by Alastair Denniston- Code-breaking From Room 40 to Berkeley Street
He was questioning the whole intelligence distribution chain which was being proposed for BP. The following letters reveal Knox’s views and AGD’s patient attempt to explain the rationale for Welchman’s plan.9
On 6 October 1940, Knox wrote:
My dear Denniston,
This Italian business has now diverted large proportions & takes almost all our time in the cottage & very much work is done in the hut. While I expressed myself willing to decode occasionally for the Naval Section, I am bound now to raise the question of circulation. Apart from consideration of our position – why should the largest & most important section not use its own existing mouthpiece? – the Enigma results are of an order of certainty differing wholly from the products of most other intelligence sections.
On personal grounds I find that I have been ?? to our arrangement of Dec 5th etc. Had I appreciated at the time the sense in which you now take it – I should have gone to any lengths to oppose it.
I must ask you to deal at once with the question. I have no intention of continuing to work as an obscure subordinate of Commander Clarke.
Yours faithfully
A.D. Knox
On 8 October 1940, AGD replied:
My dear Knox,
Here is my view of what happened. If there are any discrepancies – we can clear them up.
The meeting of December 5th decided on the division of Enigma work into Research and Production. When on January 24th the first current solution was obtained the section known as FJ (now Hut 3) was formed to translate and circulate this traffic and to study. It accepted the cover of S.I.S. and all results are attributed to Secret Service reports. That is the existing mouthpiece of the German Air–Army Enigma.
When in January the solution of the Spanish Naval Attaché Enigma messages was obtained, circulation was controlled and continues to be controlled by the Spanish Naval Section.
When the research party broke into the Naval Enigma for certain days in April, the circulation of results was made through the German naval section.
When the machine used by the German Railways was fixed early in August results were circulated from the military section.
If, as I hope, you obtain the solution of the machine used by the German Secret Service I anticipate that Strachey’s section will handle the circulation, as they have already dealt with so much traffic in other cyphers.
As far as the Italian Naval Enigma is concerned (the subject of your letter), I cannot understand why you should wish for an alteration of the practice.
Clarke deals with the circulation of all this traffic of which the Enigma forms a part. He dealt with it pre-war days when you first broke into the machine.
If the duty were given to Hut 3 it would be necessary to find Italian speaking staff to work there and to study the contents, in fact to duplicate the work which Clark’s section already does.
So far as the personal side is concerned I hope you do not underrate your own position. From the above it is obvious that the Research side of Enigma, which you direct, has met with very considerable success and it must be perfectly clear to you, to all those concerned in G.C. & C.S. and to the recipients of the decodes that without the Cottage and Huts 6 and 8 there would be no enigma traffic.
That is my view: I cannot, therefore, see any reason why the existing methods of circulation should be changed.
AGD had always had a cordial working relationship with Sinclair, who as DNI had been part of the Committee which had appointed AGD to his post. Sinclair had been suffering from cancer of the spleen and was taken to hospital in late October 1939. Characteristically, he sent a message to a friend on the morning of 4 November saying ‘First bulletin: Nearly dead’. He died at 4.30 pm on the same day. Stewart Menzies was Sinclair’s deputy and the day after Sinclair died, he gave Lord Cadogan, Permanent Under-Secretary for Foreign Affairs, a sealed letter written by Sinclair two days earlier. In it Sinclair strongly recommended that Menzies should succeed him.10 After a delay of three weeks, Cadogan noted in his diary on 27 November: ‘Tiresome letter from Menzies, with whom I sympathise. Am trying to binge up H. [Lord Halifax] to get decision [on Sinclair’s successor] tomorrow. M. [Menzies] is in a difficult position, and it’s silly of everyone to go on funking Winston.’
It seems that Churchill favoured Admiral John Godfrey, who had succeeded Sinclair as DNI. However, he had been a battleship admiral and only had some ten months in the intelligence service. The following day, at a meeting attended by the Prime Minister and the service ministers, Cadogan wrote that Lord Halifax ‘played his hand well and won the trick’. It was unanimously agreed that Menzies should have the job and on the 29th, Halifax duly offered it to him. There was a caveat that there should be ‘some enquiry’ into the organisation of the Service.11
On 18 November 1939, AGD received the following memo:
Commander Denniston.
Now that we may with some hope look forward to the state when we shall be able to deal with some of the German Enigma traffic, I think we must consider how best the traffic could be deciphered with the minimum loss of time.
If conditions remain as at present, I understand the position to be such that when the ‘Netz’ are complete we shall be able to decipher traffic from several groups which use the Standard Indicating System. When this becomes a fact I should like to see Research divorced from Production and the work organised on the following lines:
Research Section who should investigate the still unknown problems such as the Naval and T.G.D. This should be done by Knox, Kendrick, Turing, Miss Nugent, and such of the clerks as Knox requires.
The production section requires dividing into several subsections as follows:-
Receiving, Registration, sorting and W/T Liaison. This section would prepare data for Netz and Bombes. Staff: Welchman, Twinn and 4 clerks.
‘Netz’ party. The work of finding machine settings etc., from sheets punched from cyclometer results, Jeffries + X assistants
‘Bombes’ machines run by Dawson + 1 assistant.
Decyphering Section. This should include staff to test ‘Netz’ and ‘Bombes’ results. They will decipher all available traffic with minimum loss of time and pass to Service Sections for translation. It will require someone (or ones) with good German to scrutinise traffic before passing on for translation. Two female clerks must be trained by R.A.F. to work their machines.
A special hut will be required for the Production section.12
The memo itself is not signed and was certainly not written by Welchman, as he would never have proposed himself for any specific role. At the top right of the front page of the memo are the words ‘Paper? By EWT’. It is highly unlikely that Travis would have used the words ‘I should like to see’ to his superior. In all likelihood, it was written by Menzies who was already making his mark on part of his new organisation. It was clearly based on the Welchman proposal13 for an organisation which would remain basically unchanged throughout the war, with the hut numbers becoming, in effect, the cover name for their activities. The new Production section initially set up shop in the Elmers School and by late January 1940, two new wooden huts were ready for occupation. The Production section moved into Hut 6 and soon became known by that name. The linguists and intelligence officers who would translate and interpret their output moved into the adjacent Hut 3 and soon adopted that as their section name. Their naval counterparts would eventually be housed in Huts 8 and 4. Travis continued to take direct responsibility for the Enigma huts as they came on stream, their staff and the mechanisation programme.
The ‘Menzies memo’ can be seen as a direct challenge to AGD and his position as Head of GC&CS. He was very much Hall and the Admiralty’s man when he took up his post at the end of WW1. He maintained an excellent working relationship with Sinclair but his relationship with Menzies was less certain. Menzies was, after all, an Army man and Hay, the Army’s candidate to be Head of GC&CS, had been overlooked in favour of AGD. However, there is no evidence that Men
zies was party to the process which saw AGD chosen over Hay. Perhaps AGD’s letter to Menzies on 12 September, describing all of the administrative difficulties at BP had planted in Menzies’s mind, seeds of doubt about AGD’s managerial competence.
***
Both Turing and Welchman had started to think about how machines could help with the work soon after their arrival at BP. First Travis and then AGD had been won over to the potential of machines to speed up the decryption process. Turing’s work on a machine solution had reached the build stage by the autumn of 1939 and the British Tabulating Machine Company at Letchworth had been contracted to carry out the work. Their Research Director, Harold ‘Doc’ Keen needed to be briefed on BP’s requirements and one of Knox’s team, Peter Twinn, was given the task.14 By March 1940, the manufacture of the prototype Bombe, a complex electro-mechanical machine, was well under way. The first prototype, named Victory, was installed in Hut 1 on 18 March but did not prove particularly effective. It was only when a second and improved machine was installed in Hut 1 in August that real results were achieved. This machine, named Agnus, incorporated a brilliant design modification invented by Welchman and called the Diagonal Board. Victory was then moved to Wavendon as a training machine, as it was unreliable and six more machines were on order by November. The first of the even more sophisticated models, the Jumbo Bombe, arrived in Hut 11 in March 1941.
Recruitment started almost immediately for the high-quality staff that would be needed after the emergency list that AGD had drawn up the year before was quickly exhausted. A new intake was needed as soon as possible. Welchman returned to Cambridge and began recruiting former colleagues and students, while Travis recruited from the commercial world. A number of young and intelligent women were brought into the fledgling Hut 6. With recruitment came administration to support it and on 10 November, 1939, AGD issued a notice that ‘In future Paymaster A.N. Bradshaw R.N. will act as General Administrative Officer for the G.C. & C.S. and all questions in this connection should be referred to him.’15 On 8 October 1940, AGD informed staff of further changes in the administration of BP: ‘By direction of the CSS, the general administration of the War Station B.P. will in future be under the joint management of Captain Ridley R.N. and Paymaster Commander Bradshaw R.N. who will form a Joint Management Committee (short title J.M.C.).’
During 1940 and 1941 this committee issued notices on subjects such as catering, billeting, addresses, personal security, maintenance/repairs and appointment of administrative sub-sections. It was abolished on 12 May 1941 after the Joint Committee of Control (JCC) was set up in April. It was chaired by the Deputy Chief of the Secret Service (Valentine Vivian) and included Travis, Tiltman, Bradshaw, Earnshaw-Smith, Hope, Cooper, Ridley, Hastings and Woodfield. At its meeting of 5 April 1941, it dealt with the future of Elmers School, catering and the BP recreational club and tennis courts. On 12 April they agreed to recommend building a dining hall with provision for serving 1,000 at each meal. It was agreed to take over extra land if suitable.
Knox continued to be a thorn in AGD’s side and usually included a threat of resignation along with his latest complaint. He wrote to AGD on 7 January 1940,16 reminding him that ‘on our journey to Warsaw I promised to assist the Poles and the French in producing statistics’. This had not been done and Knox went on to say, ‘My personal feelings on this matter are so strong that unless they leave by Wednesday night I shall tender my resignation.’ Surprisingly, given that Knox was supposed to be at the heart of the Enigma work, he closes with: ‘I do not want to go to Paris but if you cannot secure another messenger I am actually at the moment completely idle.’ In the end Turing was sent to Paris to meet the Poles. On 9 January 1940, unknown to Knox, AGD wrote to Menzies with regards to the Poles:
Dear Menzies,
Here are the names of the three young Poles, Jerzy Różycki, Marian Rejewski, Hendryk Zygalski.
If we are faced with a change on the outbreak of war (and we begin to suspect it), the experience of these men may shorten our task by months.
We possess certain mechanical devices which cannot be transferred to France. These young men possess ten years’ experience and a short visit from them might prove of very great value.17
On 10 January, AGD wrote to Rivet, Bertrand’s superior, urging him to allow the three Poles to visit Britain for a short period. They were at that time working at a joint French/Polish intelligence station near Paris called PC Bruno, and the request was denied by the French.
AGD’s workload was increasing dramatically and not only was he dealing directly with the three Service Ministries, he was also in regular contact with intelligence chiefs, as the following memo from DNI John Godfrey, sent on 31 October, reveals:
Clarke has been complaining about delays in sending naval intelligence out to Commanders-in-Chief. He understands that the R.A.F. Section transmit direct to Cairo without reference to the Air Ministry using the R.A.F. High Speed W/T Service. This may be the origin of Clarke’s complaint.
He goes on to say that the Chiefs of Staff are instructing the three Commanders-in-Chief to set up a Combined Bureau under Jacob.
He also says ‘I am going into the question of setting up an organisation to arrange “pinches”, and I think the solution will be found in a combined committee of talent in your department and mine, who can think out cunning schemes.’ 18
On 9 April 1940, the so-called ‘Phoney War’19 ended when Germany invaded Denmark and then Holland on 10 May. A new Enigma military key appeared on 10 April for operational traffic involving all three German services. It was broken daily by Hut 6 from 15 April and as the workload increased, Hut 3 moved to a three-shift system. Intelligence reports, disguised as agents’ reports, were passed to the War Office and Air Ministry and they in turn communicated the information in secrecy to commands in Norway. The Admiralty also had a communication channel in place and had been informed as early as 5 January that messages prefixed ‘HYDRO’ would contain information ‘from a very authentic and secret source’. On 15 May, the prefix was changed to ‘ULTRA’.20 Hut 6 had decided to concentrate its limited resources on the general-purpose ‘Red’ key of the GAF although there was an increasing amount of military traffic. In early May, the Germans changed the Enigma indicator system that the Poles had exploited21 which meant that no breaks were made again until 22 May. From that point on, success was continuous as traffic increased to 1,000 messages per day. However, the Service channels were by now completely disrupted and by 24 May only one link remained, a SIS mobile unit attached to GHQ
Unfortunately, the Sigint intelligence proved to be of little tactical value at this stage for several reasons. Hut 3 lacked experience and the reference books and maps necessary to assess the information were unavailable. Ministries found it difficult to assess its significance and commanders in the field could only take the intelligence at face value as agents’ reports. Furthermore, the intelligence reports frequently arrived too late for action to be taken. Finally, there was no real military capability in the field to act on it in an effective way. GC&CS had, however, put in place a secure method of distributing intelligence to GHQ in France. Signals were typed and then checked by the No. 5 of the Hut 3 Watch.22 One copy was passed to the SIS Codes Section in BP where the message was encrypted with an OTP. This version was taken by despatch rider to Section VIII at Whaddon23 for transmission over the SIS W/T channel to the SIS representative in France for decrypting into plain text before delivery to GHQ.
By April 1940, GC&CS’s Naval Section had built up a fairly complete picture of the German W/T organisation as part of its work on traffic analysis in support of cryptanalysis. From the beginning of 1940, short reports of operational interest were flowing via teleprinter from German Naval Section to the Admiralty. Some senior staff seemed to resent this intrusion on their ‘patch’ and thus, at its prompting, the Operational Intelligence Centre (OIC) was sceptical. The sinking of the aircraft carrier HMS Glorious off Namsos by Scharnhorst and Gneisenau on 8 Ju
ne was a turning point in the OIC view of GC&CS intelligence, as they had ignored several weeks of warnings from GC&CS. The War Office and Air Ministry also showed an increasing confidence in the work of AGD’s organisation by placing officers in Hut 3. By the summer of 1940, the RAF intercept station at Chatham started its move to Chicksands.
Thanks in part to intelligence from BP, the British Government realised that the British Expeditionary Force in Europe was in a hopeless position. From 27 May until 4 June, some 338,000 men, of whom 224,000 were British troops, were rescued from the beaches of Dunkirk. The evacuation of Norway was completed by 8 June and on 10 June Italy declared war against France and Great Britain. German Panzer divisions quickly moved across France and the country was forced to surrender on 22 June.
Given that Britain now stood alone and invasion was a real possibility, AGD put together a plan to ensure that his organisation could continue to operate if Britain was overrun. On 26 June 1940, he wrote to Menzies with the details:
I attach a plan for the disposal of our records and would be glad to know which items of this plan you would sanction in order that I may take early action. My plan does entail certain risks, though risks may have to be taken at this stage. I have not mentioned a more far reaching suggestion namely to contemplate sending skeleton crews of certain Diplomatic Sections to Canada. The difficulty would be that we would obtain very little material and I doubt whether at this stage such a plan would do more than attempt to preserve continuity for a post war era.
DISPOSAL OF RECORDS
To Canada via D.M. and D.N.I. Ottawa.
Office personal records.
CXFJ records of 1940.
Plans of main machines.
One E machine.
Lloyds Bank Dunstable.
Office personal records.
Copies of main important books.