Aubretia class sloop

HMS Polyanthus as a Q-ship during World War I
Class overview
Name:	Aubretia class
Operators:	Royal Navy
Built:	1916
In commission:	1916–1932
Completed:	12
Lost:	3
General characteristics
Type:	Convoy escort Q-Ship: ("Warship-Q")
Displacement:	1,250 tons
Length:	255 ft 3 in (77.80 m) p/p 267 ft 9 in (81.61 m) o/a
Beam:	33 ft 6 in (10.21 m)
Draught:	12 ft 6 in (3.81 m)
Propulsion:	1 × 4-cylinder triple expansion engine 2 × cylindrical boilers 1 screw
Speed:	Designed to make 17.5 knots (32.4 km/h) at 2,500 ihp (1,900 kW), but actually can only make 15-16.5 knots (30.6 km/h) with this power and require 3,000 ihp (2,200 kW). for 17.5 knots (32.4 km/h).
Range:	205 tons of coal
Complement:	80 men
Armament:	Designed to mount : 3 × 12-pounder (76.2 mm) guns 2 × 3-pounder (47 mm) AA but had : 2 × QF 4 inch Mk IV guns or BL 4 inch Mk IX guns 1 × 3-pounder (47 mm) AA depth charge throwers

The Aubretia-class sloops were a class of twelve sloops built under the Emergency War Programme for the Royal Navy in World War I as part of the larger Flower class. They were also referred to as the "cabbage class", or "herbaceous borders". The Flowers were the first ships designed as minesweepers.

Like all the Flowers, the Aubretia class were originally designed as single-screw fleet sweeping vessels, with triple hulls at the bows and an above-water magazine located aft, to give extra protection against loss from mine damage when working. However, the utility of the design was found to be as a convoy escort, and as such other classes took over the minesweeping role. The Aubretias were re-classified as convoy sloops.

Unlike the preceding Flowers of the Acacia, Azalea and Arabis classes, with their unmistakable warship appearance, the Aubretias were designed to look like small merchantmen, in the hope of deceiving U-boat commanders, a tactic known as the Q-ship. These vessels were built by commercial shipbuilders to Lloyd's Register standards, to make use of vacant capacity, and the individual builders were asked to use their existing designs for merchantmen, based on the standard Flower-type hull.

Two members of the following Anchusa group, HMS Chrysanthemum and HMS Saxifrage (renamed HMS President in 1922), survived to be moored on the River Thames for use as Drill Ships by the RNVR until 1988, a total of seventy years in RN service. President was sold in 1988 and preserved, and is now one of the last three surviving warships of the Royal Navy built during the First World War, (along with the 1914 light cruiser HMS Caroline in Belfast, and the 1915 monitor HMS M33 in Portsmouth dockyard).