The Gathering Storm: The Second World War (74 page)

8. We shall shortly be engaged in bringing the leading elements of the Canadian and Australian armies to France, and for this purpose a widespread disposition of all our hunting groups is convenient. It will also be necessary to give battleship escorts to many of the largest convoys crossing the Atlantic Ocean. We intend to maintain continually the northern blockade from Greenland to Scotland, in spite of the severities of the winter. Upon this blockade, twenty-five armed merchant cruisers will be employed in reliefs, supported by four eight-inch-gun 10,000-ton cruisers, and behind these we always maintain the main fighting forces of the British Navy, to wit, the latest battleships, and either the
Hood
or another great vessel, the whole sufficient to engage or pursue the
Scharnhorst
and the
Gneisenau
should they attempt to break out. We do not think it likely in view of the situation in the Baltic that these two vessels will be so employed. Nevertheless, we maintain continually the forces necessary to cope with them.

It is hoped that by a continuance of this strategy by the two Allied Navies, no temptation will be offered to Italy to enter the war against us, and that the German power of resistance will certainly be brought to an end.

The French Admiralty in their reply explained that they were in fact proceeding with the completion of the vessels specified, and that they gladly accepted our Asdic offer. Not only would the
Richelieu
be finished in the summer of 1940, but also in the autumn the
Jean Bart.

* * * * *

In mid-November, Admiral Pound presented me with proposals for re-creating the minefield barrage between Scotland and Norway which had been established by the British and American Admiralties in 1917/18. I did not like this kind of warfare, which is essentially defensive, and seeks to substitute material on a vast scale for dominating action. However, I was gradually worn down and reconciled. I submitted the project to the War Cabinet on November 19.

The Northern Barrage

Memorandum by the First Lord of the Admiralty

After much consideration I commend this project to my colleagues. There is no doubt that, as it is completed, it will impose a very great deterrent upon the exits and returns of U-boats and surface raiders. It appears to be a prudent provision against an intensification of the U-boat warfare, and an insurance against the danger of Russia joining our enemy. By this we coop the lot in, and have complete control of all approaches alike to the Baltic and the North Sea. The essence of this offensive minefield is that the enemy will be prevented by the constant vigilance of superior naval force from sweeping channels through it. When it is in existence we shall feel much freer in the outer seas than at present. Its gradual but remorseless growth, which will be known to the enemy, will exercise a depressive effect upon his morale. The cost is deplorably heavy, but a large provision has already been made by the Treasury, and the northern barrage is far the best method of employing this means of war [i.e., mining].

This represented the highest professional advice, and of course is just the kind of thing that passes easily through a grave, wise Cabinet. Events swept it away; but not until a great deal of money had been spent. The barrage mines came in handy later on for other tasks.

* * * * *

Presently a new and formidable danger threatened our life. During September and October, nearly a dozen merchant ships were sunk at the entrance of our harbours, although these had been properly swept for mines. The Admiralty at once suspected that a magnetic mine had been used. This was no novelty to us; we had even begun to use it on a small scale at the end of the previous war. In 1936, an Admiralty Committee had studied counter-measures against magnetic-firing devices, but their work had dealt chiefly with countering magnetic torpedoes or buoyant mines, and the terrible damage that could be done by large ground-mines laid in considerable depth by ships or aircraft had not been fully realised. Without a specimen of the mine, it was impossible to devise the remedy. Losses by mines, largely Allied and neutral, in September and October had amounted to fifty-six thousand tons, and in November Hitler was encouraged to hint darkly at his new “secret weapon” to which there was no counter. One night when I was at Chartwell, Admiral Pound came down to see me in serious anxiety. Six ships had been sunk in the approaches to the Thames. Every day hundreds of ships went in and out of British harbours, and our survival depended on their movement. Hitler’s experts may well have told him that this form of attack would compass our ruin. Luckily he began on a small scale, and with limited stocks and manufacturing capacity.

Fortune also favoured us more directly. On November 22 between 9 and 10
P.M
., a German aircraft was observed to drop a large object attached to a parachute into the sea near Shoeburyness. The coast here is girdled with great areas of mud which uncover with the tide, and it was immediately obvious that whatever the object was it could be examined and possibly recovered at low water. Here was our golden opportunity. Before midnight that same night two highly skilled officers, Lieutenant-Commanders Ouvry and Lewis from H.M.S.
Vernon,
the naval establishment responsible for developing underwater weapons, were called to the Admiralty, where the First Sea Lord and I interviewed them and heard their plans. By 1.30 in the morning, they were on their way by car to Southend to undertake the hazardous task of recovery. Before daylight on the twenty-third, in pitch darkness, aided only by a signal lamp, they found the mine some five hundred yards below high-water mark, but as the tide was then rising, they could only inspect it and make their preparations for attacking it after the next high water.

The critical operation began early in the afternoon, by which time it had been discovered that a second mine was also on the mud near the first. Ouvry with Chief Petty Officer Baldwin tackled the first, whilst their colleagues, Lewis and Able Seaman Vearncombe, waited at a safe distance in case of accidents. After each prearranged operation, Ouvry would signal to Lewis, so that the knowledge gained would be available when the second mine came to be dismantled. Eventually the combined efforts of all four men were required on the first, and their skill and devotion were amply rewarded. That evening Ouvry and his party came to the Admiralty to report that the mine had been recovered intact and was on its way to Portsmouth for detailed examination. I received them with enthusiasm. I gathered together eighty or a hundred officers and officials in our largest room, and made Ouvry tell his tale to a thrilled audience, deeply conscious of all that was at stake. From this moment the whole position was transformed. Immediately, the knowledge derived from past research could be applied to devising practical measures for combating the particular characteristics of the mine.

The whole power and science of the Navy were now applied; and it was not long before trial and experiment began to yield practical results. Rear-Admiral Wake-Walker was appointed to co-ordinate all technical measures which the occasion demanded. We worked all ways at once, devising first active means of attacking the mine by new methods of mine-sweeping and fuse-provocation; and secondly, passive means of defence for all ships against possible mines in unswept, or ineffectually swept, channels. For this second purpose a most effective system of demagnetising ships by girdling them with an electric cable was developed. This was called “degaussing,” and was at once applied to ships of all types. Merchant ships were thus equipped in all our major ports without appreciably delaying their turn-round; in the Fleet progress was simplified by the presence of the highly trained technical staffs of the Royal Navy. The reader who does not shrink from technical details will find an account of these developments in Appendix H, Book II.

* * * * *

Serious casualties continued; the new cruiser
Belfast
was mined in the Firth of Forth on November 21, and on December 4, the battleship
Nelson
was mined whilst entering Loch Ewe. Both ships were, however, able to reach a dockyard port. Two destroyers were lost, and two others, besides the minelayer
Adventure,
were damaged on the east coast during this period. It is remarkable that German Intelligence failed to pierce our security measures covering the injury to the
Nelson
until the ship had been repaired and was again in service. Yet from the first many thousands in England had to know the true facts.

Experience soon gave us new and simpler methods of degaussing. The moral effect of its success was tremendous, but it was on the faithful, courageous, and persistent work of the minesweepers and the patient skill of the technical experts, who devised and provided the equipment they used, that we relied chiefly to defeat the enemy’s efforts. From this time onward, despite many anxious periods, the mine menace was always under control and eventually the danger began to recede. By Christmas Day I was able to write to the Prime Minister:

December
25, 1939.

Everything is very quiet here, but I thought you would like to know that we have had a marked success against the magnetic mines. The first two devices for setting them off which we have got into action have both proved effective. Two mines were blown up by the magnetic sweep and two by lighters carrying heavy coils. This occurred at Port A [Loch Ewe], where our interesting invalid [the
Nelson
]
is still waiting for a clear passage to be swept for her to the convalescent home at Portsmouth. It also looks as if the demagnetisation of warships and merchant ships can be accomplished by a simple, speedy, and inexpensive process. All our best devices are now approaching [completion]. The aeroplanes and the magnetic ship – the
Borde –
will be at work within the next ten days, and we all feel pretty sure that the danger from magnetic mines will soon be out of the way.

We are also studying the possible varying of this form of attack, viz., acoustic mines and supersonic mines. Thirty ardent experts are pursuing these possibilities, but I am not yet able to say that they have found a cure….

It is well to ponder this side of the naval war. In the event a significant proportion of our whole war effort had to be devoted to combating the mine. A vast output of material and money was diverted from other tasks, and many thousand men risked their lives night and day in the minesweepers alone. The peak figure was reached in June, 1944, when nearly sixty thousand were thus employed. Nothing daunted the ardour of the merchant navy; and their spirits rose with the deadly complications of the mining attack and our effective measures for countering it. Their toils and tireless courage were our salvation. The sea traffic on which we depended for our existence proceeded without interruption.

* * * * *

The first impact of the magnetic mine had stirred me deeply, and apart from all the protective measures which had been enforced upon us, I sought for a means of retaliation. My visit to the Rhine on the eve of the war had focused my mental vision upon this supreme and vital German artery. Even in September, I had raised discussion at the Admiralty about the launching or dropping of fluvial mines in the Rhine. Considering that this river was used by the traffic of many neutral nations, we could not, of course, take action unless and until the Germans had taken the initiative in this form of indiscriminate warfare against us. Now that they had done so, it seemed to me that the proper retort for indiscriminate sinkings by mines at the mouths of the British harbours was a similar and if possible more effective mining attack upon the Rhine.

Accordingly, on November 17, I issued several minutes of which the following gives the most precise account of the plan:

Controller
[
and others
].

1. As a measure of retaliation it may become necessary to feed large numbers of floating mines into the Rhine. This can easily be done at any point between Strasbourg and the Lauter, where the left bank is French territory. General Gamelin was much interested in this idea, and asked me to work it out for him.

2. Let us clearly see the object in view. The Rhine is traversed by an enormous number of very large barges, and is the main artery of German trade and life. These barges, built only for river work, have riot got double keels or any large subdivision by bulkheads. It is easy to check these details. In addition there are at least twelve bridges of boats recently thrown across the Rhine upon which the German armies concentrated in the Saarbrueck-Luxemburg area depend.

3. The type of mine required is, therefore, a small one, perhaps no bigger than a football. The current of the river is at most about seven miles an hour, and three or four at ordinary times, but it is quite easy to verify this. There must, therefore, be a clockwork apparatus in the mine which makes it dangerous only after it has gone a certain distance, so as to be clear of French territory and also so as to spread the terror farther down the Rhine to its confluence with the Moselle and beyond. The mine should automatically sink, or preferably explode, by this apparatus before reaching Dutch territory. After the mine has proceeded the required distance, which can be varied, it should explode on a light contact. It would be a convenience if, in addition to the above, the mine could go off if stranded after a certain amount of time, as it might easily spread alarm on either of the German banks.

4. It would be necessary in addition that the mine should float a convenient distance beneath the surface so as to be invisible in the turgid waters. A hydrostatic valve actuated by a small cylinder of compressed air should be devised. I have not made the calculations, but I should suppose forty-eight hours would be the maximum for which it would have to work. An alternative would be to throw very large numbers of camouflage globes – tin shells – into the river, which would spread confusion and exhaust remedial activities.