| Unit Name: | 6th Anti-Aircraft Division |
| Dates: | 21 August 1939–30 September 1942 |
| Country: |  United Kingdom |
| Branch: | Territorial Army |
| Type: | Anti-Aircraft Division |
| Role: | Air Defence |
| Command Structure: | Anti-Aircraft Command (1939–40) I AA Corps (1940–42) |
| Garrison: | Uxbridge, later Chelmsford |
| Battles: | Battle of Britain The Blitz |
The 6th Anti-Aircraft Division (6th AA Division) was an air defence formation created within Anti-Aircraft Command of Britain's Territorial Army just before the Second World War. It defended the Thames Estuary and the approaches to London during the Battle of Britain and the Blitz.
The 6th AA Division was formed during 1939 to take responsibility for the air defence of the Thames Estuary, Essex and North Kent, with its HQ at Uxbridge, Middlesex. The existing 27th (Home Counties), 28th (Thames & Medway), 29th (East Anglian) and 37th AA Brigades were transferred to this new formation, together with the new formations and units of the Royal Artillery (RA) and Royal Engineers (RE) being raised as part of the expansion of the TA after the Munich Crisis.[1] [2]
The divisional HQ was provided by duplicating the 1st AA Division's headquarter elements at RAF Uxbridge, including 1st AA Divisional Signals.[3] Major-General Frederick Hyland was promoted from command of the 31st (North Midland) Anti-Aircraft Brigade to General Officer Commanding of the new division on 30 May 1939. He continued in command throughout its existence.[2] [4] [5] [6] [7]
The divisional badge was a red arrow piercing a black and white target on a black square.[8]
The division's composition on the outbreak of war in 1939 was as follows:[2] [9] [10] [11]
27th (Home Counties) AA Brigade at Lingfield, Surrey
28th (Thames & Medway) AA Brigade at Kitchener Barracks, Chatham, Kent
29th (East Anglian) AA Brigade at South Kensington, London– came under operational command 7 September 1939[12]
37th AA Brigade at Edmonton, London
56th Light AA Brigade at Uxbridge
At this point the division had a strength of 138 HAA guns (4.5-inch, 3.7-inch or 3-inch), while in the LAA role there were 23 3-inch, 35 2-pounder 'pom-pom' and 40 mm Bofors guns, and 270 light machine guns (LMGs), together with 479 searchlights.[10] [13]
During 1940, the RE's AA Bns were transferred to the RA as Searchlight regiments, while the AA regiments were designated Heavy AA (HAA) to distinguish them from the Light AA (LAA) regiments that were being formed.[14]
The area covered by the 6th AA Division coincided with the RAF Sectors of Debden, North Weald, Hornchurch, Biggin Hill, and Kenley, being the major part of 11 Group of RAF Fighter Command. The coastal boundary ran from Lowestoft in the north to Worthing in the south, while the internal boundary was that of Metropolitan London.[13]
On the outbreak of war the division's HAA guns were contained in four main 'gun defended areas' (GDAs) at Harwich (6 guns), Thames & Medway North (59 guns emplaced along the north bank of the Thames Estuary), Thames & Medway South (74 guns emplaced along the south bank of the Thames Estuary and defending Chatham and Rochester), and Dover (including Folkestone) (6 guns). The four GDAs were controlled by 'gun operations rooms' (GORs) at Felixstowe, Vange, Chatham and Dover respectively. Each GOR was linked directly to No. 11 Group Operations Room at Uxbridge.[13] [15]
Forty-five 'vulnerable points' (VPs) in the divisional area were defended by LAA guns: these included Air Ministry Experimental Stations, fighter aerodromes, dockyards, oil depots, magazines, and factories. The armament ranged from Bofors 40 mm, 3-inch 20 cwt, and 20 mm Hispano cannon to LMGs. Searchlights were deployed in single-light stations at approximately 6000yd spacing, with 3500yd spacing along the coast and in the GDAs. Each searchlight site was equipped with AA LMGs.[13]
To deal with minelaying off East Anglia and Kent, the 6th AA Division organised a flotilla of three small Paddle steamers, each equipped with one Bofors gun and two S/Ls. Their role was to patrol the channels off the coast to engage enemy minelaying aircraft and to report the position of mines to the Royal Navy or to detonate them if possible. The flotilla fought a number of actions that caused a drop in enemy Seaplane activity. Later the vessels were replaced by larger ones carrying a gun-laying (GL Mk. I radar) radar set, while other GL positions were set up on the coast to track minelayers. It was possible to plot where a mine fell from an aircraft and then direct minesweepers to the position.[16]
Although new units were joining, AA Command had to relinquish some of the more experienced ones to supplement the AA cover for the build-up of the British Expeditionary Force (BEF) in France. The 79th (Hertfordshire Yeomanry) AA Rgt was withdrawn in January and redeployed as a Base Defence unit for the BEF. A fortnight after the Dunkirk evacuation, the regiment was evacuated from St Nazaire.[17]
In the spring of 1940, the 6th AA Division reorganised its growing AA defences. As a result, the 29th AA Brigade, which had been purely a S/L formation, transferred its sites in Kent to the 27th AA Brigade, and took over responsibility for the HAA and LAA defence of RAF air and radar stations in Essex and for a new GDA around Harwich and the nearby harbours. The 29th AA Brigade also moved its HQ from Kensington to Boxted, Essex.[12]
The Phoney War ended with the German invasion of France and the Low Countries on 10 May 1940. Home Forces became concerned about the threat from German paratroopers and AA Command's units were given anti-invasion roles. A plan to attach groups of riflemen from the infantry training centres to the 6th AA Division's widely spaced S/L sites foundered on the lack of men. Instead the S/L detachments were given the responsibility for attacking parachutists before they could organise, and spare men at company HQs were formed into mobile columns using requisitioned civilian transport to hunt them down. These arrangements were never tested in practice.[12]
In July the division was joined by the 6th AA Brigade, which had been created to command the AA units in the Norwegian Campaign.[18] [19] After the evacuation of British forces from Norway it reformed in the 2nd AA Division as a light AA brigade in southern East Anglia, commanding widely spaced S/L sites and LAA guns scattered at VPs, mainly RAF airfields. When the brigade transferred to 6 AA Division it brought with it two S/L regiments and a newly formed LAA regiment, and was given control of the 12th LAA Rgt from the 56th LAA Brigade. The 56th Light AA Brigade retained responsibility for S/L and LAA units south of the Thames Estuary.[20]
On 11 July 1940 (shortly before the Battle of Britain began), the 6th AA Division's guns were deployed as follows[7] [21] [22]
At this point 6 AA Division possessed 21 GL radar sets, which increased to 35 by October.
The Luftwaffe began its bombing offensive against the British mainland with small-scale raids on coastal targets, then in June began night raids against ports and industrial targets in the North and Midlands. This gave the AA units valuable experience, and the 6th AA Division was encouraged when its batteries shot down three raiders at night over Essex. In July, the Luftwaffe switched back to heavy daylight raids against south coast ports and shipping: the guns at Dover were in action virtually every day. Lieutenant-Colonel N.V. Sadler of the 75th HAA Rgt developed an effective system of HAA barrages over individual points in Dover Harbour and the shipping channels, underpinned by LAA fire. In one day the regiment shot down seven Junkers Ju 87 'Stukas' together with two Messerschmitt Bf 109s and a Dornier Do 215.[13] [23]
Next the Luftwaffe began targeting Fighter Command's airfields in South-East England with mass raids, and AA Command responded by shifting guns into the area. On 18 August, seven raids appeared in 4 hours, and the guns of the 28th and 37th AA Brigades, together with those of the neighbouring 1st and 5th AA Divisions, accounted for 23 aircraft of various types. Four days later a mass raid flew up the Thames Estuary to attack RAF Hornchurch and was engaged by the 28th and 37th AA Brigades in 'Thames North' and 'Thames South'. Their guns broke up the formations, allowing the RAF's fighters to press home their attacks, and the guns used 'pointer' rounds to mark the approach of fresh waves of bombers.[13] [23]
The peak intensity of the Battle of Britain came between 24 August and 15 September as the Luftwaffe put in its maximum effort to destroy Fighter Command. Mass raids aimed to saturate the defences. On 1 September over 200 aircraft attacked Maidstone, Biggin Hill, Kenley and Chatham. In joint action with the fighters, the guns of the 1st and 6th AA Divisions broke up the attacks and shot down four aircraft, but the airfields at Kenley and Biggin Hill were badly hit. Next day a mass stream of Dornier Do 17s arrived over the Medway and flew up the Thames towards Hornchurch. They at once came under heavy fire from the 3.7 and 4.5 inch HAA guns of the 28th and 37th AA Brigades on opposite sides of the river. Of about 100 bombers escorted by 190 fighters, 15 were shot down by AA fire. On 7 September over 300 aircraft approached the Thames Estuary, where the 15th HAA batteries of the 28th and 37th AA Brigade split the formations up, although the Thameshaven oil wharves, Tilbury Docks, Woolwich and West Ham were badly hit. One of the lessons of the Battle of Britain was that day bombers needed to fly in tight formation for mutual protection against fighters, but in doing so they were vulnerable to AA fire. On 8 September a formation of 15 Dornier Do 17s flew along the Thames at 15000feet. The opening salvo from a troop of four 3.7-inch guns of the 28th AA Brigade brought down the three leading aircraft and scattered the others in disorder, jettisoning their bombs as they escaped.[24] The 6th AA Division's guns were again in prolonged action during the running battles of 15 September, when the Luftwaffe made its last and biggest attempt to gain air supremacy. AA fire accounted for eight of the 60–80 German aircraft brought down that day.[13] [23] [25]
Although there were severe night bombing raids against many industrial towns and cities of the UK during The Blitz, the main Luftwaffe effort was directed against London.[26] The metropolis was covered by the 'London Inner Artillery Zone' (IAZ) under the 1st AA Division, adjoining which were the 'Thames North' and 'Thames South' belts controlled by the 6th AA Division. The Thames estuary was not only a primary route for bombers approaching the IAZ, but was also flanked by important industrial towns. There were over 20 HAA sites planned for Thames North (37th AA Brigade) from Dagenham to Thorpe Bay, of which only half were occupied in September 1940 with a mixture of 3.7-inch and 4.5-inch guns. There were also LAA guns at VPs such as Purfleet, Tilbury Docks, Thameshaven, Coryton Refinery, and RAF Hornchurch. Tactical control was under the GOR at Vange. The 6th AA Division's HQ was moved to Chelmsford in Essex as the campaign progressed. The 28th AA Brigade controlled Thames South with 25 planned HAA sites, of which 16 were occupied in September. It ran along the Kent coast from Dartford to Chatham where there was a strongly defended area around the naval dockyards and aircraft factories. VPs requiring LAA defence included Crayford, Northfleet, Rochester and the Isle of Grain on the estuary together with the nearby RAF airfields at Biggin Hill and West Malling. The Thames South GOR was at Chatham. Because of the large LAA commitments, the 6th AA Division placed these under the 56th LAA Brigade. The searchlights of Thames North and Thames South had dual roles in assisting AA guns or night-fighters. The S/L layouts had been based on a spacing of 3500 yards, but due to equipment shortages this had been extended to 6000yd by September 1940. In November this was changed to clusters of three lights to improve illumination, but this meant that the clusters had to be spaced 10400yd apart.[27]
During the London Blitz of Autumn 1940 to Spring 1941, the division was assigned to I AA Corps and was constituted as follows:[8] [28] [29] [30]
6th AA Brigade covering Essex airfields
28th AA Brigade covering South Thames, Chatham and Dover
29th AA Brigade covering Essex airfields and Harwich
37th AA Brigade covering North Thames
56th AA Brigade covering Kent airfields
In September 1940, the 6th AA Division formed the 6th Anti-Aircraft Z Regiment, Royal Artillery equipped with Z Battery rocket projectiles.[31] [32]
The Blitz ended in May 1941, but occasional raids continued. Newly formed AA units joined the division, the HAA units increasingly being 'mixed' ones into which women of the Auxiliary Territorial Service were integrated. At the same time, experienced units were posted away for service overseas. This led to a continual turnover of units, which accelerated in 1942 with the preparations for Operation Torch and the need to transfer AA units from North West England to counter the Baedeker Blitz and the Luftwaffes hit-and-run attacks against South Coast towns.[33]
The 29th AA Brigade was disbanded on 14 February 1942 and the bulk of its responsibilities taken over by the 37th AA Brigade, the remainder by 6th AA Brigade.[34] A newly formed 71st AA Brigade joined in June 1942.[35]
During this period the division was composed as follows (temporary attachments omitted):[36] [37] [35]
By December 1941, the 37th AA Brigade only had the 75th HAA Rgt under its command; it was then joined by:
By May 1942, the 56th AA Brigade only had the 4th LAA and 73rd S/L under its command; it was then joined by:
The increased sophistication of Operations Rooms and communications was reflected in the growth in support units, which attained the following organisation by May 1942:[35]
The RAOC workshop companies became part of the new Royal Electrical and Mechanical Engineers (REME) during 1942.
A reorganisation of AA Command in October 1942 saw the AA divisions disbanded and replaced by a number of AA Groups more closely aligned with the groups of Fighter Command. Most of 6th AA Division became 2nd AA Group cooperating with No. 11 Group RAF.[1] [2] [3] [47]