The Mid-Atlantic Gap is a geographical term applied to an undefended area beyond the reach of land-based RAF Coastal Command antisubmarine (A/S) aircraft during the Battle of the Atlantic in the Second World War. It is frequently known as The Black Pit, as well as the Atlantic Gap, Air Gap, Greenland Gap, or just "the Gap". This resulted in heavy merchant shipping losses to U-boats. The gap was eventually closed in May 1943, as growing numbers of VLR Liberators (Very Long Range models) and escort carriers became available, and as basing problems were addressed.
RAF Coastal Command was a formation within the Royal Air Force (RAF). It was founded in 1936, when the RAF was restructured into Fighter, Bomber and Coastal Commands and played an important role during the Second World War. Maritime Aviation had been neglected in the inter-war period, due to disagreements between the Royal Navy (RN) and RAF over the ownership, roles and investment in maritime air power.
Anti-submarine warfare is a branch of underwater warfare that uses surface warships, aircraft, or other submarines to find, track, and deter, damage, or destroy enemy submarines.
The Battle of the Atlantic was the longest continuous military campaign in World War II, running from 1939 to the defeat of Nazi Germany in 1945, and was a major part of the Naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. It was at its height from mid-1940 through to the end of 1943.
RAF Coastal Command, when it was created in 1936, lb (205 kg) depth charge; that needed Wellingtons or Sunderlands. (The other aircraft capable of carrying it, the Avro Lancaster, was Bomber Command's crown jewel.)was given responsibility for A/S (or ASW) patrol. It was equipped only with small numbers of short-ranged aircraft, the most common being the Avro Anson (which was obsolescent by the start of World War II) and Vickers Vildebeest (which was obsolete); for a time, shortages of aircraft were so severe, "scarecrow patrols" using Tiger Moths were even employed. Bomber Command routinely got higher priority for the best, longest-ranged aircraft. Only as Bomber Command transitioned to four-engined aircraft did Coastal Command receive the castoffs, such as Vickers Wellingtons, which finally had adequate range for A/S patrol. Moreover, Coastal Command's motley assortment of Ansons, Whitleys, and Hampdens were unable to carry the standard 450
The Avro Anson is a British twin-engined, multi-role aircraft built by the aircraft manufacturer Avro. Large numbers of the type served in a variety of roles for the Royal Air Force (RAF), Fleet Air Arm (FAA), Royal Canadian Air Force (RCAF) and numerous other air forces before, during, and after the Second World War.
The Vickers Vildebeest and the similar Vickers Vincent were two very large two- to three-seat single-engined British biplanes designed and built by Vickers and used as light bombers, torpedo bombers and in army cooperation roles. First flown in 1928, it remained in service at the start of the Second World War, with the last Vildebeests flying against Japanese forces over Singapore and Java in 1942.
The de Havilland DH.82 Tiger Moth is a 1930s British biplane designed by Geoffrey de Havilland and built by the de Havilland Aircraft Company. It was operated by the Royal Air Force (RAF) and many other operators as a primary trainer aircraft. In addition to the type's principal use for ab-initio training, the Second World War saw RAF Tiger Moths operating in other capacities, including maritime surveillance and defensive anti-invasion preparations; some aircraft were even outfitted to function as armed light bombers.
Coastal Command's prize was the Consolidated Aircraft Liberator GR.I, commonly called the VLR Liberator or just VLR. The Liberator B.I proved too vulnerable for bombing missions over Europe, but had excellent range and payload, ideal for A/S patrol.Top priority for these was the U.S. Navy for reconnaissance operations in the Pacific, where their long legs were equally valuable, but where they generally carried out missions of lower priority than Coastal Command's.
The Consolidated Aircraft Corporation was founded in 1923 by Reuben H. Fleet in Buffalo, New York, the result of the Gallaudet Aircraft Company's liquidation and Fleet's purchase of designs from the Dayton-Wright Company as the subsidiary was being closed by its parent corporation, General Motors. Consolidated became famous, during the 1920s and 1930s, for its line of flying boats. The most successful of the Consolidated patrol boats was the PBY Catalina, which was produced throughout World War II and used extensively by the Allies. Equally famous was the B-24 Liberator, a heavy bomber which, like the Catalina, saw action in both the Pacific and European theaters.
Consolidated Liberator I was the service name of the first Consolidated B-24 Liberator four-engined bombers to see use with the Royal Air Force (RAF).
VLRs were of particular importance in times when Bletchley Park was unable to read Kriegsmarine Enigma (Ultra). September 1942, there was exactly one VLR of 120 Squadron overhead. Fifteen U-boats converged on ON 131, only to meet aircraft, and Coastal Command sank two, while in protecting ON 136, 120 Squadron's VLRs sank U-597 on 12 October 1942. Even then, VLRs proved invaluable in co-operation with shipborne "Huff Duff". Defending SC 104, VLRs guided by HF/DF drove off three shadowers in one day, 16 October. They bettered the performance on 29 October, for HX 212, driving off five, and seven on 6 November around SC 107. "...[T]he apparent inadequacy Newfoundland-based air support was highlighted by the early interception of SC 107 and the resultant bitter and costly battle." This led RAF to belatedly move a number of Coastal Command squadrons.When ON 127 was attacked by U-584 on 11
Bletchley Park is a nineteenth-century mansion and estate near Milton Keynes in Buckinghamshire, constructed during the years following 1883 for the English financier and politician Sir Herbert Samuel Leon in the Victorian Gothic, Tudor, and Dutch Baroque styles, on the site of older buildings of the same name. It has received latter-day fame as the central site for British codebreakers during World War II, although at the time of their operation this fact was a closely guarded secret. During the Second World War, the estate housed the British Government Code and Cypher School (GC&CS), which regularly penetrated the secret communications of the Axis Powers – most importantly the German Enigma and Lorenz ciphers; among its most notable early personnel the GC&CS team of codebreakers included Alan Turing, Gordon Welchman, Hugh Alexander and Stuart Milner-Barry.
The Kriegsmarine was the navy of Nazi Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war Reichsmarine (1919–1935) of the Weimar Republic. The Kriegsmarine was one of three official branches, along with the Heer (Army) and the Luftwaffe of the Wehrmacht, the German armed forces from 1933 to 1945.
The Enigma machine is an encryption device developed and used in the early- to mid-20th century to protect commercial, diplomatic and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the German military.
The paltry nine Liberator GR.Is operating over the Atlantic,members of 120 Squadron based in Iceland, were nevertheless a worry to Admiral Dönitz, BdU. As a measure of how valuable they were, after patrols off Canada were added in 1942, only one ship was lost in convoy. Even in mid-1942, Coastal Command only had two squadrons of Liberators and Fortresses, and at the first sign of Coastal Command's success against U-boats, Harris sought to have their aircraft used in attacking German cities.
Number 120 Squadron or No. CXX Squadron is a squadron of the Royal Air Force which was established as a Royal Flying Corps unit late in World War I, disbanded a year after the end of the war, then re-established as a RAF Coastal Command squadron during World War II. Although disbanded again a month after Victory in Europe Day, during and after World War II it operated almost continuously, with maritime patrol aircraft; most recently with the Hawker Siddeley Nimrod, based at RAF Kinloss in Scotland until the type's withdrawal in March 2010. The squadron was disbanded again the following year. No. 120 Squadron stood up again in April 2018 at RAF Lossiemouth and will become the first squadron to be equipped with the Boeing Poseidon MRA1 anti-submarine warfare (ASW) aircraft in 2019.
Karl Dönitz was a German admiral who played a major role in the naval history of World War II. Dönitz briefly succeeded Adolf Hitler as the head of state of Nazi Germany.
After Convoy SC 118, Professor Patrick M. S. Blackett, Director of the Admiralty's Operations Research section, made several proposals, including diverting VLRs from Bomber Command to Coastal Command. "Despite the strength of Blackett's case, the Admiralty (not to mention the Air Ministry, Bomber Command, and the Americans) believed for some time yet that it could not afford to reduce the heavy air offensive in the Bay of Biscay or to abandon the bombing of German bases by the RAF.""The number of VLR aircraft operating in the North Atlantic in February  was only 18, and no substantial increase was made until after the crisis of March." Nor were night air patrols, recognized as necessary, initiated until the autumn of 1943.
Convoy SC 118 was the 118th 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 January 1943 and were met by Mid-Ocean Escort Force Group B-2 consisting of V-class destroyers Vanessa and Vimy, the Treasury-class cutter Bibb, the Town-class destroyer Beverley, Flower-class corvettes Campanula, Mignonette, Abelia and Lobelia, and the convoy rescue ship Toward.
The Admiralty, originally known as the Office of the Admiralty and Marine Affairs, was the government department responsible for the command of the Royal Navy first in the Kingdom of England, later in the Kingdom of Great Britain, and from 1801 to 1964, the United Kingdom and former British Empire. Originally exercised by a single person, the Lord High Admiral (1385–1628), the Admiralty was, from the early 18th century onwards, almost invariably put "in commission" and exercised by the Lords Commissioners of the Admiralty, who sat on the Board of Admiralty.
Operations research, or operational research (OR) in British usage, is a discipline that deals with the application of advanced analytical methods to help make better decisions. Further, the term operational analysis is used in the British military as an intrinsic part of capability development, management and assurance. In particular, operational analysis forms part of the Combined Operational Effectiveness and Investment Appraisals, which support British defense capability acquisition decision-making.
Bomber Command did not refuse entirely to offer assistance against U-boats. From 14 January 1943 through May, they flew seven thousand sorties against the U-boat pens in Lorient, Brest, and St. Nazaire, at a cost of 266 aircraft and crews. They accomplished no damage to the pens nor the submarines within them. Coastal Command strength never reached 266 VLRs. [ citation needed ] Missions flown against German U-boat building yards had similarly disappointing results.
Aircraft also had an important indirect role, by preventing even the formation of wolf packs. They limited the places U-boats could attack in safety, and (by reducing the ability of shadowers to find and track convoys) made shipping harder to find, thereby reducing losses. This also helped escorts, by enabling them to deal with one U-boat at a time.Despite a willingness of RCAF aircraft to fly in (perennially bad) conditions off the Grand Banks Coastal Command would never have attempted, U-boats could trail convoys beginning very soon after departure from Halifax. Without ASV, the almost "perpetual fog of the Grand Banks also allowed pack operations to penetrate within a couple of hundred miles of Newfoundland, while aircraft patrolled harmlessly above", visual detection impossible.
A means of detecting surfaced submarines at night, when they were at their most vulnerable, recharging batteries, and felt most safe, was a top priority for Coastal Command. ASV gave it to them. The previous AI.II (Mark 2 Airborne Interception) radar became ASV.II (Air to Surface Vessel Mark 2) fitted in Coastal Command aircraft. Coastal Command priority for it, however, ranked behind Fighter Command's night fighter units. m, 176 MHz), mid-VHF band emissions meant however, that a submarine was usually lost in sea return before it came in visual range, at around a mile (1,850 m), by which time it was already diving. In response, the Leigh light was developed. Though it had to overcome Air Ministry indifference, and only entered service in June 1941, it proved very successful. This, however, required a large aircraft, such as the Wellington or Liberator, to carry the generator needed to power the light, and most of Coastal Command's aircraft were incapable of it, nor were Bomber Command inclined to turn over anything better. Moreover, the Germans developed Metox, which picked up ASV's radar pulses before it was able to detect a submarine at all, rendering it useless.ASV.II's 1½-metre wavelength (actually 1.7
The appearance of H2S three gigahertz-frequency (10 cm) radar changed that, and the combination of H2S (as ASV.III) and Leigh light proved lethal to U-boats. Harris, however, denied Coastal Command any allocation of H2S systems, claiming Bomber Command needed it to find targets, in preference to Gee and Oboe, while arguing Coastal Command might lose it to the Germans. Churchill backed him up. Marshal John Slessor, head of Coastal Command, countered Bomber Command also risked having it fall in enemy hands, and having the Germans produce a countermeasure against it, before Coastal Command ever got to use it. In the event, this was exactly what happened. The first ASV.III was fitted to a Coastal Command Wellington at Defford in December 1942, with twelve based at Chivenor by February 1943, while a copy of H2S was lost 2/3 February when a Stirling Pathfinder was shot down over the Netherlands, on only H2S's second operational use. Harris made similar objections to supplying the American-created 3 cm-wavelength H2X radar units to Coastal Command (which knew it as ASV.IV), again got higher priority, and again saw it fall into German hands, almost exactly a year later, in February 1944.
As Coastal Command predicted, the Germans captured the damaged H2S, which would have been next to impossible from a Coastal Command aircraft downed at sea, rather than over land, and Telefunken produced the Rotterdam Gerät (Rotterdam Device, named for where it was captured). Coastal Command's first ASV.III-equipped patrol took place over the Bay of Biscay 1 March. ASV.III made its first U-boat contact on the night of 17 March, but unfortunately the carrier Wellington suffered a malfunction of its Leigh Light and was unable to press home the attack. The first attack using the system occurred the next night. When ASV.III did enter service, German submariners, right up to Dönitz, began to mistakenly believe British aircraft were homing on emissions from the Metox receiver, which no longer gave warning. Meantime, German scientists were perfecting the Rotterdam Gerät to create a submersible version for U-boat defense, of the aviation-utilized FuG 350 Naxos radar detector for night fighters, the submersible version getting the FuMB7 Naxos U designation. While fragile, Naxos worked. However, it entered service the same day as the 10 GHz-emissions H2X (which Naxos could not detect) became operational in Coastal Command. Naxos was replaced by FuMB36 Tunis in May 1944, and was supplemented by Stumpf, what today would be called radar absorbent material, under the codename Schornsteinfeger ("Chimneysweep").
Just before the TRIDENT Conference, Admiral Ernest J. King got control of A/S aircraft from the Army Air Force, arranging a trade of B-24s for comparable types. May), while 120 Squadron's strength doubled. This still only put all of thirty-eight VLRs over the Mid-Atlantic Gap. The arrival of 25th Antisubmarine Wing, USAAF, with its medium-range B-24s (equipped with H2S, probably built by Canadians), made it possible to free up Coastal Command VLRs without it. The growth in numbers of escort carriers meant "a dramatic increase of USAAF Fortresses and medium-range Liberators" could be based in Newfoundland. 25h Wing flew over the Bay of Biscay, where they sank one U-boat before being redeployed to Morocco.This enabled Slessor to make a deal with him to "borrow" one squadron. After attacks on ONS 166, the number of VLRs in Newfoundland finally increased. "Canadians had been pressing hard for Liberators since autumn 1942, against British doubts that the RCAF could employ them effectively, while RCAF, for its part, opposed RAF taking over a job RCAF saw as its own. The commanding officer of 120 Squadron, Squadron Leader Bulloch, confirmed RCAF's ability, and in early March 1943, the number in Newfoundland belatedly increased (though it was not enough to constitute 10 Squadron, RCAF, before 10
Increasing availability of escort carriers reduced the hazard of the Gap. After a crisis in March which nearly had Churchill and the Admiralty abandon convoys altogether,the Mid-Atlantic Gap was finally closed in May 1943, when RCAF VLRs became operational in Newfoundland, by which time the Battle of the Atlantic was largely won.
The Leigh Light (L/L) was a British World War II era anti-submarine device used in the Battle of the Atlantic. It was a powerful carbon arc searchlight of 24 inches (610 mm) diameter fitted to a number of the British Royal Air Force's Coastal Command patrol bombers to help them spot surfaced German U-boats at night.
The Battle of the St. Lawrence involved marine and anti-submarine actions throughout the lower St. Lawrence River and the entire Gulf of Saint Lawrence, Strait of Belle Isle, Anticosti Island and Cabot Strait from May–October 1942, September 1943, and again in October–November 1944. During this time, German U-boats sank several merchant ships and four Canadian warships. There were several near shore actions involving the drop of German spies, or the attempted pick up of escaping prisoners of war. Despite the 23 ships lost, this battle marked a strategic victory for Canadian forces as ultimately they managed to disrupt U-boat activity, protect Canadian and Allied convoys, and intercept all attempted shore operations. This marked the first time that a foreign power had inflicted casualties in Canadian inland waters since the US incursions in the War of 1812.
Canadian Forces Base Gander, is a Canadian Forces base located in Gander, Newfoundland and Labrador. It is operated as an air force base by the Royal Canadian Air Force and is home to air/marine search and rescue operations that cover a vast swath of the western North Atlantic and southern Arctic. Its primary RCAF lodger unit is 9 Wing, commonly referred to as 9 Wing Gander.
No 311 (Czechoslovak) Squadron RAF was a Czechoslovak-manned bomber squadron of the Royal Air Force in the Second World War. It was the RAF's only Czechoslovak-manned medium and heavy bomber squadron. It suffered the heaviest losses of any Czechoslovak formation in the RAF. In the Second World War 511 Czechoslovaks serving in Allied air forces were killed. Of these 273 (53%) died while serving with 311 Squadron.
Royal Air Force St. Eval or RAF St. Eval was a strategic Royal Air Force station for the RAF Coastal Command during the Second World War. St Eval's primary role was to provide anti-submarine and anti-shipping patrols off the south west coast. Aircraft from the airfield were also used for photographic reconnaissance missions, meteorological flights, convoy patrols, air-sea rescue missions and protection of the airfield from the Luftwaffe.
ONS 18 and ON 202 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 September 1943, the first battle in the Kriegsmarine's autumn offensive, following the withdrawal from the North Atlantic route after Black May.
SC 143 was a North Atlantic convoy of the SC series which ran during the battle of the Atlantic in World War II. It was the second battle in the Kriegsmarine's autumn offensive in the North Atlantic.
Convoy ON 127 was a trade convoy of merchant ships during the second World War. It was the 127th of the numbered series of ON convoys Outbound from the British Isles to North America and the only North Atlantic trade convoy of 1942 or 1943 where all U-boats deployed against the convoy launched torpedoes. The ships departed Liverpool on 4 September 1942 and were met at noon on 5 September by the Royal Canadian Navy Mid-Ocean Escort Force Group C-4 consisting of the Canadian River-class destroyer Ottawa and the Town-class destroyer St. Croix with the Flower-class corvettes Amherst, Arvida, Sherbrooke, and Celandine. St. Croix's commanding officer, acting Lieutenant Commander A. H. "Dobby" Dobson RCNR, was the senior officer of the escort group. The Canadian ships carried type 286 meter-wavelength radar but none of their sets were operational. Celandine carried Type 271 centimeter-wavelength radar. None of the ships carried HF/DF high-frequency direction finding sets.
RAF Thorney Island is a former Royal Air Force station located 6.6 miles (10.6 km) west of Chichester, West Sussex, England and 7.1 miles (11.4 km) east of Portsmouth, Hampshire.
No. 248 Squadron was a squadron of the Royal Air Force, active immediately after World War I, and again during World War II.
RAF Coastal Command was a formation within the Royal Air Force (RAF). Founded in 1936, it was to act as the RAF maritime arm, after the Fleet Air Arm became part of the Royal Navy in 1937. Naval aviation was neglected in the inter-war period, 1919–1939, and as a consequence the service did not receive the resources it needed to develop properly or efficiently. This continued until the outbreak of the Second World War, during which it came to prominence. Owing to the Air Ministry's concentration on RAF Fighter Command and RAF Bomber Command, Coastal Command was often referred to as the "Cinderella Service", a phrase first used by the First Lord of the Admiralty at the time A V Alexander.
Eastern Air Command was the part of the Royal Canadian Air Force's Home War Establishment responsible for air operations on the Atlantic coast of Canada during the Second World War. It played a critical role in anti-submarine operations in Canadian and Newfoundland waters during the Battle of the Atlantic. Eastern Air Command also had several fighter squadrons and operational training units under its umbrella.
Convoy HX 212 was the 212th of the numbered series of World War II HX convoys of merchant ships from HalifaX to Liverpool. The ships departed New York City on 18 October 1942 and were met on 23 October by Mid-Ocean Escort Force Group A-3 consisting of the United States Coast Guard Treasury-class cutter USCGC Campbell, the destroyer Badger and the Flower-class corvettes Dianthus, Rosthern, Trillium, Dauphin, Alberni, Summerside and Ville de Quebec. The first five escorts had worked together previously, but the last three corvettes were attached to the convoy only for passage to the eastern Atlantic in preparation for assignments on Operation Torch. Summerside was the only escort equipped with modern Type 271 centimeter-wavelength radar.
VPB-103 was a Patrol Bombing Squadron of the U.S. Navy. The squadron was established as Bombing Squadron 103 (VB-103) on 15 March 1943, redesignated as Patrol Bombing Squadron 103 (VPB-103) on 1 October 1944 and disestablished on 31 August 1945.
The Army Air Forces Antisubmarine Command was formed in the fall of 1942 to establish a single command to control antisubmarine warfare (ASW) activities of the Army Air Forces (AAF). It was formed from the resources of I Bomber Command, which had been carrying out the antisubmarine mission in the Atlantic and Caribbean since the Attack on Pearl Harbor due to the lack of long range Naval aviation in that area.
Radar, Air-to-Surface Vessel, or ASV radar for short, is a classification used by the Royal Air Force (RAF) to refer to a series of aircraft-mounted radar systems used to scan the surface of the ocean to locate ships and surfaced submarines. The first examples were developed just before the opening of World War II and they have remained a major instrument on patrol aircraft since that time. It is part of the wider surface search radar classification, which includes similar radars in ground and ship mountings.