The Kanalkampf (Channel Battle) was the German term for air operations by the Luftwaffe against the Royal Air Force (RAF) over the English Channel in July 1940, beginning the Battle of Britain during the Second World War. By 25 June, the Allies had been defeated in Western Europe and Scandinavia. Britain had rejected peace overtures and on 16 July, Adolf Hitler issued Directive 16 to the Wehrmacht (German armed forces), ordering preparations for an invasion of Britain, under the codename Unternehmen Seelöwe (Operation Sea Lion).
The Germans needed air superiority over southern England for the invasion; the Luftwaffe was to destroy the RAF and protect the cross-channel invasion from the Royal Navy. To commence the destruction of RAF Fighter Command, the Luftwaffe attacked convoys in the Channel. Historians differ somewhat about the dates of the Battle of Britain and British histories usually treat 10 July as the beginning. British and German writers and historians acknowledge that air battles were fought over the Channel between the Battle of France and Britain; systematic German attacks against British coastal targets and convoys began on 4 July. During the Kanalkampf, the Luftwaffe received modest support from shore artillery and the Schnellboote (S-boats, E-Boats to the British) of the German Navy (Kriegsmarine).
Fighter Command could not guarantee the defence of the convoys; the Germans sank several British and neutral ships and shot down a considerable number of British fighters. The Royal Navy was forced to suspend the sailing of large convoys in Channel waters and close it to ocean-going vessels until more protection could be arranged, which took several weeks. On 1 August, Hitler issued Directive 17, extending Luftwaffe operations to the British mainland and RAF-related targets. On 13 August (Adlertag, Eagle Day) the main air offensive against the RAF began. The Kanalkampf had drawn out Fighter Command as intended and convoy attacks continued for several more days. Both sides had suffered losses but the Luftwaffe had failed to defeat on Fighter Command; the Luftwaffe had yet to gain air superiority for Operation Sea Lion.
The historian Williamson Murray (1983) regarded the Channel battles as inconclusive; Peter Smith (2007) wrote that the battles could be described as a German victory of sorts. In 2000, Stephen Bungay wrote that in early August the Channel was German by day but that fact did not threaten Fighter Command. Bungay wrote that the Luftwaffe had to advance well beyond the Channel to win an aerial campaign and that Hugo Sperrle, the commander of Luftflotte 3, was already alarmed at German losses. Albert Kesselring, the Luftflotte 2 commander, could ill-afford losses at the rate suffered in July 1940 either.
The Kanalkampf (Channel Battle) was the German term for air operations by the Luftwaffe against the Royal Air Force (RAF) over the English Channel in July 1940, beginning the Battle of Britain during the Second World War. By 25 June, the Allies had been defeated in Western Europe and Scandinavia. Britain had rejected peace overtures and on 16 July, Adolf Hitler issued Directive 16 to the Wehrmacht (German armed forces), ordering preparations for an invasion of Britain, under the codename Unternehmen Seelöwe (Operation Sea Lion).
The Germans needed air superiority over southern England for the invasion; the Luftwaffe was to destroy the RAF and protect the cross-channel invasion from the Royal Navy. To commence the destruction of RAF Fighter Command, the Luftwaffe attacked convoys in the Channel. British and German writers and historians acknowledge that air battles were fought over the Channel between the Battle of France and Britain; systematic German attacks against British coastal targets and convoys began on 4 July. During the Kanalkampf, the Luftwaffe received modest support from shore artillery and the Schnellboote (S-boats, E-Boats to the British) of the German Navy (Kriegsmarine). Historians differ somewhat about the dates of the Battle of Britain and British histories usually treat 10 July as the beginning.
Fighter Command could not guarantee the defence of the convoys; the Germans sank several British and neutral ships and shot down a considerable number of British fighters. The Royal Navy was forced to suspend the sailing of large convoys in Channel waters and close it to ocean-going vessels until more protection could be arranged, which took several weeks. On 1 August, Hitler issued Directive 17, extending Luftwaffe operations to the British mainland and RAF-related targets. On 13 August (Adlertag, Eagle Day) the main air offensive against the RAF began. The Kanalkampf had drawn out Fighter Command as intended and convoy attacks continued for several more days. Both sides had suffered losses but the Luftwaffe had failed to defeat on Fighter Command; the Luftwaffe had yet to gain air superiority for Operation Sea Lion.
The historian Williamson Murray (1983) regarded the Channel battles as inconclusive; Peter Smith (2007) wrote that the battles could be described as a German victory of sorts. In 2000, Stephen Bungay wrote that in early August the Channel was German by day but that fact did not threaten Fighter Command. Bungay wrote that the Luftwaffe had to advance well beyond the Channel to win an aerial campaign and that Hugo Sperrle, the commander of Luftflotte 3, was already alarmed at German losses. Albert Kesselring, the Luftflotte 2 commander, could ill-afford losses at the rate suffered in July 1940 either.
Background
Fall of France
On 2 July 1940, in the aftermath of the French surrender, Adolf Hitler decided that an invasion of Britain could only begin after achieving air superiority. On 12 July he outlined his reasoning: aerial domination over the invasion area and its sea approaches was necessary to compensate for the weakness of the Kriegsmarine. Hitler issued a directive on 16 July, ordering the Luftwaffe to prevent all air attacks on the invasion force, destroy British coast defences at the landing points and break the resistance of the British army. The campaign did not start against the RAF until August. In the intervening period, the Luftwaffe undertook its third big operational move in two months. The first had seen it push forward its Air Fleets into the Low Countries and the second into southern France. Now it was expanded into northern France and Belgium, along the English Channel coast. It took time to establish the signal system in France owing to a shortage of trained staff officers while the units replenished after losses through the Ergänzungsverbände (supplemental formations).
The Luftwaffe and army had to repair the French and Belgian infrastructure damaged during the Battle of France. The army rebuilt bridges to supply forward bases and the Luftwaffe the former Allied air bases. This often meant short-range dive bombers and fighters were sent to forward airfields which were urgently in need of electricity and running water for personnel. Upon the French surrender the Luftwaffe supply system was breaking down. On 8 July only 20 of the 84 railway tanks with aviation fuel had reached the main depot at Le Mans. The Transportgruppen (transport groups) of supply aircraft could not cope and barely kept their own units running. Preparations continued at a glacial pace, since the men responsible for the organisation of German air power and its efficient transfer to the Channel, were enjoying the fruits of their new assignments in Paris. Senior staff members were distracted by victory parades and promotions, including Göring who was promoted to Reichsmarschall. During the Kanalkampf the Germans assembled powerful air forces to attack convoys in the Channel but it took about forty days after the French capitulation for the Luftwaffe to begin its assault on the Britain.
German strategy
Dispersion of effort was contrary to the German concept of Schwerpunktprinzip (concentration principle) and the Luftwaffe did not operate over Britain in force until after the Armistice of 22 June 1940. When German bomber crews flew over Britain they did so at night; sorties were recorded in May and June 1940. When Britain rejected Hitler's demands, the Luftwaffe undertook preparations to neutralise the country and end the war. Luftflotte 2 (Air Feet 2) and Luftflotte 3 (Air Feet 3) were transferred to France and Belgium. In June and July, sporadic attacks were carried out at night, inland and along the east and southern coasts to keep civilians awake and to damage morale. The attacks were ill-directed and German intentions were not clear to the British.
Night operations gave the Luftwaffe experience in using night navigation equipment, like the Knickebein (crooked leg) night-bombing guidance system. By taking bearings and cross-bearings in the Battle of the Beams on German medium-wave transmitters, aircraft could find their position sufficiently accurately to make the discovery of landmarks easy. On the night of 6/7 June, the first Luftwaffe bomb to fall on Greater London was dropped on at Addington and small raids continued through the month. Thirteen airfields, sixteen factories and fourteen ports were attacked to little effect. Flying at low altitudes, the German bombers could be illuminated by searchlights. Two were shot down in June by anti-aircraft guns. The bombers began to fly higher to escape anti-aircraft fire.
Operations against British sea communications did not appeal to Reichsmarschall Hermann Göring, in his view, the Luftwaffe was not prepared for naval warfare and this strategy was tantamount to blockade, which was put in effect against Britain from 18 July. The blockade required the co-operation of the Luftwaffe with the Kriegsmarine (German navy) but Göring ensured air assistance was not forthcoming. Göring loathed the navy and its Commander-in-Chief Großadmiral Erich Raeder. In Göring's eyes, Raeder and the navy represented the bourgeois clique of German society the National Socialist revolution had pledged to eliminate. The Reichsmarschall consistently refused to accept the navy's calls for assistance in the war against the Royal Navy and British commerce throughout the conflict. All of the directives issued to the Luftwaffe by the Oberkommando der Luftwaffe (OKL—High Command of the Air Force) or Oberkommando der Wehrmacht (OKW—Supreme High Command of the Armed Forces), stated that sea attacks on warships and shipping must take second place to "military objectives"; the OKW did not alter this view until February 1941.
Göring and OKL intended to strike at the RAF and establish air superiority, if not air supremacy, made clear in Göring's 30 June directive. Göring hoped that a victory in the air battle would preclude an invasion of Britain by persuading the Churchill Government to negotiate peace with Germany. This was most evident during a conference in Berlin on 31 July when Hitler outlined Operation Sea Lion and its objectives. No Luftwaffe representative was present and Göring ignored summonses by Hitler to conferences aimed and inter-service co-operation. While the army and navy made tentative steps towards an amphibious assault, OKL was engaged in an internal debate about which targets should be attacked to attain control of the air as quickly as possible. Though Göring's directive mentioned cutting off British supplies, he referred to shipping. On 11 July, the Chief of the Luftwaffe General Staff, Hans Jeschonnek, ordered that coastal shipping should be attacked as a prelude to the main battle against the RAF and its infrastructure. The Luftflotte commanders, Hugo Sperrle and Albert Kesselring, had already begun coastal operations as the indecision of OKL had left them with little else to do.
OKL decided to pursue coastal targets because these were easier to find than targets inland. The Royal Air Force (RAF) would suffer a higher degree of attrition in comparison to fighting over land, since they would be fighting over an area which would be strongly contested by the bulk of its opponent. RAF pilots that abandoned their aircraft over water would face the same peril as their German counterparts; the RAF lacked an air-sea rescue service, unlike the Luftwaffe. It was also desirable to eliminate the English Channel as a supply route to Greater London via the Thames Estuary. Shipping could travel north of Scotland but it would slow the supply of materials for the British war effort. Dowding preferred the navy to re-route its convoys to ease the burden on his forces. German intentions were exploitative at first but evolved into dual purpose operations—to close the Channel to shipping and draw Fighter Command into combat.
Luftflotte 2 and Luftflotte 3 sent small numbers of bombers against British sea communications, attacking ships and laying mines. In July, the Luftwaffe transferred air units to the European coast from Hamburg to Brest in Brittany on the French Atlantic coast. By 17 July, the two air fleets had reached their intended strength for operations against southern England and the Midlands, with 1,200 medium bombers, 280 dive-bombers, 760 single-engine fighters, 220 twin-engine fighters, 50 long-range reconnaissance aircraft (90 of the medium bombers could fly bomber-reconnaissance sorties against shipping and ports) and 90 short-range reconnaissance aircraft. Luftflotte 5 in Norway, with 130 medium bombers, 30 twin-engine fighters and 30 long-range reconnaissance aircraft, exerted an indirect effect on the Kanalkampf, by making the RAF keep fighters in the north.
Air Ministry and Admiralty
Relations between the Air Ministry, War Office and the Admiralty had been strained since the establishment of the RAF on 1 April 1918. In the early 1920s, the three services competed for resources, influence and the right of the RAF to exist. The War Office and the Navy tried to abolish the RAF and regain control of army and naval aviation. By 1940, service rivalry had diminished with the return of the Fleet Air Arm to Navy control but the Air Ministry remained suspicious of the intentions of the Army. Fighter Command cooperated with the Navy during the Battle of Dunkirk when the RAF provided fighter cover for the embarkation of the British Expeditionary Force (BEF), which was costly for both services. By 1 June, the RAF reduced its effort to conserve its fighters; a minesweeper, a transport and three destroyers were sunk and two destroyers were damaged in its absence.
The lack of air cover was not uncommon and the RAF believed itself to be more successful in battle, over-claiming German losses by 4:1. Of the 156 German aircraft lost in the west, about 35 were shot down by fire from naval vessels leaving 102, aside from other causes, likely to have been shot down by the RAF against 106 British losses. Co-operation was hindered by Fighter Command retaining rigid control of its units. The Admiralty complained that RAF methods did not permit direct contact by RAF operational staff liaising with the naval command. Time was lost and the fluidity of aerial warfare meant that RAF aircraft came into action at the wrong time or place, often in numbers too small to defend the evacuation ships.
Vice Admiral Max Horton, the Commander-in-Chief, Dover, was responsible for organising the evacuation (Operation Dynamo) and asked to meet Dowding in late June, to prevent the operational difficulties occurring again. Horton was told to put his complaints on paper and send them to Dowding, with a copy to the Air Ministry and they never met. It was felt by the Admiralty that the RAF was fighting a separate war, with little consideration given to joint operations. The protection of shipping was controversial in the RAF, since it required a substantial commitment of fighters. On average the twelve convoys passing through the Channel waters each day needed cover every day and roughly one-third were attacked. It became an immediate burden to 11 Group (Air Officer Commanding [AOC] Keith Park) which was responsible for defending south-east England. The employment of convoys from the Suffolk coast to Lyme Bay negated the value of using the sea as a protective shield because the location gave tactical advantages to the attacker. Coastal radar could give little advance warning of incoming raids since the proximity of Luftwaffe airbases, meant that German aircraft could attack and quickly withdraw, making interception difficult. Standing patrols over convoys could compensate but this exhausted pilots and handed the tactical initiative to the Germans.