Read The Secrets of Station X Online
Authors: Michael Smith
The number of staff at Bletchley Park had been
dramatically
increased in anticipation of the Allied invasion of Europe, reaching a total of 7,000 by June 1944. Morag Maclennan had by now been transferred out of the Bombe section into Hut 4, the Naval Section, where in the run-up to D-Day there was a minor security scare. ‘The girl who was most closely concerned with the Normandy beach landings went up to the Admiralty and was fully briefed,’ Maclennan said. ‘
Bigoted
was the name for anybody who was let into the great secret in the weeks
leading
up to D-Day. She was
bigoted
and immensely pleased with herself. We had this enormous map all the way down one wall of the coast of Holland right down to the south of France and she carefully underlined the beaches that they were going to land on. We were horrified at this and went along underlining every beach we could see from Holland down to France because the cleaners would come in and might notice.’
Tommy Flowers and his men at Dollis Hill were already working on an updated version of
Colossus
. ‘The first processor contained 1,600 valves,’ Flowers said. ‘It worked, as designed, well enough, but we had not been able to make the
processing
fast enough, and with use we could see that it needed to be improved in several ways.’ Flowers was told that if his new
Colossus
was not ready by the beginning of June, it would be no use at all, which he rightly assumed meant that D-Day was to be at the beginning of June.
We worked flat out for four months and met the deadline, but only just. I was at Bletchley Park on that historic day and had been since the morning of the previous day, with a number of
other men, dealing with the last few difficulties that remained. In fact, the machine was fully ready for service for the first time during the small hours of the morning of 1 June.
The decyphering girls in the Big Room of Hut 8 went on night shift just before midnight on 4 June 1944, unaware that the Allied invasion was about to be launched, said Pat Wright.
They told us that D-Day was today and they wanted every possible message decoded as fast as possible. But then it was postponed because the weather was so bad and that meant we girls knew it was going to take place, so we had to stay there until D-Day. We slept where we could and worked when we could and of course then they set off on 6 June, and that was D-Day.
Although the heads of the main sections were all
bigoted
and most people at Bletchley Park knew that the invasion of Europe was imminent, even fairly senior staff were not told when it was to come. ‘There was no point speculating when the balloon was going to go up,’ said Bill Bundy.
So you didn’t give day-to-day thought to it really and it just so happened that the evening of June 5 there was a long scheduled party. I’m sure there was a moment’s thought given on high as to whether this ought to be kept and the instantaneous
decision
was that to cancel it would be far too much of a signal. So it went ahead and I remember we had a very pleasant group and drank martinis in which the role of vermouth was played by sherry and one had a really very nice time.
Anyway, at midnight those of us who were on the night shift reported to our sections to work, and there waiting in the outer room just outside the watch was the head of Hut 6, Stuart Milner-Barry. He had been at the party and he was just sort of standing there on one leg watching the whole
proceeding
and one said: ‘Why is Stuart doing this at this hour?’ So
we went to work and suddenly about 3 o’clock there was a real rustle in the room that got the traffic first and it was patent that something was happening on a big scale. Very shortly the word spread that there had been German traffic in clear, saying that paratroopers were dropping all over the place and it happened to be nearer Calais than Normandy so I’m sure it was one of the deception operations. We later learned that they were not paratroopers, they were bunches of straw, something that would show up on the radar in the same way.
In the early hours of 6 June 1944, D-Day,
Garbo
made repeated attempts to warn his
Abwehr
controller that the Allied forces were on their way. This move was agreed by Allied commanders on the basis that it would be too late for the Germans to do anything about it but would ensure that they still believed in
Garbo
as their best-informed secret agent after the invasion had begun. As predicted it only served to increase their trust in him and paved the way for the next stage of the deception. Shortly after midnight on 9 June, as the Allied advance faltered and with the elite 1st SS
Panzer
division on its way from the Pas de Calais, together with another armoured division, to reinforce the German defences in Normandy,
Garbo
sent his most important message about the D-Day landings. Three of his agents were reporting troops massed across East Anglia and Kent and large numbers of troop and tank transporters waiting in the eastern ports.
After personal consultation on 8 June in London with my agents
Donny
,
Dick
and
Derrick
,
whose reports I sent today, I am of the opinion, in view of the strong troop
concentrations
in south-east and east England, that these operations are a diversionary manoeuvre designed to draw off enemy reserves in order to make an attack at another place. In view of the continued air attacks on the concentration area mentioned, which is a strategically favourable position for this, it may very probably take place in the Pas de Calais area.
Garbo
’s warning went straight to Hitler who ordered the two divisions back to the Pas de Calais to defend against what he expected to be the main invasion thrust and awarded Pujol the Iron Cross. Had the two divisions continued to Normandy, the Allies might well have been thrown back into the sea. On 11 June, Bletchley Park decyphered a message from Berlin to
Garbo
’s controller in Madrid saying that
Garbo
’s reports ‘have been confirmed almost without exception and are to be described as especially valuable. The main line of investigation in future is to be the enemy group of forces in south-eastern and eastern England.’ Only the messages decyphered from the
Abwehr
Enigma could have provided Allied commanders with that sort of high-level reassurance that the deception was working.
The importance of the
Abwehr
Enigma and the
Jellyfish
link in confirming the D-Day deception cannot be overstated. One of Telford Taylor’s Special Branch intelligence officers, Don Bussey, said:
Ultra
made a tremendous contribution to the success of the deception planning for the Normandy landing because we were able to follow through
Ultra
not only what the German forces were doing but also that
Fortitude
was working so well. The Germans still believed well into July that Patton had an Army in south-eastern England that was going to come across to Pas de Calais so they couldn’t send reinforcements to Normandy. This is a very important aspect of how
Ultra
contributed to strategic consideration. That’s big stuff and not to be minimised.
Brigadier Bill Williams, who was Montgomery’s intelligence officer during the invasion of Europe, said that no army ever went to war better informed about the enemy.
Intelligence officers at BP were briefed before D-Day and thereafter we made it our business in Normandy to send a daily ISUM [Intelligence Summary] from 21 Army Group
saying what we thought was happening in front of us and in general attempting in a friendly and unofficial fashion to keep the Park aware of what we were trying to do. The whole series of signals was conversational. One felt one was talking to friends and from that feeling of gratitude which we hoped was reflected in the casually worded terms sent to the Park emerged at least from the point of view of one consumer, a belief that because of them he was getting a better service. The people at the other end knew what he wanted and there seemed to be no hesitation in the answer. G (R), the staff branch responsible for deception and cover plans, was more dependent on
Ultra
than any of the rest of us. It was the only source revealing the enemy’s reaction to a cover plan. Without
Ultra
we should never have known. In the case of
Fortitude South
(the Pas de Calais cover plan) it is arguable that without
Ultra
confirmation
that it was selling, it might have been dropped.
Senior administrators at Bletchley Park were very well aware that some of the young men working there wondered whether they shouldn’t be fighting alongside their friends and relatives, who were now thrust into the thick of battle. Eric Jones, the head of Hut 3, the military and air intelligence reporting section, told his staff that the work they were doing might not be so dangerous but it was just as important to the war effort. One recent report sent out by Hut 3 had shown that enemy
dispositions
in the Cotentin peninsula in Normandy had changed. US paratroopers from the 82nd Airborne had been due to drop in the area around La Haye du Puits on the west of the Cotentin peninsula, but a Bletchley decrypt showed in late May that several German divisions had moved into the area and that any landing there would have had disastrous consequences. The resultant change to 82nd Airborne’s dropping zone had saved the lives of up to 15,000 men, Jones said.
At this moment, in far the biggest combined operation in
history, the first of the airborne troops are down. Sailors and airmen are facing frightful dangers to transport the first ground troops across the Channel and protect them on their way; more sailors and airmen are daring everything to blast holes in the German defences; and the ground troops themselves, in their thousands, will soon be literally throwing away their lives in the main assault by deliberately drawing enemy fire so that others may gain a foothold; and we are in complete, or almost complete, safety; some of us are even enjoying something akin to peacetime comfort. It’s a thought we cannot avoid and it’s a thought that inevitably aggravates an ever-present urge to be doing something more active; to be nearer the battle, sharing at least some of its discomforts and dangers. Such feelings cannot be obliterated, but they can be subjugated to a grim resolve to serve those men to the very utmost of our capacity. There is no back-stage organisation (and I think of Hut 3, Hut 6, Sixta and the
Fish
Party as an indissoluble whole) that has done more for past Allied operations and Allied plans for this assault; and none that can contribute more to the development of the
invasion
once the bloody battles for the beaches have been won.
Amid concern at the damage the U-Boats might inflict on the invasion forces, Frank Birch had arranged for a number of Royal Navy radio intercept positions to be set up in Bletchley Park. All signals indicating danger to the invasion force were dispatched from the Hut 4 ‘Z’ Watch on what was known as a ‘Rush’ basis and the OIC was normally able to pass them on to the naval escorts within thirty minutes of the Germans
sending
them. Birch’s initiative was the first and only time that any messages were actually intercepted at Bletchley Park.
‘This step was taken with some hesitation in view of the risk associated in having GC&CS associated with masts and aerials,’ said Harry Hinsley.
But it was fully justified by the exceptional speed with which
the Naval Enigma was decrypted during the crucial days in which the assault forces were crossing the Channel and getting ashore. We were able to watch the expedition going across as well as getting the first German response. We quickly realised they weren’t expecting invasion and as soon as the assault waves were ashore we started reading all the emergency messages from the German navy and sending them straight on to the invasion force leaders in their command ships off the beaches. Throughout the assault phase the average time-lag between the interception of the German signals and the delivery of the decrypts to the OIC was to be thirty minutes during those large parts of each day in which the Enigma keys were being decrypted currently.
Within forty-eight hours of the initial landings, the first of twenty-eight British and American Special Liaison Units set up to pass the
Ultra
intelligence on to the Allied commanders were reporting through their Special Communications Units that their positions were secure and they were ready to receive and pass on the reports from Bletchley.
‘Shortly after the Normandy landings, I was assigned to the European theatre to be one of the field representatives handling the
Ultra
information with the US military command, both air force and Army,’ said Don Bussey.
All US commands had these
Ultra
representatives who would ensure the security of this information and that it was handled in the proper way. I had a Special Communications Unit manned by British officers, both Army and RAF, that supported me, and they were the ones who would receive the messages over the air from Bletchley Park. It’s very important to realise that day in, day out, the most important thing that
Ultra
had to tell us was the complete German order of battle. We would know their divisions by number. We would know where they were. We would know their subordinations by
corps and army and by army group. We’d know the boundaries between division and between other units, and all this gave us the kind of information which is absolutely indispensable. I would process all this information and pass it on to the people at headquarters who were authorised to receive it.
The mobile Y Service units were already producing large amounts of information about the German reaction. In conjunction with Bletchley Park, they produced the position of one of the most important German headquarters, allowing the British to mount a series of air strikes that put paid to a counter-attack which would have driven a gap between the American and British armies.