The hands of the clock pointed to eleven when the green baize door swung quickly inwards, and a messenger came in.
He handed an official form to the BIO.
The ticking of the clock was the only sound for several seconds, while the officer read the message slowly through.
‘Forty-seven twenty. Ten-ten,’ he said at last.
The visitor glanced round at the first word, and then turned back again to the chart.
‘He’s off to Spain, then?’ he suggested, having fixed the latitude and longitude that the figures indicated.
The BIO frowned, doubtfully.
‘May be’, he grunted. ‘At the present moment he’s pumping shell into a Q-ship, and the poor devils in her are having a pretty thin time of it.’
There was a moment of tense drama! The two men sitting in safety in a cosy office on a peaceful Sabbath morning – the distant church bells had hardly ceased pealing – were discussing the martyrdom of some forty or fifty brave fellows who had challenged death in order to deal out death by stratagem. They were hundreds of miles away from that office, but the office knew all about them – and in the corner of the war with which the office was concerned even the death of those men would have been but a mere incident.
The business of the office was to acquire knowledge of the assailant. It was for others to send to the Q-ship’s succour.
The BIO walked over to the wall chart and stood beside the visitor, deep in thought.
‘It must be him,’ he said, half to himself, gazing at the little rows of flags pinned one behind the other. ‘None of the others could have reached that position.’
He stretched out his hand and selected a flag from a tray. It was black, with a white skull in the centre. He stuck it in the chart at 47.2 N. 3.13 W. and put the telegram on a spike on his desk.
It was all he could do for the moment. There would be more news later – perhaps. He returned to his task of waiting.
In a quarter of an hour another message came in.
The Q-ship had thrown off her disguise, after twenty minutes of inferno, when the U-boat was lying about 400 yards away from her on the surface. The Q-ship’s gunners had loosed off half a dozen rounds from each gun before the submarine went under water. The captain of the mystery ship considered she was sunk.
The BIO read the message over, aloud.
‘Optimist!’ was his comment. ‘No word of survivors or of wreckage. Still, it may have scared them a bit. We’ll log it as possibly slightly damaged. I wish they had sent her number.’
The comment was typical.
Facts were the vital food of the intelligence officer. He did not want guesses or suppositions. He spent half his time rejecting theories because there were no facts to support them.
And that desire to know the U-boat’s number had a two-fold origin. In the first place, it would have settled the correctness or otherwise of the previous night’s decoding of the secret letters with which the wireless talk had started. In the second place, it would have enabled the base to be sure which of the enemy submarines was in that area. As matters stood, there was just a possibility that the attack had been delivered by a U-boat on its way home from the south – a newcomer, that is to say, in the area, who would have to be tracked all the time he was moving through our particular stretch of waters.
The first of these reasons was infinitely the more important from the intelligence officer’s point of view. On the accuracy with which he decoded the secret call sign depended the accuracy of all his other information.
How was that decoding done?
There were dozens of different ways, of course, some of them still too confidential to be divulged even after this lapse of time. But a few of the more simple methods may be explained.
As is described above, our wireless directional stations would pick up the actual lettering of the message, and we knew, after long experience, that the first three or four letters gave the code number.
Let us, for the sake of simplicity, continue to use the two instances already quoted: one U-boat’s call was MON; the other’s was LRT.
With the help of the directional wireless bearings we had found the position of those two vessels on the chart. But our Base Office was a long way away from those positions. We wanted someone nearer the danger zone to discover certain facts for us. Who was available? Only time would tell us. We must wait for data as to the activity of each of the submarines.
MON at dawn sighted a small tramp steamer whose crew took to their boats. The U-boat came alongside to find out what the ship was, and perhaps to take the captain prisoner.
The keen-eyed mate spotted on the conning-tower, beneath the fresh layer of light-grey paint, the outline of letters and a number that looked like U-99, let us say. He bore it in mind, and when, some hours later, the drifting boats were picked up, he reported the fact to the commanding officer of the rescuing destroyer or patrol boat.
So the news would be passed on that the SS War Baby (to take an imaginary name) had been sunk in such and such a latitude, such and such a longitude, by a U-boat, supposed to be U-99.
In due course that news reached the base intelligence officer.
The position given agreed with the wireless directional placing of MON.
Therefore, until disproved, MON – U-99.
Five days later MO N, now operating off the south coast of Ireland, sinks another steamer, and one of her crew, taunting the drifting survivors, shouts: ‘Britain shall tremble at the name of U-99!’
The survivors are rescued and report the boastful threat.
And so, scrap by scrap, evidence piles up and proves our equation for us.
It must not be imagined that it was always as simple as in this particular case. For one thing, there might be no survivors. Once, when news was very urgently required for the purpose of establishing the identity of two submarines, one of them launched an attack. Five men got away from the sinking ship, on a raft. Several days later two of them, alive but unconscious, were picked up by a British submarine that happened, quite by chance, to sight the raft. Neither of the men was in a condition to give any information for a long time, and by then the tangle had been unravelled by other means.
Let us take the case of the identification of U-boat LRT. This case is a little different from that of MON.
Her commander is a ‘dog fox’ who never shows himself. He does his work with the torpedo. We only know that LRT is a code number that we would like to decode.
Then, suddenly, one day, we get a message from an intelligence agent in a neutral port. He has learned that a small sailing ship is putting out at night, and that local German emissaries have persuaded the skipper to take a few fresh provisions and their stores to a certain rendezvous, for delivery to the captain of U-100.
We go to the chart and scan the seas around that neutral port.
What U-boats are known to be working in that area? There is ADF about 150 miles away, but we know beyond all doubt that his number is UB-80.
Two hundred miles away is our last recorded position for LRT. He has been absent from his base more than a fortnight. Fresh provisions would be very welcome.
We begin to suspect that LRT = U-100.
That was how the work went on all through the war – slow, patient, plodding; pulling perhaps fifty wires in five different countries to extract one definite fact.
It will be realised that this was not ‘spying’ in the melodramatic sense at all. Indeed, only a man with a real imaginative sense (what the American business man calls a ‘visualiser’) would have seen the drama in the work. It was sheer intelligence, the using of one’s wits to deduce the right conclusion from a given set of facts, with, perhaps, one vital clue missing. Those vital clues, too, had the oddest way of turning up from the most unexpected sources. Few people realised the need for a rigid censorship of the press. Intelligence men did. They found so often one little ray of light in an obscure paragraph in some provincial German paper, one tiny ultimate fact
that linked up all the other information and completed a perfect jigsaw puzzle.
Sometimes that happened even with the tracking of submarines in the Atlantic, incredible as such a thing may seem to those who have never had to build up a case on scanty information.
There came a time when we had the secret code call of every German submarine deciphered and logged. They were all set out neatly in order, beginning at U-5 – we never found any trace of the four earliest boats putting to sea during the war – and going right down through the UB and UC types to the last completed vessel in each class.
Not one of them could send a wireless message without letting us know exactly who was talking and whereabouts he lay.
‘Ah!’ exclaims the intelligent reader at this point; ‘that is all very well: but codes are not like the laws of the Medes and Persians. They can be changed.’
In the intelligence department we said the same thing, at first. We knew that the British Navy had a challenge and reply code for each day, and that it was altered frequently. Surely the Germans did likewise.
We were on the alert for changes. Because MON stood for U-99 on her first trip out, we did not, six weeks later, take it for granted that MON still equalled U-99. We looked for fresh evidence.
And, to our astonishment, we learned gradually that the secret U-boat call signs did not alter. They remained the same month after month. Apparently the highly organised German system was such that it would not bear change. We could vary our wireless code calls from day to day if we wanted to, without any disorganisation. The Germans, for some reason, were unable, or unwilling, to make any variation in theirs.
Then, after many months, and almost in the last phase of the war, we were suddenly confronted by a conflict of evidence about MON. He was out in the Atlantic, and had been sighted at close quarters on the surface by a destroyer. A rift in the clouds flooded the scene with moonlight, and on the conning-tower there showed up the number – UB-17.
At the same time other calls that we had not had before began to come in from the wireless directional stations.
The Germans had changed their code system at last.
All our lists of U-boat numbers were promptly scrapped. We forgot all that we had done and started afresh. Those were pretty strenuous days in the base intelligence offices and in the ID at Whitehall. It was a race against time to get out a new list that should be complete, with not a single number missing, and not one doubtful.
The methods were the same as before, perfected by practice.
Three weeks after we had detected the change, the whole of the work was done. Every new call was decoded and fixed to its proper submarine!
CHAPTER 14
ADVENTURES IN COUNTER-ESPIONAGE
THE ONLY WIDELY known ‘fact’ about British methods of counter-espionage and the watch that was kept on German intelligence agents in this country seems to be that, twenty-four hours before the outbreak of war, all the German emissaries in Britain were rounded up and put under lock and key.
That is true enough, as far as it goes, but it is only a tiny fragment of the story. Counter-espionage went on all through the war, not only in Great Britain, but also in every neutral country. The German secret service, finding it extraordinarily difficult to place agents in this country during the war, was largely dependent on the services of neutrals. Moreover, the seas being closed to Germany’s shipping and all but closed to her men-of-war, it became necessary for the Berlin naval command to create in neutral ports supply and urgent repair bases for their submarines.
It was part of our naval intelligence duties to watch those activities, and wherever possible to circumvent them. This was one of the most difficult tasks of the war. It was full of peril, both to life and liberty. A number of the men engaged in it ‘disappeared’ without trace, and those who escaped the assassin’s knife or bullet were in constant danger of overstepping the limits that any neutral government could be expected to stand, and thus finding themselves in a foreign prison, without any hope of aid from the British consul or ambassador.
Rounding up the German agents in Britain on the eve of the war was comparatively easy, because all of them had been known to a certain department for about three years and kept under constant surveillance.
This was officially disclosed in a Home Office statement, published on 8 October 1914. The statement was as follows:
In view of the anxiety naturally felt by the public with regard to the system of espionage on which Germany has placed so much reliance, it may be well to state briefly the steps that the Home Office, acting on behalf of the admiralty and War Office, has taken to deal with the matter in this country. The secrecy that it has hitherto been desirable, in the public interest, to observe on certain points cannot any longer be maintained, owing to the evidence that it is necessary to produce in cases against spies now pending.
It was clearly ascertained five or six years ago (i.e. 1909–10) that the Germans were making great efforts to establish a system of espionage in this country, and in order to trace and thwart these efforts a special intelligence department was established by the admiralty and the War Office, which has ever since acted in the closest cooperation with the Home Office and the Metropolitan Police, and the principal provincial police forces. In 1911, by passing of the Official Secrets Act, the law with regard to espionage, which had hitherto been confused and defective, was put on a clear basis, and extended so as to embrace every possible mode of obtaining and conveying to the enemy information that might be useful in war.
The special intelligence department, supported by all the means that could be placed at its disposal by the Home Secretary, was able in three years, from 1911 to 1914, to discover the ramifications of the German secret service in England. In spite of enormous efforts and lavish expenditure of money by the enemy, little valuable information passed into their hands. The agents, of whose identity knowledge was obtained by the special intelligence department, were watched and shadowed without, in general (the department), taking any hostile action, or allowing them to know that their movements were watched.
When, however, any actual step was taken to convey plans or documents of importance from this country to Germany, the spy was arrested, and in such case evidence sufficient to secure his conviction was usually found in his possession. Proceedings were taken under the Official Secrets Act by the director of public prosecutions, and in six cases sentences were passed varying from eighteen months’ to six years’ penal servitude.
At the same time steps were taken to mark down and keep under observation all the agents known to be engaged in this traffic, so that when any necessity arose the police might lay hands on them at once, and accordingly on 4 August, before the declaration of war, instructions were given by the Home Secretary for the arrest of twenty known spies, and all were arrested. This figure does not cover a large number (upwards of 200) who were noted as under suspicion or to be kept under special observation.
The great majority of these were interned at, or soon after, the declaration of war.
It is fairly certain that the names of some of our intelligence men were also known to the Germans. The outbreak of the war found several of these men still in central Europe, and although most of them received a code warning in time to make their exit to neutral countries, there were some exceptions. These included one or two really brilliant men, of whose fate we know nothing to this day.
The British security service had two extraordinary pieces of luck in its pre-war work of tracing the men who were working here for Germany.
During 1911 a British intelligence agent home on leave was making a cycling tour with a friend, and they put up for a night or two at a hotel in an East Coast port. As it was a naval base as well as a commercial port, and holiday resorts were quite near at hand, it was precisely the sort of place in which confidential information might be picked up. But the ID man had no idea of doing any counter-espionage when he went there. The opportunity came his way by pure chance.
The wine loosened his tongue, though it had no effect on the purity of his English accent, and he became expansive.
The ID man, reconstructing the scene for a subsequent report, described it in these words:
As far as can be remembered the following is a verbatim report of his unsolicited admissions:
‘It is rather amusing to think that I, a German ex-soldier and a former private in the British infantry, who also know a good deal about naval matters through having two brothers who are Deckoffiziere (warrant officers) in the German Navy, should be holding the position I do. I know all about the strength and composition of the British naval forces in this part of the world, and, thanks to my many acquaintances among the NCO’s and men of the local garrison, I have a perfect knowledge of all the harbour defences and battery positions within this area. Wouldn’t I be a useful man to the Germans if war ever comes?’
After expressing mild surprise and interest at these disclosures, the two auditors put a few leading questions, which the man’s natural vanity and his bibulous state led him to answer. He even went to the length of admitting that he had already been in communication with certain authorities in Germany, from whom he had received instructions as to his procedure in the event of strained relations developing between Great Britain and Germany.
In other words, that English-speaking hotel manager was a self-confessed German agent of a really dangerous type, planted in the midst of a vital area in the British East Coast defences, and he had practically boasted of the fact to one of our ID men! It need hardly be said that thereafter he was kept under strict surveillance, though so unobtrusively that he never suspected it, and at the outbreak of war he was one of the twenty enemy agents who went into prison.
Strange Intelligence: Memoirs of Naval Secret Service Page 18