Operation Kanalkampf

(channel battle)

The 'Kanalkampf' (channel battle) was the German air effort against the British Royal Air Force over the English Channel in July 1940, attacking British coastal shipping in the Channel to draw RAF Fighter Command in battle under conditions favouring the Germans and thereby beginning the 'Battle of Britain' (4 July/11 August 1940).

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 his Führerweisung Nr 16 to the German armed forces ordering preparations for the 'Seelöwe' invasion of the UK.

A necessary precondition for any such invasion was air superiority over southern England: the Luftwaffe was to destroy the RAF and protect the cross-Channel invasion from the Royal Navy. To launch its destruction of Air Chief Marshal Sir Hugh Dowding’s RAF Fighter Command, the Luftwaffe attacked convoys in the Channel. Historians differ as to the dates of the Battle of Britain, and British histories usually treat 10 July as the beginning. British and German historians agree that air battles were fought over the English Channel between the 'Battle of France' and the 'Battle of Britain', and a German campaign of planned air attacks on British coastal targets and convoys began on 4 July. During the 'Kanalkampf', the Luftwaffe received modest support from shore-based artillery and Schnellboote (E-boats to the British) of the German navy.

RAF Fighter Command could not guarantee the defence of the convoys in the southern part of the North Sea and the English Channel, and 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 movement of large convoys in the waters of the English Channel and close them to ocean-going vessels until more protection could be arranged, which was a process that took several weeks. On 1 August, Hitler issued his Führerweisung Nr 17, which expanded the scope of Luftwaffe operations to the British mainland and RAF-related targets. On 13 August ('Adlertag') the main air offensive against the RAF began. By this time the 'Kanalkampf' had drawn out RAF Fighter Command as had been intended, and attacks on convoys continued for several more days. Both sides had suffered losses in the 'Kanalkampf', but the Luftwaffe had failed to defeat RAF Fighter Command, and thus the Luftwaffe had yet to gain the air superiority required for the launch of 'Seelöwe'.

On 2 July 1940, in the aftermath of the French surrender, Hitler decided that an invasion of the UK could begin only after German air superiority had been gained. On 12 July he outlined his reasoning: aerial domination over the invasion area and its sea approaches was necessary to offset the comparative weakness of the Kriegsmarine. Hitler issued a directive to this end on 16 July, which ordered the Luftwaffe to prevent all air attacks on the invasion force, destroy British coastal defences at the planned landing points and break the resistance of the British army. The campaign specifically against the RAF did not start until August. Throughout the intervening period, the Luftwaffe undertook its third major operational move within the space of two months. The first had seen it push forward its Luftflotten 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 revived the former Allied air bases. This often meant short-range warplanes, such as dive-bombers and fighters, were sent to forward airfields which had an urgent need for electricity and running water for personnel. Upon the French surrender the Luftwaffe supply system was breaking down. For example, 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) could not cope and barely kept their own units running. Preparations continued at an almost glacial pace as the men responsible for the organisation of German air power and its efficient transfer to the Channel were not available as they enjoyed the fruits of their new assignments in Paris. Senior staff members were distracted by victory parades and promotions, these officers including Göring, who was promoted to the unique rank of Reichsmarschall. During the 'Kanalkampf' the Germans assembled powerful air forces to attack convoys in the Channel, but it took some 40 days from the date of the French capitulation for the Luftwaffe to begin its assault on the UK.

Diversion of effort was contrary to the German concept of the Schwerpunktprinzip (concentration principle) and the Luftwaffe did not operate over the UK in force until after the Franco-German armistice of 22 June. When German bomber crews flew over the UK they did so at night as sorties were recorded in May and June 1940. When the UK rejected Hitler’s demands, the Luftwaffe undertook preparations to neutralise the country and end the war. Generalfeldmarschall Albert Kesselring’s Luftflotte II and Generalfeldmarschall Hugo Sperrle’s Luftflotte III were transferred to France and Belgium. In June and July, sporadic attacks were carried out at night, inland and along the eastern and southern coasts of the UK, 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, such at the 'Knickebein' (crooked leg) system. By taking bearings and cross-bearings, in the 'Battle of the Beams', on German medium-wave transmitters, aircraft could find their positions with an accuracy sufficient 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. Some 13 airfields, 16 factories and 14 ports were attacked, to little effect. Flying at low altitude, the German bombers could be illuminated by searchlights, and two were shot down in June by anti-aircraft guns. The bombers then began to fly at higher altitudes in order to evade the searchlights and thus escape anti-aircraft fire.

Operations against British sea communications did not appeal to Göring, in whose view the Luftwaffe was not prepared for naval warfare and this strategy was tantamount to a blockade, which was put in effect against Britain from 18 July. The blockade required the co-operation of the Luftwaffe with the Kriegsmarine, but Göring ensured air assistance was not forthcoming. Göring loathed the navy and its commander-in-chief, Grossdmiral Erich Raeder. In Göring’s eyes, Raeder and the navy represented the bourgeois clique of German society the Nazi revolution had pledged to eliminate. Göring 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 and Oberkommando der Wehrmacht stated that attacks on warships and shipping must take second place to those on 'military objectives', and it was February 1941 before the Oberkommando der Wehrmacht altered this view.

Göring and the Oberkommando der Luftwaffe intended to strike at the RAF and establish air superiority, if not air supremacy, as was made clear in Göring’s directive of 30 June directive. Göring hoped that a victory in the air battle would remove all need for an invasion of the UK by persuading the government of the UK, led by Winston Churchill, to negotiate peace with Germany. This was most evident during a conference in Berlin on 31 July when Hitler outlined 'Seelöwe' 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, the Oberkommmado der Luftwaffe was engaged in an internal debate about which targets should be attacked to attain control of the air as quickly as possible. Although Göring’s directive mentioned cutting off British supplies, he did not refer to shipping. On 11 July, the chief of the Luftwaffe general staff, General Hans Jeschonnek, ordered that coastal shipping should be attacked as a prelude to the main battle against the RAF and its infrastructure. Sperrle and Kesselring, the Luftflotte commanders, had already begun coastal operations as the indecision of the Oberkommando der Luftwaffe had left them with little else for their formations and units to do.

The Oberkommando der Luftwaffe decided to pursue coastal targets because these were easier to find than targets inland. The 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 as, unlike the Luftewaffe, the RAF lacked an air/sea rescue service. It was also desirable to eliminate the English Channel as a supply route to Greater London via the Thames river estuary. Shipping could travel via the waters off northern coast of Scotland, but this would slow the supply of materials for the British war effort. Dowding preferred the navy to reroute its convoys to ease the burden on his forces. German intentions were initially of an exploitative nature, but soon evolved into dual-purpose operations to close the English Channel to shipping and to draw Air Vice Marshal K. R. Park’s RAF Fighter Command into combat.

Luftflotte II and Luftflotte III sent small numbers of bombers against British sea communications, attacking ships and laying mines. In July, the Luftwaffe transferred air units to the bases along the European coast between 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 twin-engined medium bombers, 280 single-engined dive-bombers, 760 single-engined fighters, 220 twin-engined heavy fighters, 50 long-range reconnaissance aircraft (90 of the medium bombers could also fly bomber/reconnaissance sorties against shipping and ports) and 90 short-range reconnaissance aircraft. Generaloberst Hans-Jürgen Stumpff’s Luftflotte V in Norway, with 130 medium bombers, 30 twin-engined fighters and 30 long-range reconnaissance aircraft, exerted an indirect effect on the 'Kanalkampf' by making the RAF keep some of its fighters in the north.

Relations between the Air Ministry, the War Office and the Admiralty had been strained since the establishment of the RAF on 1 April 1918. During the early part of the 1920s, the three services had competed for the straitened resources which were all that the UK provided for its armed forces, for influence and for the right of the RAF to exist. The War Office and the Admiralty 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 the Royal Navy, but the Air Ministry remained suspicious of the War Office’s intentions. RAF Fighter Command co-operated with the Navy during the 'Dynamo' evacuation from Dunkirk as the RAF provided fighter cover for the embarkation of the British Expeditionary Force, but the evacuation was was costly for both services. By 1 June, the RAF had reduced its effort to conserve its fighters, and in its absence one minesweeper, one transport and three destroyers had been sunk and two other destroyers damaged.

The lack of air cover was not uncommon, but the RAF believed itself to be more successful in the battle, overclaiming 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 RAF Fighter Command’s retention of rigid control of its units. The Admiralty complained that RAF methods did not permit direct contact by RAF operational staff with the naval command, resulting in a loss of invaluable time and of the fluidity of aerial warfare, which 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 B. H. Ramsay, the commander-in-chief Dover responsible for organising the 'Dynamo' evacuation, asked to meet Dowding late in June to prevent the recurrence of operational difficulties of this nature. Ramsay was told to put his complaints on paper and send them to Dowding, with a copy to the Air Ministry, and the two officers 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. The daily average of 12 convoys traversing the Englidh Channel on a daily basis needed cover every day and roughly one-third were attacked. It became an immediate burden to Park’s No. 11 Group, which was responsible for defending south-eastern England. The employment of convoys from the Suffolk coast to Lyme Bay in Dorset 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 air bases meant that German aircraft could attack and quickly withdraw, making interception difficult. While the commitment of standing patrols to cover convoys could offset this, the practice exhausted pilots and handed the tactical initiative to the Germans.

Coast and convoy defence had a place in Air Staff fighter defence policy, but Dowding had to decide how best to employ RAF Fighter Command to meet the German threat, which he did apparently without consulting the navy. Before the war, RAF Fighter Command had expected attacks by unescorted German bombers upon the eastern regions of the UK. Then the German occupation of France had put the western areas of the UK within range of German aircraft. Dowding considered that the Germans would attack airfields and factories as well as convoys and ports in order to draw RAF fighter forces into battle and inflict losses on them. On 3 July, Dowding asked for convoys to be sent around the north of Scotland to reduce the burden of convoy escort along the southern coast and thereby preserve RAF Fighter Command for the main battle that was clearly imminent. Four weeks later the Air Ministry, ostensibly after complaints from the Admiralty, ordered Dowding to meet the Luftwaffe with large formations over shipping on the south coast route. On 9 August Churchill was still asking the navy to use the convoys as bait to lure German bombers: the tactic succeeded, but fighting over the sea cost RAF Fighter Command greater losses.

The quantity of Luftwaffe 'Enigma'-ciphered messages declined after the 'Battle of France' as the service resumed the use of land lines in preference to radio transmissions, but at the end of June decrypts of the latter revealed that the Luftwaffe was preparing for operations against the UK from Belgium and the Netherlands, and that most bomber Geschwadern would be ready by 8 July. Photographic reconnaissance showed runways being extended to suit bomber operations. Since phoro-reconnaissance had found no invasion shipping in English Channel ports, it was considered likely that only preliminary operations were then being contemplated. After about a month of small night raids, on 10 July the Luftwaffe began more substantial daylight attacks on British ports, coastal convoys and aircraft factories. Decrypts late in June enabled the Air Ministry’s air intelligence branch to predict the beginning of the German offensive, and decrypts for several earlier months had been uncovering the Luftwaffe’s organisation, order of battle and equipment. The accumulation of information allowed air intelligence and the codebreakers at Bletchley Park to glean strategic intelligence from tactical signals being sent in lower-grade codes by Luftwaffe flying units. The British estimate of the number of German bombers had been reduced from 2,500 to 1,250 by 6 July, when theactual number was in the order of 1,500 to 1,700.

Changes in Luftwaffe methods and objectives were communicated via land line, but at times it could be inferred from 'Enigma' decrypts that changes were afoot. The codename 'Adlertag' and references to the period from 9 to 13 August were uncovered but not their purpose. As the 'Kanalkampf' continued, 'Enigma' decrypts gave more notice of targets, timing and the size of raids, but this was sometimes too late to be useful and Luftwaffe short-notice changes could negate the information. Tactical information from 'Enigma' was not well co-ordinated with RAF Y intercept stations, which reported separate to 'Enigma', but RAF Y was able to give warnings of German sightings of coastal convoys and imminent attacks by eavesdropping on and decrypting Luftwaffe wireless transmissions between aircraft and the ground. RAF Y identified airborne bomber units and their bases, occasionally also uncovering the target area, although it was the middle of August before this added much to radar reports.

German voice transmissions by radio telephone were collected by listening stations around the UK within a system headquartered at RAF Kingsdown in Kent by German-speaking Women’s Auxiliary Air Force and Women’s Royal Naval Service personnel and sent to local RAF headquarters and RAF Fighter Command headquarters, of which the latter was the centre of the 'Dowding system' and where messages were collated with radar and Observer Corps reports. Voice transmissions could occasionally alert RAF Fighter Command to the assembly of German formations beyond radar range, giving the height of formations, discriminating between fighters and bombers, and hearing orders being passed to fighter escorts showing main and secondary attacks, Luftwaffe judgements about RAF intentions, meeting points and courses for return flights.

Supermarine Spitfire single-engined warplanes of RAF Coastal Command and Lockheed Hudson twin-engined aircraft of the Photographic Reconnaissance Unit flew sorties eastward to Norway and southward to French west-coast points as far as the Spanish border to photograph German-occupied ports, looking for signs of invasion preparations. Nothing was revealed until the second week of August, when accumulations of barges were found and interpreted as an invasion preparation. RAF Bomber Command sent its aircraft on a nightly basis against the German-held ports and the German aircraft industry, and also against airfields when they were unable to bomb the primary target. The Bristol Blenheim twin-engined light bombers of No. 2 Group made daylight attacks on airfields occupied by the Luftwaffe. In July ports and shipping were made the priority target but until the ports filled with invasion craft in August, RAF Bomber Command continued to attack industry and Luftwaffe ground facilities. The Germans had 400 airfields available and dispersed aircraft around them, making the bombing ineffectual. The targets were defended by large concentrations of anti-aircraft artillery, making ground strafing too risky. The Blenheim bombers were vulnerable to fighter attack and the crews had orders to abandon raids unless there was 7/10th cloud; by the end of June, 90% of planned sorties were cancelled. Together with some Fairey Battle single-engined light bombers which had returned from France, the Blenheim bombers began to operate on moon-lit nights. In July 1940, RAF Bomber Command lost 72 aircraft on these operations.

In June, RAF Fighter Command claimed 21 German bombers shot down at night over the UK. Seven German aircraft crashed and were credited to night-fighters. British night air defences remained rudimentary until a time early in 1941: there were no specialist night-fighters or reliable airborne interception radar. Coastal radar looked out to sea, so after a raider had crossed the coast it became difficult to track. At the beginning of 'The Blitz' in October, the Luftwaffe flew 5,900 sorties and lost 23 aircraft, a 0.4% loss rate. In combination with other factors, this cost Dowding his job as the head of RAF Fighter Command in November 1940.

Luftwaffe attacks on shipping were greatly facilitated by the capture of bases in France and the Low Countries. In the North Sea, the Grimsby fishing fleet had been attacked twice in June. Air attacks increased, and in July ship losses off the eastern coast of the UK exceeded those by naval mines. Attacks on minesweepers, escort vessels and anti-invasion patrols increased rapidly and were made worse by a lack of light anti-aircraft guns and the concentration of the air-defence effort in south-eastern England against a possible invasion. The Admiralty reserved the right for ships to fire on aircraft on an apparently attacking course because it had been found that a high volume of prompt, accurate fire could reduce the accuracy of bombing and sometimes shoot down the attacker. Hurried training and lack of experience in aircraft recognition among navy crews led to many RAF aircraft being taken for hostile and engaged, even when flying escort for the ships. While demanding close escort, the Admiralty required ships to engage unidentified aircraft within 1,500 yards (1370 m), a practice the RAF considered irresponsible. More training in aircraft recognition and pilots avoiding courses toward ships on tracks similar to bombing runs were obvious remedies, and with experience navy gunners made fewer mistakes.

British electricity-generating stations ran on coal from Wales, Northumberland and Yorkshire, as did the railways, manufacturing industry and shipbuilding. Coal convoys sailed south along the eastern coast to London’s docks or down the western coast then across the Bristol Channel, up the English Channel, through the Strait of Dover and finally the Thames river estuary to reach these same docks. Trade convoys along the eastern coast were FN northbound and FS southbound. The area between the English, French and Dutch coasts was about 400 miles (640 km) long, 110 miles (175 km) at its widest point and 22 miles (35 km) at its narrowest between Dover and Calais. These waters abounded with shoals, sandbars, shipwrecks and the minefields laid by each side, sometimes forcing ships to sail in line. A CE (coal east) convoy assembled at Glasgow, joined by ships from South Wales in the Bristol Channel. The ships rounded Land’s End into the English Channel, where the convoy was usually escorted by two destroyers and six armed merchant trawlers. Off Falmouth four escorts, usually destroyers of Plymouth Command, joined until relieved by ships from Portland Command relieved in turn by ships from Portsmouth Command off the Isle of Wight. At Dungeness, Dover Command minesweeping trawlers took over until the Thames river estuary, where they were relieved by Thames Command ships. The Dover Command ships then took over a CW (coal west) convoy for the reciprocal passage. Coal convoys were slow and within easy range of German aircraft operating from France, but the south coast ports needed 40,000 tons of coal per week and land transport capacity was insufficient.

When using radio telephony, convoy names such as CW.7 were undesirable, being long-winded and liable to problems with reception. Convoys expected to receive air cover were given a codename such as 'Bread' taken from a list created by the RAF and given by Naval Control of Shipping as convoys were formed. The list was long enough to avoid duplication and the names were reused as a convoy was unlikely to need a codename for more than two weeks, and indeed often only two or three days. The codenames could be broadcast to convoys to warn them of air attack but merchant ships were not allowed to broadcast them, this being reserved for the use of the escorts and itssenior officer.

The German occupation of the Channel islands group had begun on 30 June, and on 1 July early morning mist curtailed operations by Luftflotte II and Luftflotte III, but reconnaissance sorties by the air fleets' Aufklärungsgruppen took place and two Dornier Do 215 twin-engined aircraft were shot down by the British ground defences. A Junkers Ju 88 twin-engined aeroplane of the 3(F)./Aufklärungsgruppe 121 was also lost to mechanical failure. Several Blenheim light bombers, escorted by Hawker Hurricane single-engined fighters of No. 145 Squadron, reconnoitred Abbeville for no loss. Supermarine Spitfire single-engined fighters of No. 72 Squadron shot down a Heinkel He 59 twin-engined floatplane, whose crew was rescued by a British cruiser, complaining that they were a Red Cross service and should not have been engaged. The British issued a warning that aircraft operating near convoys did so at their own risk. A scramble was ordered soon afterwards to protect Convoy Jumbo as it approached Portsmouth, and the convoy was attacked by Ju 87 dive-bombers, which left before the fighters arrived. Blenheim Mk IF twin-engined fighters of No. 235 Squadron claimed a Dornier Do 17 twin-engined bomber damaged and Spitfire fighters of No. 64 Squadron engaged and shot down a Do 17 of Kampfgeschwader 77 which was approaching RAF Kenley.

Some 20 ships of the OA.177G outbound Atlantic convoy departed Southend on 1 July, consisting of local coasters carrying coal to the ports along the coast, and 10 large ocean-going ships joined the convoy at Plymouth and Falmouth, en route to Gibraltar, by which point most of the coasters had entered port. On 2 July, Ju 87 dive-bombers of Sturzkampfgeschwader 2 attacked the convoy, and the 10,058-ton British steamer Aeneas was sunk 23 miles (37 km) to the south-east of Start Point in Devon, 18 members of her crew members being killed and the survivors rescued by the destroyer Witherington. StG 2's attack also damaged the 3,178-ton British steamer Baron Ruthven, causing five casualties, of whom two died before the ship reached Portsmouth despite the attentions of a doctor transferred from a destroyer. The motor torpedo boat S-23, looking for the convoys, was damaged by a mine and sank as it was being towed home. To make it closer to the coast, Dowding transferred No. 79 Squadron from RAF Biggin Hill to RAF Hawkinge in place of No. 245 Squadron, which was moved to RAF Turnhouse in Scotland.

During the morning of 4 July, the Luftwaffe attacked Portland harbour. Messerschmitt Bf 110 twin-engined heavy fighters of the V(Z)/Lehrgeschwader 1 and two Staffeln (squadrons) of Messerschmitt Bf 109 single-engined fighters of the I/Jagdgeschwader 1, redesignated as the III/JG27 on the next day, escorted Ju 87 dive-nombers of the II/StG 51, redesignated as the II/StG 1 on the next day. At 08.15 the dive-bombers arrived and, with no RAF fighters in sight, attacked the auxiliary anti-aircraft ship Foylebank armed with four twin 4-in (101.6-mm) high-angle guns, two quadruple pom-pom guns and 0.5-in (12.7-mm) machine guns. The ship had been sent to Portland on 9 June to protect the harbour. The gunners on Foylebank did not have the time to man their weapons properly and 104 bombs were dropped, many striking the vessel. Foylebank's tender was hit and sank immediately, and 176 sailors being killed or died of their wounds. The dive-bombers sank Silverdial and damaged the 4,358-ton merchant vessel East Wales, 5,004-ton merchant vessels William Wilberforce and 6,630-ton merchant vessel City of Melbourne. The StG 51 lost one Ju 87, shot down by Foylebank's gunners, and another dive-bomber and a Bf 109 fighter were slightly damaged.

The OA.178 convoy of 14 ocean-going merchantmen and local collier traffic left the Thames river estuary, bound for the west coast, and passed Dover safely on 3 July. German radar detected the convoy and the Luftwaffe was ordered to intercept the ships after attacking Portland. A Ju 88 reconnaissance aeroplane of the 1(F)./Aufklärungsgruppe 123 flew across the English Channel and reported that the convoy was to the south-west of Portland. The I/StG 2 lifted off from Falaise with 24 Ju 87 dive-bombers escorted by a Staffel of fighters from the I/JG 1. The attack was followed by 23 Ju 87 dive-bombers of the III/StG 51 after they had been hastily refuelled and rearmed. The 4,592-ton Dallas City was bombed, engulfed in flames and collided with the 4,674-ton Flimson, which was also hit. The ships were disentangled only after 15 minutes. Dallas City later sank. The 5,225-ton Antonio limped into Portland Harbour with Flimson, where the anti-aircraft ship Foylebank was on fire and sinking. The 1,796-ton Deucalion and 3,526-ton Kolga and 5,225-ton Britsum were sunk and the Canadian Constructor was damaged. The Germans suffered no loss.

Late in the evening, Hurricane fighters of No. 79 Squadron were scrambled to defend shipping off Dover being attacked by Do 17 bombers of the KG 2. Several ships were badly damaged, a freighter was beached to avoid sinking, and Bf 109 fighters of the II/JG 2 shot down one Hurricane, whose pilot was killed. The Germans suffered only damage to one Do 17. The day was a success for the Luftwaffe, the attack on Portland inflicting the worst ever loss of life on British military personnel based in the UK. Churchill was perturbed and submitted an 'Action This Day' memo to the Admiralty, asking 'Could you let me know on one sheet of paper what arrangements you are making about the Channel Convoys now that the Germans are all along the Channel coast? The attacks yesterday both from the air and by E-boats, were very serious, and I should like to be assured this morning that the situation is in hand and the Air is contributing effectively.'

Ramsay regarded the episode as disgraceful, and the Admiralty complained to the prime minister, who demanded that RAF Fighter Command do more to protect English Channel shipping.

The weather was poor on 5 July. No. 65 Squadron shot down an He 111 of 8./KG 1 over the sea with the loss of all five crew. Late in the evening, No. 64 Squadron flew a reconnaissance patrol over Calais and Bf 109 fighters of JG 51 shot down one Spitfire, its pilot being killed, and damaged another for no loss to the German fighters. Evidence grew that the main Luftwaffe attack would fall in the south and as RAF Fighter Command squadrons were rebuilt with pilots from operational training units, Dowding agreed with Park on the tactics to be used. On the following day, Air Vice Marshal Trafford Leigh-Mallory, commander of No. 12 Group, started to move some of his squadrons to bases closer to the coast. The Air Staff expected German attacks from the Cherbourg peninsula and No. 609 Squadron was moved from RAF Northolt to RAF Middle Wallop on Salisbury Plain; No. 87 Squadron moved to Exeter to cover Bristol, Plymouth and the Western Approaches.

Convoy patrols were resumed on 7 July in defence of CW and CE west- and east-bound coal convoys along the south coast and No. 145 Squadron shot down a Do 17P reconnaissance aeroplane over the Channel, No. 43 Squadron shot down another shadowing an eastbound convoy and another Do 17 fell to No. 601 Squadron later on. Thre Jagdgeschwader were encouraged to embark upon freie Jagd (free hunt) sorties to engage RAF fighters wherever possible, with no bombers to protect. As No. 54 Squadron prepared to attack a lone He 111, it was attacked by Bf 109 fighters: two of the British squadron’s aircraft force-landed and another was damaged, the pilots surviving. At 19.30, as the convoy passed Dover, 45 Do 17 bombers of I and II/KG 2 took off from Arras and attacked at 20.15, sinking one ship and damaging three more. The radar stations at Pevensey, Rye and Dover gave good warning of the attack and seven Spitfire fighters of No. 64 Squadron were aloft from RAF Kenley, together with another six of No. 65 Squadron from RAF Hornchurch. The fighters took off too late, could not prevent the attack and No. 65 Squadron was bounced by 70 Bf 109 fighters of JG 27. Three Spitfire fighters were shot down, all three pilots being killed, and two Bf 109 fighters were claimed destroyed, though neither can be identified through Luftwaffe loss records. The fighters of No. 64 Squadron damaged a Do 17 which crash-landed at Boulogne, and inflicted minor damage on another. Before dark, He 111 bombers attacked Portland harbour, near-missed the steamer British Inventor, killing one man, and hit the paddle-wheel auxiliary minesweeper Mercury, whose crew lost four dead and three wounded. Dowding was now in no doubt that the Luftwaffe was concentrating on ships and harbours and that the seven coastal convoys and deep-sea convoys at sea would be attacked. Dowding regarded convoy escort as wasteful and feared that RAF Fighter Command would be depleted before the start of the main battle. The Germans had lost seven reconnaissance aircraft in a week and the Jagdgeschwadern were ordered to provide escorts.

On 8 July, the weather was favourable for the Luftwaffe, with thick cloud extending from 1,500 to 20,000 ft (460 to 6095 m) shielding the bombers from RAF fighters. A convoy sailing up the Bristol Channel was shadowed by a Do 17, which was intercepted by No. 92 Squadron and claimed destroyed, though this is not shown in German records. In the early hours a large CW convoy put to sea from the Thames river estuary to pass Dover at 12.00. At 11.30, a He 111 found near the convoy off the North Foreland was claimed shot down by Spitfire fighters of No. 74 Squadron and appears to have escaped, though seen on fire, landing gear lowered and diving into cloud. An hour later, radar picked up considerable aerial activity over the Pas de Calais. An unescorted Staffel of Do 17 bombers was intercepted by No. 610 Squadron off Dover and the German aircraft dropped their bombs wide of the ships.

The Spitfire fighters damaged a bomber but lost a pilot killed to return fire. Six more Spitfires sighted Do 17 bombers escorted by a Staffel of Bf 109 fighters, and one Bf 109 was claimed without loss. Hurricane fighters of No. 79 Squadron took off from RAF Hawkinge and to the north of Dover were attacked by Bf 109 fighters and lost two pilots killed. Ju 88 bombers of the KG 54 made ineffectual attacks and Ga pilot of No. 85 Squadron shot down an He 111 of the KG 1. A Bf 109 of the 4./JG 51 was shot down by No. 74 Squadron, its pilot being taken prisoner, and Squadron Leader D. Cooke of No. 65 Squadron was killed in the afternoon.

On 9 July Kesselring committed the Zerstörergeschwadern (destroyer wings) to battle en masse for the first time against the UK. The initial engagement took place when No. 257 Squadron damaged a Do 17 of the KG 3, which crash-landed near Antwerp, Belgium with one crew member dead. A cold front generated thick cloud and caused the Luftwaffe to curtail operations. Park ordered section-strength standing patrols, each of three or four fighters, over six small coastal convoys and moved No. 609 Squadron to RAF Warmwell, to cover Portland. A number of single-aircraft raids penetrated the defences and Do 17 bombers attacked Cardiff docks, damaging the steamers San Felipe and Foxglove. A nearby airfield was bombed and two pilots were killed on the ground.

At 12.45, Dover radar detected the build-up of a large formation behind the Pas de Calais and, in order to prevent the Luftwaffe from using the cloud cover to approach unseen and attack the convoys from the trailing edge of the cloud base, Park ordered six of No. 11 Group’s squadrons into action. At 13.00 six Hurricane fighters were ordered up from RAF North Weald, where the station commander, Wing Commander Victor Beamish, became so impatient that he ordered his aircraft to be readied and took off in support, leading No. 151 Squadron. The Hurricane fighters were confronted with a formation of 100 bombers and fighters in a formation stepped up from 12,000 to 20,000 ft (3660 to 6095 m). The six Hurricane fighters formed two sections of three, one against the bombers and the other after the 60 Bf 109 and Bf 110 fighters. The German bomber crews exaggerated the number of Hurricane fighters and split into six formations, one finding itself over the convoy but its bombing was scattered and no ships were hit. One Hurricane was shot down and another damaged. In return, the III/ZG 26 lost three aircraft destroyed and one damaged after being intercepted by No. 43 Squadron. No Bf 109 fighter appear to have been lost, and the presence prevented the RAF fighters from reaching the bombers.

Another Luftwaffe raid was mounted and Park, who had moved three squadrons to RAF Manston, was positioned to intercept. The German raid reached the North Foreland at about 15.50, No. 65 Squadron engaged the formation and shot down one Bf 109 of II/JG 51. No. 17 Squadron Hurricane fighters reached the area and shot down an He 111 of KG 53. Kesselring ordered Seenotflugkommando 1 with He 59 floatplanes to rescue survivors, covered by a Staffel of Bf 109 fighters. One He 59 found itself above a convoy and was attacked by Spitfire fighters of No. 54 Squadron. The He 59 was forced down on the Goodwin Sands and its crew was captured. Two Spitfire pilots were killed by the escorts from II/JG 51 for another Bf 109. The bombers hit the 1,456-ton Kenneth Hawksfield and the 804-ton Pol Grange with no casualties, and Kenneth Hawksfield was beached, patched two days later and returned to London docks.

The last sorties of the day were flown by 27 Ju 87 dive-bombers of I/StG 77. Escorted by Bf 110 machines, the dive-bombers attacked the Portland naval base. Intercepted by No. 609 Squadron, the Gruppe lost its commander, and a Spitfire was shot down by the Bf 110 escort. One Bf 110 escort of 13./LG 1 was also lost. The 7,085-ton freighter Empire Daffodil was damaged.

Göring’s 30 June order had delegated responsibility for attacks on British shipping to Generalleutnant Bruno Loerzer’s II Fliegerkorps and Generalmajor Wolfram Freiherr von Richtofen’s VIII Fliegerkorps as these contained most of the Ju 87 units. Loerzer appointed Oberst Johannes Fink, the Geschwaderkommodore of KG 2, as the Kanalkampfführer (channel battle leader). Oberstleutnant Theo Osterkamp’s JG 51 was based at Wissant, close to KG 2, and until other Jagdgeschwader could be brought into action, was the Jagdwaffe's spearhead over England and had been carrying out fighter sweeps over Kent, but commitment to bomber escort deprived the fighters of freedom of action. Fink devised a compromise in which the Bf 110 wings flew close escort and the Bf 109 fighters roamed to engage British fighters at a tactical advantage.

On 10 July, a Do 17 of 4(F)./Aufklärungsgruppe 121 was despatched to reconnoitre the English Channel in thick cloud and rain, accompanied by a Staffel of I/JG 51's Bf 109 fighters, and No. 74 Squadron scrambled six Spitfire fighters to an interception which damaged the Do 17 for two Spitfire machines damaged by the Bf 109 escort. Eight convoys were at sea at this time, and the German formation had time to report the composition and heading of CW.3 before being intercepted. The convoy was sailing in ballast from the Thames river estuary and rounded the North Foreland at 10.00. Fink alerted KG 2, with III/ZG 26 as close escort and JG 51 as high cover. While the operation was being prepared, a Bf 109 Staffel on a sweep over Dover shot down a No. 610 Squadron Spitfire. At 13.15, Park sent up a patrol of No. 32 Squadron over the convoy, and at 13.30, when it was clear the Germans were mounting a stronger raid, also despatched Nos 56, 111 and 74 Squadrons. Some 20 minutes later, over the convoy, the British squadrons met the German formation of about 26 Do 17 bombers of I/KG 2, all three Staffeln of I/ZG 26 and two Staffeln of I/JG 3, the last of which had just arrived in France. Mistaking the Bf 110 machines for Do 17 bombers, the leader of No. 32 Squadron reported 60 bombers and called for reinforcements; Park had already ordered three more squadrons into action.

A dogfight between some 100 aircraft broke out. It was difficult for the RAF fighters to co-ordinate their attacks as the airwaves were full of chatter between pilots, and the Bf 109 fighters frustrated British attacks on the bombers. No. 111 Squadron made head-on attacks into the Do 17 bombers and a Hurricane collided with a bomber, both aircraft being lost. The interception managed to disrupt the bombing and only a 700-ton coaster sloop was sunk by one of the 150 bombs dropped. Six Spitfire fighters of No. 64 Squadron then arrived and harassed the Germans all the way back to the French coast. A Bf 110 was shot down by No. 64 Squadron and another by No. 56 Squadron, a Do 17 was shot down by aircraft of Nos 111 and 66 Squadrons, and two more were shot down by No. 32 Squadron. A Bf 109 of 2./JG 3 and one of II/JG 51 were shot down and two were damaged, and a Hurricane of No. 111 Squadron was damaged.The 466-ton Dutch steamer Bill S was badly damaged and sank 6.7 mi (10.8 km) off Dungeness, all the crew surviving.

In other attacks, Luftwaffe bombers sank the 6,499-ton British tanker Tascalusa in Falmouth harbour. The 5,840-ton Greek steamer Mari Chandris of the HG.33 convoy, which had been towed to Falmouth during June after a collision, was set on fire by Tascalusa's demise, the crew of the Greek steamer being rescued. The 1,905-ton British steamer Waterloo was sunk by Ju 88 attacks and the crew rescued. The 7,085-ton British tanker Chancellor, from the OA.170 convoy, was damaged by an aeroplane off Falmouth and the Dutch salvage tug Zwarte Zee was sunk by bomb fragments from near-misses.

On 11 July, von Richthofen ordered the VIII Fliegerkorps to prepared for operations at first light and, taking off at 07.00 from the Cherbourg peninsula, Ju 87 dive-bombers of StG 2 attacked coastal shipping. The dive-bombers intercepted and sank the 1,124-ton British naval auxiliary steam yacht Warrior, which suffered only one casualty. No. 501 Squadron had scrambled but was engaged by the Bf 109 escort and lost one pilot shot down and drowned. No. 609 Squadron arrived as the Ju 87 machines began their dives. The six Spitfire fighters divided, one section of three engaging the dive-bombers and the other taking on the escort. Overwhelmed by odds of 6/1, the squadron was routed, with the loss of two pilots killed for no loss to the Germans. None of the merchant vessels was hit.

A relay of German reconnaissance aircraft kept watch over British waters during the morning, the Luftwaffe aircraft flying as far north as Scotland. Over Yarmouth, a Hurricane was damaged by return fire from a Do 17, and then the Dornier was shot down by a Hurricane of No. 242 Squadron based at Coltishall. Encouraged by the relative immunity of the dive-bombers in the morning’s attack, Sperrle ordered Luftflotte III to follow up the attack, with Bf 110 fighters of ZG 76 as escorts in place of the Bf 109 fighters. At 11.00, Hurricane fighters of No. 601 Squadron were scrambled to intercept a reconnaissance Do 17, missed it and inadvertently found a formation of Ju 87 dive-bombers of III/StG 2 escorted by about 40 Bf 110 heavy fighters that radar had failed to locate. The escorts were too high above the dive-bombers to prevent the first British attack. Most squadrons in the Middle Wallop sector were refuelling but six of No. 238 Squadron’s Hurricane fighters were scrambled, with three more from Nos 501 and 87 Squadrons and nine from No. 213 Squadron near Exeter. None arrived in time to stop the attack on Portland at 11.53, but little damage was done and only one vessel was damaged.

A dogfight occurred near the Dorset coast when No. 87 Squadron attacked the escort out of the sun: the British commander hit Oberleutnant Gerhard Kadow’s Bf 110, which crash-landed and Kadow was shot by approaching soldiers as he attempted to destroy his aeroplane. Another Bf 110 crashed into a cliff top at the Verne Citadel on the Isle of Portland, both members of its crew being killed. Four Bf 110 fighters were lost, along with their crews. A Ju 87 was destroyed and another force-landed, the dive-bombers' light losses resulting from the fact that it was the Bf 110 fighters which bore the brunt of the British attacks. One Hurricane was slightly damaged. The 704-ton British steamer Kylemount was damaged off Dartmouth and the steamers Peru (6,961 tons) and City of Melbourne (6,630 tons) were damaged in Portland harbour. the 1,-37-ton Eleanor Brooke was damaged off Portland and the 309-ton Dutch steamer Mies was damaged to the south of Portland Bill.

During the evening, a He 59 off the Cornish coast was forced down by engine failure and another landed to rescue the crew. Coastguards sighted the Germans and two destroyers were sent from Plymouth to capture the aircraft. Blenheim bombers of No. 236 Squadron shot down a Ju 88 and damaged a He 111 of KG 55 which tried to intervene. One of the He 59 floatplanes was lost and the other evacuated the crew.

The dawn of 12 July was typified by showers from a grey and overcast sky when the large Booty convoy departed the Thames river estuary steaming to the south-west 14 miles (22 km) off Orfordness on the Essex coast and the 'Agent' convoy was off the North Foreland in Kent. German aircraft of the Luftwaffe and Italian aircraft of the Regia Aeronautica attacked 'Booty' and No. 17 Squadron took off from RAF Debden to patrol over the convoy, the British pilots being warned en route of a raid. No. 85 Squadron from RAF Martlesham, No. 242 Squadron from RAF Coltishall, six Boulton Paul Defiant single-engined turret fighters of No. 264 Squadron from RAF Duxford and 11 Hurricane fighters of No. 151 Squadron from RAF North Weald were dispatched. Two Do 17 Staffeln of II/KG 2 and III/KG 53 were intercepted by No. 17 Squadron and attacked at 08.48 even as the Germans began to bomb. One He 111 and one Do 17 were shot down. The bombers flew in a tight formation and their crossfire damaged several Hurricane fighters and shot down two. Two He 111 and two Do 17 bombers were shot down. Trawlers from 'Booty' rescued German aircrew despite the falling bombs. Another He 111 of Stab/KG 55 was shot down by Spitfire fighters on armed reconnaissance.

The 2,162-ton Hornchurch of the FS.19 convoy was sunk and her crew was rescued by the patrol sloop Widgeon. The 1,926-ton steamer Josewyn was damaged 9.2 miles (15 km) to the west-north-west of St Catherine’s Point. Having missed the chance to attack the 'Agent' convoy, Luftflotte III despatched more He 111 and Do 17 aircraft on reconnaissances to track shipping. An He 111 of KG 55 was lost during the afternoon against Hurricane fighters of No. 43 Squadron, and the Luftwaffe failed to find and attack any more convoys.

On 13 July a number of smaller convoys ran the gauntlet of the English Channel. A Ju 88 of II/KG 51 was shot down by a Spitfire of No. 43 Squadron while shadowing a convoy. The convoy was heading to the west and was in the area of Lyme Bay when Nos 238 and 609 Squadrons, with 12 Hurricane and three Spitfire fighters respectively, were ordered to mount an aerial guard. The CW.5 convoy was late, so the British fighters found just some 50 Luftwaffe aircraft searching for the convoy. Two Do 17 bombers were shot down for one pilot killed in a forced landing. Bf 110 fighter-bombers of V/LG 1 attempted to engage but became embroiled in a dogfight with RAF fighters, which claimed three damaged for no loss.

As the Bread convoy steamed out of range, the smaller convoy was attacked by StG 1 escorted by three Staffeln of JG 51. No. 56 Squadron engaged the dive-bombers with 11 Hurricane fighters before the Bf 109 escorts could react: two dive-bombers were damaged but the escorts shot down two Hurricane fighters. No. 54 Squadron Spitfire machines attacked the Bf 109 fighters, and the Luftwaffe’s losses amounted to six aircraft destroyed and eight damaged, while the RAF’s losses comprised four Hurricane fighters shot down and one Spitfire brought down in error by the Dover defences. The destroyer Vanessa was disabled by near-misses and was taken under tow by the tug Lady Duncannon and and repaired in November 1940.

Adverse weather over the next few days reduced operations, and on 14 July Kesselring sent the Ju 87 dive-bombers of IV (St)/LG 1 against convoys. The fighter escorts provided by III/JG 3 and II/JG 51 shot down one Hurricane of No. 615 Squadron, but only one Ju 87 and one Bf 109 were destroyed and another force-landed. The air battle took place over a convoy, which sustained no damage, though the armed merchant cruiser Esperance Bay, carrying £10 million on gold bullion was badly damaged off Land’s End, seven of her crew being killed. The Turkish navy’s minelaying sloop Yüzbaşı Hakki was damaged off Weymouth on delivery passage to the Mediterranean. The CW.5 and CW.6 convoys were also attacked: the 614-ton British Mons and 1,129-ton Norwegian steamer Balder were damaged and the 779-ton British Island Queen was sunk. The 139-ton Belgian trawler Providentia blew up with the loss of all hands, probably as a result of bombing by IV (StG)/LG 1.

On 15 July, a Hurricane was shot down and the Luftwaffe lost a He 111, a Ju 88 and a Dornier Do 18 twin-engined flying boat to RAF fighters. The 2,855-ton steamer Heworth of the FN.223 convoy was damaged and taken in tow for Harwich but ran aground. Four crewmen were killed and the survivors were rescued by the destroyer Valorous. The 1,359-ton steamer City of Limerick was sunk, and the destroyers Mackay and Broke went to rescue the crew. Two men were killed and the survivors were rescued by the Belgian trawler Roger Jeannine. The 2,088-ton Polish steamer Zbaraz of the FN.223 conboy was badly damaged by German bombs 12 miles (19 km) to the south of the Aldeburgh light vessel, taken in tow by the tug St Olaves but sank, with no casualties and the survivors rescued by the trawler Vidonia and the tug Muria. The 853-ton Portuguese steamer Alpha was sunk and her crew rescued by the destroyers Bedouin, Tartar and Mashona.

On 16 July the RAF had no losses and shot down a Ju 88 of KG 54, and a Do 17 intruder of 5.(Nacht)/JG 1 was shot down by RAF bombers. On the following day, a He 111 and a Ju 88 of III/KG 26 and I/KG 51 were shot down, and one of No. 64 Squadron’s Spitfire fighters was lost, with the pilot wounded.

The 'Kanalkampf' was now having a serious effect on RAF Fighter Command’s capabilities. The total number of losses was not on paper high, but the attrition of continuous patrols, four-fifths of them over the sea, and poor weather tired pilots and slowed the training of replacements. The dispersal by the Luftwaffe of its raids kept British pilots in action rather than resting, and RAF Fighter Command lost a disproportionate number of experienced squadron leaders and flight commanders from the one-third of its squadrons engaged. The growing number of Hurricane fighters in the hands of RAF Maintenance Command meant that each squadron was allotted 18 fighters, allowing two flights of six for operations and six in reserve for training and maintenance.

On 18 July, two Spitfire fighters of No. 609 Squadron were shot down by Ju 88 bombers of I and II/KG 54, which themselves lost one Ju 88 destroyed and one damaged. A spitfire fighter of No. 603 Spitfire was damaged by a He 111, while KG 27 lost its Geschwaderkommodore, Oberst Bernhard Georgi and his crew killed in action by Hurricane fighters of No. 145 Squadron for one Hurricane damaged. A Spitfire of No. 152 Squadron was damaged and another of No. 610 Squadron was shot down by Bf 109 fighters. One Ju 88 of LG 1 succumbed to anti-aircraft fire, while a Do 17 reconnaissance aeroplane of StG 77 was destroyed by No. 152 Squadron over a convoy.

On 19 July nine convoys were at sea as German aircraft scouted the shipping lanes early in the morning. A Do 17 of 4.(F)/Aufklärungsgruppe 121 was shot down by No. 145 Squadron at 07.04. No. 264 Squadron, flying the Defiant turret fighter, had operated with success over Dunkirk eight weeks earlier and its sister unit, No. 141 Squadron with 12 aircraft, was moved from RAF West Malling to RAF Hawkinge. This latter unit was inexperienced and while the aircraft were being fitted with constant-speed propellers early in the summer, the crews had been offered little time to train in the air, and the squadron’s gunners were uneasy about escaping their turrets in an emergency. Dowding and Park were dubious about the capabilities and survivability of the Defiant, but ordered No. 141 Squadron to escort a convoy that morning.

Osterkamp, the Geschwaderkommodore of JG 51, used a break in the weather to lead III/JG 51 on a patrol over the Dover area and spotted a formation of RAF aircraft at 12.45. Identifying these as Defiant aircraft, Osterkamp ordered his fighters to attack from the rear and below and thereby avoid return fire from the turret. Four Defiant fighters were shot down on the German fighters' first pass and another as it sought cloud cover. The Bf 109 machines were now interrupted by No. 111 Squadron, which shot down a Bf 109 into the sea and so allowed the four surviving Defiant fighters to escape: one crash-landed, one was written off and the other two were damaged. Osterkamp noted that the pilots' delight with their success was tempered with knowledge of their own mortality after this mission.

Analysis suggested that the RAF controller failed to get the squadron airborne before the German aircraft arrived, because a scramble had been ordered only after the German fighters had been spotted by observers at RAF Hawkinge. The Bf 109 fighters, then loitering with the advantage of height, led to disaster for No. 141 Squadron. German pilots now quickly learned to distinguish the Defiant from other fighters and see its manifest disadvantages. Dowding reported on the battle to Churchill, telling him that many men had died: Churchill acknowledged Dowding’s misgivings with the Defiant and turned away. The surviving Defiant turret fighters saw very little action for the remainder of the battle, and 19 July was the worst defeat of RAF Fighter Command during the 'Kanalkampf' as the RAF lost 10 aircraft against four from the Luftwaffe. Encouraged by the Luftwaffe successes, Hitler made his last 'appeal to reason' on that day, and millions of copies of the speech were circulated in the UK.

Off Portland harbour, No. 87 Squadron intercepted Ju 87 dive-bombers without result, and No. 64 Squadron shot down a Heinkel He 115 twin-engined floatplane mining the Thames river estuary. III/KG 55 lost one of its bombers to No. 145 Squadron, and in action against Bf 109 fighters, Nos 1 and 32 Squadrons each lost one Hurricane, No. 43 Squadron lost two and one damaged; two pilots were seriously wounded and one was killed. No. 141 Squadron lost 10 crew killed and one wounded. Although the losses on this day were small in numerical terms, the British fighters had been defeated in each engagement. The Germans were more experienced and operating in greater numbers, and the Bf 109 units were fighting with greater flexibility. Operating at generally higher altitudes, the finger-four formation tactic (a Schwarm of two Rotten) used by German fighter pilots proved far more effective than the close and inflexible formations of British pilots. All the German pilots could scan the air but the British had to rely on the formation leader while concentrating on tight formation-flying.

At 12.15, StG 1 attacked the destroyer Beagle off Dover and the British warship replied with her anti-aircraft guns and high-speed manoeuvres to escape the deluge of bombs from 40 to 50 dive-bombers. Several near misses damaged Beagle's gyro compass and engines, but there were no casualties and Beagle made it back to Dover. At 16.00, German formations appeared over Dover and nine Do 17 bombers of KG 2 and Ju 87 dive-bombers of StG 1 attacked the harbour in shallow dives. Some 22 bombs were dropped: the oiler War Sepoy blew up, the tug Simla, the drifter Golden Drift and the destroyer Griffin were damaged.

At about 00.00 on 19/20 July, a Focke-Wulf Fw 200 Condor four-engined reconnaissance bomber of KG 40 ventured too far inland and was shot down by ground defences near Hartlepool, and another aeroplane of the same type and unit was lost over Northern Ireland. German records show the losses on different dates but British sources are clear that both losses occurred ton his night. At dawn, 12 Hurricane fighters of No. 54 Squadron were scrambled to engage 40 German aircraft approaching the Thames river estuary: the raid had been ordered on the erroneous report of a convoy’s presence. The German formation split into smaller groups searching for the ships, and British radar tracked the raiders, but No. 54 Squadron’s fighters failed to effect any interception. Aircraft of No. 56 Squadron took off at four minutes later, 05.45, met a formation of Ju 88 bombers of KG 4), and forced one down near St Osyth. Several lightships had been sunk along the coast: the vessels were anchored and therefore little more than sitting ducks. Radar usually picked up German raiders before they reached the target area, but the raids often occurred in poor light. Keith Park and Leigh-Mallory were concerned the Luftwaffe would attack lightships off the East Coast and agreed to launch a programme of air patrols over the coast near such vessels.

The Bosom convoy sailed from Lyme Bay and Hurricane fighters of No. 238 Squadron chased three Bf 109 fighters away from it. The Hurricane fighters then spotted a He 59 rescue and ambulance floatplane of Seenotflugkommando 4 at 14:30 and shot it down, killing the four crew. As Bosom steamed eastward, another He 59 from Seenotflugkommando 1 shadowing the convoy was attacked by No. 43 Squadron. A Hurricane was shot down, the pilot bailing out but them drowning, and the He 59 escaped into cloud. Aircraft of No. 601 Squadron took over and the Heinkel was located and shot down, its crew bailing out at too low an altitude for their parachutes to open. As Bosom reached the area covered by the RAF Kenley and RAF Biggin Hill sectors, there had been plenty of time for He 59 floatplanes to report it, and Park ordered standing patrols of 24 fighters over it, split evenly between Spitfire and Hurricane units.

At 18.00, II/StG 1 took off to attack the Bosom convoy with about 50 Bf 109 fighter escorts of I/JG 27, some Bf 110 heavy fighters, and Bf 109 fighters of I and II/JG 51 in support. Radar alerted the British, and Hurricane fighters of Nos 32 and 615 squadrons, with Spitfire high cover of Nos 5 and 610 Squadrons, had time to assemble and dive out of the sun. Two dive-bombers were shot down and another four damaged. The Geschwader also lost its Do 17 reconnaissance machine, which was shot down near the convoy. The Bf 110 heavy fighters remained out of the action asa result of the British opposition’s strength, but the Bf 109 fighters reacted quickly and a 30-minute dogfight began. Three of the Bf 109 machines were shot down by Spitfire fighters of No. 615 Squadron. Single Bf 109 fighters of I and II/JG 51 were lost to Nos 32 and 65 Squadrons, and No. 32 Squadron lost one Hurricane and its pilot against JG 51. No. 501 Squadron lost a fighter and its pilot, one Spitfire of No. 610 Squadron was written off and its pilot severely wounded.The most notable German loss was Hauptmann Helmut Riegel, commanding officer of I/JG 27. While the RAF fighters were dogfighting, the dive-bombers exploited the opportunity to attack the convoy, and the coaster Pulborough was sunk. The dive-bombers then attacked the destroyer Brazen, which was hit by several bombs and broke in two.

On 21 July, Park established standing patrols of 12 fighters over the westbound CW.7 convoy that passed through the Strait of Dover. A Bf 110 over Goodwood and a Do 17 were shot down by No. 238 Squadron. The convoy reached the Isle of Wight at daybreak and Do 17 bombers escorted by some 50 Bf 109 and Bf 110 fighters of III/JG 27 and V/LG 1 attacked the convoy to the south of the Needles, where No. 43 Squadron engaged the formation, shooting down a Bf 109 and a Bf 110 for one of its own pilots killed; No. 238 Squadron claimed the Bf 110, and the bombers failed to damage the ships. The only other daylight action was the destruction of a Do 17 of 4.(F)/Aufklärungsgruppe 121 by Hurricane fighters of No. 145 Squadron.

It was quiet on 23 July, although a Ju 88 of 4.(F)/Aufklärungsgruppe 121 was shot down by No. 242 Squadron near Yarmouth. A small convoy passed through the Strait of Dover on 24 July and was attacked by Do 17 bombers of KG 2. Spitfire fighters of No. 54 Squadron intercepted the attack, no ships were hit and no aircraft were shot down. During the afternoon, dive-bombers of StG 1 sank Terlings and the Norwegian steamer Kollskegg.

Luftflottee II carefully timed its fighter and bomber sweeps throughout 25 July to exhaust the RAF Fighter Command’s standing patrols. Once British fighter opposition had spent itself against the Bf 109 fighters, large bomber formations could therefore attack the convoys before reinforcements arrived. At 12.00, No. 65 Squadron engaged JG 52 and shot down one Bf 109. Nine Hurricane fighters of No. 32 Squadron and 11 of No. 615 Squadron engaged more than 40 Bf 109 fighters in a dogfight near Dover and one Hurricane was badly damaged. As the battle receded, Ju 87 dive-bombers of 11.(Stuka)/LG 1 and III/StG 1 attacked the convoy. Distress calls from the ships were answered by No. 54 Squadron which despatched nine Spitfire fighters but Bf 109 fighters shot down two of the British aircraft for no loss.

Park noted the German attempts to saturate the defences and now opted to send only small numbers of fighters over convoys until it became clear that a larger attack was developing. In the afternoon, eight Spitfire fighters of No. 64 Squadron engaged 30 Ju 88 bombers of III/KG 4 escorted by a force of more than 50 Bf 109 fighters. Three more Spitfire aircraft of No. 64 Squadron scrambled, followed by 12 Hurricane machines of No. 111 Squadron from RAF Hawkinge. These delivered head-on attacks to break up the formation, which abandoned the attack and retreated with the Bf 109 fighters covering their withdrawal. So many Luftwaffe fighters were airborne that British ground controllers were unable to tell which raids contained bombers, as opposed to fighter aircraft, and the standing patrols were never numerous enough to prevent four dive-bomber attacks.

The CW.8 convoy of 21 ships had set out from the Medway river at 11.00 on 25 July with a standing patrol overhead, and was attacked by 18 Do 17 bombers escorted by 40 Bf 109 fighters of III/JG 26. No. 43 Squadron attacked JG 26 while six Spitfire fighters of No. 65 Squadron joined and No. 610 Squadron scrambled to cut off the German return route. No. 65 Squadron could destroy none of the Do 17 bombers as a result of the limitations imposed by the British practice of formation flying and the Germans' defensive cross-fire. JG 26 lost two Bf 109 fighters. Running short of fuel, the Bf 109 fighters used the advantage of their fuel-injected engines to dive away. The RAF pilots thought that they had been shot down and claimed six, together with eight probables. Bf 109 fighters of III/JG 52 covered the withdrawal of JG 26, running into Spitfire fighters of No. 610 Squadron: the Germans lost three Bf 109 fighters, and the British suffered the loss of one Spitfire pilot killed and another injured in the course of a forced landing.

A Ju 88 of I/LG 1 and an He 111 from an unidentified unit were lost with their crews. The CW.8 convoy was attacked by Ju 87 dive-bombers of 11.(Stuka)/LG 1 and III/StG 1 off Folkestone, five ships being sunk and four damaged, including the destroyers Boreas and Brilliant before No. 56 Squadron arrived. Nine S-boote attacked the convoy and hit three with gunfire. Three and 10 Spitfire fighters, of No. 64 Squadron and No. 54 Squadron respectively, then arrived. The Bf 109 fighters kept the RAF fighters at bay, shooting down one Spitfire and killing its pilot. Some of the dive-bombers were damaged by naval gunfire. Two Bf 109 fighters of JG 52 were shot down by No. 610 Squadron. On 26 July, S-boote sank three ships and only 11 ships passed Dungeness. The German attacks on the convoy showed that considerably larger numbers of fighters would be needed to protect convoys in the Strait of Dover.

On 26 July, the VIII Fliegerkorps sent 30 Ju 87 dive-bombers to attack the CW.8 convoy off Portland, but these were intercepted by Hurricane fighters of No. 38 Squadron, which shot down one dive-bomber before the Bf 109 escorts intervened. A second wave of Ju 87 dive-bombers and Ju 88 level bombers was protected by Bf 109 fighters, which countered the Hurricane fighters of No. 238 Squadron, and No. 609 Squadron lost one Spitfire. By dusk, the Admiralty had decided losses to merchant shipping had become prohibitive and cancelled all traffic through the Strait of Dover. A Hurricane of No. 32 Squadron was damaged and its pilot wounded, No. 54 Squadron lost three Spitfire fighters and two pilots killed, No. 64 Squadron lost two Spitfire fighters and another damaged with two pilots killed, and No. 152 Squadron lost a pilot killed by Bf 109 fighters. II/KG 51 lost one Ju 88, StG 1 one Do 17 and one Ju 87, III/JG 27 one Bf 109, and JG 52 four Bf 109 machines. A Ju 88 of KG 4 was lost over the Bristol Channel and an He 111 was shot down off Wick.

Early on 27 July news reached the headquarters of Luftflotte III in Paris that a large convoy was departing Portland and 30 Ju 87 dive-bombers of I/StG 77 were launched from Caen at 08.00, linking with their Bf 109 escort from JG 27 while flying toward the target. No. 10 Group despatched three Hurricane fighters from RAF Middle Wallop, and these arrived just as the dive-bombers began to attack and shot down a Ju 87 before the German fighters could intervene. This Bosom convoy reached Swanage at 09.45 and a second wave of Ju 87 dive-bombers arrived. Nine RAF fighters tried to intercept but failed and lost a pilot of No. 610 Squadron killed. Hurricane fighters of No. 615 Squadron later shot down an He 59 off Deal. He 111 bombers attacked shipping off Dover and sank the destroyers Codrington at Dover and Wren off Aldeburgh, KG 53 taking credit for the latter vessel, for the loss of one He 111, probably to No. 504 Squadron. The loss of two destroyers led the Admiralty to abandon Dover as an advanced base for such warships.

The weather on 28 July was sunny and clear as Spitfire fighters of No. 234 Squadron were ordered to a plot to the south of Plymouth, found a Ju 88 of II/LG 1 and shot it down. Major attacks were anticipated and the Biggin Hill, North Weald and Hornchurch sector controllers moved eight squadrons to RAF Hawkinge, RAF Manston and RAF Martlesham. At 13.50 a large raid was detected as it formed up, and set course to Dover, and No. 74 Squadron took off to intercept. Several other units were sent aloft with instructions for the Hurricane fighters to attack the bombers and the Spitfire fighters to engage the fighters. The bombers flew off to the south without bombing, but the British fighters engaged I and II/JG 51, led by the Geschwaderkommodore Major Werner Mölders, on his first sortie over England, and the German fighters were also engaged by No. 41 Squadron. JG 51 lost three of its fighters shot down with two pilots killed and one missing, three fighters force-landed. Mölders’s machine was 80% damaged and he was wounded. No. 74 Squadron lost three Spitfire fighters, with two pilots wounded and one killed. Single Bf 109 fighters of II/JG 27 and III/JG 53 force-landed, their pilots wounded, probably by No. 41 Squadron. Two Ju 88 bombers of 9./KG 4 were damaged by anti-aircraft fire over the Thames river estuary, with one crew member killed and seven wounded. Seenotflugkommando 1 and Seenotflugkommando 3 lost two He 59 floatplanes rescuing airmen in the English Channel. KG 4 was engaged in minelaying operations during July.

On 29 July, the dawn mist cleared and the fine weather and cloudless skies promised much German activity. The Kent sector operations room received news of a German build-up over Calais. There were two convoys in the English Channel in No. 11 Group’s area, but the controllers waited. At 07.20 it became clear as the convoys passed the Strait of Dover that Dover was the target and 11 Spitfire fighters of No. 41 Squadron were ordered to attack the right flank and 12 Hurricane fighters of No. 501 Squadron the left flank. The German formation comprised 48 Ju 87 dive-bombers from six Staffeln of IV(Stuka)/LG 1, II/StG 1 and II/StG 3, and 80 Bf 109 fighters of JG 51 and III/JG 26, the former led by Major Adolf Galland as Mölders was recovering from the wound received the day before.

The leading escort formation was on the extreme right, looking down-sun at the dive-bombers, but when No. 41 Squadron dived to attack the Ju 87 machines they were not seen by III/JG 26. JG 51 engaged the Spitfire fighters, which divided to engage the German escorts. No. 41 Squadron lost one Spitfire shot down and its pilot killed, and four damaged and forced to crash-land. While No. 41 Squadron fought the fighters, No. 501 Squadron attacked the dive-bombers as they began their dives, and the harbour suffered little damage. StG 1 and LG 1 each lost two Stukas, and II/StG 3 reported one damaged. No. 501 Squadron suffered no losses. The steamer Gronland was sunk in the outer harbour with the loss of 19 of her crew killed, having already been damaged in the attacks of 25 July. The patrol yacht Gulzar was sunk but her crew was saved; the tug Sandhurst was destroyed.

III/KG 76 sent Ju 88 bombers under the British radar to bomb the convoys from low altitude, but the bombers scored no direct his or near misses. The Gruppenkommandeur, Major Adolf Genth, was killed when he flew into a balloon cable off Dungeness and another was lost, with all its crew, when it was shot down by the escort ships. Observers called for fighter assistance and Spitfire fighters of No. 610 Squadron were sent but the Ju 88 bombers were long gone. The other convoy was attacked by KG 2 after a Dornier of the wing’s staff squadron had reported its position and was then chased to the French coast by Spitfire fighters of No. 85 Squadron, damaged and made a forced landing at St Inglevert airfield. Eight Bf 110 fighters of the 1. Staffel and three of the 2. Staffel were met near Dunkirk by 30 Bf 110 escorts of ZG 26, and were attacked by Hurricane fighters of No. 151 Squadron. Two of the Hurricane fighters force-landed, their pilots unharmed, an a Bf 110 of Erprobungsgruppe 210 was damaged and ZG 26 suffered no losses as the attackers claimed hits on a 1,000-ton vessel and an 8,000-ton ship.

At 19.25 dive-bombers of II/StG 2, led by the Gruppenkommandeur, Major Walter Enneccerus, sank the destroyer Delight some 15 miles (24 km) off Portland. The ship was crippled and on fire as the Stukas left the scene unchallenged and Delight made for the coast off Portland. The destroyers Vansittart and Broke rescued 147 men and 59 wounded, but 19 of the crew were killed. The burning vessel remained afloat until 21.30, when there was a large explosion and the destroyer sank. The Admiralty withdrew all destroyer flotillas from the English Channel and ordered no convoy to move in the English Channel in daylight. This order had been given on 26 July before Delight sailed and some sources note that standing orders had been broken. The Admiralty had issued instructions to abandon the Dover area as a merchant shipping route on 26 July, and when on 29 July RAF reconnaissance discovered that the Germans were assembling long-range guns at Calais, the Admiralty ordered the abandonment of Dover as a base in favour of Harwich and Sheerness. There was no desire on the part of the Admiralty to maintain a destroyer division at Dover. Only one seaworthy destroyer, Vivacious, remained, and she was used to escort the crippled Walpole and damaged Brilliant, towed by Lady Brassey, to Sheerness. Skate, the Royal Navy’s oldest destroyer, was lent to Dover Command by Portsmouth Command, and the force was reinforced by Bulldog until the return of the damaged vessels.

The Germans viewed the British naval withdrawal and suspension of merchant traffic as a success, but the lack of targets for the Germans removed the need for RAF Fighter Command to engage the Luftwaffe over the English Channel. The Germans now had to fly over southern England, which put the Bf 109, the best German fighter, at the limit of its endurance. Hitler’s Führerweisung Nr 17 expanded the scope of the air offensive from the English Channel to British airfields, and when he held a meeting with the Oberkommnado der Luftwaffe staff at The Hague on 1 August, Göring emphasised the need for German fighters to conserve fuel, which remained a severe handicap for the Germans.

The Admiralty suspended convoys until they could be better defended, but in the last week of the month, the busiest of the 'Kanalkampf', 103 ships had been escorted in convoy through the straits. The British losses to air attack amounted to 24,000 tons between 10 July and 7 August, substantially less than sinkings resulting from mines. Convoy escort was made a combined operation and RAF Fighter Command sent bigger formations over the convoys, since smaller formations had been shown to be too vulnerable against the tactical advantages of greater numbers, height and surprise enjoyed by the Luftwaffe. The larger formations could not prevent attacks on convoys but the standing patrols were less likely to be overwhelmed by German fighters. A Mobile Balloon Barrage Flotilla of small ships was established to inhibit air attacks, and first sailed with the CW.9 convoy on 4 August and kites were later used in place of balloons, which were too vulnerable to gunfire. A Channel Guard of sailors was trained at the gunnery school at Portsmouth to use light machine guns and two to three such teams joined each westbound ship on the Thames river. After the convoy’s westbound passage, its guard joined eastbound ships or took the train back to Southend.

The size of convoys was reduced by half and modern 'Hunt' class escort destroyers, better equipped for anti-aircraft operations, replaced the older escorts. More escorts were provided and convoys had minesweeper trawlers ahead, two destroyers in close escort, three or four anti-submarine trawlers, six Motor Anti-Submarine Boats or Motor Launches, six to eight Mobile Ballon Barrage Flotilla ships and larger formations of fighters overhead. The presence of greater numbers of escorts could not prevent ships being sunk, but the larger number of RAF Fighter Command aircraft made dive-bombing much more difficult and losses never again became serious. On 5 August, the CE.8 convoy sailed to the east from Falmouth at night, sheltered in ports during the day and reached the Thames river estuary without loss. On 7 August, the CW.9 convoy sailed from the Thames river estuary with 25 ships. The convoy was attacked by S-boote during the night and lost three ships sunk. By the morning, when the Luftwaffe attacked, the remaining ships were scattered over 10 sq miles (26 km²), but the raid was intercepted by No. 145 Squadron and no ships were sunk.

On 30 July, Southern England was covered by low cloud and continuous rain. Dowding expected the Germans to exploit the weather to hide their attacks, and patrols were sent over convoys and minesweeper units, but the Luftwaffe did not operate in strength. He 111 bombers of KG 26 harassed the Scottish coast from bases in Norway, near Suffolk two Bf 110 fighters of Erprobungsgruppe 210 stalked a convoy, but were intercepted by two British fighters and after a long chase one German aeroplane was shot down. The following day the weather improved but haze covered southern England. The Luftwaffe attempted some raids but could not find their targets, the RAF made two interceptions and Hurricane fighters of No. 111 Squadron damaged a Ju 88 of III/KG 76. At 16.00, six squadrons with 30 Spitfire and 24 Hurricanes fighters were scrambled to Dover, where Bf 109 fighters were strafing barrage balloons. The 12 Spitfire fighters of No. 74 Squadron engaged two Staffeln of JG 2 under the command of the Geschwaderkommodore, Oberleutnant Harry von Bülow-Bothkamp. One flight of No. 74 Squadron’s fighters engaged the Bf 109 machines at equal height but the second flight was attacked while climbing and lost two Spitfire fighters and one pilot killed. The day ended with one Bf 109 of 7./JG 2 destroyed and one pilot wounded, in exchange for two Spitfire fighters lost and one damaged; two RAF pilots were killed.

On 1 August, Dowding returned the establishment of fighter squadrons to the pre-'Battle of France' figure of 20 aircraft plus two in reserve. The number of RAF Fighter Command pilots also increased, and 1,414 pilots were in service in July compared with the establishment figure of 1,454 pilots. The success of pilot training led Dowding to increase the figure to a minimum of 1,588 pilots, creating a paper deficiency that led to the belief that RAF Fighter Command was undercrewed. The number of operational pilots never fell below the number available at the end of July. Dowding was more concerned by the dilution of pilot quality, losing more than 80 regular pilots and flight commanders, whose place was taken by less experienced men.

A Henschel Hs 126 single-engined tactical reconnaissance aeroplane was shot down by Hurricane fighters of No. 145 Squadron, but not before the rear gunner had killed one of the British pilots. Bombers of I/KG 4 crossed the coast near Norfolk while the Coltishall sector controller was busy organising convoy protection. The Boulton Paul factories near Norwich and the Thorpe railway goods yards were damaged and the Germans escaped, despite the fact that the airfields of Nos 66 and 242 Squadron were a mere 10 minutes' flying time distant. On 2 August, He 111 bombers of KG 26 attacked a convoy off Scotland and anti-aircraft fire brought down one on the deck of the steamer Highlander, which arrived in Leith, where the aeroplane was displayed, and another He 111 was shot down. Erprobungsgruppe 210 sank the 590-ton trawler Cape Finisterre.

For the next five days both sides suffered almost no combat casualties.

At 07.00 on 7 August, the CW.9 convoy, codenamed Peewit and carrying coal, departed Southend. A Do 17 of KG 2 on patrol over the English Channel spotted two minesweepers as they searched for mines dropped by He 115 floatplanes of Küstenfliegergruppe 106. The crew flew northward into the North Sea, missing the large convoy approaching from the west and landed soon afterwards. Peewit continued through the English Channel and reached Dover at 14.30, with three Hurricane fighters of No. 85 Squadron overhead. Winds were light but fog down to 2,000 ft (610 m) gave the convoy cover, with visibility from 2.3 to 5.8 miles (3.7 to 9.3 km). As Peewit rounded Dover, it was escorted by Hurricane fighters of Nos 32, 615 and 501 Squadrons, and just under four hours later reached Dungeness unseen; as visibility improved, a German 'Freya' radar station at Wissant detected the convoy. At 18.30 the sighting was relayed to the headquarters of Generaladmiral Alfred Saalwächter, commander of the German navy’s Marinegruppekommando 'West'. The information was then passed to Kapitänleutnant Heinz Birnbacher, commander of the 1st Schnellbootflottille in Cherbourg, where S-20, S-21, S-25 and S-27 were ordered to readiness. The British ordered four motor torpedo boats from Dover to head to the west in order to reconnoitre German movements among the French Channel ports. The motor torpedo boats sighted the S-boote but did not engage, considering their mission was one of reconnaissance. Birnbacher suspected a trap and took position off Beachy Head and Newhaven, and at 02.00 on 8 August the German attack began.

Leutnant Herman Büchting’s S-27 sank the 1,216-ton steamship Holme Force with torpedoes within one minute, the cargo of coke spilling into the sea and six of the crew’s 13 men being killed. The British were caught entirely by surprise and thought that the noise of the Schnellboote was an air attack. The 946-ton Norwegian steamship Tres stopped her engines and avoided attracting attention, while the 367-ton Fife Coast increased her speed to 12 kt and zigzagged. With surprise gone, the Germans fired flares to illuminate the ships and Fife Coast was spotted and sunk. The destroyer Bulldog arrived on the scene but could do little in the darkness, its gunners struggling to see the Schnellboote. The 380-ton Polly M steamed through the wreckage of Fife Coast, and this threw off the German attackers. The 1,048-ton steamship Rye survived an attack by S-27: she was sunk on 7 March 1941 by the same vessel. Leutnant Siegfried Wuppermann’s S-20 attacked the steamships Polly M and John M (380 and 500 tons respectively), whose captains evaded the torpedoes, but Wuppermann raked Polly M with cannon and machine gun fire: the crew abandoned ship, only to reboard during the next morning, and the ship limped into Newhaven. The steamship John M was engaged for nearly two hours but remained afloat. The Schnellboote crews claimed to have sunk 17,000 tons of shipping, but in reality sank 2,588 tons. At 04.20, Blenheim warplanes of No. 59 Squadron took off from RAF Thorney Island to intercept the Schnellboote, but returned without success after three hours.

The following day was fine and Peewit was scattered over 10 sq miles (26 km²), the leading ships with only the barrage balloon vessel Borealis to guard against air attack. A Do 17P from 4.(F)/Aufklärungsgruppe 14 had been sent to report on the convoy, found 17 vessels to the south of Selsey Bill and reported the ships, and the VIII Fliegerkorps despatched elements of StG 1 to attack the convoy. The Stukas dive-bombed the convoy from 09.00 to 10.45, covered by Bf 109 fighters of JG 27. The 942-ton Dutch vessel Ajax, carrying a cargo of wheat, was sunk in five minutes with four men killed and four wounded, and the 1,597-ton British Coquetdale was sunk with two men wounded. Hurricane fighters of No. 601 Squadron soon arrived, but Spitfire fighters of Nos 609 and 234 Squadrons arrived too late to engage, despite flying at full speed, and three of their aircraft made emergency landings due to fuel shortage. Three Hurricane fighters of No. 145 Squadron made contact, later joined by others. In a confused engagement, III/StG 1 lost two dive-bombders, II/StG 1 suffered one Ju 87 damaged, and three Bf 109 fighters were shot down by No. 145 Squadron for a loss of two Hurricane fighters and their pilots at 09.00.

Late in the morning, StG 2, StG 3 and StG 77 from Angers, Caen and St Malo were escorted by Bf 110 heavy fighters of V/LG 1, to attack the convoy in the area to the south of the Isle of Wight, with about 30 Bf 109 fighters of II and III/JG 27 providing high cover. From 12.20, Spitfire fighters of No. 609 Squadron and Hurricane fighters of Nos 257 and 145 Squadrons attacked the German formations, joined later by No. 238 Squadron. The dive-bombers severely damaged the steamer Surte, the motor vessel Scheldt and steamer Omlandia, and sank the stamer Balmaha soon after this. The steamer Tres was sunk by StG 77. The 1,042-ton steamer Empire Crusader, in the lead, was hit by StG 2 and sank several hours later. Thus four ships had been sunk and another four damaged. Between 20 and 30 RAF fighters attacked the German aircraft and I and II/StG 2 each suffered one damaged Ju 87, StG 3 lost three Stukas from its I Gruppe and two damaged. LG 1 lost one Bf 110 and had three others damaged, JG 27 lost three Bf 109 fighers of its II Gruppe and had another two aircraft damaged. Three Hurricane fighters of No. 238 Squadron were shot down and two pilots were killed by Bf 109 fighters. Squadron Leader H. A. Fenton was wounded while shooting down an He 59 floatplane, and was rescued by the armed trawler Basset. No. 64 Squadron lost one Spitfire and No. 65 Squadron lost two over Dover between 10.45 and 12.07, along with the three pilots in unrelated engagements. JG 27 lost nine Bf 109 fighters.

I/StG 1 looked for the convoy and while reporting 9/10 cloud cover, far from ideal for dive-bombing with the cloud base from 3,500 to 4,000 ft (1065 to 1220 m) above the sea, and the Gruppenkommandeur, Hauptmann Paul-Werner Hozzel, abandoned the mission. Hauptmann Waldemar Plewig, the commander of II/StG 77, used his discretion to fly over the convoy from Le Havre in the unit’s Do 17P reconnaissance aeroplane, found the conditions good enough for an attack, and 82 dive-bombers of III/StG 1, I/StG 3 and the Stab, II/StG 77 were alerted. Major Walter Sigel led StG 3 to rendezvous with Bf 110 escorts of II/ZG 2 and LG 1, and Bf 109 fighters of II/JG 27 provided cover.

III/JG 26, II and III/JG 51 flew a fighter sweep to clear the skies before the attack and engaged Nos 41, 64 and 65 Squadrons, claiming eight Spitfire fighters. A Blenheim of No. 600 Squadron was lost with its crew after taking off from RAF Manston in the middle of the battle. A Spitfire of No. 64 Squadron was shot down, with the pilot seriously wounded, at 12.07, also at Manston. No. 41 Squadron suffered no losses and probably damaged a Bf 109 of II/JG 53 and one from III/JG 54 No. 65 Squadron lost two Spitfire fighters at 10.45.

The Peewit convoy’s ships of Peewit had continued their passage, and the anti-submarine yachts Wilna and Rion, and the armed trawlers Cape Palliser, Kingston Chrysoberyl, Kingston Olivine and Stella Capella were attacked as they searched for survivors: Cape Palliser and Rion were badly damaged. RAF Fighter Command sent Nos 145 and 43 Squadrons to defend the convoy. Just after 16.00, three of No. 145 Squadron’s Hurricane fighters were lost, together with their pilots, against Bf 110 aircraft, and three more were lost by No. 43 Squadron, five of the pilots being killed. Three of StG 77's Stukas were shot down by No. 145 Squadron and four were damaged by No. 43 Squadron. LG 1 suffered damage to a pair of Bf 110 aircraft, and three Bf 109 fighters of II/JG 27 were lost, two shot down by No. 43 Squadron and one damaged. No ships were hit. Nos 152 and 238 Squadrons tried to intercept but failed to make contact with the attackers: No. 152 Squadron met Bf 109 fighters of JG 53 12 miles (19 km) to the south of Swanage and two of its Spitfire fighters were damaged and force-landed, their pilots unhurt. Operating from Guernsey, II/JG 53 claimed one Hurricane and two Spitfire fighters for no loss.

The Luftwaffe flew few sorties on 9 and 10 August.The start of 'Adlerangriff' had been postponed as a result of adverse weather. On 11 August the size and tempo of German air operations increased now that a long period of clear and fine weather was predicted. The Luftwaffe attacked Nos 10, 11 and 12 Groups and ships in the English Channel. Kesselring hoped to draw out and disperse RAF Fighter Command by sending out large numbers of single Staffeln. With the exception of the early morning, Park did not take the bait. While a high proportion of No. 11 Group aircraft were forced into the air, Kesselring’s aim of forcing the diversion of British reinforcements from the other groups was not achieved.

During the morning Hauptmann Walter Rubensdörffer led 17 Bf 110 fighter-bombers of Erprobungsgruppe 210 on a strafing attack on Dover covered by a flight of Bf 109 fighters, which downed three of No. 961 Balloon Squadron’s eight barrage balloons. The Bf 110 fighter-bombers released light bombs but did little damage. Park despatched No. 74 Squadron, which ran into three Staffeln of Bf 109 fighters of JG 51. The closing speed was so great that only a fleeting firing pass could be made by the opposing fighters, which resulted in one British pilot ditching in the sea, later to be rescued. Hurricane fighters of No. 32 Squadron tried to engage the Bf 109 fighters of I/JG 2, and No. 64 Squadron also engaged. Two Bf 109 fighters were shot down, one pilot being wounded and the other killed.

Radar detected a large German build-up over the Cherbourg peninsula and Park ordered Nos 609 and 1 Squadrons from RAF Warmwell and RAF Tangmere to operate over Portland. Six other units from RAF Middle Wallop, RAF Exeter, RAF Tangmere and RAF Warmwell were ordered to readiness. Some 53 fighters were now involved as the Germans approached in strength late in the morning. Around 54 Ju 88 bombers from I and II/KG 54 were supported by 20 He 111 bombers of KG 27; I and II/ZG 2 provided 61 Bf 110 escorts, which were reinforced by 30 Bf 109 fightersof III/JG 2, and JG 27 provided withdrawal cover. It was the largest raid yet sent against a British target and at 10.04, Nos 145, 152, 87, 213 and 238 Squadrons were scrambled to support the two squadrons already airborne.

The Bf 109 and Bf 110 fighters swept ahead of the bombers and were engaged by No. 609 Squadron at 23,000 ft (7010 m). The Spitfire fighters fell onto the flank of the Bf 110 formation and fired full-deflection shots which enabled his pilots to avoid the heavy fighters' battery of fixed forward-firing cannon and machine guns, and shot down five of the German warplanes. Among the dead was the Gruppenkommandeur of I/ZG 2, Major Ernst Ott, who was shot down. Most of the British fighters became entangled with the escort, only four of No. 152 Squadron’s Spitfire fighters spotting the bombers as they headed for Portland and Weymouth. The He 111 bombers attacked from an altitude of 15,000 ft (4570 m), while the Ju 88 bombers descended to 10,000 ft (3050 m) and hit the oil storage tanks. The destroyers Scimitar and Skate were damaged in Portland. The trawler Peter Carey was severely damaged and the steamer Kirnwood and tanker Oil Trader were hit.

JG 27 covered the withdrawal of the bombers and lost three of its fighters to Nos 238 and 145 Squadrons in exchange for four of No. 238 Squadron’s Hurricane fighters, all of whose pilots were killed, and damaged another. No. 145 Squadron suffered two pilots killed, two Hurricane fighters destroyed and two more damaged. The dogfight resulted in the loss of 16 Hurricane fighters, 13 of whose pilots were killed and two wounded. A Spitfire of No. 152 Squadron was shot down and its pilot drowned. German losses were six Bf 110, five Ju 88, one He 111 and six Bf 109 warplanes. Both sides searched for survivors, two Blenheim machines of No. 604 Squadron covered by Spitfire fighters of No. 152 Squadron scouted the Strait of Dover and found a He 59 floatplane protected by Bf 109 fighters. The Spitfire machines held off the German fighters while the Blenheim machines destroyed the He 59; No. 610 Squadron also caught and destroyed a He 59 but was attacked by Bf 109 fighters and lost two Spitfire fighters and two pilots killed.

Rubensdörffer led Erprobungsgruppe 210 and eight Do 17 bombers of 9./KG 2, whose crews were low-level attack specialists. The Germans spotted the Booty convoy off the Harwich/Clacton coast at 22.00. Some 20 Bf 110 fighters of ZG 26 provided high cover for the bombers, but were intercepted by 11 Spitfire fighters of No. 74 Squadron, Hurricane fighters of No. 85 Squadron and six Hurricane fighters of No. 17 Squadron. Three Bf 110 fighters were shot down by No. 85 Squadron and the Hurricane fighters disposed of another. Two Bf 110 and three Do 17 aircraft were also damaged. ZG 26 destroyed one Hurricane and damaged another of No. 17 Squadron, killing one pilot, and two pilots of No. 74 Squadron were shot down and killed.

Another German raid followed, timed to catch the British fighters when they were low on fuel. The second wave of 45 Do 17 bombers and a Staffel of Stukas of II/StG 1 and IV/LG 1 arrived over the Thames river estuary to attack the Agent and Arena convoys, which were hugging the coast. The formation was protected by Bf 109 fighters of JG 26 commanded by Galland. Nos 111 and 74 Squadrons were scrambled, led by Squadron Leader A. G. Malan leading, who claimed a Bf 109 which crash-landed in France; one Stuka of StG 1 also fell to Malan’s unit before the Bf 109 escort arrived. No. 111 Squadron lost four Hurricane fighters, and a fifth such aeroplane crash-landed; four pilots were killed, two believed drowned. The weather forced the Germans to curtail operations in the early afternoon and the lull lasted until the following morning with the 'Adlertag'. The raid sank two armed trawlers, Tamarisk and Pyrope, 12 of whose men were killed.

On 12 August, which was 'Adlertag' and marked the start of the main German effort in the 'Battle of Britain', the Germans began to bombard convoys with long-range artillery emplaced at Cap Gris Nez to protect their planned invasion force. Coaster crews sailing past at 5 or 6 kt found the bombardments highly stressful, but none of the ships were hit. After the operations against the CW.9 convoy, the Luftwaffe campaign moved against inland targets and although the coastal convoys remained vulnerable, the traffic continued. Losses to the Luftwaffe were only a small proportion of the 4 million tons of shipping which sailed along Englands’s southern coast during the 'Kanalkampf', but at its peak it sank or damaged one-third of the ships off the southern coast. Had losses continued at such a rate, it would have become impossible to find new crews for the ships.

The 'Kanalkampf' began the 'Battle of Britain'. The Germans had needed time to establish airfields along the French and Belgian coasts for the air assault on south-eastern England, to link these into the Luftwaffe’s communications systems and to replace the losses of May and June. Hitler and the Oberkommando der Wehrmacht had been uncertain about how to proceed, and attacks on shipping were the only way for the Luftwaffe to engage RAF Fighter Command during this period. Hitler had issued Führerweisung Nr 16 on 16 July ordering the preparation of an invasion fleet, but Göring was against an invasion and up to 1 August failed to attend any of the conferences to improve inter-service co-operation for a landing. Göring may still have believed that the British would negotiate and was content for the English Channel battles to continue. On 19 July, Göring approved a directive to destroy British air power. Hitler issued Führerweisung Nr 17 on 1 August, intending the operation to be a prelude to invasion, and this expanded the scope of Göring’s directive. The campaign against the RAF was to begin on about 5 August, depending on the weather being suitable for mass air operations.

Göring met his staff officers in The Hague on 1 August. Göring believed the inaccurate German intelligence dossiers from Abteilung 5, the Luftwaffe intelligence department, that the RAF was weak and could be defeated within days. Göring hoped that an aerial victory would encourage the British to sue for terms, which would preclude a risky cross-Channel invasion against the might of the Royal Navy; Göring was confident the battle would be over quickly. In the second week of August, Luftflotte II, Luftflotte III and Luftflotte V were ready to begin the assault on England proper. Operations over the Channel and against shipping lost importance as the air war intensified over English air bases.

The British official history, The Defence of the United Kingdom, deemed the German operations a failure, sinking only 30,000 tons of shipping from the nearly 1 million tons of weekly coastal shipping in the English Channel. In 34 days, RAF Fighter Command flew more than 18,000 day sorties, an average of 530 per day. The official history speculated that the Luftwaffe’s daily sortie rate was lower and that many flights were not connected with the 'Kanalkampf'. Even so, the Luftwaffe managed to outnumber the British fighters, which suffered 148 losses, almost half of these in three days in the second week in August. The Luftwaffe losses were put at 286 aircraft, most of them in operations over the English Channel. The German loss of single- and twin-engined fighters was 105, and on the three days of high British losses in August (73 aircraft) the Luftwaffe lost 100 aircraft.

It seems likely, therefore, that between 4 July and 11 August, the RAF lost 115 aircraft shot down and 42 damaged, while the Luftwaffe lost 215 aircraft shot down and 92 damaged.

The mercantile shipping losses of the UK, allied merchant navies and neutral states were 35 ships sunk along with seven fishing vessels, and the Royal Navy lost four destroyers, with at least 176 men killed among about 300 casualties.