Secret Life of Bletchley Park - McKay Sinclair [52]
The reason, say the conspiracy theorists, is this: that to have deflected the bombing by sabotaging the navigation beams – or allowing RAF fighters to defend the city from the air – Churchill would have been effectively telling the Germans that he had access to their most secret transmissions. The Prime Minister, this theory goes, was therefore faced on 14 November with a hideous dilemma. Could he step in with this foreknowledge and order that Coventry be given full protection from the onslaught – but by doing so alert the enemy to the fact that its messages had been read? Or instead, should he allow the city to be put to the sword so that the secret of Bletchley remained unguessed at?
In fact, the entire premise is flawed; but it none the less emphasises a wider truth about the work of Bletchley. For as soon as Enigma was broken, it became utterly vital that the Germans should never suspect that this was the case. As many veterans have pointed out, if German Intelligence suspected that its communications had been breached, they would instantly have been rendered much more complex and potentially impenetrable.
There was the later occasion, for instance, of the sinking of the Bismarck in 1941. The truth of the matter was that the German warship had been tracked after Bletchley had succeeded in cracking certain codes. But for the Germans not to suspect this, a pantomime was necessary. And so, hours before the ship was sunk, the RAF arranged for four reconnaissance planes to conduct a survey of that area of the ocean. When one of the planes ‘spotted’ the Bismarck, it was spotted in turn by the ship’s crew, who alerted High Command. Thus it looked as if the vessel had been located by chance. A number of Bletchley’s other intelligence tips also had to be made to look like the inspired sleuthing of spies and agents on the ground.
But the theory proposing that Coventry was sacrificed omits certain essential details. First, Churchill had left London for the country that afternoon before getting the message. When he was told that there might be a vast raid on London, his car turned back to the city. It was only when he returned to Whitehall in the evening that it was confirmed that the target was to be Coventry.
Moreover, the jammers of the navigation beams were apparently set to the wrong frequency, an error that was not corrected until the following month. It also happened to be the case that Coventry did have anti-aircraft defences. But in the face of such an onslaught, such defences would always be of only limited use. ‘Coventry could never have been evacuated in time,’ recalled WAAFY Service operative Aileen Clayton. ‘It would certainly have been a physical impossibility to get all the guns and searchlights needed for defence, as well as the fire engines and other equipment, moved from other places to the target zone … with the information that was available to us, there was no way in which the city and its people could have been saved from that suffering.’3
And so the centre of Coventry was consumed in flames, the molten lead of the gutters pouring hissing into the streams, the cathedral transformed into russet-glowing ruins. Some 558 men, women and children were killed, and thousands more were injured.
It is a subject that occupies Bletchley veterans to this day. Oliver Lawn – who, it should be remembered, worked on decrypting messages concerning German bomber flight paths – still thinks there is some ambiguity about the issue: ‘You will find people going on both sides of that argument. Now that’s a typical case. But there are other cities where the codes were broken in time and the bombs were diverted. Coventry is still controversial.
‘The head of our section – Stuart Milner-Barry – felt