(b) We should then be forced to patrol the whole area between Orkneys and Norway with fish hydrophone vessels. We have not sufficient craft to do this.

In the British plan the patrol vessels, with up-to-date hunting gear, are looked upon as the primary means of stopping the submarines, and the mine fields are only laid with two objects:

(a) By means of the notified area to bluff the submarines into using channels which are sufficiently narrow to allow of them being efficiently patrolled.

(b) The deep mine fields to help the patrol craft to kill the submarine.

It is submitted that, re Admiral Sims's letter A:

(a) It is first necessary to see whether the submarines avoid the notified area. If they do not, it will be necessary to go on strengthening the notified area until they do avoid it.

(b) Before committing ourselves to mining the whole area up to the surface it is necessary to find out whether the American mine is efficient.

By the end of the summer the mine barrage should be sufficiently thick to make the passage of submarines through it prohibitive, and it will probably be desirable to continue the barrage up to the surface so as to reduce our patrols on the Norwegian coast to a minimum during the winter months when the weather is bad and the nights long.

It is considered by submarine experts that it is of infinitely more importance to make the barrage efficient down to 200 feet than to have a thinner mine field down to 300 feet.

3. As the Americans are mainly responsible for the center (notified) area it is considered they should have as much latitude as possible, and it is therefore suggested that the proposal to make the length of the antennæ in the lower lines 100 feet should be concurred in.

This should only be done, however, if it is quite certain that the American mines can withstand the pressure at 300 feet.

4. When the main lines of the barrage have been completed the situation should be reviewed and further mine fields laid as proposed by the American officers where experience shows them to be necessary.

5. It is not considered essential to have the bottom of the barrage at the same depth right across. To extend the mine field downward in the case of the American mines only necessitates lengthening the antennæ, whereas in the British mine fields it entails laying extra lines of mines.

As already stated, it is considered of much more importance to make the mine field effective down to 200 feet before extending the

mine field lower, and in the case of the British fields the deeper mines should not be laid until the present barrage is completed.

There does not appear to be any reason, however, why this should prevent the American mine field being extended downward.

Re Admiral Sims's letter B:

1. It is considered the areas allocated to each country should remain as at present until it is seen what progress is made, viz:

British mines to be laid in Areas B and C.

American mines to be laid in Area A.

Should it be desired at a later date to mine Area B (western area) up to the surface with American mines, it could be done with the ordinary sinkers and mooring ropes, e. g., those similar to the ones in the center Area A.

To mine the eastern area up to the surface with American mines will require special long mooring ropes.

It is suggested, therefore, that the principle of the possibility of having to mine the eastern area up to the surface at a later date be accepted, and that the United States be asked on the completion of the mining of the center area with three systems to have sufficient sinkers with long mooring ropes ready to lay two lines of surface mines across that area.

NOTE. The British mooring ropes provided for the eastern area are of a sufficient length to enable surface mines to be laid in that area should it be desired later.

3. Propose to inform the United States that the necessary navigational buoys and other marks are being provided by us for all mine fields.

[Extracts from Memorandum No. 71, "History of Planning Section."] MEMORANDA NOS. 1 (31 DECEMBER, 1917), 3 (5 JANUARY, 1918), 17 (12 MARCH), 35 (11 JUNE), 42 (30 JULY), 43 (21 AUGUST), 51A (18 SEPTEMBER).

Subject: "Northern Mine Barrage."

From its organization the Planning Section was thoroughly convinced of the desirability of completing the barrage at an early date according to a design which would render the passage of submarines north about as hazardous as practicable.

Believing that the speedy completion of an effective barrage required agreement in advance upon a plan by the two navies which had jointly undertaken the project, frequent discussions and conferences were held with British officials. These developed important differences of opinion as to the general characteristics of the barrage. Repeated efforts were made to reconcile these differences and to reduce to writing a concrete plan which would be acceptable to both navies. These efforts met with failure in so far as formal agreement upon a written plan was concerned, the British apparently desiring to reserve the privilege of altering the plan when expediency so dictated. They were probably influenced to adopt this attitude by the intentions (not then disclosed) to undertake extensive mining operations in "the Bight," and at

Dover, which might interfere with any agreements they made with respect to the Northern Barrage. Possibly some skepticism also existed as to the ability of the Americans to execute satisfactorily their part of the project. Doubt as to the practicability of the barrage, as well as to its strategic importance, was frequently manifested by many high British officials, notably the Commander in Chief Grand Fleet, under whose general direction the laying operations and their protection were placed. This attitude was reflected in the Deputy Chief of Naval Staff, whose department in the Admiralty handled fleet affairs. It was upon the recommendation of the Commander in Chief that the position of the barrage was moved about 50 miles northward, placing the American Section in depths of water somewhat deeper than the original position. This incident alone put back American preparations about three weeks. It became known in about September, 1918, that the hostility of the Commander in Chief to the barrage was caused in large measure by the interference that the barrage would cause to the weekly Norwegian convoy, for the protection of which the Commander in Chief was held responsible.

The British Assistant Chief of Naval Staff was hostile to the barrage, apparently because of the probable influence which it would have to reduce the number of vessels available for convoys, for which duty he was primarily responsible.

For similar reasons, affecting their own job, practically every influential British official afloat and ashore was opposed to the barrage, except the British Plans Division.

This situation caused the American Planning Section constantly to urge orally expedition in the completion of the barrage, and to emphasize its great importance in the above memoranda, as well as in other papers upon more general subjects.

It is believed that the influence of this Section, exerted so constantly, considerably advanced the completion of the barrage. But for the lack of a proper agreement in the early stages of the project, and for the opposition of British officials, it is probable that the barrage might have become effective in the early summer of 1918.

MEMORANDUM No. 2.

DUTIES OF PLANNING SECTION.

2 January, 1918.

The cablegram from Admiral Benson which expressed his desire that a Planning Section be organized in London stated as follows:

[Cablegram.]

From: Admiral Benson.

To: Navy Department.

From my observation and after careful consideration, I believe that plans satisfactory to both countries can not be developed until we virtually establish a strict Planning Section for joint operations here (in London), in order that the personnel therein may be in a position to obtain latest British and allied information and to urge as joint plans such plans as our estimates and policy may indicate. This action appears to be all the more necessary considering the fact that any offensive operations which we may undertake must be in conjunction with British forces and must be from bases established or occupied within British territorial waters. The officers detailed for this duty should come here fully imbued with our national and naval policy and ideas. Then, with intimate knowledge which they can obtain here from data available, actual disposition of allied forces, the reason therefor, they will be in a position to urge upon British any plans that promise satisfactory results. BENSON.

(Signed)

NOTE.-Above cablegram was dated November 19, 1917.

In conversation with the First Sea Lord on New Year's Day, he expressed the opinion that one of the Planning Section might be attached to the staff of Rear Admiral Keys at Dover; that another might be detailed in the Material Section of the Admiralty; and that the third officer might possibly be in the Operations Section of the Admiralty. The First Sea Lord offered these suggestions as tentative only, but seemed to dwell with some insistence on the Dover detail.

The proposed arrangement is not at all in accord with the expressed ideas of Admiral Benson and would but serve to nullify our usefulness as a Planning Section.

It is therefore proposed that it be pointed out to the First Sea Lord that the duties of the Planning Section must necessarily be more general. The United States is now involved in this war to an enormous degree. The naval vessels, and the troops on this side of the

water, are no correct measure of our participation in the war. Loans to the Allies, aggregating seven billion dollars, are being made with prospect of further loans. Our entire military effort is by way of the sea. We are intensely concerned in the measures taken to drive the Germans from the sea and in the measures taken to handle shipping at sea.

It is therefore appropriate that the Planning Section of Admiral Sims's staff shall be free to consider those questions that seem to him and to the members of the section most urgent.

It appears to us that the principle that should govern our relations with the Admiralty is: The privileges of the Admiralty with complete freedom of action so far as the Admiralty is concerned.

These privileges and this freedom of action are essential if the Planning Section is to attain its maximum usefulness to our joint

cause.

In presenting to the First Sea Lord such of these ideas as may be approved, we recommend that emphasis be placed upon our keen desire to be of the maximum possible usefulness to our joint cause.

It appears to us that we can be of most use if we work as a unitall of us-considering, as a rule, the same subject simultaneously. We think it desirable that we keep a continuous general estimate of the naval situation.

We think that the following special subjects should be studied by us very carefully at as early a date as possible:

(1) The Northern Barrage.

(2) The English Channel.

(3) The Straits of Otranto.

(4) The tactics of contact with submarines.

(5) The convoy system.

(6) Cooperation of United States naval forces and naval forces of the Allies.

(7) A joint naval doctrine.

Other subjects will undoubtedly present themselves faster than we can consider them, but the above illustrates the lines along which we believe our greatest usefulness lies.