Strange Intelligence: Memoirs of Naval Secret Service (15 page)

To take an example from our own experience: the night before the Dogger Bank battle it was known all over Edinburgh that the battlecruisers were going out, partly because of the sudden departure early in the afternoon of officers who were on shore and the procession of taxicabs taking them to Hawes Pier, partly because of the countermanding of orders for provisions from various messmen. The difference was that in our case no German agent seems to have got the news, or, if he did, was unable to transmit it to Germany in time to be of service to his side.

The position was much the same on the eve of the Battle of Jutland.

Admiral Scheer began to plan the ‘enterprise towards the north’, which led to that battle at least three weeks beforehand. His own report (accessible to us long afterwards, of course) indicates that he had two plans in view: one, a bombardment of Sunderland; the other, a demonstration off the Skagerrak. He actually made the initial move in his operations a fortnight before the battle took place, when he sent out U-boats to lie off the Firth of Forth, Cromarty, and Scapa Flow. Part of their mission was to ambush the Grand Fleet, but they were also to enact the rôle of scouts, just as our submarines operated in the Bight.

These movements of German submarines became known to us, and it was not long before we had each group located. The fact that they were lurking in areas not prolific in mercantile targets was significant, and fully confirmed the suggestions of our agents in the German ports.

An essential element of Scheer’s Sunderland scheme was airship reconnaissance; but weather conditions from 15 May onwards made that impossible, and from day to day he delayed
sailing. In the end he was compelled to make a move by the fact that his submarines were approaching the limit of their cruising orders. As weather conditions still kept the Zeppelin scouts in their sheds, he had to follow the alternative of an advance to the north, a mere demonstration. And as we studied the weather conditions as closely as he did, it was not difficult, once we knew he was on the move, to judge the direction in which he was steering.

Apropos of weather conditions, the Germans had rather a neat piece of intelligence work to their credit. About noon on 31 May the Neumünster wireless station informed Scheer that a wireless signal from Scapa had been intercepted, giving a weather report for the North Sea. The Neumünster people added that they had noticed that such reports were only sent out when Jellicoe or Beatty were at sea in force. Although the information may not have been of much value to the German Commander-in-Chief, it is worth noting as typical of the infinitesimal detail that goes to the building up of a complete picture by intelligence experts. It also shows the unwisdom of cultivating too regular habits in wartime!

Scheer’s other sources of information failed him badly. The reports from his submarine scouts were inadequate, containing little or no detail of ships seen, and it must have been impossible for his staff to have formed any definite idea of the whereabouts of Beatty and Jellicoe from such messages as they received.

So much for the German side.

On our side we had already, as it were, seen the red flag; but the High Seas Fleet had been so long inactive that it seemed too much to hope that the picture we had built up from our various reports and deductions was about to materialise.

However, the morning of 30 May brought pregnant news. At
10.48 a.m. (German time) a wireless signal was made by Scheer ordering all German vessels to concentrate in the outer roads of Wilhelmshaven at eight o’clock that night. That wireless signal we picked up. It was in code, of course, and it has been said, with more or less official sanction, that we were unable to decipher it. Perhaps it would be more fair to the brilliant men who undertook the brain-wearing task of reading cryptic ciphers for us to say that the version they produced could only be regarded as partial guesswork that was not accepted ‘officially’.

At all events, when the German official history came out, with an appendix of the chief signals made by Scheer in the course of the action, those who, on that May morning in 1916, had concentrated all their mental efforts on the attempt to unravel the tangle of letters, discovered how nearly they had succeeded. The version given above is based on the official German wording, and not on the decoding.

The speed with which this particular department worked is perhaps indicated by the fact that at 11.58 GMT, or two hours and ten minutes after Scheer made the signal, the admiralty were already issuing warnings to those forces under their immediate jurisdiction (Dover Patrol, East Coast, and Thames Estuary), and it is fairly obvious that Jellicoe also was told something previous to the telegram of 5.40 p.m., because at the very moment that telegram is timed he hoisted the preparatory signal for putting to sea, as did the admiral in the Second Battle Squadron at Cromarty.

Reading between the lines of the official record of signals, there are good grounds for the inference that, whether or not the decoding was accepted officially, it was considered reliable enough to pass privately to the Commander-in-Chief for his information.

In his despatch on the Battle of Jutland published during the war, Admiral Jellicoe stated – no doubt for the purpose of misleading the enemy – that the Grand Fleet, ‘in pursuance of the general policy of periodical sweeps through the North Sea, had left its bases on the previous day.’ Consequently there has grown up in the public mind an idea that the meeting with the German High Seas Fleet, which we call the Battle of Jutland, was a purely accidental encounter – in other words, that we really ‘muddled through’ in our traditional fashion.

That assumption is grossly unfair to our intelligence men, and it is important to note that the misleading phrase quoted above is omitted from the final official version of the despatch, as published in ‘Jutland Papers’ in 1920. There full acknowledgment is made of the fact that the Grand Fleet proceeded to sea in consequence of information received.

There is much that still cannot be published as to the means by which that information was gathered, but it is due to the courageous agents who were stationed in enemy ports, and to the skilful men who used their brains to piece the fragments of news together, that public recognition should now be given to the fact that we knew Scheer was coming out and the direction he was likely to take.

S
OME OF THE
hardest work done by intelligence men during the war had no spice of personal danger in it, but for all that it was full of thrills.

Performed in the base intelligence offices at various points round the coast, it was the cornerstone of the whole system by which we countered the German submarine menace. The effectual use of the 5,000 patrol vessels and convoy craft, which were engaged in the actual work of hunting the U-boats, depended very largely on the intelligence men. It was the hard thinking done in the base intelligence office that made possible the proper planning of the dispositions of these anti-submarine craft.

It is, of course, a commonplace that the submarine’s strongest asset is the secrecy with which it can move from place to place. The task of the base intelligence office was to get behind that
veil of secrecy; to determine, to within a mile or two, the whereabouts of every German submarine on any given day. And that knowledge referred, not only to the fifty or sixty boats actually at sea, either in northern waters, in the Channel, in the Atlantic or in the Mediterranean, but also to the others that had just gone back to port, those that were undergoing repairs, and those that were about to put to sea again.

At first sight this may seem an impossible task. How, it may be asked, could our intelligence people possibly know what was happening in the enemy dockyards of Wilhelmshaven and Kiel and Danzig during wartime? It was difficult enough to obtain any definite information about submarines during peacetime.

The task was not impossible, however. Indeed, by 1918 it had become almost as simple as a mathematical problem of the less abstruse order. In September of that year our intelligence people had a forecast of the dates on which every German submarine then in dockyard would reappear at sea. In every single instance the forecast was correct to within twenty-four hours.

Intelligence work of this kind is largely a matter of common sense, used by a mind trained to weigh the value and the meaning of the smallest clue. It depends upon accurate deduction. If one can imagine Sherlock Holmes solving a mystery without moving from his rooms in Baker Street, working solely by the accurate piecing together of little items of news given to him by this person or that, one has a rough idea of the way the base intelligence office grappled with the difficulty of keeping track of the U-boats.

The sources of information were many and varied. The most valuable of all were the wireless directional stations round our coasts. Directional wireless has, of course, made remarkable
strides since those days, but even then we had developed it sufficiently to gather accurate news day by day from the enemy’s own transmitting sets.

Reduced to its simplest terms, the method was this. A U-boat somewhere off the north of Ireland called up a consort with whom she had a rendezvous. One of our wireless directional stations on the Scottish coast would hear her call. We will label that Station X.

Another station on the north-east Irish coast would hear the call. Label that Station Y.

And yet another station on the north-west Irish coast would pick up the call. Label that Station Z.

Each of those stations would report to a central base intelligence office not only what it heard, but also the direction from which the sounds were coming. The power of the sounds would increase or decrease as a part of the receiving machine was turned round by the operator. The point at which the signal strength was most marked gave the bearing or direction of the source.

At the base intelligence office those reports would be worked out on a large-scale chart. A line drawn from X, a line drawn from Y, and a line drawn from Z in the direction that each station had reported, ought to meet somewhere.

Somewhere within a radius of about 2 miles or less round the point where the three lines meet is the U-boat.

That was the simplest and easiest sort of problem for the intelligence officer. With only one U-boat calling there was not much chance of confusion. When several calls were reported at the same time, however, the problem became more difficult. Three or four calls might be notified at about the same time, some from our original three stations X, Y and Z, some from other stations.
Then arose the possibility of all sorts of confusion. The wrong line might be drawn. A report from Station X might be made to tally with a report from a station in the south of Ireland, and the point where the two lines met would be somewhere 100 miles out in the Atlantic – and there would be no U-boat there at all.

It was, therefore, necessary to find a means of isolating the calls, to discover which U-boat was talking, and which boat each station was reporting.

The British intelligence service owed a deep debt of gratitude to the Germans for their loyal adherence to method. The Germans had a plan, and they kept to it. No chopping or changing for them. There were no sudden or frequent alterations of system.

The U-boats always began their conversation by sending out their own secret code numbers. It was an invariable rule, and we thus came to know that the first letters of a call gave the code numeral of the submarine that was talking. This saved us a great deal of trouble.

When the intelligence officer at the base received simultaneously six reports from different stations, he looked at once for the first letters of each message. Three of the messages would begin with (let us say) MON. Three would begin with LRT.

And at once he had – again within a circle of 2 miles’ radius – knowledge of the whereabouts of those two U-boats.

This sort of information, of course, was not intended merely for the entertainment of the shore staff, nor for the compilation of pretty dossiers to be filed in the Base Office.

It was passed at once to the senior naval officers concerned, for them to take the necessary steps to direct the patrols and the convoys that were in the path of the enemy.

Meantime the base intelligence officer (BIO) would turn to
the large-scale chart on the wall of his office and stick a pin with a coloured flag in the place where the U-boat was assumed to be.

Those flags represented not only the U-boats of which his own directional wireless stations (and other sources) had given him news; the chart covered a wide sweep of the seas, and showed the sections that were the immediate concern of neighbouring BIOs, as well as that under the control of his own base. They used the same flags as he did. It was not unlike the plan of working a railway, where one signal-box passes a train to the next. The U-boats were invisibly shadowed the whole time they were at sea, and signalled from one section to the next.

Sometimes the chart would simply bristle with pins. At other times there would be very few pins. This was because the intensity of the U-boat campaign was subject to violent fluctuations. The Germans were not always able to keep up the pressure.

The busiest month of all was June 1917. During that month the first of the big U-cruisers put to sea. There were twenty-seven boats of all types working in the North Sea and the Atlantic, thirteen in the Channel, fifteen in the Mediterranean, three in the Baltic, and two in the Black Sea. Yet in November of the same year the number of boats at sea had shrunk to thirty, while some thirty-five were located at various dockyards undergoing overhaul.

Anti-submarine intelligence work was not confined to such material facts as the position of the enemy. It was also very important to know the personal characteristics of the men in command. No two submarine commanders possessed the same skill, or the same courage, or pursued the same tactics. And our methods of dealing with them varied according to their characteristics. One man, known to be a dangerous and skilful
opponent, would be tackled and trailed from the moment he was located. Another man, known to be a braggart, who fired torpedoes haphazard and returned home claiming to have sunk tens of thousands of tonnes of shipping – when his total bag was really one small sailing ship, holed but not sunk – could be safely left alone if he was not near any of our shipping lanes. It is a rather remarkable fact, which few except those who were closely engaged in anti-submarine work have ever realised, that only two out of the twenty best German submarine officers were killed during the war, and both lost their lives, not in action, but by their submarines hitting mines and blowing up.

Lieut-Commander Arnauld de la Perière, the most successful of all the U-boat captains, sank 400,000 tonnes of shipping, and Lieut-Commander Walther Forstmann was only 20,000 tonnes behind him. Whenever we picked up the trail of any submarine ‘ace’, the patrols and the Q-ships were specially warned.

These differences between the characteristics of the U-boat commanders were considered to be so important that each was represented on the wall chart by a different flag.

Thus, to go back to our imaginary pair, whose positions we noted from directional wireless reports a few pages back, MON would perhaps have a white flag with one black star on it, while LRT would be a black flag with a white line running across it diagonally. Everybody in the base intelligence office who had access to the anti-submarine room was thus presented with a clear picture of the position at sea from hour to hour. When further reports of the movements of those two submarines came in, an extra flag of each kind would be put on the chart to mark the new positions, and so we were able to trace the course the U-boat commander was steering and to obtain some idea of his
objective – whether he was making for the Irish Sea to attack the Liverpool traffic, or whether he was on his way to the Atlantic and the Queenstown area.

In the same way, at Queenstown, they would be able to judge whether he was prowling in the Chops of the Channel, or whether he was aiming to work further south in the Bay of Biscay. In the latter event the Allied bases on the Biscayan coast would be able to pick him up and shadow him until he started on his way home again, when he would again be watched through the Queenstown area, and so up the Irish coast into the Scottish region, and round by the extreme north.

It is important here to point out that, though we kept this close watch on the movements of the submarine, our knowledge of its position was always approximate. Sometimes, of course, it was possible to get patrol ships to the spot very quickly and to harry the submarine, but the Atlantic is a very wide ocean, and more often than not the submarine’s position was miles and miles away from our nearest ships.

Let us recall a typical scene in the base intelligence office at an important centre.

It was Sunday morning. Things were quiet. The wall chart had all the midnight positions of the U-boats marked up. It had nearly all their 8 a.m. positions, too. There was one that was missing, however. Nothing had been heard of him since midnight.

His various flags on the chart showed him to be steering southwards, and he had just reached the point where it was important for us to know whether he was going on south to the Bay of Biscay and the Spanish coast, or whether he would turn eastwards and worry us off the mouth of the Channel. There were patrolling destroyers on his line of route. They
might sight him, if they were lucky, but it was more likely that the first news we should get of him would be an attack on some merchant ship, perhaps within 20 miles of where we were sitting ashore.

Some U-boat commanders were full of guile, and it was no uncommon occurrence for us to lose touch with them for two or three days on end. One of these ‘dog foxes’, whose pin had been stationary on the wall chart for some time, had not been using his wireless. He might be in trouble, or he might be preparing trouble. Watching U-boats, as the reader will have gathered by this time, involved much guessing and a great deal of patient waiting.

It was very quiet in the office. A clerk was silently docketing information at a little desk in the corner. The base intelligence officer, leaning back in his swing chair, was smoking his pipe, waiting with that indomitable patience that intelligence men learn to cultivate. The visitor stood before the wall chart, studying the whole position – which was new to him, since he had only arrived the previous night – weighing up the various factors, and mentally digesting the information that had been given to him.

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.