The bomber stream was a

saturation attack Saturation attack is a military tactic in which the attacking side hopes to gain an advantage by overwhelming the defending side's technological, physical and mental ability to respond effectively. During the Cold War and after, the conventional ...

tactic Tactic(s) or Tactical may refer to: * Tactic (method), a conceptual action implemented as one or more specific tasks ** Military tactics, the disposition and maneuver of units on a particular sea or battlefield ** Chess tactics ** Political tacti ...

developed by the

Royal Air Force The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...

(RAF)

Bomber Command Bomber Command is an organisational military unit, generally subordinate to the air force of a country. The best known were in Britain and the United States. A Bomber Command is generally used for strategic bombing (although at times, e.g. during t ...

to overwhelm the nighttime

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

aerial defences of the

Kammhuber Line The Kammhuber Line was the Allied name given to the German night air defense system established in July 1940 by Colonel Josef Kammhuber. It consisted of a series of control sectors equipped with radars and searchlights and an associated night fig ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. The Kammhuber Line consisted of three layers of zones of about 32 km long (north–south) and 20 km wide (east–west). In each zone there were two German

night fighter A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after the Second World War) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used i ...

aircraft receiving ground-directed guidance from their own ''Himmelbett'' controller within each zone. While the Himmelbett control center could only handle two fighters, this was adequate for dealing with the RAF Bomber Command tactic of sending its night time bombers individually, with each bomber plotting its own route to the target, to avoid flak concentrations. At the urging of British scientific military strategist

R. V. Jones Reginald Victor Jones , FRSE, LLD (29 September 1911 – 17 December 1997) was a British physicist and scientific military intelligence expert who played an important role in the defence of Britain in by solving scientific and technical pr ...

, Bomber Command reorganized their attacks into streams carefully positioned to fly right down the middle of a cell. The introduction of the GEE navigation system allowed the RAF bombers to fly a long, tight, formation in the dark—a 'stream of bombers' flying a common route at the same speed to and from the target, each aircraft being allotted a

height Height is measure of vertical distance, either vertical extent (how "tall" something or someone is) or vertical position (how "high" a point is). For example, "The height of that building is 50 m" or "The height of an airplane in-flight is ab ...

band and a time slot in a bomber stream to minimize the risk of formation

collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great fo ...

. In one of the first applications of statistical

operational research Operations research ( en-GB, operational research) (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a discipline that deals with the development and application of analytical methods to improve decis ...

, the RAF estimated the number of bombers likely to be lost to enemy night fighters and

flak Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based ...

, and how many would be lost through collisions. Minimizing the former demanded a densely packed stream, as the controllers of a night fighter flying a defensive 'box' could only direct a maximum of six potential interceptions per hour, and the flak gunners could not concentrate on all the available targets at once. A typical bomber stream of 600 to 700 aircraft was on average broad, and deep.''The World at War'' Episode 12 – "Whirlwind" – 1973 The bomber stream allowed a bombing raid to be completed in a shorter timeframe, further overwhelming the defensive tactics of the German forces. The earlier RAF tactic of sending bombers on individual routes meant that it could take four hours before all its planes would pass over their target; the bomber stream reduced this window to 90 minutes. The first use of the bomber stream was the first 1,000 bomber raid against Cologne on the night of 30–31 May 1942. The tactic proved successful and was used until the last days of the war, when centrally-organised German air defences had ceased to exist.

See also

References

Further reading