,
off the island of Ambon
52 Dai-10-Gō Sōkaitei
( 第十 号 掃 海 艇 )
minesweeper number 10 		Ishikawajima Zosen ,
Tokyo 		December 21, 1937 September 22, 1938 February 15, 1939 sunk on December 10, 1941 by air raid,
off Vigan ( Japanese invasion of the Philippines )
53 Dai-11-Gō Sōkaitei
( 第十一 号 掃 海 艇 )
minesweeper number 11 		Uraga shipyard,
Yokosuka 		May 30, 1938 December 28, 1938 July 15, 1939 sunk on March 28, 1945 by air raid
in Makassar
54 Dai-12-go Sōkaitei
( 第十二号掃海艇 )
minesweeper No.12 		Ishikawajima Zosen,
Tokyo 		May 28, 1938 February 18, 1939 August 15, 1939 sunk on April 15, 1944 by americans USS Besugo submarine ,
off Flores Island

technical description

Use of a clearing machine for mechanical mine clearing, similar to the one used by the Imperial Japanese Navy.

hull

The hull of the boats of the W-7 class was 72.27  meters long, 7.96 meters wide and had a draft of 2.6 meters with an operational displacement of 762  tons .

drive

It was driven by two steam generators - Kampon boilers of the Yarrow type - and two geared turbine sets with which a total output of 3,850  hp (2,832  kW ) was achieved. The power was delivered to two shafts with one screw each . The top speed was 20  knots (37  km / h ). The maximum travel distance was 2,000  nautical miles (3,704 km) at 14 knots.

crew

The crew had a strength of 88 men.

Armament

artillery

The artillery armament consisted of three 12 cm guns with a caliber length of 45 in single mounts. From 1944, one gun was given ashore and replaced by anti-aircraft guns.

Air defense

For air defense two 2.5 cm were machine guns Type 96 available.

Due to the threat posed by the Allied forces during the Pacific War , the anti-aircraft armament of all remaining boats was reinforced in 1944. The armament now consisted of nine 2.5 cm automatic cannons, which were distributed over the boat.

Submarine hunting equipment

The anti-submarine armament consisted of a Y- type 94 depth charge launcher with 18 depth charges, which were located on the quarterdeck. From 1944 the number of depth charges was increased to up to 36, which could now be used through two drainage rails and the launchers.

Mine detection equipment

For mechanical rooms of sea mines ( moored mines ) possessed the class over Minenräumgeschirr consisting of Räumottern (engl. Paravanes) which by means of two davits were drained at the stern. These clearing otters were pulled to the side by the towing vehicle and held at the same height by wings. The taut towing cable could now lead the anchor ropes from the anchor mine to the clearing otter, where it was cut by cable cutters and the mine floated. It could then be detonated using handguns or ship artillery. If the anchor rope was not cut, the mine and the clearing otter would collide and explode. The towing cable could then be retrieved and any existing replacement device could be attached. Up to six clearing otters were carried on board.

Sensors

sonar

To search for submarines one was echolocation system of the type 93 and a hydrophone -Set the Type 93 scaffolded. This hydrophone set consisted of two groups of eight sensors each, one group on each side of the boat.

See also

literature

  • Harald Fock: Fleet Chronicle - The active warships involved in the two world wars and their whereabouts . Koehlers Verlagsgesellschaft, Hamburg 2000, ISBN 3-7822-0788-2 , p. 173-200 .
  • Hansgeorg Jentschura, Dieter Jung, Peter Mickel: Warships of the Imperial Japanese Navy 1869-1945 . US Naval Institute Press, Annapolis 1977, ISBN 0-87021-893-X , pp. 209 (English).

Web links

Commons : Imperial Japanese Navy Minesweepers  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Japanese depth charges in WWII. In: navweaps.com. Retrieved July 1, 2020 .
  2. ↑ Japanese Sonar and Asdic (USNTMJ E-10). (PDF) US Navy Technical Mission to Japan, December 14, 1945, pp. 7 and 11 , accessed on July 1, 2020 .