The Halcyon class was a class of 21 oil-fired minesweepers (officially, "fleet minesweeping sloops") built for the British Royal Navy between 1933 and 1939. They were given traditional small ship names used historically by the Royal Navy and served during World War II. Design There were 21 ships in the Halcyon class, built in two groups; the first using reciprocating steam engines, with steam turbines in the latter. They were generally smaller versions of the escort sloops. Niger and Salamander of the reciprocating group used vertical triple expansion engines, instead of the vertical compound engines of their sisters. As a result of the increased installed power they had a half knot speed advantage, even though they used slightly shorter hulls. The turbine ships used the same shorter hulls as Niger and Salamander, but with lower installed power, speed dropped back to . Gleaner, Franklin, Jason and Scott were completed as unarmed survey vessels, Sharpshooter and Seagull being converted to follow suit. They were all re-armed and deployed in their original role on the outbreak of war. Seagull had the first all-welded hull built for the Royal Navy. Service history Halcyons served in Home waters, at Dunkirk, on Arctic convoy duty, and in the Mediterranean Sea. On 3 February 1940 (Cdr. J. R. N. Taylor, RN) was sweeping an area north of Kinnaird Head when attacked by enemy aircraft. A bomb pierced the fo'c'sle deck and exploding destroying the fore part of the ship. She remained afloat and was taken in tow by Halcyon but steadily flooded and capsized and sank. The wreck was later washed ashore north of Lybster and was sold for scrap. The Commanding Officer and forty of the men were killed in the explosion. (Lt.Cdr. F. B. Proudfoot, RN) was attacked and sunk by a force of German dive bombers off De Panne, Belgium on 1 June 1940. On board Skipjack were between 250 and 300 soldiers just rescued from the Dunkirk beaches during Operation Dynamo. Eyewitness William Stone said "she just disappeared". Halcyons were pressed into service as anti-submarine escorts; this task slowly decreasing as the ships specifically designed for this task, such as s, came off the slips. Halcyons accompanied most of the Arctic convoys, serving both as minesweepers and anti-submarine escorts. Several spent extended periods working out of Soviet naval bases in Northern Russia, such as Murmansk. Four Halcyons were lost during this period.