The Flower-class corvette was a British class of 294 corvettes used during World War II by the Allied navies particularly as anti-submarine convoy escorts in the Battle of the Atlantic. Royal Navy ships of this class were named after flowers.
HMS Gladiolus was a Flower-class corvette of the Royal Navy, the first ship of her class.
The first USS Twiggs (DD–127) was a Wickes-class destroyer in the United States Navy during World War I. She was named for Major Levi Twiggs. She was later transferred to the Royal Navy, as HMS Leamington and to the Soviet Navy as Zhguchy, before returning to Britain to star in the film The Gift Horse, which depicts the St. Nazaire Raid.
This is a timeline for the Battle of the Atlantic (1939–1945) in World War II.
The first USS McCook (DD-252) was a Clemson-class destroyer in the United States Navy. Entering service in 1919, the ship had a brief active life before being placed in the reserve fleet. Reactivated for World War II, the ship was transferred to the Royal Navy and then to the Royal Canadian Navy and renamed HMCS St. Croix. Assigned as a convoy escort in the Battle of the Atlantic, St. Croix was torpedoed and sunk on 20 September 1943.
The Mediterranean U-boat Campaign lasted from about 21 September 1941 to 19 September 1944 during the Second World War. Malta was an active British base strategically located near supply routes from Europe to North Africa. Axis supply convoys across the Mediterranean Sea suffered severe losses, which in turn threatened the fighting ability of the Axis armies in North Africa. The Allies were able to keep their North African armies supplied. The Kriegsmarine tried to isolate Malta but later it concentrated its U-boat operations on disrupting Allied landing operations in southern Europe.
During the Battle of the Atlantic, British merchant shipping was formed into convoys for protection against German submarine attack. In March 1943 convoys HX 229 and SC 122 were the focus of the largest convoy battle of the war. Kriegsmarine tactics against convoys employed multiple-submarine wolfpack tactics in nearly simultaneous surface attacks at night. Patrolling aircraft restricted the ability of submarines to converge on convoys during daylight. The North Atlantic winters offered the longest periods of darkness to conceal surfaced submarine operations. The winter of 1942–43 saw the largest number of submarines deployed to the mid-Atlantic before comprehensive anti-submarine aircraft patrols could be extended into that area.
The River class was a class of fourteen destroyers of the Royal Canadian Navy (RCN) that served before and during the Second World War. They were named after Canadian rivers.
Convoy SC 121 was the 121st of the numbered series of World War II Slow Convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. The ships departed New York City 23 February 1943; and were met by the Mid-Ocean Escort Force Group A-3 consisting of the United States Coast Guard (USCG) Treasury-class cutter USCGC Spencer, the American Wickes-class destroyer USS Greer, the British and Canadian Flower-class corvettes HMS Dianthus, HMCS Rosthern, HMCS Trillium and HMCS Dauphin and the convoy rescue ship Melrose Abbey. Three of the escorts had defective sonar and three had unserviceable radar.
Convoy SC 107 was the 107th of the numbered series of World War II Slow Convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. The ships departed New York City on 24 October 1942 and were found and engaged by a wolfpack of U-boats which sank fifteen ships. It was the heaviest loss of ships from any trans-Atlantic convoy through the winter of 1942–43. The attack included one of the largest non-nuclear man-made explosions in history, when U-132 torpedoed ammunition ships SS Hobbema and SS Hatimura - both were sunk, one exploded, with the German submarine also being destroyed in the explosion.
Convoy SC 42 was the 42nd of the numbered series of World War II Slow Convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. SC 42 was attacked over a three night period in September 1941, losing 16 ships sunk and 4 damaged. This was the worst Allied loss following the attack on convoy SC 7 the previous year. Two attacking U-boats were destroyed.
Convoy SC 130 was a North Atlantic convoy which ran during the battle of the Atlantic in World War II. It was the 130th of the numbered series of Slow Convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. SC 130 was one of several convoy battles that occurred during the crisis month of May 1943.
Mid-Ocean Escort Force (MOEF) referred to the organisation of anti-submarine escorts for World War II trade convoys between Canada and Newfoundland, and the British Isles. The allocation of United States, British, and Canadian escorts to these convoys reflected preferences of the United States upon their declaration of war, and the organisation persisted through the winter of 1942–43 despite withdrawal of United States ships from the escort groups. By the summer of 1943, United States Atlantic escorts were focused on the faster CU convoys and the UG convoys between Chesapeake Bay and the Mediterranean Sea; and only British and Canadian escorts remained on the HX, SC and ON convoys.
ONS 20 and ON 206 were North Atlantic convoys of the ONS/ON series which ran during the battle of the Atlantic in World War II. They were the subject of a major U-boat attack in October 1943, the third battle in the Kriegsmarine's autumn offensive.
HMS Peony was a Flower-class corvette of the Royal Navy. In 1943 she was transferred to the Royal Hellenic Navy as RHNS Sachtouris, serving throughout World War II and the Greek Civil War. She was returned to the Royal Navy in 1951 and scrapped in April 1952.
ON 207 was a North Atlantic convoy of the ONS/ON series which ran during the Battle of the Atlantic in World War II. It was the subject of a major U-boat attack in October 1943, the fourth battle in the German autumn offensive.
An Escort Group consisted of several small warships organized and trained to operate together protecting trade convoys. Escort groups were a World War II tactical innovation in anti-submarine warfare by the Royal Navy to combat the threat of the Kriegsmarine's "wolfpack" tactics. Early escort groups often contained destroyers, sloops, naval trawlers and, later, corvettes of differing specifications lacking the ability to maneuver together as a flotilla of similar warships, but rigorously trained in anti-submarine tactics to use teamwork emphasizing the unique sensors, weapons, speed, and turning radius of each ship. The development of these 'escort groups' proved an effective means of defending shipping convoys through the Battle of the Atlantic.
Convoy HX 90 was a North Atlantic convoy of the HX series which ran during the Battle of the Atlantic in World War II.
German submarine U-568 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She conducted five patrols, sinking one merchant ship, two warships, and severely damaging another warship. On 28 May 1942, she was depth charged and sunk in the Mediterranean Sea; all hands survived.
Convoy ON-153 was the 153rd of the numbered series of ON convoys of merchant ships Outbound from the British Isles to North America. The World War II convoy departed Liverpool on 11 December 1942 and was met on 12 December by Mid-Ocean Escort Force Group B-7. Two merchant ships and the escort group leader were sunk in a North Atlantic battle with U-boat Wolf pack Raufbold before reaching the Western Ocean Meeting Point (WOMP) where the Western Local Escort Force assumed responsibility for the convoy on 23 December. Surviving ships reached New York City on 31 December.
Kriegsmarine 
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