Fly-class gunboat

Class overview
Name	Fly class
Builders	Yarrow Shipbuilders
Operators	Royal Navy (1915–1918); British Army (1918–1924);
In service	1915–1924
Completed	16
Lost	3
Retired	13
General characteristics
Type	River gunboat
Displacement	98 long tons (100 t)
Length	126 ft (38 m)
Beam	20 ft (6.1 m)
Draught	2 ft (0.61 m)
Propulsion	1 shaft VTE, single yarrow type mixed firing boiler, 175 ihp (130 kW)
Speed	9.5 kn (10.9 mph; 17.6 km/h)
Complement	22
Armament	1 × 4-inch (102-mm) gun; 1 × 12-pounder (76-mm) gun; 1 × 6-pounder (57-mm) gun (some); 1 × 3-pounder (47-mm) gun; 1 × 2-pounder (40-mm) pom-pom; 4 or 5 machine-guns;

The Fly-class river gunboats (or small China gunboats), collectively often referred to as the "Tigris gunboat flotilla", were a class of small well-armed Royal Navy vessels designed to patrol the Tigris river during the Mesopotamian Campaign during the First World War (the China name was to disguise their function).