click to take you to Bletchley Park      Click here to see U534 for yourself

Updated: 15 July 2007

Enigma - The Truth

The American Film industry, in it's infinite wisdom, has decided to rewrite history many times in the past.  But their latest examples of historical (hysterical?) facts leave a lot to be desired.  One such film rewrites history with regards to the German Naval Code Machine - Enigma.  The truth according to the film industry, is the American's decided to help out their "poor" British Allies by stealing the machine from the German's to assist us in breaking the German War Codes.  Phooey!  We already had enigma before America joined the war.  The truth was printed in The London Times Supplement dated June 1st 2000. Written by Hugh Sebag-Montefiore. Here it is reproduced. I have since also bought his excellent book.

At the beginning of 1940, Turing spent some time in France with the exiled Polish cryptographers ,whilst back at Bletchley Park, he has already made a ground breaking invention. It was an electro-mechanical device, which became known as the "bombe"  (Not to be confused with the "bombi" used by the Poles, the "bombe" was a more sophisticated version) which could work out the wheel settings and plug board connections used by the Germans on any given day. Similar to the Polish "bombi", the more sophisticated British version consisted of a series of Enigma machines wired together which could be rotated through each wheel setting to test whether or not a setting worked or could be ruled out. It was here that any similarity to the original Polish version ended. The "bombi" could only work out settings as long as the Germans continued their practice of a double transmission of settings for example a wheel setting would be ABC for that date, when passed though the Enigma it emerged at STD, the message would then begin STD STD. Turing's "bombe" would still work if the Germans dropped the settings to only one eg STD.  Turing once remarked to a colleague that "if I had 10,000 chinamen at my disposal, the bombe would not be required. The "bombe" did in fact, work on finding that were NOT correct, thereby arriving at the correct solution by default. The first "bombe" was installed at Bletchley Park on 18 March 1940 but failed in its task. Gordon Welchman suggested to Alan Turing some modifications, Turing readily agreed, and the "bombe" went through some modifications. Turing then made even further modifications and the machine began to produce results. This was then known to the code breakers as the "spider".

The Germans made a glaring mistake in their use of Enigma and this was picked up by the eagle eyes of the staff at Bletchley Park. When it was Hitler's birthday every German unit, in whatever theatre, would send birthday greetings to Berlin. The signals would invariably end with "Heil Hitler" - as did many other communications as well. When spotted the cryptographers had a small insight, with the settings for H, E, I , L, T and R known. It was not much, but every little bit helped. A young Winchester graduate, Pendered, was sent to the factory making the "spiders" where he tested the machine thoroughly, making tweaks and refinements. Then, one day, the "spider" produced the required results, in German, and on 8th August 1940, was installed in Bletchley Park.

Before the next section it might be worth visiting my page on the U-33 and the story of the Enigma Wheels here on its own page: U-33 which took place in February of 1940 and slightly precedes the remainder of this narrative.

The Crucial Capture

April 15th 1940 the U-49 was sunk after being forced to the surface by the Royal Navy and an important opportunity to gather intelligence was lost. The Admiralty was livid and gave out some specific instructions to ships commanders.

At 1030 hrs on April 30th 1940, the Destroyer HMS Griffin was patrolling off Norway when a lookout spotted a vessel that seemed at first sight to be a Dutch trawler.  The craft might not have attracted a second glance had it not been that John Lee-Barber, Griffin's Commander, had received a radio signal that another British warship in the vicinity had been attacked by a German armed trawler, posing as a Dutch fishing vessel, which led him to suspect that the ship in his gun sights might not be what it seemed.  Lee-Barber signalled the ship to heave-to.  Then, ignoring the very rough seas, he asked Alex Dennis, his First Lieutenant, to lead a boarding party to check it out.  From a distance the vessel, which had the name Polares painted on its bow, looked like any other neutral trawler, and it was flying the Dutch flag.

But as Alex Dennis and his boarding party rowed closer in their whaler, he saw something that made his blood freeze.  He had caught sight of a deck gun "dressed up" with a canvas cover so that it looked like a rowing boat.  The large number of men milling around on the deck made Dennis feel only more uneasy.  His suspicions were quickly confirmed when he jumped from his whaler onto the trawler deck.  He was greeted by a bemused sailor who blurted out "German Ship" in a guttural German accent.  As Dennis looked around he observed two torpedo tubes concealed under fishing nets, that could have inflicted serious damage on the Griffin had the destroyer attempted to approach the trawler.  Dennis eventually established that the ship was the German Schiff 26, a trawler commandeered by the German Navy that had been on the way to Narvik to deliver ammunition, guns and mines to the occupying German army.

As other members of Dennis's boarding party leapt aboard, one of them let off his pistol by mistake, which startled him but served the purpose of terrifying the Germans.  After that they queued up obediently on the deck so that they could be taken back to the Griffin as prisoners.  Meanwhile another drama was being played out in the sea on the opposite side of the Polares.  The German crew had thrown two huge bags of confidential documents and cipher apparatus into the water.  One bag sank immediately  but the other floated tantalisingly on the surface until Griffin's gunner, Florrie Foord, dived into the water in a last minute attempt to recover it.  He caught hold of the bag but the line to which he was attached broke while he was being hauled on board, and he fell back into the rough sea.  For one ghastly moment it seemed that nobody on Griffin would ever see either Foord or the bag again, but he appeared once more, still gallantly clutching the bag, and gratefully grasped a second line that was thrown to him.

Once again his one handed grip was not strong enough, and he disappeared under the water before bobbing up yet again.  When the line was thrown to him a third time, he managed to secure a makeshift lasso over his shoulders and was hauled up, frozen, with the all important bag.  Whilst Foord was drying himself, Dennis and his men made preparations to sail Polares to Scapa Flow, the British Naval base in the Orkneys. What happened there was to horrify John Godfrey, the Head of Naval Intelligence.  The trawler should have been met by an alert reception committee and placed in a quiet corner, well out of the way of prying eyes, so that the documents on board could be inspected in secret. Instead it sailed into the centre of Scapa Flow - with the Swastika that Dennis and his men had raised provocatively overhead, and swept past the fleets flagship.  Security was so lax that nobody stopped a Universal film crew filming the event. Fortunately the film was confiscated before it could be shown.

(On Jan 17th 2007, I received an email from Dennis Molnar, who lives in Canada. He knows Alex Dennis, now 88 years of age. Dennis sent me the following information from Alex himself.

..... our bridge had sighted a trawler marked with a big painted Dutch Flag steaming  northwards. As we approached her it became obvious that a “boat” abaft her funnel was nothing more than a canvas mock-up. There wasn’t time to be more than normally frightened and in only a minute or two we were alongside, heaving up and down in the swell. Johnny Blackmore and I leaped on board, to be confronted by a slightly dazed looking individual who at once announced the words “German Ship”. The canvas mock-up covered a gun and right away I could see her two torpedo tubes barely covered by fishing nets. ... the rest of my party scrambled aboard and we quickly got the German crew on deck. We brandished our loaded .45 pistols just like in the movies. …they didn’t resist but threw overboard all their confidential books, ciphers and charts. The books did not sink at once and were recovered very gallantly by Florrie Ford who dived from Griffin’s quarterdeck into the rough sea. ... he was not far from drowning  but was successfully hauled back with his bag of books.

Meanwhile we were getting busy on board Polares. I put Kenyon on the bridge where he succeeded in stumbling and letting off his pistol. … this had good effect in that it cowed the Germans on the well deck who could not see what had happened. I went around the ship to make sure they (the Germans) were on top and that she was not being scuttled.  …one of the crew approached me and warned me in English that the hatch leading to the magazine was booby-trapped. I (also) disposed of the trawler skipper and all the German army people who looked to be a more dangerous lot than the sailors.

So, feeling a little lonely, I shaped course for home. This was not all that easy, as our initial position was uncertain and I soon discovered all the charts and navigational equipment had gone overboard. So off we went, …me on the bridge, a German helmsman and a Stoker P.O in the boiler room with a number of German stokers who seemed willing enough. We were slightly outnumbered but kept alert and close to our weapons. The trip home was great fun. A big fat Bavarian chef cooked us some huge meals of bacon and eggs - Polares had just come from Denmark. We painted out the Dutch insignia and couldn’t resist flying the White Ensign over the Swastika, although I suppose this might have given the game away to a U-Boat. Her actual cargo was recorded by the Admiralty later as;  2 Torpedo tubes with torpedoes, 4 magnetic mines, 2 field guns, 1 concealed gun, 1 anti-aircraft machine gun, depth charges, “a mountain of explosive stores” It took two days to reach Scapa Flow. I made what I felt was a triumphant entry into Scapa Flow)

Looting was allowed after the boarding party had departed but before Naval Intelligence was able to inspect what was left on the ship, Intelligence Officers found the deck littered with papers, among them Enigma cipher documents and pages from a cipher pad.  These documents, and those recovered from the water by Foord in the freezing waters off Norway, were to enable the naval enigma code to be broken, on May 11 1940, for the first time in the war. The signal pad pages with plain text German and the matching cipher text on them were all that was needed for the "bombe" machines developed by Alan Turing, the Bletchley Park code breaker,  to work out how the Enigma had been set on the day it was captured. Once that had been established, the code could be broken for that day; if the scrambling elements inside Enigma, the three rotors and the plug board, could be set  in exactly the same position as that set by the sender when enciphering his messages, the code breaker merely had to tap out the cipher text on the Enigma keyboard and the letters constituting the German plain text message would light up the Enigma lamp board.

However, the documents recovered provided the key for only 5 days, Apr 22 - 27 1940. The Enigma settings were changed each day, and Bletchley Park still had to find a way of working out the settings for days when there were no captured clues.  Another document from the Polares was to be of much greater significance, for it laid out the procedure  used by senders of messages to indicate to legitimate receivers how to set the scrambling elements in their Enigma machines so that the receivers could unbutton the messages they received.  Knowledge of this "indicating procedure" enabled Alan Turing to devise another ingenious, though long winded, method of breaking the naval enigma code. This method was known as banburismus.  The name for this device came from the town of Banbury, where the sheets were mostly made. This eliminated many "possibles", leaving only "probables". However, it could be used in practice only if he had access to so called "bigram tables" which, in the course of the indicating procedure, were used to convert pairs of letters of the alphabet selected by the message sender into other pairs.  Unfortunately, the bigram tables were not included in the sheaves of paper discovered on the Polares. Bletchley Park's code breakers had to wait almost a year before the seizing of more Enigma codebooks enabled them to make the next breakthrough.

One thing was crystal clear and had to be dealt with urgently. The Enigma codes had to be got hold of once and for all. At the beginning of May 1940, the Germans dropped the double transmission of settings (as mentioned earlier) and the Polish "bombi" would now have become obselete. After 7 years of reading German codes, the Allies were struck blind. However, in Norway, the Germans continued to use the double transmission, so at least there, Bletchley Park could continue to operate. As things sometimes occur, a "miracle" happened. John Herivel, a 21 year old mathematician, had reasoned, months before, that if all the codes on a particular day were checked, the initial settings of rings could be marked on a chart, the settings with the most marks against should be the code settings for that day! For months this setting was used without success until after May 1940, when the Germans had reduced the settings transmissions, did his idea become important again. After 3 weeks of these attempts, Herivel walked into the Luftwaffe and Kriegsmarine hut to find that the night shift had produced a code! This became known as the Herivel Tip. His tip not only threw up settings but revealed other German errors. On 22 May 1940 the German Air Force code was broken. It was fed into the Bombe and, with very few exceptions, remained broken for the remainder of the war.

Intelligence is only as good as its results however, and to that end it failed insomuch that although the German Blitzkrieg plans lay open for all to read, the superior weapons of the Germans made little difference to the knowledge of what they would do, and when. Coupled with the disbelief in Commanders when handed such intelligence, in many cases, information was simply not passed on.

Admiral Doenitz, on the other hand, was becoming increasingly suspicious when he noticed that a convoy, positions known to the German Intelligence, suddenly "disappeared" from its position and never reappeared. He reasoned that the British knew where his U boats were waiting and had acted accordingly. This could only mean that they could read Enigma messages. He asked about Enigma's efficiency only to be assured by B-Dienst (German Intelligence) that the codes were safe. They had long ago broken the British Admiralty codes and saw nothing indicating such knowledge in British signals. Doenitz was not convinced. The disappearance of U boats, the Schiff26 and two patrol boats off Norway did nothing to alarm the Germans, putting it down to coincidence as 2 destroyers had already been sighted in the vicinity of Trondheim and had suddenly materialised alongside a German trawler. German enquiries revealed nothing to cause them any concern. Meanwhile, the Polish codebreakers, in Paris, realised that nothing was being done with the information being supplied to the French Government. They had been given full details of impending air raids on some car plants in Paris by the Luftwaffe. Dates, times, heights, courses, numbers of aircraft, fighter escorts and targets. And, when the known raids materialised, nothing at all was done by the French. not a single show of resistance was shown, had the French already "given up"? By the time Paris fell, the Poles were in Toulouse, then moved to Oran in Algeria, only to find themselves back in Vichy France in a Chateau, much to the annoyance of the British who felt they were unnecessarily being put into danger by French Intelligence.

In March 1941 another trawler, Krebs, was captured off Norway in the course of a Commando raid by the British Army and the Royal Navy in an attack on the Lofoten Islands. On the trawler were the Enigma settings for the month of February 1941. Using these settings, Turing and his staff were able more or less to reconstruct the missing bigram tables and then to attempt to apply  Turing's banburismus technique.

But it was not to be Turing or any of the other brilliant mathematicians working alongside him who were to make the leap that would allow the code to be broken once and for all.  Turing's banburismus method did not work at first, and the naval enigma code might not have been broken for months had it not been for the lateral thinking of Harry Hinsley, then aged 22, a history undergraduate, who had interrupted his studies to join Naval Intelligence at Bletchley. It was Hinsley who, at the end of April 1941, identified the Enigma's fatal flaw.  Turing had told him that the code breakers were still stuck. So Hinsley knew that the only material he had to work with were the February 1941 decrypts read as a result of the March 1941 capture of the Krebs.  That did not deter Hinsley who, in the course of his medieval studies, had become adept at making the most of scant historical evidence.  While he was pouring over the messages once again, it dawned on him that he had missed something that had been staring him in the face for days; the same enigma code books used on the heavily armed U Boats that were so difficult to capture were also being used aboard isolated and unprotected trawlers.  The trawlers, which were transmitting weather reports to the Germans, were in their turn being sent naval enigma messages.

Although the weather ships were not enciphering their weather reports on enigma machines, they had to have one of the machines on board if they were to decode the enigma signals transmitted to them.  This was an act of almost unbelievable folly since, if the code books could be captured from one of these vulnerable trawlers, the naval enigma system, used by the U Boats, Nazi Germany's most effective weapon, would be compromised.  Hinsley had discovered Enigma's Achilles heel!  He immediately told the Admiralty what he had found out.  Then he explained how the discovery might best be exploited.  If the Royal Navy were to send a warship to board one of the weather ships, the German crew would doubtless have time to throw their current enigma settings into the sea before they were boarded.  However, Hinlsey was almost certain that the next month's Enigma settings would be locked in a safe.  That being the case, he reasoned, if the Germans were frightened sufficiently by the warships guns, the locked up codebooks might well be forgotten when the ships were abandoned.  The Admiralty accepted Hinsley's hypothesis. At the beginning of May 1941, no fewer than seven destroyers and cruisers were sent to the northeast of Iceland where the Munchen, one of the weather ships, was operating.  In the course of the raid, the weather ship, and the Enigma settings for June 1941, were captured.  As a result of this planned capture, and not as a result of the fortuitous capture of the U-100 two days later, naval enigma messages transmitted during June 1941 were read almost as soon as they were sent.

But halfway through June 1941, Turing had to ask for Hinsley's help again. The German's had replaced the bigram tables worked out so painstakingly by the British code breakers. This was a serious problem for the code breakers. Since Bletchley Park needed to read Enigma messages for about a month to be able to construct the new tables, and since the code breakers only had Enigma settings for the two week period ending at the end of June, there would be a code breaking blackout unless further settings were captured.  But Hinsley and the Admiralty were concerned that capturing another weather ship might give the game away. There was no point in seizing the settings if the Germans immediately altered them because they knew they had been captured.  So there were agonised discussions about what to do before the Admiralty decided to take a risk.  On June 25th 1941 four warships set out from Scapa Flow to capture the codebooks from the Lauenburg, another weather ship operating north of Iceland, which Hinsley had selected.  On the way Kim Skipwith, the Commander of the Destroyer HMS Tartar told his men that they were looking for a meteorological ship that was providing the Luftwaffe with weather reports. "If you chaps don't want your homes to be bombed, you'd better find her", he told them. He then warned Tom Kelly, his chief gunners mate, that when they found the ship he would be instructed to open fire but he must on no account hit the target. "That'll be very easy", Kelly retorted impudently. "I just want to encourage the crew to abandon ship, pronto", Skipwith explained.

At about 7pm on June 28th, a lookout on Tartar shouted "There's something over there, behind that iceberg!".  That something was the Lauenburg. Shortly after Kelly's gunners opened fire, two lifeboats full of the Lauenburg's crew were seen being rowed away from the weather ship.  Minutes later Tartar steamed alongside and a boarding party led by Lieutenant Hugh Wilson leapt aboard.  They were joined by Allon Bacon, a Naval intelligence officer.  "There's nothing much here", Wilson told him.  Nodding dismissively at the disorganised piles of paper lying in the charthouse and on the deck, he added "You don't want this rubbish do you?". To which Bacon replied that he wanted it all and declared himself satisfied only when all the paper had been bagged and taken to Tartar.  Only then was Kelly instructed to fire on and sink the Lauenburg.  On the journey back to Scapa Flow, Bacon closeted himself in the Officer's day cabin to sort out the documents. Wilson looked in from time to time to offer him a cup of gin, but Bacon refused to be distracted. When Tom Kelly popped his head round the door and asked Bacon if he had found what he was looking for, Bacon, who had disappointed the Task Forces Commander by not bringing back an enigma machine said, "No, but I've found something a damn sight more important".  Among the mass of charts and signaling papers he had come across three loose sheets that Hinsley had hoped he would find. Two of these were headed Steckerverbindungen  (plug connections) and one was a list of the Innere Finstellung (inner settings) i.e.: the enigma wheel order, and the settings for the rings around the wheels that could be altered only by fiddling around inside the Enigma machine.

It was thanks to these documents that naval enigma messages were read throughout most of July 1941, and also that the latest set of bigram tables were finally reconstructed, which opened the way for Turing and his team to exploit his banburismus procedure.  From the beginning of August 1941 Turing and his colleagues were able to break the naval enigma code using the banbarismus procedure with an average delay of about 50 hours. For the moment the battle for the naval enigma code was won.  Enigma could put a message into code in over 150 MILLION MILLION MILLION different ways.

Alan Ross worked at Bletchley Park on a section that dealt with the German code RHV which was used primarily for small vessels using the Norwegian coast and by other vessels, including U Boats, not fitted with Enigma machines. RHV means “Reservehandfahren” which is, I think, self explanatory. This code was broken for the first time in June 1941, the U-110 had on board some RHV codebooks. But, as we are becoming used to reading, the Germans had made an error otherwise this could not have been read. They did not, for some reason, change the codes as often as say, enigma (Key M was the German name for the machine). RHV translations were not really of any help to the Royal Navy but they were very helpful to Bletchley Park. Messages sent via Enigma were, very often, repeated in RHV – if the RHV cipher was broken then the plain text could also be used as a crib for the still obstinate Naval Enigma.

The code used by naval dockyards, small ships in dockyards and by harbours was known as Werftschlussel. Schlussel being “key” in German. However, it was also used by capital ships and warships to communicate with these yards. Werftschlussel was broken in 1940 and made a significant contribution in October 1941. Bletchley Park was baffled by a new code on the 3 – 5 October 1941 used by U Boats to communicate to the docks.  Bletchley Park used the Werftschlussel as a crib, discovered that the U boats were using a new code. Doenitz had introduced a new key amidst his concern that U Boat positions were being compromised. During this time Bletchley Park was taking in new recruits and new fresh eyes began spotting German errors. One of these recruits, a chap called Jack Good, actually dreamt that an order of code had been reversed. When he awoke he went and tried it out and it worked! In November 1941 the Germans replaced the Bigram sheets with new copies, thereby depriving Bletchley Park of the fuel for the banburismus procedures. This did not stop decoding but time taken to achieve the required result was extended to unacceptable proportions. The problem was alleviated somewhat as Bletchley Park could use 15 bombes.

In December 1941 plans were in place for two consecutive raids on Norway, one in the Lofoten Islands. Naval Intelligence was instructed to accompany these raids in order to assist Bletchley Park with the acquisition of new code books and, hopefully, bigram sheets. Whilst the Navy was conducting street fighting on the island of Vogsoy, Alan Bacon, of Naval Intelligence was searching the armed trawler Fohn, now abandoned, and he found new bigram sheets, enigma setting tables and five enigma wheels. In fact he filled two sacks with relevant information. Another Armed Trawler, the Donner, taken at sea, yielded a complete enigma machine, more bigram tables and 5 wheels.

Further up the coast another raid was taking place and HMS Ashanti had a German Trawler cornered. Due to an error on board the Ashanti, nobody had ordered her main guns trained on the trawler. This was noticed and someone ordered her guns trained upon the Trawler, where the German crew was being held at gunpoint on deck. The sudden movement of the ships armament startled the crew, who thought the trawler was about to be blasted to kingdom come, causing the crew to jump ship in a hurry! A shell from one of the guns was actually fired; it passed straight through the radio room and out the other side, causing the radio operator to abandon ship without calling for help. When boarded, an enigma machine, bigram tables, code books were all transferred to Ashanti, the trawler was then sunk. Both raids had yielded very valuable prizes and by 1^st January 1942, all had arrived safely at Bletchley Park. Back in business! But the success of the raids was short-lived when, in February 1942, the Germans introduced the 4^th wheel to Enigma.

Banburismus ground to a halt. It could only work on messages with similar settings. This downturn, coupled with the breaking of the Royal Naval Cipher 3 by B Dienst, enabled the U Boats to enjoy a period of relative success as Doenitz could direct his boats to convoys but the British could not divert them away.  The breaking of the Royal Naval codes was a mixed blessing in that it protected the knowledge that the British were “blind” from the Germans, thus ensuring that the secret remained so for a while longer.

Britain was also very reluctant to pass on information to the USA due to concerns over security at the American end. The Americans wanted to know why information was drying up but Britain did not inform America of the 4^th wheel and subsequent lack of decoded information. This reluctance was well founded as shall be seen later on. By April 1942 Britain told the Americans about the lack of information due to the new 4^th wheel being added to Enigma and therefore unreadable and on 13 May 1942, allowed America access to the enigma files. The Americans, armed with blueprints, began construction of their own “bombes”. The Americans told Britain at the same time that they had cracked the Japanese Military “purple” codes. Autumn 1942, the U Boats had the upper hand in the Atlantic Ocean. Doenitz now had 126 U Boats operational. Things looked grim until once again, a U Boat came to Britain’s rescue. This time it was the U Boat U-559 which had been spotted off the Egyptian coastline by a Sunderland Flying boat’s radar screen. No less than 5 destroyers were dispatched to the “kill”. One of these was HMS Petard captained by a man who had a burning ambition to take a U Boat intact! Some of his crew had burning ambitions towards him as well, he drove them quite hard.

The U Boat proved to be a difficult opponent, diving too deep for the depth charges to attack. At that time depth charges were unable to attack deep lying submarines which could dive a lot deeper than British experts imagined. One of the crewmen, and it’s a shame we do not know his name, had the bright idea of putting soap into the holes of the depth regulator, thereby causing the depth charge to detonate much deeper than planned. The soap worked and it forced the U-559 to move away, giving ASDIC operators on the surface a stronger echo. Repeated attacks took its toll on the beleaguered submariners, they were cracking. Grown men broke down in tears under the incessant hammering on the hulls of the explosions. U-559 was also leaking badly. The incoming water was upsetting the delicate balance of the boat and, after discussions; the order was given by Captain Heidtmann, to surface. There was precious little time left. Yet again, under the intense pressure of battle, a German (Gunther Graser) or one of his section, made a serious mistake. Whilst evacuation was under way, they were supposed to open vents to fill the diving tanks, causing the submarine to dive again but someone had not removed the levers retaining pins which bent and the levers became jammed. The Captain of HMS Petard, Thornton, getting his prize, shouted at his boarding party to search every single sailors pockets, he knew what he was looking for.

16 year old Canteen Assistant, Tommy Brown, had joined the boarding party and it was he who assisted the 1^st Lieutenant to remove all the codes from the submarine. The Lieutenant could not remove the enigma machine as it was bolted quite firmly in place. Tommy remembers the Officer hammering away at the fittings in an attempt to break them. Time was short. The water was getting deeper and deeper and Tommy made three trips to the boat with codes and books. Thornton ordered his men not to utter a single word about this to anyone, it was to remain secret. But 2 men from an accompanying destroyer were later overheard by police talking about the escapade in a public bar. They were whisked away and told in no uncertain terms to keep their stupid mouths shut. It turned out to be an important find as the new weather reporting code books were amongst the papers and could be used as cribs for other codes, including Enigma. But once again, they had got away with it and the Germans knew nothing about the fate of the U-559.

It was not until December 1942 that another breakthrough occurred, again, through German errors. The 4^th wheel, it was discovered, was always set to A with its ring setting to Z; which meant that only 3 wheels were still being used. Due to apparent operators laziness the 4 wheel enigma was only being used as a 3 wheel machine! Seven months later, King George VI was handing out medals to the Petard crew and he asked the ASDIC operator, Ken Lacroix, “We are still not allowed to discuss this are we?” “No Sir, it’s still a secret” “Well, congratulations”, said the king. (See footnote on Ken Lacroix). On the 17^th February 1943 came another breakthrough with the forcing to the surface of the U Boat U-205 off the coast of Libya by HMS Paladin and HMS Gloxinia. A large amount of documents were removed from the submarine. HMS Gloxinia attempted a tow but the U-205 went down in the bay by Ras el Hillal.

In the Atlantic events were reaching their peak in the battle against the U boat. During March 1943 627,000 tons of shipping was lost to the U boat. On 19^th March, code breakers got into the code once again, with the help of books taken from both the U-505 and the U-205. Even a bigram sheet change by the Germans made little difference as Bletchley Park had no less that 70 “bombes” now working, running codes.

After March 1943 All Allied plans for tackling the U Boats came together in unison and the peak of the Battle of the Atlantic was passed. Anti submarine hunter killer groups, like Captain Walkers ships, long range aircraft closing the gaps over the ocean and quicker decrypts of Enigma were the main causes. Better defended convoys too aided the cause. In Africa, enigma decodes enabled Montgomery to inflict a massive defeat on Rommel by reinforcing a weak defensive section in time to combat a German offensive. The defeat was so emphatic that the Afrika Korps sent messages back to Berlin hinting at “code betrayal”. At sea, ships were equipped with the latest centimetric radar, which U boats could not detect. Ships could now take on the U Boat on their own but long range aircraft also were fitted with the same radar. Many aircraft flew from the increasing number of escort carriers becoming available.

May 1943 saw a significant downturn in the numbers of ships being sunk by the U Boat, 264,000 tons compared to 600,000 in March. Doenitz noted that this was at a loss of 31 U Boats, which was unacceptable. Doenitz ordered all boats out of the area to southwest of the Azores – they had lost the Battle of The Atlantic, although the battle would continue to the last days of the war, it was effectively game set and match to the Allies. On 21^st September, Churchill revealed to a cheering House of Commons that in the previous 4 months of the war, not one single ship had been lost to a U Boat in the North Atlantic. The corner had well and truly been turned.

The Role of Enigma in the Sinking of the Scharnhorst 

Due to the withdrawals of U boats from the Atlantic, the role of Enigma diminished but was counterbalanced by the assistance it gave to a grateful Royal Navy in the Arctic Ocean. Not only did the U Boat threat remain but also the convoys to Murmansk and Archangel were within range of Norwegian based German bombers and also surface ships were in Norway’s Fiords. Tirpitz was out of action, crippled in Trondheim Fiord and the Lutznow had fled back to German National waters. But, still alive, and very much kicking, was the Scharnhorst. Her presence tied up much of the Home Fleet in Arctic waters. Admiral Fraser was receiving enigma reports on the state of readiness of Scharnhorst. Fraser, on board Duke of York, personally took convoy JW55A to Kola in December 1943. Much to the surprise of the Russians. He then returned to bring convoy JW55B which was due to leave Loch Ewe, Scotland on 20 December 1943.

As JW55B sailed Fraser received notice that Scharnhorst was on 3 hours readiness, and on Dec 21^st was back on 6 hours notice. Then he was informed on 22^nd December that, on 21^st December, Scharnhorst was back up to 3 hours notice. Enigma decoding had become relatively fast but there were delays, counted in hours, when codes were changed. News received on Dec 23^rd was such a case.

Part of the German coding system on enigma was the Offizier Procedure for anything of utmost importance, one off messages. The method involved an officer setting up an enigma with the same settings as normal, but using different plug board settings. The list of settings changed only once a month. After encoding his message, the transcript was then handed to an operator who encoded it yet again.

But Bletchley Park managed to work around even this extra hurdle using cribs which often contained the word “fort” or “continuation” (fortsetzung) and the time of origin of each message. Leslie Yoxall, 26 years of age, a mathematician, exploited yet another German oversight. As soon as the board settings were discovered, they were valid for the remainder of the month. Yoxall managed to decode a message containing only 80 characters, whereby the normal message length required was in the region of 200.

Nevertheless, it took 48 hours to inform Fraser that, on Dec 22^nd, Scharnhorst had been told to make ready for sea. This coupled with enigma news of increased Luftwaffe reconnaissance warned him that something was about to happen. If the Offizier Code has been more readily decoded he would have heard that “Battle Group is to be at 1 hours notice from 1300 hrs 25^th December. Scharnhorst to acknowledge”. It took 31 hours for this message to reach Admiral Fraser on the battleship Duke of York. But by this time it was too late to influence events.

Even when a message could not be decoded it was not the end of matters. Harry Hinsley, Bletchley Park, used a method that, if messages were more frequent than normal, then something really major was occurring, or about to occur. He phone Denning in the OIC at the Admiralty and related this fact. When he had first arrived at this conclusion, nobody took any notice of him, and the Royal Navy lost HMS Glorious and several destroyers to Scharnhorst and Gneisenau.  Now, when Harry spoke, people listened.

Fraser was informed that Scharnhorst has sailed when a message warned a patrol vessel to expect Scharnhorst to pass her at approximately 1800 hrs 25^th December. Fraser recorded that, at 0339 hrs 26^th December, he received a signal stating that Scharnhorst was at sea. Fraser was too far from convoy JW55B to be of any use. He broke radio silence to order JW55B to steer to the north, away from Scharnhorst. The Germans picked up Fraser’s messages but did nothing to inform Scharnhorst or to recall her. Even when a Luftwaffe reconnaissance aircraft called in to report “5 warships, one apparently big” to its base still the Germans did nothing. The aircraft has found Fraser but not Vice Admiral’s Cruiser Group which was already entertaining Scharnhorst. Scharnhorst escaped one encounter but inexplicably turned directly into the Cruiser Group again and eventually ran into Duke of York. The full story of the Scharnhorst can be found on my web page: Scharnhorst  and back at Bletchley Park as Pondered read the penultimate signal from Scharnhorst to base timed at 1819 hrs which he sent onto the Admiralty at 2347 hrs, he wondered if the message intercepts had had any bearing on the outcome. Scharnhorst succumbed to the guns of the royal Navy at about 1945 hrs that same evening.

Whilst events like the sinking of the Scharnhorst were unfolding. Events in France and elsewhere were also unfolding. The French Intelligence, instrumental in getting enigma out of Poland into British hands, were playing a dangerous game in that the Poles were still on French soil and could be caught at any time. They were in a chateau in Vichy (unoccupied) France. And some members of French Intelligence were active Resistance fighters. They all had one thing in common, they all knew that England had enigma. Their continued liberty was something causing London concern.

One of these agents had been captured and had informed the Germans that the Poles had had Enigma for 10 years before the war but did not bring England into the topic. He revealed Schmidt, the German who had sold Enigma’s secrets to the French for profit. Schmidt was arrested but had committed suicide in Prison. In August 1943 the German Intelligence, B Dienst, in Switzerland, filed a report about Enigma. It caused severe panic in U boat HQ and consternation in Berlin. It stated that “over the past few months, Germany’s naval ciphers, which are used to provide operational orders to the U Boats, have been successfully broken. All orders are being read currently. The Source is a Swiss American in an important position in the US Navy Dept”. German Naval Communications refuted the report, again stating that it was impossible! Doenitz wrote in his diary that from 12 June – 1 August, 13 of 21 U Boat meetings had been undisturbed, but between 3 – 11 August 10 meetings had taken place and ALL had been disturbed.

The mysterious Swiss American’s intelligence became a concern when, on August 18^th 1943, more details were filed by B Dienst. This person was “related to the Military Attaché and often traveled to London with the US Navy delegations” and “a special office had been set up for code breaking since war started, for several months it had been very successful” – those who could have done something about it also knew of the refusal to believe it could be happening, citing the numbers of permutations required on the wheels and message settings alone, let alone the plug boards. This voice in Washington had told the Germans about the existence of Bletchley Park but the Germans would not believe it. The previous British reluctance to share information with America had proved to be correctly founded, the Americans simply could not be trusted and these leaks bore this out.

The Germans were so sure of their infallibility that their errors were really quite amazing. Bletchley Park found yet another of these errors when messages sent out on one of the nets, codenamed Dolphin, used by the arctic U boats, were repeated on another of the nets codenamed Shark, used by the Atlantic U boats.  The breaking of Dolphin intercepts became a high priority to enable decode of Shark messages. In July 1943, the 4^th wheel was introduced with a “reflector”. Either of these two new elements could be inserted instead of the normal 4^th wheel. This was used on the Atlantic Shark net. Luckily (!) during the short period Shark became unavailable, U boats were not operational in the Atlantic, and Royal Naval Submarine tracking rooms were able to use HF/DF (High Frequency Direction Finding) to pinpoint a location of a U Boat or U boats. Shipping losses rose from 20 ships in June to 46 ships in July. And, once again, Richard Pendered was triumphant in breaking the latest code. This is the same man who had read the Italian codes prior to giving Admiral Cunningham a great victory in the Battle of Matapan and he used a similar method to crack the Shark code.

On August 290^th Bletchley Park reported a 100% decode of all traffic from 1^st – 18^th August. So much so, that redundant “bombes” were redirected to deal with Army and Air Force codes. The Americans by now where building their own “bombes” but ran into trouble by trying to rush it where Bletchley Park “walked”. Bletchley Park insisted that cribs being used by the Americans were useless and, up to the end of 1943, had nothing to show. After the beginning of 1944 and the acceptance of what Bletchley Park was saying, results began to pour in. The American section was known as Op - 20 – G.

With the arrival of 1944, Enigma was to switch its attentions to the U Boats in the Indian Ocean. Many of these had arrived there from being released from the Atlantic. Here in the Indian Ocean they were replenished from tankers such as the Charlotte Schliemann. Thanks to an Enigma intercept, she was found and sunk. Her replacement, the Brake, arrived and the Admiralty was reluctant to attack as it could again compromise Enigma intercepts but the heavy signal rate from and between U Boats alleviated that particular concern as they could have been found by normal means and so the Brake was to be put to the sword also. Once sighted by aircraft, HMS Roebuck was sent in to sink it. HMS Roebuck began firing from a range of 9 miles and an hour later the Brake was sunk. A U boat in the vicinity later reported in that it presumed refueling point had been basically compromised. They had seen the aircraft and assumed a large carrier in the vicinity. It was noted in Germany that “it can be assumed that the enemy knew about the meeting point either by reading our signals or information provided by a traitor”.

Doenitz then instructed U boats to ignore code books and to use certain crew members first names as cribs but this did nothing to halt or slow down Bletchley Park. In March 1944 the Allies were reading of a meeting point in an area west of Cape Verde, off West Africa and ordered all ships to avoid the area so as not to compromise Enigma. But American vessels ignored the warnings and sank 2 U Boats. Admiral Cunningham (Now First Sea Lord) and Admiral King (USN) had a very heated discussion. And once again luck was on the side of the Allies, with the Germans assuming increased aircraft activity and airborne radar as being to blame. At the same time the U-744 had been found 200 miles south of Iceland. Her Captain had fired on what he thought was a solitary destroyer before diving deep. They heard an explosion and assumed a hit, coming back up they were shocked to hear the thunder of screws bearing down upon them, it was another 6 ships! They subjected the U-744 to an all night attack and by morning the crew was suffering from oxygen starvation, lying on the floors, and the batteries had almost expired. The U Boat simply had to surface, 29 hours after the attack had begun. As it surfaced the warships opened fire taking both the Captain’s legs off, and he fell unconscious, onto the deck. Scuttling charged were being set as a boarding party from HMCS Chilliwack came alongside. A crewman, Bert Martin, had the code books and latest charts stuck inside his life jacket when a large wave hit the U Boat, knocking him overboard, never to be found. Enigma codes had been in allied hands and the Germans failed to heed the warning from surviving crew members who sent back word from the POW camp in Canada. Eventually they decided that the U boat had sunk before the boarding party had got on board. A misleading newspaper report helped matters by stating that the U boat sank “as we came alongside”. The secret was still preserved.

On 20^th June 1944, more code books and documents arrived at Bletchley, this time courtesy of the US Navy when they captured the U-505. However this did not go down well with London as the crew had seen the books etc being removed. Heated and speedy discussions ensued before the crew was declared “dead” at sea and were not even returned to Germany until 1947. They were hidden from Red Cross visitors and appeared not to “exist”.

The U-505 now resides in Chicago after being towed across the Atlantic by the USS Guadalcanal and tugs sent over.

On the night of the invasion of Europe, 6^th June 1944, the crews at Bletchley Parks sat and waited for the inevitable rush of intercepts when the invasion was discovered. Mastery of the German codes was practically complete by this time. The code breakers waited anxiously for signs of retaliation and movements to attempt to counter D Day. A weather station in the Bay of Biscay had for months been sending out messages all starting with the same sentence “Weather forecast for Biscay” which was an ideal crib and was used for every code change.  The Germans even sent out a rebuke to the station which had no effect. Harry Hinsley, by now assistant to the Station Chief, sat looking at a map of France. Another fact that speeded up the decoding of intercepts had been found in Washington. The Americans noted that when a wheel had been used it was not put back into the system for 6 months, thus greatly reducing the number of variations required to crack a new code. Yet another German mistake exploited to the full by the Allies.

Harry’s opposite number in SHAEF (Supreme Headquarters of the Allied Expeditionary Force) would ring him from time to time to see if anything had appeared.  His first German Naval coded message was decoded just about 0300 hrs 6 June. Soon afterwards the phone rang and a lady asked if that was Harry. Yes he said, the lady replied that the Prime Minister would like to speak to him. “Has the enemy heard we are coming yet” the voice asked him. Harry told the PM that the first signal was just in and that it was on the printer now.  The pm put down the phone without a word.  90 minutes later the PM was on the phone again, How’s it going? He asked Harry. They had received a signal only 32 minutes ago, already decoded, which read that German torpedo boats were ordered to destroy landing ships off Port en Bessin and Grandchamp. The phone went dead again. He did not allow himself to sleep until lunchtime on 6^th June, 24 hours at the desk. Harry’s war had been won. Harry was knighted in 1985 and died of lung cancer in 1998.

Summary

The Shark net had been broken every single day since 12 September 1943 as had the Dolphin net. It was not until May 1945, at the end of the war, that the Germans introduced a system that used more than one initial wheel setting; too little too late. Bletchley Park was sure that they could have reconstructed the bigram tables, or captured more, but the Germans surrendered before it was necessary, yet again, throwing luck in the direction of the British code breakers of Bletchley Park.

Reading about all those “lucky” incidents, incorrect assumptions and deception would make a religious person believe that “a god” was very definitely on our side in WW2, misdirecting the Germans into making mistakes, and covering any blunders made from the Allies side. Even the words of a traitor within the US Navy Department failed to convince the Germans that we could read Enigma. And the words of a captured agent should have set alarm bells ringing in German High Command, and again, nothing happened. To tell the Germans that the Poles had been in possession of Enigma for a whole 10 years before the war even started should have told the Germans that others too were more than likely to have been in on it, nothing happened. The Poles who had been hidden in a Chateau with all their work, escaped with only hours to spare as Germans arrived and took it over.

For those of you who wish to know, and possibly understand, the technical details of how everything worked I thoroughly recommend the book Enigma The Battle For The Code written by Hugh Sebag - Montefiore published by Phoenix first published 2000 and read the Notes at the rear of the book.

Appx 1 covers the Polish Code breaking Techniques.

Appx 2 – The Bombe.

Appx 3 -  Naval Enigma.

Appx 4 – Cillis.

Appx 5 – Rodding.

Appx 6 – Naval Enigma Offizier, how it was broken.

Notes abound disclosing masses of detailed information.

Part 2 - How Enigma Worked

Messages transmitted to and from U-boats were intercepted in Britain by Royal Air Force 'listening' stations, known as 'Y' Stations. The 'Y' Stations also intercepted thousands of other enemy messages each day. Outside a 'Y' Station a forest of tall aerials picked up radio signals from as far away as the Soviet Union and Japan. Inside, a team of Morse code operators worked 24 hours a day, listening in to coded messages and writing them down. Your job would be to translate the Morse signals into letters and write them down as fast as you could - at least 90 letters a minute. If you made just ONE mistake it would be impossible for the code-breakers to break the code.

Bletchley Park was the home of the secret Government Code and Cypher School. This was the centre of British code-breaking during the war.  The code-breakers were specially chosen from among the cleverest people in the country. Some were brilliant mathematicians or linguists. On the left above is Alan Turing, a Cambridge mathematician and code-breaker who helped to invent the world's first computer (Colossus) at Bletchley Park. By 1944 they had a big team to help them. Seven thousand men and women worked in shifts round the clock in small wooden or concrete buildings known as 'Huts'. Many did repetitive but important jobs like filing or operating the code-breaking machines. They were not allowed to tell anyone - not even their family or friends - about their work. On average more than 3,000 coded messages arrived at Bletchley Park each day from the 'Y' Stations. Messages were taken to different 'Huts', depending on whether they had come from the German army, air force, navy or another source. A message from a U-boat would go to Hut 8. There the code-breakers would study it. The only way they could break the code was to compare the message with others to see if they could work out exactly how the U-boat commanders had set their Enigma rotor wheels and plug board settings that day. Imagine their task - to find the RIGHT ANSWER out of 150,000,000,000,000,000,000 POSSIBILITIES - and start all over again every 24 hours. Sometimes messages began with the same words, such as a weather report. This gave clues (called a CRIB) about how the rest of the message had been encoded. When the code-breakers eventually worked out what the CRIB letters might be, they tested them on the machine shown below, called a BOMBE. (Invented by Turing) Bombes were huge, noisy electro-mechanical machines which could check through combinations of letters far quicker than a human being could. When the Bombe stopped, this meant that the code-breakers' guesses were right. All that days U-boat messages could then be decoded.

Sometimes a code could be cracked in less than an hour. But when the U-boats started to use 4-rotor Enigma machines in February 1942 it took TEN MONTHS to break the code. The decoded messages were in German in blocks of five letters. They had to be carefully translated into English. On the 9th of May, 1941, U-110 had been about to attack an Allied convoy when it was forced to surface by British ships protecting the convoy. The German crew surrendered. The photographs below shows the boarding party from the destroyer HMS Bulldog, rowing out to the half-submerged U-boat. (U-110 later sank while being towed to a British naval base in Iceland).

The British sailors climbed into the conning tower and began a search of the deserted submarine. The bookshelves still contained books of every description - navigation manuals, seamanship manuals, code books and signal books. The Bulldog's telegraphist pointed to an interesting piece of equipment that looked like a typewriter. This, along with all the books from the shelves, was transferred with utmost care to HMS Bulldog. It was important that everything was kept dry as the code books and signal books were printed in ink that disappeared if they were dropped in seawater. On Bulldog's arrival back in Britain they were met by a representative from Bletchley Park, who photographed every page of every book. The 'interesting piece of equipment' turned out to be an Enigma machine, and the books contained the Enigma codes being used by the German navy. The British were anxious to make sure that the Germans did not find out that U-110 and its codebooks had been captured. All the sailors who took part in the operation were sworn to secrecy. If the Germans had found out, they would almost certainly have changed their codes. This would have made the code-breakers' job far more difficult - but by 1943 they had the help of Colossus - the world's first programmable electronic digital computer. This British Naval message shown below dated 10th May reads: "a) Capture of U Boat 110 is to be referred to as operation Primrose. b) Operation Primrose is to be treated with greatest secrecy and few people allowed to know as possible..."

Colossus was built for the code-breakers at Bletchley Park by post office engineers in 1943.The computer was as big as a room - 5 metres long, 3 metres deep and 2.5 metres high - and was made mainly from parts used for post office telephone and telegraph systems. It was a development from the mechanical Bombes.  Colossus worked by 'reading', through a photoelectric system, a teleprinter tape containing the letters of the coded message. It read 5,000 letters a second. All possible combinations of the coded message were checked with the cypher key generated by Colossus. A teleprinter typed out the results of Colossus's search, revealing the settings which had been used by the Germans to send their messages.

Ten Colossus Mark 2s were eventually built. They cracked the Enigma codes and even more complicated ones devised by the Germans on their 12 -rotor cipher machines. A complete Mark 2 Colossus machine has recently been rebuilt and is on display at Bletchley Park. The information revealed by the code-breakers at Bletchley Park was called ULTRA. ULTRA was so secret that only those who needed to know about it - like the British Prime Minister, Winston Churchill - were told of its existence.

For many years after the war, the work of the code-breakers remained a secret. The ULTRA files were locked away. Today more is known about Enigma and ULTRA. Historians can study the effects they had on the course of the war. Code breaking did not win the war, but it probably helped to shorten it - perhaps by a year or more. It also contributed to the success of many Allied campaigns from 1941 onwards.

North Africa, 1942 - By breaking codes used by Rommel's forces, the Allies could attack his supply routes, helping to
ensure Montgomery's victory in the Western Desert.

Battle of the Atlantic, 1940 - 1944 - Until convoys were better protected by escort ships and aircraft, one of the only
ways of fighting the U-boat threat was to use ULTRA to divert ships away from danger. This led Doenitz to suspect
that codes were being read, but his suspicions fell on deaf ears, enigma was unbreakable they said.

D-Day, 1944 - ULTRA revealed the size and location of German forces in Normandy before the Allied landings began.

At other times ULTRA was not used effectively. It did not prevent the Allied setbacks at Arnhem and the Ardennes in north-west Europe during the last year of the war. To prevent the Germans from suspecting that their codes were being broken, the Allies sometimes took no action even when they knew their enemy's plans.

The code-breaking methods used in the Second World War seem very old-fashioned to us. But the work at Bletchley Park led directly to the development of the computers we use today. The computing power of the room-sized Colossus can now be put into a Pentium microprocessor no bigger than your thumb. Modern computers can create incredibly complicated codes. These can only be broken by other computers thousands of times more powerful than Colossus. The codes which protect the security of vast networks such as banking systems and the Internet were thought to be unbreakable. But computer hackers have already found their way into these systems.

The Enigma machine, first patented in 1919, was after various improvements adopted by the German Navy in 1926, the Army in 1928, and the Air Force in 1935. It was also used by the Abwehr, the Sicherheitsdienst, the railways, and other government departments. From then until 1939, and indeed throughout the war, successive refinements were introduced, varying from service to service, and there were detailed changes in operating procedure until 1945. The following short description can therefore summarize only its main features and mention only a few of the Enigma variations.

The Enigma (see diagram below) was used solely to encipher and decipher messages. In its standard form it could not type a message out, let alone transmit or receive it. From the cipher operator's point of view, it consisted of first a keyboard of 26 letters in the pattern of the normal German typewriter:
 

     Q  W  E  R  T  Z  U  I  O
       A  S  D  F  G  H  J  K
     P  Y  X  C  V  B  N  M  L

Enigma being used on board a U Boat

Hugh Sebag-Montefiore's book "Enigma - the Battle for the Code" is published by Weidenfeld & Nicholson at £20.

An enigma machine was also found on the U Boat 534, which was raised and has its own page here.

http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=56827&lngWId=1

Part 3  - Footnotes & Describing A visit

A Description of a Visit to Bletchley Park

With the publicity given to Bletchley Park through television programmes, the new film and the theft of one of its Enigma machines, there was no lack of interest on a coach outing amongst us from the Chelmer and Blackwater Committee of King George’s Fund for Sailors. Bletchley Park Mansion Some of them were ex-Wrens, others ex-naval personnel and one lady who actually worked at Station X during the war, We were shown the various huts dotted around the 55 acres of ground surrounding the Bletchley Park’s Victorian mansion that MI6 first took over in 1938. In these huts the de-coding took place, with no one group knowing what the others were doing. During the war, Bletchley Park became more and more active, ending up with 12,000 people working there - all in the greatest secrecy keep track of enemy activities. maintained for many years afterwards. German messages, picked up at various Y radio stations around the country and overseas, were rushed to Bletchley - Park to be de-coded, sometimes at dead of night. With some help from German code tables captured from German weather ships and from the submarine U-110 in 1941, Bletchley Park was able to keep track of enemy activities.

Those of us who had our convoys diverted or re-routed during the Battle of the Atlantic had no idea why. We naturally suspected that through intelligence U-boat positions had been obtained and our courses had been changed accordingly. But we had no idea how the Enigma machine and decoding of German U-boat messages by Bletchley Park achieved this. Situated mid-way between Oxford and Cambridge, it was able to draw on the best brains available from these universities to find ways of de-coding German messages. Alan Turing, a young Cambridge professor, was reputed to be a genius, if a little eccentric, as were some of the other brilliant minds that worked there. The task of decoding was very exacting and was carried out by people who included professors, mathematicians and crossword addicts. Hitler had such confidence in the Enigma machine that he was quite confident we would not be able to crack the codes it produced. Another machine we saw was a reproduction of the great Colossus used towards the end of war, which was the first world’s computer. It worked at fantastic speeds to decode secret German messages. Our guide took us to the stable yard where homing pigeons were housed in aloft. They would be occasionally dropped over enemy occupied territory, to be picked up by members of the Resistance, who would attach messages to them and release them to return to Bletchley Park. In this way Germans could not pick up radio messages. There’s a tennis court at Bletchley Park constructed at the instigation of Winston Churchill who thought it necessary the people should have some form of recreation.

But it was not all pleasure for the staff at Bletchley. In order to get the German messages decoded quickly it was necessary for them to work in continuous shifts. Early in the war they found the Luftwaffe codes relatively easy to break. The naval ones were more difficult. But, in May, 1941, they de-coded a message confirming the Bismarck was making for Brest as the Royal Navy desperately searched for her. “Sink the Bismarck,” Churchill boomed. They did, but only because Bletchley told them where she was heading for. Our tour was completed by a visit to the Faulkner Museum where uniforms, model aircraft and aero engine parts - amongst other artefacts - were displayed. Finally we were taken through the cryptology trail which showed re-constructed de-coding rooms and H Block where the Colossus machine has been re-built. We were also invited to operate an Enigma machine on which we were able to press the letter keys that illuminated a different letter to each key pressed, thereby producing a code. Our successful visit provided a real insight into what went on behind the scenes in the last war. Bletchley Park, now run by a trust formed at the instigation of some of those who worked there, is a monument to their great efforts that shortened the war by at least two years.

By 1946. every scrap of evidence of code-breaking had been removed from Station X. Bletchley Park Trust was formed to preserve the site for the nation Bletchley Park is open every weekend from 10-3Oam to 5pm with last admission at 3.3Opm. Admission is £5 (adults) and £4 for concessions. There is free parking and Bletchley railway station is a 200 yard walk along a sign posted footpath. For further information, visit their website at www.bletchleypark.org.uk. Prices and times as at Nov 2001.

From a Ministry of Defence News Item 6 July 2005: The code-breaker who revolutionised British reading of the Enigma code, Marian Rejewski, was honoured by Chief of the Defence Staff, General Sir Michael Walker, and his Polish counterpart, General Czeslaw Piatas at a ceremony on 4 July 2005. Rejewski's work has been described "the mathematical theorem that won World War II".  Rejewski returned to Poland at the end of hostilities and died in 1980.  As a result of the Cold War, he never received his 1939 - 45 War Medal and his story has gone largely untold. Marian's daughter, Mrs Janina Sylwestrzak, received her father's War Medal on his behalf in the ceremony at Lancaster House. Marian's work on Enigma's "Ultra" code started in Poland in 1932 and included clandestine meetings with British intelligence staff in the Kabaty Woods South of Warsaw, immediately prior to the outbreak of war.  His work continued in Vichy France during 1942 before he fled France and was imprisoned in Spain. He finally escaped through Gibraltar in an old Dakota aircraft and arrived in Britain to continue his work at Bletchley Park in 1943.  Chief of the Defence Staff, General Walker said: "The work of Marian Rejewski, and his colleagues at Bletchley Park, substantially altered the course of the war.  His story and the obstacles he had to overcome to make his vital contribution are truly remarkable and it is a privilege to honour him with this medal today."

Biography and History

Marian Rejewski was born on 16 August 1905 in Bydgoszcz, Poland. He was a mathematics graduate of Poznan University who, as a student, had attended a cryptology course organized by the Polish General Staff's Cipher Bureau. He joined the Biuro Szyfrow (Cipher Bureau) of Polish Military Intelligence in September 1932.  There he studied ways of cracking the German Army's Enigma cipher machine, which had come into service in 1930. His achievements jump-started British reading of Enigma in World War II ("Ultra"), and the intelligence so gained may have substantially altered the course of the war.

Rejewski fundamentally advanced cryptanalysis by applying pure mathematics - permutation theory - to break the Enigma cipher for the first time. Previous methods had exploited patterns and statistics in natural language texts such as letter-frequency analysis.  Rejewski's mathematical techniques, combined with material supplied by French military intelligence, enabled him to develop methods of breaking the periodic as well as individual keys used in encrypting messages on the Enigma machine.

Rejewski devised a mathematical theorem that wartime Bletchley Park luminary, Professor I J Good, has described as "the mathematical theorem that won World War II." Details of the Polish achievements were revealed to British and French intelligence representatives in a meeting at a secret Polish Cipher Bureau facility at Pyry, in the Kabaty Woods south of Warsaw, on 25 July 1939. The Germans had made changes to Enigma equipment and procedures in 1938 and 1939 that increased the difficulty of breaking messages; and as it became clear that war was imminent and Polish resources would not suffice to optimally keep pace with the evolution of Enigma encryption, the Polish General Staff and government had decided to bring their western allies into the secret.

With the crucial Polish contribution of reconstructed sight-unseen German Enigma machines and the Poles' cryptological techniques and equipment, the British at Bletchley Park, and later the Americans, were able to continue the work of breaking German Army, Air Force, Nazi Party SD, and (though with substantially greater difficulty) Naval Enigma traffic. In September 1939, after the outbreak of World War II, Rejewski and his fellow Cipher Bureau workers were evacuated from Poland via Romania to France.  At "PC Bruno," outside Paris, they continued their work at breaking Enigma ciphers, collaborating by teletype with their opposite numbers at Bletchley Park. When "Bruno" was evacuated upon Germany's invasion of France, the Polish cryptologists and their ancillary staff worked for two years in unoccupied southern (Vichy) France and outside of Algiers in French North Africa. Following the German takeover of the "Free Zone" in November 1942, the secret French-Polish "Cadix" centre in southern France was evacuated.  Its Polish military chiefs were captured and imprisoned by the Germans but protected the secret of Enigma decryption. Rozycki, the youngest of the three mathematicians, had died in the January 1942 sinking of a French passenger ship as he was returning from a stint in Algeria to "Cadix" in southern France. Rejewski and Zygalski fled France for Spain, where they were arrested and imprisoned for three months.  Released upon the intervention of the Polish Red Cross, almost three months later, in July 1943, they made it to Portugal; from there, aboard the HMS Scottish, to Gibraltar; and thence, aboard an old Dakota, to Britain.

Here Rejewski and Zygalski were inducted as privates into the Polish Army (they would eventually be promoted to lieutenant) and employed at cracking German SS and SD hand ciphers. After the war, Zygalski remained in Britain while Rejewski took a big risk and returned to Poland to reunite with his wife and two children.  He worked as a bookkeeper at a factory-bringing disfavor on himself when he discovered irregularities-until his retirement, and was silent about his work before and during the war until, in the 1970's, he contacted the military historian Wladyslaw Kozaczuk. He published a number of papers on his cryptological work and contributed generously to books on the subject. Rejewski died on 13 February 1980 in Warsaw and was buried at the Powazki Cemetery, one of Poland's pantheons of the great and valiant.

The Polish Mathematical Society has honoured him with a special medal. An odd footnote to the story of Rejewski's cryptologic contributions is that his role in World War II had been so obscure that one best-selling book (William Stevenson's A Man Called Intrepid, 1976) not only did not credit him with the work he had done but identified him as "Mademoiselle Marian Rewjeski."

Footnote on Ken Lacroix: In June 2007 I received an email from a gent, Geoffrey Ellis, in which he casts doubt on the award that Ken received, claiming he only received a Mention in Despatches and, consequently, would not have made a trip to the Palace. He mentions: I hold to question the suggestion of an award of a medal to Ken Lacroix as he was only "Mentioned in Despatches". In which case it is unlikely that he would have been presented to the king in my opinion. My information comes from the Supplement to the London Gazette in which all awards are registered - and if it doesn't appear here, it didn't happen. Geoff is of course quite right about the London Gazette. He goes on: (Gazette Edition, Issue 36169, 10-September-1943), in the LH column there appears a section headed "For leadership and devotion to duty in action with enemy submarines in the Mediterranean, while serving in HM Ships Packenham, Petard, Hero, Dulverton & Hurworth". There the follows a list of DSO awards, DSC awards, DSM awards, and finally "Mention in Despatches". This listing flows over into the RH column where you will find Able Seaman Kenneth Vivian Lacroix, P/SDX1471 mentioned. From this it is unclear what part he played in the recovery of the Enigma documents and whilst his contribution to the exercise was not insignificant, it is certain that he was not awarded anything other than a 'mention in despatches'. In a second email Geoff tells me that: In the doorway of the Newhaven Local & Maritime Museum I just happened to see a photocopy of a newspaper that credited Ken Lacroix (a local man, no longer with us) with the glory of having rescued the Enigma Code books from the sinking submarine and being awarded the DSM. I was unaware of this thought it would make an interesting point to include in the presentation. However, the award of a DSM seemed to me to be pretty small beer for such an action so I decided to investigate further. The Newhaven Historical Society Secretary was quite bemused that I should challenge this report and told me "For an authoritative account of the incident read "Seizing the Enigma" by David Khan, Chapter 18 The George Cross. For my money our version stays". I don't have this book so I cannot read it. For my part I would be delighted to think that a local man was key to this piece of history, but when the true credit for this action has been registered in the London Gazette, and Tamworth Town has dedicated a special monument to these heroes (which would not have been done with considerable research) see www.alanwiseman.co.uk/General/Grazier.htm, it would be less than honourable to propagate the claim that the glory for retrieving the Code books belongs to Ken Lacroix. Many medals were awarded according to the London Gazette, and a dozen or so MIDs of which Ken Lacroix was one.

Thanks to extensive research from Geoffrey Ellis the mystery has been solved. Ken was awarded the Mention in Despatches for the enigma incident BUT was awarded the DSM for another action involving a submarine later in the war. The fact that the London Gazette spelt his name wrong, La Croix, caused the confusion in the first place. Geoff tells me: " Further to the apparent non-appearance of entries in the London Gazette for Lacroix, the conundrum has now been solved. His is twice credited (once for MID, and once for his DSM) in LG's for 31/3/44 and 28/4/44 under the name of "La Croix". What a difference a space makes!" What has arisen from this investigation is that Lacroix was awarded his DSM for his part in destroying a U-boat on 12 February 1944 when Petard was escorting a convoy close to the Maldives Islands and the convoy was attacked by a Japanese submarine; many months and thousands of miles apart from the alleged incident. Lacroix got a second Mention in Dispatches on 04 April 1944 for actions in the Aegean also whilst on board HMS Petard. Now, the conversation may well have took place with HM THE King but it would have been in 1944.

Visit Geoffrey's site, its amazing!!! http://www.secret-tunnels.co.uk/

Ken's London Gazette entry: 

http://www.gazettes-online.co.uk/archiveViewFrameSetup.asp?webType=0&PageDup
 licate=n%20%20%20%20%20%20%20&issueNumber=36169&pageNumber=0&SearchFor=Lacroix&selMedalType=&selHonourType=
 

Geoff sent me some references, of which I have not yet, at the time of typing, had a chance to cross examine:

Other websites referring are...

www.ellsbury.com/ultrafassongrazier.htm and

www.lawbuzz.com/tyranny/u571/u571_ch8.htm and

http://en.wikipedia.org/wiki/Unterseeboot_559 and

Navy News...

www.navynews.co.uk/articles/2002/0202/0002020401.asp

The MOD...

www.royal-navy.mod.uk/server/show/nav.3951

Family (Tommy Brown's sister) account on the BBC WW2 archive...

www.bbc.co.uk/ww2peopleswar/stories/16/a5147516.shtml

In a third email Geoff tells me:  I made a point of visiting the Newhaven Local & Maritime Museum this morning to find out more about the offending newspaper article. The photocopy appears to be of a full centrefold article of The Mirror dated Monday, 12 June 2000 and contains an (approx:) A5-size picture of Ken Lacroix proudly brandishing 9 or more medals he won for outstanding bravery, including helping to retrieve vital codebooks from a German U-boat, with the heading "Seizing the Enigma: Sole survivor tells of U-Boat raid". (See attachments).  I apologise for the quality of the images but my camera was confused by the encapsulation and the less than perfect resolution of the photocopy itself. These are the best of about twenty images, none of which are satisfactory. I may have to return to the museum with my mp3 recorder, dictate the text and transcribe it manually if necessary. The article goes on to describe how he was on the conning tower... and relates the alleged conversation with the King. A typed appendix states "Ken Lacroix, a man of this town, Newhaven, was awarded the Distinguished Service Medal for his bravery in recovering the latest Enigma Codes from the sinking German 'U' Boat, U-559."  It then mentions a proposed trip to BP. I cannot imagine that this article went down with Tommy Brown's family, nor with the North Tyneside Veterans' Committee who in partnership with the North Tyneside Council have since named a room after Tommy Brown and commissioned a stained glass window at the Saville Exchange Building, North Shields, or indeed the local ex-service and civic organisations of Tamworth who later erected a monument to the three brave souls Grazier, Fasson and Brown for their heroic deeds. I await the results of Geoff's investigation with eagerness.

July 2007

  Click to email me

References:
Although linked from this page, I have used material from only one or two these sites:

http://www.spybooks.pl/en/enigma.html my thanks to Darek for this link

http://www.turing.org.uk/turing/scrapbook/ww2.html

http://raphael.math.uic.edu/~jeremy/crypt/enigma.html

http://www.militaryhistoryonline.com/wwii/atlantic/enigma.asp

http://www.iwm.org.uk/online/enigma/eni-intro.htm

http://www.pbs.org/wgbh/nova/decoding/