28th (Thames and Medway) Anti Aircraft Brigade

Origin

German air raids by Zeppelin airships and Gotha bombers on London and other British cities during World War I had shown the need for strong anti-aircraft (AA) defences in any future war. When the Territorial Army (TA) was reformed in the 1920s it included a number of dedicated AA units of the Royal Artillery (RA) and Royal Engineers (RE). At first these were concentrated in London under 26th and 27th Air Defence Brigades, but in 1925 55th (Kent) Anti-Aircraft Brigade, RA was formed to defend the Medway Towns of North Kent. 28th Air Defence Brigade (ADB) was then formed at Tunbridge Wells. to command the AA defences in the area, even though it only had 55th AA Bde under its command, and that in turn consisted only of 163rd (Kent) AA Battery at Tunbridge Wells. (There were also 313 and 314 independent AA searchlight companies of the RE (TA) in Kent, but these were not formally subordinated to 28 ADB at this time.)

At first, 28th ADB was subordinate to the Home Counties Area of Eastern Command, but as Britain's AA defences expanded during the 1930s, higher formations became necessary. 1st AA Division was formed to cover London and the Home Counties in 1935. The 28th AD Bde was reorganised as 28th (Thames & Medway) Anti-Aircraft Group, based at Kitchener Barracks, Chatham, and commanding all the gun and searchlight units in the area.

Order of Battle 1935

The composition of 28 AA Group in December 1935 was as follows:

28th and other Anti-Aircraft Groups adopted the more normal formation title of 'Brigades' after the Royal Artillery redesignated its Brigades as 'Regiments' in 1938.

Order of Battle 1939

By 3 Sep 1939 the London and searchlight units had left 28th AA Brigade, which was now entirely composed of Heavy AA artillery regiments drawn from Kent. It was serving in 6 AA Division, which was formed in 1939 to take responsibility for air defence of the Thames Estuary, Essex and Kent.

The 89th AA Regiment sailed for Egypt in December 1939.

Phoney War

Opportunities for action were rare during the Phoney War, but on the night of 22/23 November 1939 the HAA guns of 28 AA Bde ('Thames South') combined with those of 37 AA Bde on the other bank of the river ('Thames North') to engage at least two enemy mine-laying aircraft that had strayed into the mouth of the Estuary. One wrecked aircraft was found on the marshes and credited to 206 Bty of 58th HAA Rgt at Allhallows, Kent.

In 1940, AA units equipped with 3.7-inch and similar guns were redesignated 'Heavy Anti-Aircraft' (HAA), while units equipped with guns like the Bofors 40 mm gun were designated 'Light Anti-Aircraft' (LAA).

In the summer of 1940, the brigade was joined by 53rd (City of London) HAA Regiment, which had been evacuated (without guns) from Marseille after the Fall of France.

28 AA Bde was responsible for the defences on the south side of the Thames Estuary (Thames South) including the Royal Naval Dockyard at Chatham, as well as the Port of Dover. By 11 July 1940, the Thames South AA layout operated by 28 AA Bde had a total of 70 HAA guns (3.7-inch and 4.5-inch).

Battle of Britain

The brigade was heavily engaged throughout the Battle of Britain. On 18 August, for example, German air raids appeared over RAF airfields at West Malling, Manston, Kenley, Biggin Hill, Gravesend and the town of Sevenoaks, all within four and a half hours in the afternoon. The guns of 28 AA Bde and its neighbours were in action and accounted for 23 enemy aircraft. Four days later a mass raid flew up the Thames Estuary to attack RAF Hornchurch on the Essex shore: the raid was broken up by 28 and 37 AA Bdes, and then the fighters of No. 11 Group RAF attacked. Follow-up raids were marked for the fighters by 'pointer' rounds of HAA fire. On 1 September over 200 aircraft attacked Maidstone, Biggin Hill, Kenley and Chatham: in joint action with the fighters, the guns broke up the formations and shot down four aircraft, but the airfields at Biggin Hill and Kenley were badly hit. Next day a mass raid arrived over the Medway and flew up the Thames towards Hornchurch. They came under heavy fire from the 3.7s and 4.5s of 28 and 37 AA Bdes and 15 were shot down before the fighters took over. On 7 September heavy raids up the estuary attacked oil wharves at Thameshaven, Tilbury Docks and Woolwich Arsenal: a total of 25 aircraft were destroyed by AA guns and fighters.

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 Do17s flew along the Thames at 15,000 feet. The opening salvo from a troop of four 3.7-inch guns of 28 AA Bde brought down the three leading aircraft and scattered the others in disorder, jettisoning their bombs as they escaped. On 15 September, remembered as the zenith of the battle, the guns of 28 AA Bde were in prolonged combat, especially with aircraft over Chatham in the morning, and again in the afternoon.

The Blitz

After 15 September the intensity of Luftwaffe day raids declined rapidly, and it began a prolonged night bombing campaign over London and industrial towns (The Blitz). This meant that 28 Bde was in action night after night as the bomber streams approached the London Inner Artillery Zone, but even with the assistance of searchlights, the effectiveness of HAA fire and fighters was greatly diminished in the darkness. By now Thames South had a planned layout of 25 HAA sites (of which only 16 were occupied). It ran from Dartford to Chatham, where there was a strongly defended area containing the naval dockyards at Chatham and Sheerness and the aircraft factory at Rochester. This was controlled from a Gun Operations Room (GOR) at Chatham. 28 AA Bde was so stretched that 6 AA Division gave responsibility for LAA cover for Vulnerable Points (VPs) at Crayford, Northfleet, Rochester and the Isle of Grain to 56 LAA Bde. The searchlight layout in Thames South had the dual role of assisting guns or night fighters. The whole was under the operational control of No 11 Group RAF.

Operational research

One of the operational sites in Thames South, TS21, was taken over by AA Command's Operational Research Group under Patrick Blackett ('Blackett's Circus') to combat-test and develop the new technologies coming forward such as Gun-Laying (GL) Radar and Searchlight Control (SLC) Radar. Improved GL Mark I E/F sets began to appear in November 1940, replacing sound-location for HAA sites, and the number of rounds that required to be fired for each 'kill' began to fall. The GL radar was also effective in providing target heights for fighters, and the SL batteries were able to pass these to the night fighter controllers at RAF Kenley.

Order of Battle, Winter 1940–41

On 24 November 1940, 75th HAA Regiment was transferred to 62 AA Bde to defend the North Midlands, but 28 AA Bde was strengthened by 90th HAA and 4th LAA regiments:

In February 1941, 53 (City of London) HAA Regiment moved to Croydon and transferred to the command of 48 AA Bde. In November 1942, 55 (Kent) HAA Regiment sailed from the UK to the Middle East, where it joined Eighth Army, while 58 (Kent) HAA Regiment went to North Africa with First Army.

In March 1944, 90th HAA and 4th LAA Regiments left AA Command and joined Second Army to prepare for the Normandy Landings (Operation Overlord).

Postwar

When the TA was reconstituted on 1 January 1947, the Thames and Medway AA Brigade was reformed, now numbered as 54 (Thames and Medway) AA Brigade (the TA AA brigades were now numbered 51 and upwards, rather than 26 and upwards as in the 1930s; the wartime 54 AA Bde was renumbered 80). Once again, it had the two Kent HAA regiments under its command, now renumbered 455 and 458 rather than 55 and 58. It also had 564 Searchlight Regiment, the prewar 29 (Kent) Searchlight Regiment. It was based at Gillingham, Kent, and was subordinate to 1 AA Group (AA Command's corps and divisions had been disbanded in 1942 and a group structure introduced; 1 AA Group controlled the air defences of the London region). However, 54 AA Bde was disbanded the following year, completely disappearing in September 1948.