W-1 class
 Mine sweeper number 3 in 1923
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The W-1 class ( Japanese 第一 号 型 掃 海 艇 , Dai Icih Gō-gata Sōkaitei , Eng . "No. 1 class minesweepers") was a class of six minesweepers of the Imperial Japanese Navy , which during the 1920s were built and were used in World War II .
history
Development history
At the beginning of the 1920s, the Imperial Japanese Navy did not have any anti-mine vehicles , such as the British ( Hunt class) , German ( minesweeper 1916 ) or American Navy ( Lapwing class ), but the clearing of sea mines was made possible by their destroyers carried out. Therefore, as part of the second eight-eight fleet program ( Hachihachi Kantai ), considerations were made about a vehicle which would be better suited to clearing the routes of the capital ships of sea mines and to be able to serve them as an escort vehicle. Due to the requirement to serve as an escort vehicle , value was placed on strong armament and relatively high speed compared to mine sweeper classes in other countries.
construction
Six units were approved for the fleet construction plan of 1922 based on a draft with the designation I-1 . However, since budget restrictions arose after the conclusion of the Washington Fleet Treaty , only three boats were keeled at three private shipyards in 1922 and put into service at the end of June 1923. The construction of a fourth boat was delayed so much that it was only laid on the keel at the naval shipyard in Sasebo in December 1923 and entered service until the end of April 1925.
W-5 subclass
Boats No. 5 and No. 6 were created according to a slightly modified design with the designation I-2 between March 2928 and February 1929 at two civilian shipyards as part of the fleet construction plan of 1927. This slightly modified design resulted in an increase in length and width of the hull, which increased the speed by one knot and instead of a pole mast, a three-legged mast was installed.
Prewar changes
In 1927, the front 12 cm gun on all four existing boats was equipped with protective shields and the front chimney was raised to improve smoke extraction. For the other two boats, these measures were already taken into account during the planning phase. During a stay in the shipyard between the end of 1934 and 1935, the 7.62 cm gun was removed from boats 5 and 6 as a result of the Tomoruru incident , and ballast was added to the hull to reduce the top- bulkyness . This increased the operational displacement to 826 ts (839 t). The same measures were carried out on the first four boats while they were in the shipyard in 1938, and their operational displacement increased to 807 ts (820 t).
List of ships
| Surname | Shipyard | Keel laying | Launch | Commissioning | Whereabouts | |
|---|---|---|---|---|---|---|
| 1st group | ||||||
|
Dai-1-Go Sōkaitei ( 第一号掃海艇 ) minesweeper No.1 |
Harima Zosen , Kobe |
May 10, 1922 | March 6, 1923 | June 30, 1923 | sunk on August 10, 1945 by americans Air raid in Yamada Bay | |
|
Dai-2-Go Sōkaitei ( 第二号掃海艇 ) minesweeper No.2 |
Mitsui Zosen , Tamano |
April 13, 1922 | March 17, 1923 | June 30, 1923 | sunk on March 1, 1942 during the battle of the Sunda Strait by torpedo from the Japanese cruiser Mogami in Bantam Bay |
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Dai-3-go Sōkaitei ( 第三号掃海艇 ) minesweeper No.3 |
Osaka Iron Works , Osaka |
March 29, 1923 | June 30, 1923 | sunk on June 9, 1945 by americans USS Parche submarine , northeast of Sendai | ||
|
Dai-4-go Sōkaitei ( 第四号掃海艇 ) minesweeper No.4 |
Sasebo naval shipyard | December 1, 1923 | April 24, 1924 | April 29, 1925 | Spoils of war Great Britain, sunk on July 13, 1946 in the Strait of Malacca | |
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2nd group ( W-5 sub-class) |
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Dai-5-Gō Sōkaitei ( 第五号掃海艇 ) minesweeper No.5 |
Mitsui Zosen, Tamano |
March 25, 1928 | October 30, 1928 | February 25, 1929 | sunk on 4th November 1944 by the British submarine HMS Terrapin in the Straits of Malacca | |
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Dai-6-Gō Sōkaitei ( 第六号掃海艇 ) minesweeper No.6 |
Osaka Iron Works, Osaka |
March 10, 1928 | October 29, 1928 | February 25, 1929 | sunk on December 26, 1941 by the Dutch Air raid near Sarawak | |
technical description
hull
The hull of boats 1 to 4 was 76.2 meters long, 8.03 meters wide and had a draft of 2.32 meters with an operational displacement of 713 tons . The two boats No. 5 and No. 6 had a length of 77.05 meters, a width of 8.26 meters and a draft of 2.29 meters with an operational displacement of 729 tons .
drive
It was driven by three coal-fired steam generators - Kampon boilers of the Yarrow type - and two geared turbine sets with which a total output of 4,000 hp (2,942 kW ) was achieved. The power was delivered to two shafts with one screw each . The top speed was 20 knots (37 km / h ). 199 tons of coal could be bunkered, which led to a maximum driving distance of 3,000 nautical miles (5,556 km) at 10 knots.
crew
The crew had a strength of 91 men.
Armament
artillery
When commissioned, the artillery armament consisted of two 12 cm guns with a caliber length of 45 in single mounts. These were set up in the boat center line in front of the bridge structure and behind the aft deckhouse. From 1944 the front gun was given ashore and replaced by anti-aircraft guns.
Air defense
A 7.62 cm gun with a caliber length of 40 Type 3 was available for air defense . This gun achieved a rate of 13 to 20 rounds per minute and the maximum range was about 7.2 kilometers at 75 ° elevation. The 3.35 tonne central pivot mount could be rotated 360 ° and had an elevation range of −7 ° to + 75 °. Starting in 1938, the 7.62-cm gun was given by board during all boats and by a 13.2 mm machine gun of the type 93 replaced. This fired around 250 rounds per minute in use, the range was around 4.5 kilometers with an 85 ° rise in the barrel. The 314 kilogram carriage could be rotated 360 ° and had an elevation range of −15 ° to + 85 °.
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 five 2.5 cm automatic cannon type 96 , a single carriage inflated to 12 cm, another between the two chimneys, and a drilling carriage on the old position of the front 12 cm gun.
Submarine hunting equipment
The submarine armament was made up of two type 81 depth charges 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 two launchers.
Mine detection equipment
For mechanical rooms of sea mines ( moored mines ) possessed the class over Minenräumgeschirr consisting of two Räumottern (engl. Paravanes) which by means of 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.
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. 207 .
Web links
- Japanese mine layers and mine hunters on ww2technik.de
- Minesweeper on combinedfleet.com (English)
- W-1 class on combinedfleet.com (English)
- W-5 class on combinedfleet.com (English)
Individual evidence
- ↑ Type 3 3-inch cannon. In: navweaps.com. Retrieved June 27, 2020 (English).
- ↑ Type 93 13.2 mm machine gun. In: navweaps.com. Retrieved June 27, 2020 (English).
- ↑ Japanese depth charges in WWII. In: navweaps.com. Retrieved June 29, 2020 .
- ↑ Japanese Sonar and Asdic (USNTMJ E-10). (PDF) US Navy Technical Mission to Japan, December 14, 1945, pp. 7 and 11 , accessed on June 27, 2020 .