11th Anti-Aircraft Division (United Kingdom)

11th Anti-Aircraft Division (11 AA Division) was an air defence formation of the British Army during the early years of World War II. It defended the West MIdlands during The Blitz, including the notorious raid on Coventry, and the subsequent Baedeker Blitz, but only had a short career.

Mobilisation
11th Anti-Aircraft Division was one of five new divisions created on 1 November 1940 by Anti-Aircraft Command to control the expanding anti-aircraft (AA) defences of the United Kingdom. The division was formed by separating two Territorial Army (TA) brigade areas (34 (South Midland) and 54) from 4 AA Division in North West England and adding a Regular Army headquarters (1 AA Bde) that had recently returned from the Dunkirk evacuation.

The divisional headquarters (HQ) was at Birmingham and the first General Officer Commanding (GOC), appointed on 14 November 1940, was Major-General Sidney Archibald, who had been Major General, Royal Artillery, of Home Forces and was a former commander of 34 (South Midland) AA Bde. 11 AA Division formed part of 2 AA Corps.

The Blitz
The division's fighting units, organised into three AA Brigades, consisted of Heavy (HAA) and Light (LAA) gun regiments and Searchlight (S/L) regiments of the Royal Artillery. The HAA guns were concentrated in the Gun Defence Areas (GDAs) at Birmingham and Coventry, LAA units were distributed to defend Vulnerable Points (VPs) such as factories and airfields, while the S/L detachments were disposed in clusters of three, spaced 10,400 yards apart.

Coventry Blitz
At the time 11 AA Division was created, the industrial towns of the UK were under regular attack by night, to which the limited AA defences replied as best they could. The West Midlands had already suffered badly, with Birmingham and Coventry receiving heavy raids in August and October. The new division was still being formed when the Luftwaffe launched a series of devastating raids, beginning with the notorious Coventry Blitz on 14/15 November.

The Coventry raid was preceded by a dozen pathfinder aircraft of Kampfgeschwader 100 riding an X-Gerät beam to drop flares and incendiary bombs on the target. The huge fires that broke out in the congested city centre then attracted successive 40-strong waves of bombers flying at heights between 12,000 and 20,000 feet to saturate the defences. The AA Defence Commander (AADC) of 95th HAA Rgt had prepared a series of concentrations to be fired using sound-locators and GL Mk. I gun-laying radar, and 128 concentrations were fired before the bombing severed all lines of communication and the noise drowned out sound-location. Some gun positions were able to fire at S/L beam intersections, glimpsed through the smoke and guessing the range. Although the Coventry guns fired 10 rounds a minute for the whole 10-hour raid, only three aircraft were shot down over the UK that night, and the city centre was gutted.

The change in enemy tactics led to HAA guns being moved from London to the West Midlands (for example, 6 HAA Regt).

Birmingham Blitz
The Coventry raid was followed by three consecutive nights (19–22 November) of attacks on Brimingham and other Black Country industrial towns including West Bromwich, Dudley and Tipton were all hit. Birmingham was bombed again during December (3, 4, 11) and on 11 March 1941, but the full Birmingham Blitz came in April 1941, with heavy raids on the nights of 9/10 and 10/11 of the month, causing extensive damage and casualties.

The Blitz is generally held to have ended on 16 May 1941 with another attack on Birmingham. By now the HAA sites had the advantage of GL Mk I* radar with an elevation finding (E/F or 'Effie') attachment, and several attackers were turned away by accurate fire and their bombs scattered widely, some on nearby Nuneaton. The city was attacked again in July, but the Luftwaffe bombing offensive was effectively over. The West Midlands had been the hardest hit area of the UK after London and Merseyside.

Order of Battle 1940–41
The division's composition during the Blitz was as follows:


 * 1 AA Bde – HQ Crewe: responsible for Staffordshire, airfields and VPs; left by May 1941
 * 1st HAA Rgt
 * 106th HAA Rgt
 * 45th LAA Rgt
 * 63rd LAA Rgt – new regiment raised in October 1940
 * 61st (South Lancashire) S/L Rgt
 * 78th S/L Rgt
 * 83rd S/L Rgt – new regiment raised in January 1941 at Crewe


 * 34 (South Midland) AA Bde – HQ Coventry: responsible for Birmingham and Coventry GDAs
 * 6 HAA Regt – arrived from London 24 November 1940
 * 60th (City of London) HAA Rgt
 * 95th HAA Rgt
 * 110th HAA Rgt – new regiment raised in October 1940
 * 112th HAA Rgt – new regiment raised in October 1940
 * 22nd LAA Regt


 * 54 AA Bde – HQ Sutton Coldfield: responsible for S/L provision to West Midlands GDAs
 * 45th (Royal Warwickshire Regiment) S/L Rgt
 * 80th S/L Rgt – new regiment raised in October 1940


 * 10th AA 'Z' Rgt – divisional Z Battery rocket unit formed January 1941


 * 11 AA Divisional Signals, Royal Corps of Signals (RCS) – formed at Birmingham November–December 1940 as duplicate of 4 AA Divisional Signals
 * 11 AA Divisional Royal Army Service Corps (RASC)
 * 254 and 912 Companies
 * 11 AA Divisional Company, Royal Army Medical Corps (RAMC)
 * 11 AA Divisional Workshop Company, Royal Army Ordnance Corps (RAOC)

By March 1941, 1 AA Bde HQ together with the Regular 1st and 6th HAA Rgts had returned to the War Office (WO) Reserve pending deployment overseas, but temporarily remained part of AA Command. By mid-May 1941, 1 AA Bde had handed over its units and responsibilities to a new 68 AA Bde and left AA Command, while 67 AA Bde had also been created by splitting 34 AA Bde.

Mid-War
By October 1941 the availability of S/L control radar was sufficient to allow AA Command's S/L sites to be 'declustered' into single-light sites spaced at 10,400-yard intervals in 'Indicator Belts' in the approaches to the GDAs, and 'Killer Belts' at 6000-yard spacing to cooperate with the RAF's Night-fighters.

Although the Luftwaffe 's so-called Baedeker Blitz of 1942 was mainly aimed at unprotected cities, Birmingham was hit on several occasions in June and July that year.

Newly-formed AA units joined the division, the HAA and support units increasingly becoming 'Mixed' units, indicating that women of the Auxiliary Territorial Service (ATS) were fully integrated into them. At the same time, experienced units were posted away to train for service overseas. This led to a continual turnover of units, which accelerated in 1942 with the preparations for the invasion of North Africa (Operation Torch) and the need to transfer AA units to counter the Baedeker raids and the Luftwaffe 's hit-and-run attacks against South Coast towns.

Order of Battle 1941–42
During this period the division was composed as follows:


 * 34 AA Bde
 * 6th HAA Rgt – left in September 1941 for overseas service; captured in Java March 1942
 * 55th (Kent) HAA Rgt – from 6 AA Division by December 1941; to WO Control December 1941, left February 1942 for Persia and Iraq Command (PAIFORCE)
 * 57th (Wessex) HAA Rgt – from 1 AA Division March 1942; to 9 AA Division May 1942
 * 60th HAA Rgt – to 68 AA Bde Summer 1941
 * 71st (Forth) HAA Rgt – from 3 AA Division by December 1941; to 6 AA Division May 1942
 * 95th HAA Rgt – returned from 67 AA Bde December 1941; left January 1942, arrived in India April 1942
 * 107th HAA Rgt – from 4 AA Division by May 1942; to 5 AA Division June 1942
 * 110th HAA Rgt – to Orkney and Shetland Defences (OSDEF) May 1941
 * 122nd HAA Rgt – new regiment formed in February 1941; to 67 AA Bde by December 1941
 * 134th (Mixed) HAA Rgt – new regiment formed in September 1941
 * 142nd (Mixed) HAA Rgt – from 67 AA Bde June 1942
 * 22nd LAA Rgt – returned from 67 AA Bde by December 1941; to 54 AA Bde June 1942
 * 42nd LAA Rgt – left Summer 1941; to Middle East Forces by December 1941
 * 10th AA 'Z' Rgt – to 67 AA Bde Summer 1941; returned by December 1941


 * 54 AA Bde
 * 22nd LAA Rgt – from 34 AA Bde June 1942; to WO Control September 1942; later to Operation Torch
 * 111th LAA Rgt – from 2 AA Division July 1942
 * 128th LAA Rgt – from 67 AA Bde June 1942; to 68 AA Bde July 1942
 * 30th (Surrey) S/L Rgt – from 10 AA Division by May 1942; to WO Control September 1942; later to Operation Torch
 * 45th S/L Rgt – converted into 122nd LAA Rgt February 1942, joined 68 AA Bde May 1942
 * 59th S/L Rgt – to OSDEF May 1941
 * 80th S/L Rgt
 * 83rd S/L Rgt – from 68 AA Bde Summer 1941


 * 67 AA Bde
 * 95th HAA Rgt – from 34 AA Bde by May 1941, returned December 1941
 * 122nd HAA Rgt – from 34 AA Bde by December 1941; to 68 AA Bde December 1941
 * 138th HAA Rgt – from 9 AA Division August 1942; to 3 AA Division September 1942
 * 142nd (Mixed) HAA Rgt – new unit formed December 1941; to 34 AA Bde June 1942
 * 22nd LAA Rgt – from 34 AA Bde by May 1941; returned by December 1941
 * 79th LAA Rgt – new unit formed July 1941; to PAIFORCE by May 1942
 * 10th AA 'Z' Rgt – from 34 AA Bde Summer 1941; returned by December 1941

By May 1942, 67 AA Bde consisted only of 142nd (M) HAA Rgt; thereafer it was joined by:
 * 119th HAA Rgt – from 8 AA Division June 1942; to OSDEF September 1942
 * 143rd (Mixed) HAA Rgt – new regiment formed January 1942, joined July 1942
 * 87th LAA Rgt – from 8 AA Division June 1942; to unbrigaded July 1942
 * 128th LAA Rgt – converted from 87th S/L Rgt, joined May 1942; to 54 AA Bde June 1942
 * 135th LAA Rgt – new regiment formed in January 1942; joined July 1942; to 8 AA Division September 1942
 * 37th (Tyne Electrical Engineers) S/L Rgt – from 9 AA Division July 1942; returned September 1942

In June 1942, 67 AA Bde transferred to 9 AA Division, and by October 1942 it once again consisted of a single regiment (143rd (M) HAA).


 * 68 AA Bde
 * 60th HAA Rgt – from 34 AA Bde Summer 1941; to 12 AA Division by December 1941
 * 106th HAA Rgt – from 1 AA Bde; to 2 AA Division Summer 1941
 * 115th HAA Rgt – from OSDEF September 1942
 * 122nd HAA Rgt – from 67 AA Bde December 1941; to unbrigaded July 1942
 * 45th LAA Rgt – from 1 AA Bde; to 2 AA Division December 1941
 * 63rd LAA Rgt – from 1 AA Bde; to WO Control September 1942; later to Operation Torch
 * 98th LAA Rgt – new unit formed by a cadre from 45th LAA Rgt December 1941; to 4 AA Division by May 1942
 * 122nd LAA Rgt – from 87th S/L Rgt, 54 AA Bde, May 1942; to 6 AA Division by September 1942
 * 128th LAA Rgt – from 54 AA Bde July 1942
 * 38th (The King's Regiment) S/L Rgt –  from OSDEF June 1941
 * 61st S/L Rgt – from 1 AA Bde
 * 83rd S/L Rgt – from 1 AA Bde; to 54 AA Bde Summer 1941
 * 78th S/L Rgt – from 1 AA Bde

The increased sophistication of Operations Rooms and communications was reflected in the growth in support units, which attained the following organisation by May 1942:


 * 11 AA Division Mixed Signal Unit HQ, RCS
 * HQ No 1 Company
 * 11 AA Division Mixed Signal Office Section
 * 68 AA Brigade Signal Office Mixed Sub-Section
 * 118 RAF Fighter Sector Sub-Section (RAF Atcham)
 * 320 AA Gun Operations Room Mixed Signal Section (Crewe)
 * 344 AA Gun Operations Room Mixed Signal Section (RAF Valley)
 * 20 AA Line Maintenance Section
 * HQ No 2 Company
 * 401 AA Gun Operations Room Mixed Signal Section (Birmingham)
 * 1 AA Sub-Gun Operations Room Mixed Signal Sub-Section
 * 2 AA Sub-Gun Operations Room Mixed Signal Sub-Section
 * 3 AA Sub-Gun Operations Room Mixed Signal Sub-Section
 * 4 AA Sub-Gun Operations Room Mixed Signal Sub-Section
 * 413 AA Gun Operations Room Mixed Signal Section (Coventry) – formed from 4 Sub-GOR July 1942
 * 34 AA Brigade Signal Office Mixed Sub-Section
 * 54 AA Brigade Signal Office Mixed Sub-Section
 * 119 RAF Fighter Sector Sub-Section (RAF Honiley)
 * 28 AA Line Maintenance Section
 * 29 AA Line Maintenance Section


 * HQ 11 AA Div RASC
 * 254, 912 Companies
 * 11 AA Div RAMC
 * 11 AA Div Workshop Company, RAOC
 * 11 AA Div Radio Maintenance Company, RAOC

The RAOC companies became part of the new Royal Electrical and Mechanical Engineers (REME) during 1942.

Disbandment
A reorganisation of AA Command in October 1942 saw the AA divisions disbanded and replaced by a smaller number of AA Groups more closely aligned with the groups of RAF Fighter Command. 11 AA Division merged with 4 AA Division into 4 AA Group based at Preston and cooperating with No. 9 Group RAF.

11 AA Divisional Signals was amalgamated back into its parent 4 AA Divisional Signals as 4 AA Group (Mixed) Signals.

General Officer Commanding
The following officer commanded 11th AA Division:
 * Major-General Sidney Archibald (11 November 1940–30 September 1942)

External sources

 * British Military History


 * Generals of World War II


 * Royal Artillery 1939–1945 (archive site)