Insect-class gunboats designed for the Danube

The Insect class was intended for the Danube, with the label "large China gunboats" used to conceal that purpose. Ships of the class also served in Mesopotamia and northern Russia before spending much of the interwar period in the Far East. Triple-expansion engines were chosen because local infrastructure could support them more easily. Six-inch guns, twelve-pounders, and machine guns gave the boats substantial river firepower, while some later received other weapons. Their armour is described as improvised.