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— CH. 1 · STRATEGIC ORIGINS AND OBJECTIVES —

Kanalkampf

~6 min read · Ch. 1 of 6
6 sections

  • On the 16th of July 1940, Adolf Hitler issued Directive 16 to the German armed forces. The directive ordered preparations for an invasion of Britain under the codename Operation Sea Lion. Germany needed air superiority over southern England to protect the cross-channel invasion from the Royal Navy. The Luftwaffe aimed to destroy the RAF and prevent British resistance at landing points. This strategic goal required clearing the skies above the English Channel first. By the 25th of June, the Allies had been defeated in Western Europe and Scandinavia. Britain rejected peace overtures after the fall of France. The Germans began attacking convoys in the Channel to commence the destruction of RAF Fighter Command. Historians differ on when the Battle of Britain officially started, with some citing the 10th of July as the beginning date. Systematic German attacks against British coastal targets and convoys began on the 4th of July. The campaign did not start against the RAF until August, but preliminary operations were already underway.

  • Relations between the Air Ministry, War Office, and Admiralty had been strained since the establishment of the RAF on the 1st of April 1918. In the early 1920s, the three services competed for resources and influence regarding army and naval aviation control. By 1940, service rivalry had diminished with the return of the Fleet Air Arm to Navy control. However, the Air Ministry remained suspicious of Army intentions. Fighter Command cooperated with the Navy during the Battle of Dunkirk when providing cover for the British Expeditionary Force. This cooperation was costly for both services. On the 1st of June, the RAF reduced its effort to conserve fighters while a minesweeper, transport, and three destroyers were sunk. Vice Admiral Max Horton, Commander-in-Chief at Dover, asked to meet Dowding in late June to prevent operational difficulties. He was told to put complaints on paper and send them to Dowding without meeting face-to-face. The Admiralty felt the RAF fought a separate war with little consideration for joint operations. Protection of shipping required substantial fighter commitment that exhausted pilots. Standing patrols over convoys handed tactical initiative to German forces. Coastal radar gave little advance warning due to proximity of airbases.

  • Decryption efforts by Bletchley Park revealed German preparations for operations against Britain from Belgium and Holland. Most bombers would be ready by the 8th of July according to decrypts from late June. Photographic reconnaissance showed runways being extended but found no invasion shipping in Channel ports. Codebreakers gleaned strategic intelligence from tactical signals sent in lower-grade codes by flying units. The British estimate of German bombers was reduced from higher numbers to between 1,500 and 1,700 by the 6th of July. Changes in methods communicated via landline or inferred from Enigma decrypts. Voice transmissions collected by listening stations around Britain provided height and formation details. These messages were collated with reports from Radar Direction Finding systems. Coastal radar looked out to sea but tracking became difficult when raiders crossed the coast. At night, British defenses remained rudimentary until early 1941. There was no specialist night fighter or reliable aircraft interception radar available at the time. RAF Y-stations reported separately to Enigma but could give warnings of German sightings of coastal convoys. This system occasionally alerted Fighter Command to formations assembling beyond RDF range. It helped discriminate between fighters and bombers while hearing orders passed to fighter escorts.

  • On the 2nd of July, Ju 87 dive-bombers of Sturzkampfgeschwader 2 attacked Convoy OA 177G south-east of Start Point, Devon. The British troopship Aeneas moving at ten knots was bombed, killing twenty-one men. Twelve survivors were rescued by the destroyer HMS Walker before the ship sank off Portland Bill. StG 2 also damaged the SS Baron Ruthven causing five casualties. On the 4th of July, the Luftwaffe attacked Portland harbor where Foylebank gunners failed to man weapons properly. One hundred four bombs hit the vessel which had been sent to protect the harbor on the 9th of June. Foylebank's tender sank immediately with one hundred seventy-six sailors killed or dying of wounds. The attack caused the worst ever loss of life on British military personnel based in Britain that day. Churchill submitted an Action This Day memo to the Admiralty regarding the disaster. On the 10th of July, a convoy named Bread sailed from the Thames Estuary rounded North Foreland at 10:00. Twenty-six Do 17s from I./KG 2 and three Bf 110s from ZG 26 engaged British fighters over the convoy. A dogfight involving around one hundred aircraft broke out when formations met. No ships were hit despite one hundred fifty bombs dropped during the engagement. Sixty-four Squadron Spitfires arrived later to harass Germans all the way back to French coast.

  • Continuous patrols over the sea exhausted pilots and slowed training of replacements before August. Eighty percent of operations occurred over water in poor weather conditions. Fighter Command lost a disproportionate number of experienced squadron leaders and flight commanders. Growing numbers of Hurricanes in RAF Maintenance Command meant each squadron was allotted eighteen fighters. Two flights of six operated while six remained in reserve for training and maintenance. On the 19th of July, nine convoys were at sea as German aircraft scouted shipping lanes early morning. Four Defiants from 141 Squadron were shot down on first pass by Bf 109s attacking from rear below. Another crashed into cloud cover seeking escape. The surviving Defiants saw very little action for remainder of battle. This day marked worst defeat of Fighter Command losing ten aircraft against four from Luftwaffe. Although losses numerically small, British fighters defeated in each engagement. German pilots more experienced operating greater numbers with flexible tactics. Finger-four formation used by German fighter pilots proved far more effective than tight British formations. All German pilots could scan air while British relied on formation leader keeping station.

  • Historian Williamson Murray regarded Channel battles as inconclusive in his 1983 analysis. Peter Smith wrote in 2007 that battles could be described as German victory of sorts. Stephen Bungay stated in 2000 that early August the Channel was German by day but fact did not threaten Fighter Command. Bungay argued Luftwaffe had to advance well beyond Channel to win aerial campaign. Hugo Sperrle commander of Luftflotte 3 already alarmed at German losses during July operations. Albert Kesselring Luftflotte 2 commander could ill-afford losses suffered rate in July 1940 either. Both sides suffered losses yet Luftwaffe failed to defeat RAF Fighter Command. Air superiority remained elusive for Operation Sea Lion preparations. Convoy attacks continued several days after main offensive began Eagle Day on the 13th of August. Systematic German attacks against coastal targets and convoys started four July before official start dates recognized by historians. British histories usually treat ten July as beginning date despite earlier engagements. The Germans drew out Fighter Command intended but failed gain air superiority needed invasion. Hitler issued Directive 17 one August extending operations to British mainland and RAF-related targets.

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Common questions

When did Adolf Hitler issue Directive 16 for Operation Sea Lion?

Adolf Hitler issued Directive 16 on the 16th of July 1940. The directive ordered preparations for an invasion of Britain under the codename Operation Sea Lion.

What date marked the start of systematic German attacks against British coastal targets and convoys during Kanalkampf?

Systematic German attacks against British coastal targets and convoys began on the 4th of July 1940. Historians differ on when the Battle of Britain officially started, with some citing the 10th of July as the beginning date.

How many sailors died when the Foylebank tender sank after the Luftwaffe attack on Portland harbor?

One hundred seventy-six sailors were killed or dying of wounds when the Foylebank tender sank immediately. This event caused the worst ever loss of life on British military personnel based in Britain that day.

Why was the Finger-four formation used by German fighter pilots more effective than British formations?

The Finger-four formation allowed all German pilots to scan air while British relied on formation leader keeping station. This flexibility proved far more effective than tight British formations during engagements over the English Channel.

When did Hitler issue Directive 17 extending operations to the British mainland?

Hitler issued Directive 17 on the 1st of August 1940. The directive extended operations to British mainland and RAF-related targets following the initial Kanalkampf phase.

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All sources

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