The turbine-powered ships displaced 850LT at standard load and 1125LT at deep load. The ship measured 225feet long overall with a beam of 35feet. The turbine group had a draught of 11feet. The ships' complement consisted of 85 officers and ratings.[1]
The ships had two Parsons geared steam turbines, each driving one shaft, using steam provided by two Admiralty three-drum boilers. The engines produced a total of 2000shp and gave a maximum speed of 16.5kn. The ships carried a maximum of 660LT of fuel oil that gave them a range of 5000nmi at .[1]
The Algerine class was armed with a QF 4abbr=onNaNabbr=on Mk V anti-aircraft gun[2] and four twin-gun mounts for Oerlikon 20 mm cannon. The latter guns were in short supply when the first ships were being completed and they often got a proportion of single mounts. By 1944, single-barrel Bofors 40 mm mounts began replacing the twin 20 mm mounts on a one for one basis. All of the ships were fitted for four throwers and two rails for depth charges.[1]
Rattler was laid down on 14 April 1941 at Harland and Wolff, Belfast, launched on 9 December 1942 and commissioned on 22 April 1943.[3] [4] She was adopted by the community of Ripley, North Yorkshire after a Warship Week national savings campaign in March 1942.[5] [6]
After commissioning she was assigned to the 18th Minesweeping Flotilla, joining them in June 1943, when she was renamed Loyalty.[3] [7] She and the other ships of the flotilla carried out sweeping operations in Lyme Bay and the English Channel. She and other ships of the flotilla were transferred to Harwich in August to sweep areas of the North Sea, but was soon transferred to the 9th Flotilla, at Dover. On 25 August Loyalty was part of Operation Starkey, an attempt to attract German aircraft to unusual minesweeping operations near the French coast. The ships of the flotilla came under fire from shore batteries, and was damaged. They returned to Dover, but were mistakenly fired on by British shore batteries, causing further damage. Loyalty did not return to minesweeping duties until October.
In November Loyalty transferred to Scapa Flow to join the 15th Minesweeping Flotilla with the Home Fleet. She transferred again in December to the Orkney and Shetland Command, operating out of Seidisfjord on anti-submarine patrols and local convoy escort duties. She remained here until being nominated to return to the UK in March 1944 and in April underwent a refit at Portsmouth, after which she was assigned to Force G to give minesweeping support to the Allied landings in Normandy. Loyalty spent May carrying out exercises and rehearsals, and also escorted sister ship into Portsmouth after she had been damaged by a mine. Loyalty then took part in the assault operations of 6 June, clearing Channel 6, and then remaining deployed off Gold Beach to cover operations. She remained off Normandy after the landings and throughout July, carrying out sweeps of the anchorages.
Loyalty was still off Normandy on 22 August. She was returning to Portsmouth with the minesweepers,, Hydra and when the sweep wires parted. Loyalty and the minesweeping trawler Doon were dispatched to recover the sweep. As they were doing this Loyalty was attacked and sunk by the German U-boat at position 50.15°N -41°W in the English Channel. She capsized in less than seven minutes, with the loss of her captain and 18 ratings. There were 30 survivors. Loyalty was replaced in the flotilla by sister ship . The wrecksite is designated as a protected place under the Protection of Military Remains Act 1986.