 This class was consequently upgraded by doubling the number of engines and shafts, and most units were built by the Wusong Shipyard at Shanghai.This minesweeper carries Type 317 magnetic sweeping gear, Type 318 mechanical sweeping gear, Type 318 acoustic sweeping gear, and Type 319 infrasonic sweeping gear, and it can also be used as a minelayer with capability to carry 6 mines.The boat is powered by 4 M50 diesel, and more than half a dozen have entered Chinese service.