W-1-class minesweeper

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 12 cm 11th Year Type naval gun| 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. No.5 class • Project number I2. 2 vessels were built in 1928 and 1929. Improved model of the No.1-class. In terms of their appearance, their foremast was changed to a tripod-type. ==Photos==

File:Japanese_mine_sweeping_squadron_consisting_of_No._1_through_No._6.jpg|1st Minesweeping Squadron W-3 and W-2 in front File:Japanese minesweeper MSC4.jpg|W-4 in July 1930 File:Japanese minesweeper MSC5.jpg|W-5 in the 1930s (after the Tomozuru-Incident) File:Japanese minesweeper No6 in 1933.jpg|W-6 on 28 May 1933 ==Footnotes==