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.[11][14]
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.[15]
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.[14][16]
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 6,000 yards (5,500 m) spacing, with 3,500 yards (3,200 m) spacing along the coast and in the GDAs. Each searchlight site was equipped with AA LMGs.[14]
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.[17]
Phoney War
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.[18]
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.[13]
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.[13]
In July the division was joined by the 6th AA Brigade, which had been created to command the AA units in the Norwegian Campaign.[19][20] 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.[21][22][23]
On 11 July 1940 (shortly before the Battle of Britain began), the 6th AA Division's guns were deployed as follows[8][24][25]
Dover – 18 HAA
Thames & Medway South – 70 HAA
Thames & Medway North – 46 HAA
Harwich – 17 HAA
Aerodromes – 37 HAA
Aerodromes, vital points etc. – 101 LAA + 376 AA LMGs
At this point 6 AA Division possessed 21 GL radar sets, which increased to 35 by October.
Battle of Britain
3.7-inch guns of the 75th HAA Regiment at Dover, 1940.
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.[14][26]
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 41⁄2 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.[14][26]
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 15,000 feet (4,600 m). 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.[27] 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.[14][26][28]
The Blitz
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.[29] 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 6,000 yards (5,500 m) 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 10,400 yards (9,500 m) apart.[30]
73rd (Kent Fortress) Searchlight Regiment, RA – as above
In September 1940, the 6th AA Division formed the 6th Anti-Aircraft Z Regiment, Royal Artillery equipped with Z Battery rocket projectiles.[32][33]
Mid-War
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 Luftwaffe's hit-and-run attacks against South Coast towns.[34]
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.
[35] A newly formed 71st AA Brigade joined in June 1942.[36]
Order of Battle
During this period the division was composed as follows (temporary attachments omitted):[37][38][36]
6th AA Brigade
121st HAA Rgt – from the 29th AA Brigade February 1942
131st LAA Rgt – converted from the 81st S/L Rgt in the 29th AA Brigade; joined April 1942 but rostered for overseas service and became unbrigaded soon afterwards
29th S/L Rgt – to the 8th AA Division January 1942
73rd S/L Rgt
6th AA 'Z' Rgt – to the 1st AA Division Summer 1941
12th AA 'Z' Rgt – new unit formed March 1941; to the 28th AA Brigade January 1942[32]
By May 1942, the 56th AA Brigade only had the 4th LAA and 73rd S/L under its command; it was then joined by:
84th HAA Rgt – from the 37th AA Brigade August, left September 1942, later in Operation Torch[42][43]
101st HAA Rgt – joined June 1942, left July 1942, later to India[47]
66th LAA Rgt – joined June 1942, to the 71st AA Brigade same month
28th S/L Rgt – from the 37th AA Brigade June 1942
32nd S/L Rgt – from the 6th AA Brigade August 1942
71st AA Brigade – joined June 1942
72nd HAA Rgt – from WO control (previously the 28th AA Brigade) June, left July 1942; later to Operation Torch[42][43]
76th HAA Rgt – from the 28th AA Brigade July 1942; left September 1942, later in Operation Torch[42][43]
85th HAA Rgt – from the 28th AA Brigade July 1942; later in Operation Torch[42][43]
90th HAA Rgt – from unbrigaded (previously the 28th AA Brigade) September 1942
127th HAA Rgt – from the 28th AA Brigade June 1942
66th LAA Rgt – from the 56th AA Brigade June 1942; left September 1942, later to MEF[44]
122nd LAA Rgt – converted from 45 S/L Rgt, joined July 1942[32]
129th LAA Rgt – converted from 35 S/L Rgt, joined September 1942, then to the 28th AA Brigade[32]
132nd LAA Rgt – converted from 85th S/L Rg, joined June 1942, to the 28th AA Brigade July 1942[32]
The increased sophistication of Operations Rooms and communications was reflected in the growth in support units, which attained the following organisation by May 1942:[36]
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.[2][3][4][48]
Cole, Howard (1973). Formation Badges of World War 2. Britain, Commonwealth and Empire. London: Arms and Armour Press.
Basil Collier, History of the Second World War: The Defence of the United Kingdom, [1]
Gen Sir Martin Farndale, History of the Royal Regiment of Artillery: The Years of Defeat: Europe and North Africa, 1939–1941, Woolwich: Royal Artillery Institution, 1988/London: Brasseys, 1996, ISBN1-85753-080-2.
J.B.M. Frederick, Lineage Book of British Land Forces 1660–1978, Vol II, Wakefield, Microform Academic, 1984, ISBN1-85117-009-X.
Joslen, H. F. (2003) [1960]. Orders of Battle: Second World War, 1939–1945. Uckfield, East Sussex: Naval and Military Press. ISBN978-1-84342-474-1.
Norman E.H. Litchfield, The Territorial Artillery 1908–1988 (Their Lineage, Uniforms and Badges), Nottingham: Sherwood Press, 1992, ISBN0-9508205-2-0.
Cliff Lord & Graham Watson, Royal Corps of Signals: Unit Histories of the Corps (1920–2001) and its Antecedents, Solihull: Helion, 2003, ISBN1-874622-92-2.
C. Digby Planck, History of the 7th (City of London) Battalion London Regiment, London: Old Comrades' Association, 1946/Uckfield: Naval & Military Press, 2002, ISBN1-84342-366-9.
Brig N.W. Routledge, History of the Royal Regiment of Artillery: Anti-Aircraft Artillery 1914–55, London: Royal Artillery Institution/Brassey's, 1994, ISBN1-85753-099-3.
Col J.D. Sainsbury, The Hertfordshire Yeomanry Regiments, Royal Artillery, Part 2: The Heavy Anti-Aircraft Regiment 1938–1945 and the Searchlight Battery 1937–1945, Welwyn: Hertfordshire Yeomanry and Artillery Trust/Hart Books, 2003, ISBN0-948527-06-4.
United Kingdom
Territorial Army
