The W1 class minesweeper (第一号型掃海艇,, Dai Ichi Gō-gata Sōkaitei) was a class of minesweepers of the Imperial Japanese Navy (IJN), serving during the 1930s and World War II. 6 vessels were built in 1922–29 under the Eight-eight fleet plan. They have two sub-classes, this article handles them collectively.
Background
In 1920, the IJN developed an Eight-eight Fleet Plan which would provide them with eight modern battleships and eight battle cruisers. However, they did not forget the Hatsuse and Yashima, which had struck naval mines during the Russo-Japanese War; afraid of such events occurring again, the IJN also ordered the No.1-class of purpose-built minesweepers, to replace converted old destroyers in the minesweeping role.
As the IJN anticipated its minesweepers to operate in front of the main battle fleet, and therefore to encounter enemy warships, the No.1-class were more heavily armed than minesweepers of other nations, with each ship mounting two 120 mm (4.7 in)L/45 naval guns. In addition each ship could carry 50 naval mines, making them multi-purpose vessels visually resembling small destroyers.
Ships in classes
No.1 class
Project number I1. 4 vessels were built in 1922–1925. W-4 was behind with the laid down by the Washington Naval Treaty.
Sunk by friendly torpedo by Mogami or Mikuma[2] at Bantam Bay during the Battle of Sunda Strait on 1 March 1942; removed from naval ship list on 30 November 1945.
^Minesweeper W-1 (第一号掃海艇, Dai 1 Gō Sōkaitei). The same shall apply hereinafter.
^In the neighborhood of spot, many parts of the Type 93 torpedo were discovered. The Japanese destroyers which participated in Battle of Sunda Strait were not equipped with Type 93 torpedo.
Bibliography
Jentschura, Hansgeorg; Jung, Dieter & Mickel, Peter (1977). Warships of the Imperial Japanese Navy, 1869–1945. Annapolis, Maryland: United States Naval Institute. ISBN0-87021-893-X.
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.50, Japanese minesweepers and landing ships, "Ushio Shobō". (Japan), April 1981