Secret Life of Bletchley Park - McKay Sinclair [45]
But before the extraordinary and exceedingly fortunate retreat at Dunkirk, Bletchley made another vitally important breakthrough. In a further triumph for the Herivel Tip, it broke the ‘Red’ Enigma key. To have a way into the German air force messages was a glittering prize. ‘The Red became of vital importance immediately,’ commented one veteran of Hut 6, ‘and remained so all the way through the war and in all the main theatres of war except Africa … The Red was the great standby that kept Hut 6 going. I cannot remember any period when we were held up [in decoding] for more than a few days at a time.’
From that point onwards, the Park was able to read, on a daily basis, every single Luftwaffe message – something in the region of one thousand a day. The messages also gave vital clues as to the movements of land troops. The latest setback was that the messages were also filled with technical jargon: abbreviations, equipment terms, out-of-date map references. In the short term, the intelligence yielded was of no use whatsoever to the thousands of British troops gathered on the French beaches at Dunkirk, awaiting the deliverance of the little ships. But in principle it was a fantastic breakthrough; and the difficulties would be overcome with time and experience.
There was an important psychological point too, one that would have been relayed to Churchill; in the midst of all these decrypts, it was obvious that the main German concern at that moment was the successful conquest of France. There was no mention at that stage in May 1940 of plans to invade Britain. Not one of the thousands of decrypts had suggested that there was going to be an incursion from across the Channel.
By June 1940, however, the decrypts were throwing up intelligence concerning the refit of the Luftwaffe, which strongly suggested that a bombing campaign against Britain was imminent. ‘Enigma gave general warning of the approach of the Battle of Britain,’ wrote codebreaker Sir Harry Hinsley. ‘The fact that Enigma had now been producing intelligence for some months on the German Air Force’s organisation, order of battle and equipment was also of great strategic value.’3
Indeed, thanks to Bletchley Park – the information was described as ‘heaven-sent’ and ‘apparently sure’ – Air Intelligence and the RAF gained a much more realistic idea of German bomber strength, and was given a vital boost of confidence; the enemy forces were not quite as multitudinous as had been first thought. On top of this, the cumulative effect of listening in to so many messages had the effect of bolstering Churchill’s determination. Thanks to the decrypts, he knew that he and the British had just a little extra time.
In fact, on 16 July 1940, with the German subjugation of France consolidated, Hitler issued Directive no. 16, involving preparations for ‘a landing operation against England’. The plan was called ‘Operation Sea Lion’ – a phrase that, ominously, was picked up with increasing frequency thereafter by the decrypters – and an initial air offensive was to begin on 5 August.
This then was the background to the Battle of Britain – that extraordinary moment when, as Bletchley veteran Captain Jerry Roberts now puts it, ‘one tiny blob to the north of the map of Europe’ stood its ground while all others around it fell. Even though Bletchley could not be of practical assistance to British planes as the battle was fought, the help it had provided beforehand was immeasurably valuable.
And in the midst of the national anxiety, there was one other small, but vital fillip for the Chiefs of Staff: they had learned that the Germans could be outwitted. Their sheer physical force may have seemed unbeatable but to have advance notice of plans and manoeuvres made their threat, at last, surmountable in theory.
Initially, the bombe machines were operated and serviced by specially picked RAF technicians, headed by a Sergeant Jones.