Sunday 2 August 2015

British Radar: It's not what you've got - it's what you do with it!


British radar has widely been credited as being a major reason for the RAF being able prevent the Luftwaffe from gaining air superiority over the UK during the Battle of Britain.

British radar could determine the distance and height of aircraft approaching the coast from 200 miles away and could even detect low flying aircraft from a distance of 100 miles away.

This allowed RAF Controllers to have sufficient early warning to be able to scramble fighters and direct (vector) them to intercept raids without having to fly standing patrols, giving exhausted pilots much needed respite at the height of the battle.

It is thought that the effectiveness of British radar largely neutralised the advantage that Germany should of had from its superiority in numbers making the Battle much more closely matched. Without radar the RAF would probably have been overwhelmed by the Luftwaffe and the Battle of Britain may well have been lost. 

Why didn't the Luftwaffe knock out the British radar stations? 

It wasn't because radar was a military secret or because Germany couldn't work out what the strange masts were for. They knew exactly what they were and what they were capable of.

Germany actually had much better radar than Britain during the Battle of Britain. Their radar sets were smaller; easier to rotate, move and position; higher resolution and able to detect smaller targets.

Whilst their Freya radar sets were better, they were of a more complex design and they only had 8 operational by the start of the war, leaving large gaps between covered areas.

British radar was simpler and easier to make and by the start of the war there was a complete chain of radar stations looking out to sea all along the southern and eastern coasts (Chain Home or CH).

Germany was successfully detecting RAF bomber raids in great detail with their radar but they were having big problems communicating any useful information in time to their intercepting fighters. They therefore assumed that the RAF would have the same problem so didn't see British radar as a high priority target.

Curiously, whilst Germany was having problems getting radar data to fighters, they did seem to have some success in vectoring bombers onto shipping targets they'd detecting some 60 miles away.

At the start of the Battle of Britain, Germany did try to attack British radar using two different methods: dive-bombing and jamming.

Dive-bombing met with little success, primarily because the huge masts of open steel construction were quite resilient to bomb damage. A few of the radar stations were taken off line temporarily but only for few hours. It is perhaps worth considering what might have happened if Germany had realised their importance and been more persistent in their raids.

Jamming only met with temporary success. In July 1940 a simple method of jamming was used by Germany but was easily defeated. In September 1940 a more elaborate method of jamming was used but this too was quickly defeated.

The Dowding System

What was exceptional about the British radar, was not the radar itself but the command and control method developed before the war by Dowding and his commanders.

British radar could only look out to sea, once the raid was over land, the radar was no help and plotting raids over land had to be done with the help of the Observer Corps.

The UK was divided up into small areas, each with it's own designation and there would be an Observer Corps detachment responsible for each. Each detachment would be connected by telephone to the same filter rooms as the radar stations allowing a battle plan be updated,almost in real time so the commanders could decide how to respond.

The UK had solved the problem of getting useful radar data to the intercepting fighters!

It also had radar stations that were resilient to bombing, a design that was simple and quick to construct, a radar coverage that was complete with no holes, a backup system with the Observer Corps and a radar design that was capable of being quickly modified to counter jamming.

Britain didn't have the best radar - but it did know what to do with it!

by Steve Dunster




3 comments:

  1. Interesting post, and I like the blog. Plenty of info about Battle of Britain, keep it up.

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  2. Proving it's not always the technology, but the process and the human factors. Interesting blog.

    ReplyDelete