The Secrets of Station X

by Michael Smith

Plans were put in place well in advance to keep the Torch commanders supplied with Ultra. They were agreed at a conference in Broadway attended by Nigel de Grey, representing Travis; Harry Hinsley, on behalf of the Naval Section in Hut 4; and Eric Jones, the head of Hut 3. Four separate Special Liaison Units were set up to pass the material on, one to serve Eisenhower’s headquarters, one with the forward elements of the troops pushing eastwards and two others with the occupation forces in Oran and Casablanca.

  A number of codebreakers from Bletchley Park, including Noel Currer-Briggs, a member of Tiltman’s Military Section, were sent out to reinforce a mobile Y unit, 1 Special Wireless Section. Their role was to help in breaking the Double Playfair hand cypher that was used by the German Army for its medium-grade messages, while Bletchley concentrated on the Luftwaffe cyphers and a new Army Enigma introduced for the campaign which Hut 6 designated Bullfinch.

  The mobile Y unit set up its base in an old Foreign Legion fort at Constantine in eastern Algeria, Currer-Briggs recalled. ‘Fort Sid M’Cid was built in true Beau Geste tradition on top of a hill above the astonishing gorge which bisects the city of Constantine,’ he said.

  It may have looked romantic, but it was the filthiest dump imaginable. One of my most vivid memories of it is cleaning the primitive latrines, a row of stone holes set in the thickness of the wall over a fifty-foot drop which had to be emptied through an iron door set in the base of the ramparts. It would be a good punishment if somebody had done something wrong but nobody had. So the adjutant and I said: ‘Let’s get on and do it’, and we started shovelling shit. I can still smell it. I recall with more pleasure, reading Virgil on the battlements. Hardly typical of military life but in the true tradition of BP.

  The Tunisian campaign was to be dominated by Rommel’s last two throws of the dice. In the first, Ultra was to demonstrate its potential frailties; partial intelligence turned out to be wrong; German orders that seemed to indicate one option had already been superseded by the time they were decyphered. As a result Rommel trounced the Americans in the Kasserine Pass, a vital communications link through the Atlas mountains, before turning round and heading east with the intention of taking on Montgomery, who had advanced to Medenine in eastern Tunisia.

  Ultra gave Montgomery full details of Rommel’s plans to throw the whole of the Afrika Korps against the Eighth Army positions. Throughout the last week of February and the first week of March, information from Bletchley and from 1 Special Wireless Section, now moved closer to the British commanders, built up a complete picture of Rommel’s plans.

  ‘This was a most exciting time for us,’ said Currer-Briggs.

  Traffic was coming in thick and fast. We were theoretically working in shifts but there was so much to do that we hardly ever took time off, and frequently worked when we should have been resting. It was far too exciting to twiddle one’s thumbs in idleness.

  For the codebreakers in Hut 6 and their intelligence reporting colleagues in Hut 3, this was seen as final payback for Crete. Whereas in Crete they had every detail of the German plans but no way of preventing it happening, now they had every detail of Rommel’s plan and the forces ready and waiting to counter it.

  By the time Rommel’s troops attacked the Eighth Army positions on the morning of 6 March with a total of 160 tanks and 200 guns, they were faced by a solid wall of 470 anti-tank guns, 350 field guns and 400 tanks. Fed by the codebreakers with every detail of his planned assault, the British simply sat and waited for the Desert Fox. By evening, his tanks largely reduced to burning wrecks, Rommel called the battle off. Three days later, he left Africa, never to return.

  The fighting in Tunisia continued for two more months but the North African campaign had effectively ended and the British were already making plans for one of the necessary side-effects of victory. The Ultra-led attacks on the Axis supply convoys had been carried out with the future need to be able to feed a large number of prisoners in mind, said Edward Thomas. ‘While those with cargoes of tanks, fuel and ammunition had been selected for attack, ships known from the decrypts to be carrying rations had been spared.’

  Although Montgomery claimed them as his own, it was his victories in North Africa which finally persuaded the British Army and the RAF that Ultra was an extremely powerful weapon and one that could win the war. It was one of the main reasons behind the British defeat of the Afrika Korps, said Jim Rose. ‘If you look at the position at the Fall of Tobruk in July 1942, that’s only a few months before el Alamein, Rommel was really in the ascendant. Things looked desperate when Churchill was with Roosevelt and he heard about the fall of Tobruk, but then six months later they had completely changed. That would not have been possible without Ultra.’

  For the codebreakers themselves, two and a half years of hard slog had enabled them to create an efficient organisation capable of ensuring that, while individual keys might occasionally be lost, the bulk of the German’s top secret communications would be read, and that the information they contained could be passed to the men who were able to make best use of it: the commanders in the field. North Africa was where Ultra finally proved itself to be the source of intelligence the military could trust. Until then, the RAF and the Royal Navy had derived real benefits from the Enigma decrypts and understood their importance. The Army had placed a lot of trust in its eventual value, providing the bulk of the intercept operators who intercepted Enigma messages and many of those who worked on them at Bletchley, but had been slow to see the tangible value the Ultra reports could provide. That changed in North Africa, said Lucas.

  From the summer of 1941 until the surrender in Tunisia in May 1943, a very large part of our work was concerned with North Africa, where it may be said without hesitation that ‘Source’ was decisive. This was because, at long last, efficient arrangements had been made for passing our information to those who could best use it, the operational commands.

  Partly in consequence of certain differences in the character of War Office and Air Ministry, partly because of the scantiness of military, as compared with air, intelligence from Hut 3, relations with these two ministries also differed. While Air Ministry looked to BP for their most important source, the War Office received comparatively little. They therefore treated Hut 3 as a very subsidiary source.

  It was not until the African campaign that Hut 3 established itself in the eyes of the War Office as a purveyor of goods which were priceless, unobtainable elsewhere, and already well processed when issued. In the African campaign, every formation, every unit, had been known and placed, no reinforcement could accrue to the enemy across the Mediterranean without due warning.

  More than that, Ultra had come of age. The new organisation sketched out by Welchman and Travis had taken over from the GC&CS of the inter-war years. The dedication and enthusiasm that had characterised the inter-war years remained but the need to work in new ways to cope with the huge scale of wartime codebreaking had been fully embraced.

  ‘Until Alam Halfa, we had always been hoping for proper recognition of our product,’ said Ralph Bennett of his return to Bletchley Park from Egypt in March 1943. ‘Now the recognition was a fact of life and we had to go on deserving it. I had left as one of a group of enthusiastic amateurs. I returned to a professional organisation with standards and an acknowledged reputation to maintain.’

  The War Office now saw sense in sending potential codebreakers to Bletchley where previously it had felt that it was not getting enough in return for the effort its intercept operators and intelligence analysts were putting in. Members of the Army and the ATS were quartered at Shenley Rd Military Camp, about half a mile from Bletchley Park. Bernard Keefe, who worked on Japanese codes, recalled that the camp was commanded by an infantry officer, Colonel George Fillingham.

  He was quite mad, probably too much even for the Durham Light Infantry, who no doubt gladly shot him off to what the rest of the Army regarded as a nuthouse. He was not allowed into BP and wasn’t told what was going on. He took out his frustration on u
s; he hated the sight of long-haired intellectuals and used to stop them and give them sixpence to get a haircut. He organised boxing – I was put into the ring with someone six inches taller and just about survived; then he started cross-country runs before breakfast. I shall never forget the sight of Staff-Sergeant Asa Briggs, future professor and historian of the BBC, trying to keep up with less portly young blades.

  BP was an astonishing community. I was born to a poorish family in Woolwich. My father was a clerk in the local Co-op society, my family descendants of illiterate Irish immigrants who fled the famine in 1849. I shall never forget the impact of arriving in BP; it was a microcosm of the highest intellectual life. I discovered there was a lively opera group run by James Robertson, later Music Director of Sadlers Wells – I sang with orchestra for the first time as the Gardener in The Marriage of Figaro and the Constable in Vaughan Williams’s Hugh the Drover. Soon after I arrived I organised lunch-time concerts in the Assembly Hall outside the main gate. There were many professional musicians – Captain Daniel Jones, the doyen of Welsh composers, Lieutenant Ludovic Stewart, violinist, Jill Medway, a singer, Captain Douglas Jones (later Craig), singer and later company manager at Glyndebourne. There was a choir conducted by Sergeant Herbert Murrill, future Head of Music at the BBC. Working with me on the Army Air codes was Lieutenant Michael Whewell, bassoonist, and later producer in charge of the BBC Symphony Orchestra. There was a great deal of bed-hopping, the odd pregnancy and post-war divorces; all that was much easier for the civilians who lived in outlying villages; we had to make do with the Wrens in whatever nest we could find.

  The Allies now turned their attention to the invasion of southern Europe, for which Operation Torch had been a necessary precursor. They began by disguising their intentions using a deception plan worked out by the Double Cross Committee which did not involve a double agent at all, but did rely heavily on the codebreakers being able to confirm that the Abwehr had been fooled. The most obvious stepping stone to Italy was Sicily, just a short hop across the Mediterranean from Tunisia. The problem was to find a way of giving the Germans the impression that General Dwight Eisenhower and his British colleague General Harold Alexander had other plans, forcing the Germans to reinforce other areas and weakening the defences in Sicily.

  Charles Cholmondley, the RAF representative on the Double Cross Committee, devised Operation Mincemeat, a plan centred around the known level of collaboration between the Spanish authorities and the Germans. The idea was to drop the body of a dead ‘British officer’ off the coast of Spain, close enough to ensure it would be washed up on the beach, with the intention of making it look as if it had come from a crashed aircraft. He would be carrying documents indicating that the main thrust of the Allied attack would be somewhere other than Sicily. The Spanish were neutral but their sympathies lay with the Nazis and they would undoubtedly pass these on to the Germans, who would reinforce their garrisons in the suggested targets at the expense of the real one.

  Ewen Montagu, the Royal Navy representative, took charge of the operation, acquiring the body of a dead tramp from a London hospital and giving it the identity of Major William Martin, Royal Marines, an official courier. Attached to Martin’s wrist by a chain was a briefcase containing a number of documents, including a letter from one senior British general to another discussing planned assaults on Greece and an unspecified location in the western Mediterranean, for which Sicily was to be a cover. A further letter from Lord Mountbatten, the Chief of Combined Operations, referred jocularly to sardines, which was rightly thought enough of a hint to make the Germans believe the real attack was going to be on Sardinia.

  The members of the Double Cross Committee were highly inventive in their choice of other documents to be planted on the body. Two ‘used’ West End theatre tickets for a few days before the intended launch of the body were in his pocket to show that he must have been travelling by air. A photograph of Martin’s ‘fiancée’, actually that of a female MI5 clerk, was placed in his wallet. For several weeks, Cholmondley carried two love letters from the ‘fiancée’ around in his pocket to give them the proper crumpled look. There was even an irate letter from Martin’s bank manager.

  The body was floated ashore near the southern Spanish town of Huelva from a submarine. The Allies now had to find out if the Germans had swallowed the bait and the only sure way of knowing was from Ultra, and in particular from the Abwehr Enigma traffic between Madrid and Berlin. Following the death of Dilly Knox, his ISK section had been taken over by Peter Twinn with Mavis Lever still one of its key members. The Abwehr officers in Madrid were as anxious to find out Berlin’s ruling on the documents as the codebreakers and the deception planners. ‘We were asked to look out for German reactions and the delighted Double Cross Committee knew as soon as Berlin had decided, following a detailed investigation, that “no further doubts remain regarding the reliability of the captured documents”,’ Lever said.

  Noel Currer-Briggs was still in Tunisia with 1 Special Intelligence Section, when the Mincemeat deception reached its denouement.

  We were stationed at Bizerta on top of a hill just outside Tunis and I remember we were inspected one day by Alexander and Eisenhower. There we were working away at the German wireless traffic coming from the other side of the Mediterranean and we were saying: ‘Oh yes. They’ve moved that division from Sicily to Sardinia and they’ve moved the other one to the Balkans’ and these two generals were jumping up and down like a couple of schoolboys at a football match. We hadn’t a clue why. We thought: ‘Silly old buffers.’ It wasn’t until 1953 when Ewan Montagu’s book The Man Who Never Was came out that we realised we were telling them that the Germans had swallowed the deception hook, line and sinker.

  When Bletchley decyphered the Abwehr intercept confirming the results of the German investigation, which showed that the Germans were totally taken in by the deception, a message was sent to Churchill, then in the US for the Trident Conference with US President Franklin D. Roosevelt, saying simply: ‘Mincemeat swallowed whole.’

  The ability the Allies now had, through Ultra, to tell whether or not the enemy had been fooled by deception operations was another crucial contribution made by the codebreakers to Allied intelligence operations, said Ralph Bennett.

  No other source could have proved the efficacy of the deception planners’ rumour-mongering so conclusively, relieving the operational commanders’ minds as they prepared an amphibious undertaking on an unprecedented scale. Ultra demonstrated Mincemeat’s success by showing, more clearly than any other source could have done, that German troops and aircraft movements over the following weeks conformed to the deception; this enabled planning for the assault to go ahead in an atmosphere of confidence.

  Even two months later, when the invasion of Sicily had been launched, German intelligence continued to insist that the original plan had been to attack Sardinia and Greece and that it had only had been switched to Sicily at the last moment.

  CHAPTER 10

  THE BIRTH OF THE MODERN COMPUTER

  The Allied landings first in Sicily in July 1943 and then in Italy itself in September, followed swiftly by the Italian surrender, provided Ultra with its first strategic test. Hitler’s reaction was uncertain. Would he accept Rommel’s advice and take the logical course and retreat to the Alps, saving men and material, or would he fight every inch of the way as proposed by the German commander in Italy, Field Marshal Albert Kesselring? Bletchley Park was able to follow Hitler’s decision-making, as he initially agreed with Rommel and then accepted the argument of Kesselring that the Germans must make a stand on successive defence lines all the way up the peninsula. ‘This was the strategic prize of the greatest moment,’ said Ralph Bennett. ‘It enabled the Allies to design the Italian campaign to draw maximum advantage from the willingness Hitler thus displayed to allow Italy to drain away his resources.’

  The German ability during the Italian campaign to use long pre-established landline communications limited the ability of
Hut 6 to produce useful material from the Enigma decrypts. The breaks into the Red continued but while other Enigma keys could be broken intermittently, sometimes in floods, it was more often in a trickle that could not be used to produce reporting of any great substance. One former Hut 6 codebreaker said:

  Brief spells of heavy traffic sometimes led to breaks which could not be followed up because the flow dried up as suddenly as it had begun. For the cryptographer this was dispiriting; for Hut 3 it meant that intelligence from Italian Army keys tended to be fragmentary and mostly of low grade. The result was normally a grey picture of difficult breaking and low-grade intelligence, brightened occasionally by spectacular flashes of brilliant success and priceless information.

  Fortunately, the Bletchley Park codebreakers now had another source of high-grade German intelligence that more than filled the gap in Italy, and ensured they not only knew what Hitler and his generals were thinking but also had a constant and comprehensive guide to all the German dispositions and intentions.

  The Germans were using an encyphered radio teleprinter system for communications between Hitler and his senior commanders. The earliest indications of this encyphered radio teleprinter system came in the second half of 1940 when the Metropolitan Police unit at Denmark Hill under Harold Kenworthy picked up unidentified German non-Morse signals. No effort was put into intercepting these transmissions until mid-1941 when an RAF station at Capel-le-Ferne, near Folkestone, picked up similar signals. ‘The transmissions were erratic,’ said Kenworthy. ‘But on one occasion, a secret teleprinter message in clear was intercepted reporting the removal of a Flak [Fliegerabwehrkanone – anti-aircraft gun] battery to the Eastern Front.’ Denmark Hill was asked to take a closer look at the teleprinter signals with the assistance of the GPO intercept station at St Albans.