11th Anti-Aircraft Division (United Kingdom)


The 11th Anti-Aircraft Division was an air defence formation of the British Army during the early years of the Second World War. 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

The 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 defences of the United Kingdom. The division was formed by separating two Territorial Army brigade areas from the 4th AA Division in North West England and adding a Regular Army headquarters from the that had recently returned from the Dunkirk evacuation.
The divisional headquarters was at Birmingham and the first General Officer Commanding, 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 the 34th AA Brigade. The 11th AA Division formed part of II AA Corps.

The Blitz

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

Coventry Blitz

At the time the 11th 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 of the 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.

Birmingham Blitz

The Coventry raid was followed by three consecutive nights of attacks on Birmingham and other Black Country industrial towns including West Bromwich, Dudley and Tipton were all hit. Birmingham was bombed again during December 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 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:
By March 1941, the 1st AA Brigade HQ together with the Regular 1st and 6th HAA Rgts had returned to the War Office Reserve pending deployment overseas, but temporarily remained part of AA Command. By mid-May 1941, the 1st AA Brigade had handed over its units and responsibilities to a new 68th AA Brigade and left AA Command, while the 67th AA Brigade had also been created by splitting the 34th AA Brigade.

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 intervals in 'Indicator Belts' in the approaches to the GDAs, and 'Killer Belts' at 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 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 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:
By May 1942, the 67th AA Brigade consisted only of 142nd HAA Rgt; thereafter it was joined by:
In June 1942, the 67th AA Brigade transferred to the 9th AA Division, and by October 1942 it once again consisted of a single regiment.
The increased sophistication of Operations Rooms and communications was reflected in the growth in support units, which attained the following organisation by May 1942:
The RAOC companies became part of the new Royal Electrical and Mechanical Engineers 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. The 11th AA Division merged with the 4th AA Division into the 4th AA Group based at Preston and cooperating with No. 9 Group RAF.
The 11th AA Divisional Signals was amalgamated back into its parent 4th AA Divisional Signals as the 4th AA Group Signals.

General Officer Commanding

The following officer commanded 11th AA Division: