From Flower-class sloops to interwar specialists

World War I Flower-class sloops expanded beyond their intended minesweeping and Q-ship duties into escort and anti-submarine work. Their triple-expansion engines were comparatively easy to produce, but their size, shape, and persistent noise made them difficult to quieten. Interwar construction carried that experience through Bridgewater and Hastings into further experiments with sloop size and armament. The very small Kingfishers tested the lower practical limit, while Bittern and Egret offered larger hulls. This sequence developed a specialist anti-submarine branch whose experience fed into the Black Swans.