HMASSwan in 1945
Class overview
Builders	Chatham Dockyard Cockatoo Docks & Engineering Co. Devonport Dockyard R. & W. Hawthorn, Leslie & Co.
Operators	Royal Navy (8)  Royal Australian Navy (4)  Royal Indian Navy (1)
Preceded by	Shoreham class
Succeeded by	Kingfisher class
Cost	£220,000 for Australian ships
Built	1933–1940
In commission	1934–1966
Completed	13
Lost	4
Preserved	1
General characteristics RN Ships[1]
Displacement	RN ships : 990long tons (1,006 t) standard 1,480–1,510 long tons (1,504–1,534 t)
Length	266 ft 3 in (81.15 m)o/a
Beam	36 ft (11.0 m)
Draught	RN ships : 9 ft 11 in (3.02 m) – 10 ft 1 in (3.07 m)
Propulsion	Parsons gearedsteam turbines 2 Admiralty 3-drumwater-tube boilers 2 shafts 2,000 shp (1,500 kW)
Speed	16.5knots (30.6 km/h; 19.0 mph)
Complement	100
Armament	2 ×4.7 in (120 mm) Mark IX guns 1 ×QF 3-inch 20 cwt anti-aircraft gun 4 ×3-pounder guns 15–90depth charges

TheGrimsby class were a class of 13sloops laid down between 1933 and 1940. Of these, eight were built in the United Kingdom for theRoyal Navy, four in Australia for theRoyal Australian Navy and one for theRoyal Indian Navy. Main armament was initially two 4.7-inch (120 mm) guns for RN ships and three 4-inch (100 mm) for Australian ships, but armament varied considerably between ships, and was increased later.

Losses duringWorld War II wereGrimsby,Indus,Yarra, andParramatta. Some survivors of this class served into the 1960s. One ship,Wellington, is preserved as the headquarters of theHonourable Company of Master Mariners.

The Royal Navy started to build replacements for theFlower-class andHunt-classsloops of theFirst World War, when the two vessels of theBridgewater class were laid down in 1928, with the similar four-shipHastings class laid down in 1929 and the eight ships of theShoreham class being laid down in 1929–31. All of these ships were designed to combine theconvoy-escort role of the Flower class with theminesweeping duties of the Hunt class, being fitted with equipment for both roles. By 1932, however, it became clear that what was needed was ships dedicated to a single role. Development therefore began of theHalcyon-classminesweepers as a cheaper mass-production minesweeper, while a new class of sloops would be built that was more closely matched to the escort role.^[2][3]

The new class of escort sloops, theGrimsby class, had a heavier gun armament than its predecessors, with two4.7-inch (120 mm) Mark IX guns mounted fore and aft replacing the 4-inch (102 mm) guns of the earlier ships. As the 4.7-inch guns were low-angle guns, not suited to anti aircraft use, a singleQF 3-inch 20 cwt anti-aircraft gun was mounted in "B" position. Four 3-pounder saluting guns completed the ships' gun armament.^[1][4] The ship was powered by two gearedsteam turbines driving two shafts, fed by twoAdmiralty 3-drum boilers. This machinery produced 2,000shaft horsepower (1,500 kW) and could propel the ships to a speed of 16.5knots (30.6 km/h; 19.0 mph).^[1]

Eight ships of the class were built for the Royal Navy, being laid down between 1933 and 1935 and completing between 1934 and 1936. The last two ships built for the Royal Navy,HMS Aberdeen andHMS Fleetwood had differing armaments, withAberdeen replacing the 4.7 and 3-inch guns with two4-inch anti-aircraft guns, and adding a quadruple.50-inch anti-aircraft machine gun mount, whileFleetwood had a main gun armament of two twin 4-inch anti-aircraft mounts, with a short-range anti-aircraft armament of four .50 in machine guns.^[5]

TheRoyal Australian Navy also adopted theGrimsby class, with two ships being laid down in 1934–35 and completed in 1935–36, with two more ships laid down in 1938–39 and completed in 1940. The first two ships were armed with three single 4-inch anti-aircraft guns, while the third and fourth ships having one twin and one-single 4-inch mount, with short-range armament a quadruple machine gun mount in all four ships.^[6]

The armament of most of the class was reinforced during theSecond World War, with several gaining additional 4-inch guns, with the close in anti aircraft armament being supplemented by the addition ofOerlikon 20 mm cannon. The ships'depth charge complement increased from 15 at the start of the war to 40 for Australian ships and up to 90 for Royal Navy ships, while several ships were also refitted with aHedgehog anti-submarine projector.^[1]

Wikimedia Commons has media related toGrimsby class sloop.

• List of corvette and sloop classes of the Royal Navy
• List of Royal Australian Navy ships

• Campbell, N. J. M. (1980). "Great Britain (including Empire Forces)". In Chesneau, Roger (ed.).Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. pp. 2–85.ISBN 0-85177-146-7.
• Friedman, Norman (2008).British Destroyers & Frigates: The Second World War and After. Barnsley, UK: Seaforth Publishing.ISBN 978-1-84832-015-4.
• Gillet, Ross (1977).Warships of Australia. Graham, Colin (illus.). Adelaide, Australia: Rigby Limited.ISBN 0-7270-0472-7.
• Hague, Arnold (1993).Sloops: A History of the 71 Sloops Built in Britain and Australia for the British, Australian and Indian Navies 1926–1946. Kendal, UK: World Ship Society.ISBN 0-905617-67-3.
• Lenton, H. T. (1998).British & Empire Warships of the Second World War. Annapolis, Maryland: Naval Institute Press.ISBN 1-55750-048-7.
• Rohwer, Jürgen (2005).Chronology of the War at Sea 1939–1945: The Naval History of World War Two (Third Revised ed.). Annapolis, Maryland: Naval Institute Press.ISBN 1-59114-119-2.
• Shores, Christopher; Massimello, Giovanni; Guest, Russell (2012).A History of the Mediterranean Air War 1940–1945: Volume One: North Africa: June 1940 – January 1942. London: Grub Street.ISBN 978-1-908117-07-6.

• HQS Wellington, home of the Honourable Company of Master Mariners

• Grimsby-class sloops
• Military history of Grimsby
• Ship classes of the Royal Navy
• Sloop classes

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