Strange Intelligence: Memoirs of Naval Secret Service (16 page)

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!

T
HE 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:

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 hotel manager, apparently British-born, was a friendly sort of person, full of good stories. One night, for some unknown reason, he chose to ‘celebrate’ in company with the two cyclists, inviting them into his private office to keep up the jollification after the business of the day was done.

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:

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.

For three years previously his correspondence had been subjected to close scrutiny. One of his letters, which really did contain vital information, was so skilfully ‘touched up’ before it left England that its purport must have conveyed an utterly erroneous impression to the addressees in Berlin.

His accommodation address in Newcastle-on-Tyne was discovered in less than a week after he had committed his blazing indiscretion.

The clue that led right to the heart of the German secret service in Britain was due to another indiscretion, which had not even the excuse of being committed under the influence of drink. Regarded from any angle, it was an unpardonable piece of folly.

Among the members of the Kaiser’s suite on one of his visits to England was an officer holding a very high position in the German Admiralty. He was known by the British security service to be keenly interested in the work of the German secret service, but they hardly supposed that he would take any active part in such work while he was in England. More as a matter of routine than for any definite purpose, his movements were unobtrusively shadowed.

Late one evening he left the house in which he was quartered in London, wearing mufti, and drove away. The car was followed, though it seemed quite likely that he was only bound for some official reception or dance.

To the surprise of the shadower, the car drove on into the suburbs, and one of the poorer suburbs, of north London. It stopped outside a small shop, already closed for the night; but the visitor was evidently expected, for the side door opened as soon as the car stopped, and he went straight in without knocking.

He stayed a considerable time, and, on coming out, got into the car quickly and was driven back to his quarters.

This shop, at 402a, Caledonian Road, was not known to the civil police authorities to be a cloak for any illicit business, so the security people took the matter in hand.

The man who kept the shop, one Karl Gustav Ernst, was soon found to be the clearing agent for the reports of more than half the men working in England for the German secret service. (It was revealed in the subsequent proceedings against him that he had been paid the munificent salary of £1 a month by the German secret service!) Thereafter all his correspondence was watched until the war broke out, when he was arrested.

It was a remarkable fact that, before the war, intelligence men in all countries used the post with the utmost freedom, trusting to luck, presumably, that no suspicion attached to them. Little more organisation, and little more expense, would have been needed to institute a service of couriers carrying the letters on their travels to and from neutral countries, where the correspondence would not have been subject to surveillance. As soon as the war began, the Germans did start to try to build up such a service from England to Holland, and there must be quite a number of perfectly honest and innocent Dutch business men who still remember the severity with which they were examined and cross-examined every time they entered or left Harwich.

Those who were couriers for the German intelligence department became very astute at hiding incriminating documents in order to smuggle them through. One man whom it took us a long time to catch with the evidence on him became so accustomed to being searched that he once said, jokingly, to the searchers at
Harwich that he automatically began to take his clothes off as the train slowed up at the platform, and before he left the carriage!

The way we got him in the end was rather neat. The ID knew for a fact that he had been in touch with a suspect here, from whom he had received some information that must be put on paper. It could not possibly have been memorised. Therefore, somewhere on his person that writing was concealed.

He went into the search room at Harwich with the usual smile on his face. Sitting at the table was a strange officer, of senior rank, watching the search, but taking no part in it. All the usual tests were applied – false heels, false soles, hiding places in the lining of the hat, and so on. Nothing was found. All this time the strange officer had not said a word. He just watched.

The searchers seemed to be beaten. The chief man scratched his head, and looked round in amused bewilderment at the officer.

The latter rapped out a brusque order.

‘Take out your false teeth!’

The courier made a movement of protest.

‘Out with them!’

The head of the search-party had an inspiration. ‘Seize his arms,’ he shouted, before the courier could put hand to mouth. Then the searcher gently forced the mouth open, took out the top denture, and from the roof of the man’s mouth a tiny packet of oiled silk, not the thickness of a postage stamp, fell on his tongue. Inside the packet was the information in microscopic writing.

Those who had to travel abroad during the war were often puzzled by the regulation that no newspapers or books should be taken out of the country. Although this rule was enforced more rigidly in France than here, we frequently put it into operation ourselves. The reason was that information of which the printer
and the publisher knew nothing could still be conveyed by the printed page. A pinprick alongside certain selected words could be ‘read’ by those in the secret, and the pricked words would make up a complete message.

Invisible inks and other tricks of that sort were, of course, child’s play to the security service. We knew them all long before the war, and as a matter of fact no competent intelligence man in any service ever relied on them. Codes were a different matter. It is fairly well known now that a certain type of mind has a genius for evolving and solving cryptograms. Sir Alfred Ewing, the director of naval education, possessed such a mind, and he has publicly told the story of ‘Room 40’, where he and a staff of similarly gifted assistants grappled with the problems of codes all through the war.

He disclosed the secret in a speech before the Edinburgh Philosophical Institution in December 1927.

He said that in 1914 he was director of naval education at the admiralty. On the day war was declared he was asked to undertake the task of dealing with enemy ciphers. That was the beginning of what grew to be an important organisation for collecting and deciphering enemy messages.

He enlisted a few friends to come in and help: they worked hard and had remarkable luck, so that the deciphering staff was soon established as a separate branch of the admiralty under his direction. Numerous listening stations were set up.