Dowding system
The dowding system describes the English air defense concept in World War II , based on radar , central information processing and radio- guided interceptors . The name goes back to the commander in chief of the RAF Fighter Command Hugh Dowding, who was responsible until October 1940 . Although the principle of air defense in London was already introduced by Major General E.B. Ashmore was developed in 1918 , its full effectiveness was only achieved with the incorporation of radar and modern fighters . The dowding system reached its greatest importance during the Battle of Britain .
radar
The result of a test to locate aircraft on February 26, 1935 convinced Dowding so much that he had tax money available for the further development of this technology. The responsible technician Watson-Watt also ran an interdisciplinary project for operational research , the results of which were extremely profitable for the quick and effective commissioning of the entire air defense concept. At that time still known as Radio Direction Finding and regarded as top secret, this technology became known from 1943 under the name Radar , used by the USA .
The English coast seemed to be made for the development and use of this technology. By 1939, 18 stations of the Chain Home radar chain (CH) had been set up, mainly on the English south and south-east coast, each consisting of several transmitting and receiving systems. There was also the Chain Home Low Radar Chain (CHL), which was used to detect objects flying low.
Although Germany had a technological lead in the research and development of radar (under the name of radio measurement ), the application-oriented application of the existing equipment from locating enemy aircraft to managing interceptors was highly effective.
observer
As early as 1916, the Metropolitan Observation Service was formed by Major-General EB Ashmore to defend London against air raids . Initially manned by regular troops from the British Army , this service was subsequently carried out by better trained police officers .
In 1925 Ashmore expanded the post over Essex and Hampshire and formed the Observer Corps , which was under the control of the Army. In 1929 it was handed over to the Ministry of Aviation . It was mostly made up of volunteers. The cooperation with the General Post Office , which was responsible for the telephone connection , was further expanded and the number of posts increased.
Since in 1939 the possibilities of radar detection were still limited and error-prone and failed especially over the mainland, the integration of these observation and eavesdropping posts was an integral part of the air defense.
On April 9, 1941, the name Royal Observer Corps was given by King George VI. awarded in recognition of the institution's professional work.
presentation
The collected information first went to the so-called filter room in the headquarters of the Fighter Command in Bentley Priory near Stanmore . There, on a map table, the movements of the own and enemy aircraft were shown with different colored symbols, which also had a colored directional arrow. Based on the assessment of known weaknesses of the system, such as duplicate reports or false friend-foe detection, the movements that were considered to be faulty were removed.
The filtered information was passed on to the headquarters of the four groups responsible for air defense (10th – 13th Fighter Group ) and to the operational rooms of the Sector Headquarters , the Sector Stations such as Kenley and Biggin Hill , and displayed there on similar map tables shown. The flight movements recorded in this way were updated every five minutes. Lights on wooden panels in the headquarters indicated the status of the operational readiness of the individual squadrons. The interceptors were alerted and managed from there.
Hunter management
In the 1930s, Dowding pushed for the switch from double-deckers made of wood as the main material to all-metal monoplane with retractable landing gear , such as Hawker Hurricane , Supermarine Spitfire and Boulton-Paul Defiant . The latter was an unconventional concept that deviated from the principle of rigid forward-facing armament and instead featured a rotating turret with high firepower. After a few missions, the Defiants were withdrawn from daytime fighting due to high casualties and used with some success as night fighters. The Hawker Hurricane , which was already obsolete in 1940, was supposed to be the English aircraft with which most German aircraft were shot down by the end of the Second World War. The Spitfires , on the other hand, were more feared by the opponents and technically up to date.
In order to be able to use the available squadrons quickly and effectively, the associations were divided into four groups:
- South West England and Wales: 10th Fighter Group , commanded by Sir Christopher Quintin Brand
- South East England with Greater London: 11 Fighter Group , commanded by Air Vice Marshal Keith Park
- Central England: 12th Fighter Group , commanded by Air Vice Marshal Trafford Leigh-Mallory
- North: 13th Fighter Group under the command of Air Vice Marshal Richard Saul
The groups were again divided into sectors, with each sector having a sector headquarters and sometimes several satellite airfields.
The headquarters of the 11th Group, which bore the brunt of the Battle of Britain, was located in an underground bunker near Uxbridge . From there, the relevant sectors were alerted and it was determined which units should start operations. The sector headquarters then took over the leadership in the air up to the enemy units.
From there, the Hurricane and Spitfirestaffeln means were RF - voice in the Ground Controlled Intercept method introduced to the enemy forces. However, communication via high frequency only allowed a short range. From September 1940, the fighters were equipped with the more powerful VHF intercoms.
The hunter management was supported by the decryption of the German Enigma code in Bletchley Park . This also provided important information about the attacks by the Germans. To address the pilot shortage, pilots from the Commonwealth , France, the United States , Poland and Czechoslovakia were deployed under the command of the Royal Air Force.