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.
‘In that way,’ Sir Alfred said,
A close and constant watch was kept on the German fleet. The branch of the admiralty where this was done was called Room 40, to avoid any description that might betray the secret or excite curiosity. The fact that such work was going on was known to very few persons, even in official circles or in the fleet. It remained a secret to the end, and was probably the best-kept secret of the war.
Sir Alfred Ewing also referred to the fact that we took in Schwieger’s triumphant message from U-20 announcing the sinking of the Lusitania.
‘Besides intercepting naval signals,’ he added, ‘the cryptographers dealt successfully with much cipher to Germany’s agents in Madrid, North and South America, Constantinople, Athens, Sofia, and other places. One group of deciphered messages threw useful light in advance on the Easter Rebellion in Ireland, and another on the German intrigues in Persia.
Among the many political messages read by the staff was the notorious Zimmermann telegram, which revealed a conditional offer to Mexico of an alliance against the United States. President Wilson was then hesitating on the brink of war, reluctant to plunge, clinging painfully to the idea of neutrality, which seemed almost part of his religion. The message was communicated, very confidentially, by Lord Balfour to Mr Page (the US ambassador), and through Mr Page to President Wilson, who gave it to the American press.
During the war our efforts to decipher enemy codes were facilitated by captures from German ships. The first piece of luck came our way when the German cruiser Magdeburg ran ashore in fog on the island of Odenholm in the Baltic. She had to be abandoned by her crew, and measures were taken to blow her up. But, for some
inexplicable reason, her confidential books, including signal books and ciphers, were not destroyed. This could not have been overlooked in the haste of abandoning ship, for the Magdeburg’s captain, Commander Habenicht, declined to leave the ship, and was captured by the Russians.
Anyway, the code books fell into the hands of the Russians, who promptly communicated their contents to the British Admiralty, thus enabling us, for some time at any rate, to decode German wireless messages without any trouble.
German submarines now and again sank in water shallow enough to allow of salvage operations. In their case the possibility of destroying the confidential books was small, as will be realised, and from the wrecked hulls we now and again extracted useful papers. UC-44 was a case in point.
So far as naval intelligence work was concerned, the last three years of the war were almost exclusively concerned with the submarine campaign. Tracking the U-boats was the province of the base intelligence office, but there was also work for men who operated less officially in neutral countries, keeping track of the German agents who were working in the neutral ports to assist the U-boats.
Presumably by this time the venerable legend about secret dumps of petrol is dead, but, lest it should still survive, let us put on record here that all the German submarines from U-19 onwards were driven by heavy-oil engines, the German Admiralty having obtained as far back as 1911 a satisfactory four-stroke engine from the Augsburg works.
True, the earlier U-boats had Körting engines driven by petrol, but they were soon in a minority in the fleet, and were always disliked on account of the fumes that revealed their presence. Indeed, Spiess says of U-9 that her exhaust pipes glittered with sparks, and even with flames, which betrayed her presence at night. Moreover, so far as cruising endurance was concerned, these petrol boats in the winter of 1912–13 had stayed at sea alone for eleven days, without mother ships or fuel ships. So there was never the slightest need for hoards of petrol, in two-gallon tins, in secret islands or lonely coves on neutral shores, for the use of the U-boat captain. And since a moderate-sized submarine carries anything from 50 to 75 tonnes of heavy oil, it will be obvious that a dump of half a dozen barrels would not be any great help. It may be taken as a fact that no secret hoards of petrol for German submarines ever existed: consequently our intelligence officers had no adventures in looking for them.
Von Tirpitz seemed to be under the impression that such secret bases were suspected, and that his agent in Sardinia was interned because he was supposed to be running such a base. But the reason for that gentleman’s internment had nothing to do with petrol. (In the course of the extravagant proceedings in the Aegean and the wild-cat adventures of the self-styled ‘secret service men’ who were let loose on that unhappy area, certain stories about U-boat petrol bases appear to have been circulated – perhaps fomented would be the better word. They were unworthy of the inventive ability of any novelist, and a poor testimony to the professional knowledge of the foreign naval officer concerned in the propaganda.)
On the other hand, supplies of spare parts to replace damaged machinery became indispensable as the U-boats’ radius of action increased. A boat damaged somewhere in the south of the Bay of Biscay, and consequently unable to dive, could hardly hope to get back to her base in the Bight of Heligoland. Repairs had to be effected somehow. Under international law a warship in need of repairs to make her seaworthy may shelter in a neutral port for twenty-four hours, but no longer. This meant that an efficient shore staff had to be available to lend a hand in getting the work done, and the maintenance of a fairly wide range of spares for any emergency.
We knew where all these repair depots were situated just as well as the U-boat captains, and we, too, had an efficient shore staff ready to lend a hand – to prevent the repairs from being made.
Here is one typical case.
A U-boat operating well out in the Atlantic had a breakdown in the engine room. While the damage was not fatal, it was crippling to her activity, especially if she were harassed by enemy craft and compelled to keep down for too long. The captain and the crew both knew, from experience, what they would have to face on the long journey back, and they could not afford to make too wide a detour, lest the supply of oil fuel ran out. Their expenditure had been calculated to a nicety.
Consequently, unless repairs could be effected the outlook was gloomy. So the submarine stood in towards the neutral coast and wirelessed her needs to the local German agent. The submarine expert on the spot knew exactly what was wanted, but he had not got that particular spare part in stock. Nor could he procure it anywhere in the port. It would have to be sent from another German depot in another part of the country.
It was useless for the submarine to come in under the plea of stress of circumstances unless the repair could be carried out within twenty-four hours. So, after much wireless conversation, it was arranged that the U-boat should remain off shore for a few days until the required parts could be obtained.
All this time our intelligence men in the port were on the watch. They knew something of what was toward, and they guessed most of the rest. Their essential task was to keep in touch with the German submarine expert ashore and to learn what he was doing. By means that need not be detailed, this was soon known to us. The problem then before us was how to trap the submarine.
Two days later the German submarine came into harbour, where her captain formally applied for permission to remain twenty-four hours, to effect the repairs necessary to make her seaworthy. He was rather surprised at the coldness of his reception. The local authorities had a reputation for being pro-German, or so the German agents had always reported. What he did not know was that the chief of the port had received very urgent instructions from headquarters, forbidding on this occasion any deviation from the strict rule. And those instructions had been originated by diplomatic pressure from the British side.
There was perturbation at the German headquarters at this development, for the submarine commander had come into harbour twelve hours earlier than they had expected him. In point of fact his crew had got more than a little nervous at remaining in the same area so long, for they quite expected to be attacked by some of the Allied patrol craft, or possibly blockaded in the neutral port.
What had happened was that the German repair party had arranged for the wanted parts to arrive that afternoon by train, and they had not looked for the submarine until next day. It was going to be a strenuous business to get the work done, even if the train came in punctually.
Actually, it arrived two hours late. Then there was a great scurrying of the German agents to get their goods unloaded. They had previously used a great deal of palm oil to facilitate matters.
But the vans with the precious parts were not on the train!
The air was thick with guttural curses as the Germans tore frantically up and down the train, cross-examining employees of the railway. The head of the British intelligence branch in the port, who happened to be passing that way – quite by chance, of course – smiled to see the commotion, and went back to his office quite satisfied with his after-lunch stroll.
It was a most hectic afternoon for the Germans. They made telephone inquiries all up and down the line, but could not trace the missing wagons. These had apparently vanished into thin air.
A very crestfallen group sat in conference on board the U-boat that night. It was impossible to replace the missing fittings within the fifteen hours that remained. The crew could not face the trip home without the security of being able to dive and stay under when emergency arose.
In the end the U-boat captain went to the port commander and told him that, as the repairs could not be completed within the specified twenty-four hours, he would have to offer himself and his boat for internment. And interned they stayed for the rest of the war.
What had become of the missing wagons?
It was quite simple. Knowing as we did what the wagons would contain, it was necessary to see that they did not arrive. So, while t
he train was being made up in the goods yard of the town from which the parts were being despatched, two British agents, with a thorough knowledge of the customs and regulations of that railway line, were working there. They found the two wagons – and rubbed out the destination marks they bore. Then they chalked other destination marks on the wagons, and those destinations were right away on the other side of the country.
The goods-yard superintendent in that distant port was puzzled at receiving two wagons that he knew nothing about. He shunted them into a siding, and then began a correspondence about them that may be going on to this day.
That same country, though not the same port, was the scene of another railway comedy.
In the tower of a house near the seaboard, the German secret service had a wireless installation that they used quite openly to communicate with their submarines. We repeatedly made formal protests to the local authorities, but without effect. There were many influential German sympathisers along that stretch of coast. The officials were quite polite to us, but they professed themselves unable to do anything. At last, however, we persuaded headquarters to move. The local people were peremptorily ordered by the government to dismantle this wireless station forthwith, in view of the evidence received as to its existence and purpose.
The Germans were quite unmoved by the decision. They had l aid their plans to meet just such an emergency. All they had to do was to despatch the entire equipment by train a little further along the coast, into another province where a fresh set of local authorities would be concerned – and the game would begin all over again.
But they had reckoned without the British intelligence service.
The wireless station was dismantled and the parts loaded on the train for despatch, according to plan. The train left the goods yard according to timetable. And that was the last ever seen of that German wireless equipment. As the train rumbled on through the night, two British agents who had hidden themselves on board broke open the crates and scattered the gear all along the lines, in the ditches and the fields and the ravines through which the railway ran.
Strange Intelligence: Memoirs of Naval Secret Service Page 19