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).
The Aubrietia-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 Aubrietia 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 Aubrietias were re-classified as convoy sloops.
Unlike the preceding Flowers of the Acacia, Azalea and Arabis classes, with their unmistakable warship appearance, the Aubrietias 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.
A further six ships were ordered in December 1916:
HMS Andromeda — built by Swan Hunter and Wigham Richardson, Wallsend on Tyne, launched June 1917. Transferred to French Navy, later renamed Ville d'Ys.
HMS Gaillardia — built by Blyth Shipbuilding, launched 19 May 1917. Mined in the North Sea 22 March 1918.
HMS Hibiscus — built by Greenck and Grangemouth, launched 17 November 1917. Sold for breaking up 18 January 1923.
HMS Lychnis — built by William Hamilton and Company, Port Glasgow, launched 21 August 1917. Transferred to Royal Indian Marine in September 1921, renamed Cornwallis; sold 1946.
HMS Montbretia — built by Irvine's, launched 3 September 1917. Sold 25 January 1921, becoming mercantile Chihuahua (Clan Line).
HMS Polyanthus — built by Lobnitz, launched 24 September 1917. Sold 25 January 1921, becoming mercantile Colima (Clan Line).
References
The Grand Fleet, Warship Design and Development 1906-1922, D. K. Brown, Chatham Publishing, 1999, ISBN1-86176-099-X
Jane's Fighting Ships of World War I, Janes Publishing, 1919