NOTES BY THE FIRST LORD OF THE ADMIRALTY
(Address to the Admiralty War Staff)
The problem of oversea attack requires to be examined under three heads:—
(1.) Absolute surprise to-morrow (19th April): everything going on as usual—Bolt from the Blue.
Objectives of raiders—to prevent the Expeditionary Force being sent to help France, and incidentally, if possible, to damage naval arsenals and dockyards.
(2.) The whole expeditionary army has gone to India or some other distant theatre of war. The war has been going on some time: the Territorials have been embodied, but great numbers have been allowed to proceed on leave. The Second Fleet has been completed to full strength by the closing of the schools. The Immediate Reserve has been called out; and the whole of the First and Second Fleets are in those harbours which enable them to reach their actual war stations as quickly as possible. The patrol flotillas are mobilised in their war stations. The forts are manned, and the coastal look-out is active. But this has been going on for several months while complete peace continues in Europe. The tension has begun to be somewhat relaxed, and we have settled down to our ordinary way of life, while at the same time taking special precautions and having our forces so disposed that they are easily and readily available on the slightest sign of danger. This may be called “Bolt from the Grey.” The only adequate objective of the enemy in this case would be invasion in such force as to overcome the comparatively feeble military establishment on foot in the United Kingdom.
(3.) War with Germany has begun. All the fleets are fully mobilised and in active operation against the enemy according to the war plans of the Admiralty. The objectives open to the enemy would be minor raids to destroy naval arsenals and dockyards: the seizure of bases for flotilla action (this last may occur also in 1 and 2), and threats or attempts to invade in force to distract or divide the British fleet simultaneously with bringing about a great fleet action.
All these three situations with their variants deserve patient examination.
2. The first condition governing the dimensions of oversea attack from Germany is the number of troops available—
(i.) Instantly;
(ii.) In twenty-four hours; and
(iii.) At any time after a general mobilisation is complete.
5. A second great limiting condition is the shipping available in German ports. For all phases after the war has become open, whether under 1, 2, or 3, ample shipping is available of every class required, and the matter need not be further considered. But in case 1, the invading force is limited by the amount of suitable shipping available instantly at the right ports, and secondly, by what is available after 24 hours: in case 2 by the amount of shipping available instantly. After that, when war has actually begun, there is no difficulty in finding the ships or the men; the only difficulty is to get them across.
6. The third condition is the time taken to embark, transport, and land the various forces at different points concurrently and alternatively. This requires separate calculations in every case. These are complicated by the hours of daylight and darkness, the tides, the weather, and other uncertain features. Each case must be worked out separately, and risked on its merits.
7. The last consideration is the distance of the practicable objective from the landing-point. Here again each case must be considered individually:—
Harwich is invaluable because it threatens London, and is unquestionably the best place for so doing. In no other way could you react so instantaneously upon British public opinion. On the other hand, once the invaders were turned out, the actual damage done would be small.
Immingham is a purely local injury not worth touching before war breaks out, and afterwards belonging to the ‘driblets’ phase.
Blyth or the Tyne are striking places for Newcastle, involving considerable moral effect and immense permanent damage, not of a vital character.
The Tay (Dundee) is valuable as affording a good landing-place and ample supplies for a large army (if it could get there), within effective striking distance of Glasgow and the Clyde.
Cromarty, as long as it is undefended by land and if undefended by ships, would be a good place of disembarkation for a large force, but they would be isolated in barren country with great natural difficulties between them and any real vulnerable point. Cromarty and the Invergordon oil tanks might, however, be the object of a minor raid in the ‘driblets’ phase, if undefended.
Balta Sound, in the Shetlands, and those islands generally would be of the greatest value as a flotilla base to the Germans. Until they were expelled from them, which would be costly both in ships and men, all attempts to blockade the North Sea would be rendered futile.
On the West Coast there are numerous undefended landing-places in sheltered waters suitable for the disembarkation of a large force (if it could get there). Oban, 60 miles away from the Clyde, deserves special attention. The mouth of the Clyde itself, which is lightly defended by land and has only three submarines at Lamlash, is suitable both for the landing of a large force and also for a raid on an arsenal. The same may be said of Barrow.
This would seem to exhaust the principal serviceable landing-places which should be considered, but there may be others.
NOTES BY THE FIRST LORD OF THE ADMIRALTY
(Addressed to the First Sea Lord.)
A.
The following assumptions appear to me, as at present advised, to be justified:—
1. That not more than 20,000 men could be collected and embarked in German North Sea Ports without our knowing it before the expedition actually sailed; but that up to that number might actually put to sea before we were warned.
2. That no military expedition of upwards of 10,000 men could reach the British coast before the general alarm was given.
3. That the intention of the German Government to attack us would either (a) be discovered or (b), more probably, formally declared while the expedition was in transit.
4. That, having regard to the time taken in transit, three to six hours’ warning would have been given throughout the country, along the coasts, and at all ports, and preparations advanced accordingly.
5. That any expedition arriving at a port must expect to encounter resistance from whatever forces or defences are on the spot after three hours’ alarm notice; but that no one place can be considered more certain than another, and that only the ordinary preparations prescribed under our existing mobilisation arrangements have been made at each particular place.
6. That any German expedition seeking to seize a port defended or otherwise must be provided with an escort sufficient to overcome the local defences and to beat off the British torpedo craft or cruisers known to be in the vicinity.
7. That the moment chosen will be one when the British Battle Fleet is on the south-west or west coasts of Great Britain or Ireland.
8. That the return of the Battle Fleet to the North Sea will be obstructed by mines and submarines, and at night by flotilla attacks.
9. That pending the return of the Battle Fleet the German Navy will have the command of the North Sea, and that so long as it holds the command of the North Sea it can continue, though at considerable risk, to pass individual vessels, in addition to the original 20,000 men, into the defended harbour which has been seized. The maximum time which in the most unfavourable circumstances would elapse before the return of the British Fleet to the North Sea and consequent resumption of British naval superiority is therefore a vital matter, |The time-table given in your “Bolt from the Blue” is quite sufficient, and cannot be varied to any appreciable extent.| and should be worked out in as many variants as possible by the staff.
10. That the British Fleet when it has returned to the North Sea, whether northabout or through the Straits of Dover, may have to fight a general battle at once with the whole strength of the enemy; |It is almost hopeless to forecast what may happen during this critical time. No escorts could then be spared.| and that during the preliminaries, the progress, and the aftermath of this battle attempts may be made either to reinforce the original landing or to make further landings at other points on the British coasts.
11. That sabotage, i.e. acts of treachery before a declaration of war, are improbable, but that they may occur simultaneously with the first military hostilities, and that in any case they are not included in the present phase of the inquiry which deals essentially with military operations.
B.
1. It is useless labour to work out in detail a series of conventional operations. It is only necessary to work out real operations, i.e. the sort of operations an enemy might be expected to attempt. The numbers of these are limited: there are only four types.
2. First, sabotage, by which is meant acts of treachery perpetrated by persons or vessels in disguise before any declaration of war. Instances of these acts are given by Captain Hankey in his paper. They are an important study, but they do not touch the problems we are now examining, and they are therefore excluded for the present.
3. Secondly, a military raid on Blyth for the purpose of destroying Elswick.
We have hitherto assumed 10,000 men for Blyth-Newcastle; either more or less may be required. The force must be numerous enough to make its way in the face of sporadic opposition by unmobilised territorials and by the population, from Blyth to Elswick; to seize and destroy effectively the Elswick Works and the ships in the Tyne. It seems improbable that less than 10,000 men would be sufficient.
4. Thirdly, a raid of not less than 20,000 men on Harwich, with the object of stopping the regular army from going to France.
The Harwich operation is essentially—
(a.) The secret concentration and embarkation of 20,000 men.
(b.) The destruction of the floating and land defences of Harwich by the escorting hostile squadron.
(c.) The disembarkation of 20,000 men with a proportion of artillery before the British Fleet can arrive in sufficient force to give battle.
5. Fourthly, a landing in the Firth of Tay.
This is not worth doing unless the force landed is at least 35,000 men. It is assumed that war has begun before the enemy actually completed their embarkation; that the British Fleet has been forced to concentrate to the southward |It is almost hopeless to forecast what may happen during this critical time. No escorts could then be spared.| in order to fight a general battle with the German Fleet; that in consequence the northern waters of the North Sea are denuded of ships; and that the passage of fifteen or twenty independent transports to a fixed rendezvous, as suggested, will not be obstructed by any naval force which could not be overcome by the German warship escort. |I doubt if much in the way of escort could be spared. The enemy must be prepared to meet our entire superior force in North Sea.| In this case the forts are fully manned and the whole coast is alarmed and vigilant. The enemy’s transports must be escorted and protected by cruisers or old battleships; the opposition of the forts must be beaten down, and any resistance by local territorials on land must be overcome and quelled. The objective of the invaders is Glasgow and the Clyde. The whole six divisions of the expeditionary force have left England for a distant war. |On the whole this seems a very risky undertaking, but by no means impossible, and on the assumption above, quite worth trying.|
The question to be resolved is whether these are all the operations which need be considered at the present time. Are they practicable? |First three certainly.| And if so, to what extent? |With limitations.| How could they be achieved? |As described.| What are the circumstances most favourable to their success? |Knowledge that we intend to send army to France, the strongest inducement, amounting almost to military necessity.| What are the measures which should be taken in each case?
Provide sea defences for Blyth.
Strengthen existing ones (notably Harwich) on East Coast.
Man them on the principle of a ship in commission with nucleus crew.
Provide local submarine defence flotillas at the principal East Coast ports.
Army—
Adhere rigidly to the Committee of Imperial Defence recommendations (1908), as accepted by His Majesty’s Government, [i.e. retain two divisions at home.]
The times and conditions which I have prescribed are illustrative of the problem; and before any attempt is made to work out these cases in detail the conditions should be formulated exactly.